Three months of videos but if you pay attention when he's pulling up the graphs, some of these tests go back to 2007/8 if not further. They are an amalgamation of the tests he's done in print for 20+ years.
You have to watch generlizations. The reason this picked up so much is because the duration was so undersized to begin with. If you have much larger duration on this and do the same thing, the reverse will start to become true where a bunch more overlap kills low end
If I ever get a chance to either build or simply can swap an LS all I have to do is watch your video series, pick the combo I think will work best for my intended vehicle and just duplicate it. You’ve take all the guess work out of it for us all. What a service you’re providing. Thank you.
If I had Richard & Brian Tooley a large bank account a time machine a girl with a short skirt and a Long Jacket small hands...that would be all I need, ok the girl has a twin sister, That would be all I need, 😏
I did the same test on a 4.6 2v back in '09 for my buddy David Vizard... My results mirror what you came up with on the LS! David is a huge fan of tight LSA's and he even has come up with the controversial 128 rule.... Awesome job like always!
DV's 128 formula says an LSA 107 should be ideal for this combination. I'd like to see a cam test using an LSA of 107 with duration numbers starting at 225 and increasing by 15-25 degrees. I think this could show how David's thinking works across the range of street to race cams.
Exactly! LCA is a calculated using the ci & intake valve size. AKA allowing enough time for fill. We advance the cam to help lower the rpm when it will start making power. Every 2 degrees advanced lowers it 100rpm, aka 4 deg = 200 rpm sooner. This is a total shift, top rpm is also lowered the same amount.
Crazy part is BTR thinks LCA is a mear byproduct, I don't follow that line of thinking. I have never gone as tight as 104, 106 is my tightest & I usually shoot for a 108 by using better heads. Different rocker ratios (larger) can also allow a slightly wider LCA but is limited & small. All about choosing the correct combination of parts that will all work together.
My NHRA SS/J 66 Chevy II uses a custom ground solid roller with a 109 LSA I had ground using David Vizards 128 rule. My heads are NHRA Superstock legal Edelbrock highly modified by Edelbrock to coincide with NHRA rules. I shift @ 9000 so its wound up pretty tight and pulling off a consistent 8.60s with a .060 over 327 and M22 tranny is no easy feat. Listening to David Vizard and reading his books has made not only my Superstock fast but my Stock Eliminator K/SA Monte Carlo SS (with the factory L69 305). This test Richard just run backed up the 128 rule big time. For big blocks and Fords is 127 and he has videos on it if you are wanting to learn. Thanks for this video Richard you are very entertaining and easy to listen to unlike Freiburger and Dulcich.
David Vizard been saying that for years and I believe it`s true. 106 seems to be the magic number for circle track and higher compression, 2bbl seems to like the wider LSA along with bigger CID like 454 and bigger.. There are so many contributing factors I don`t think a person could pick the perfect cam with out a dyno, back when I was a kid cams were listed by lift, duration (advertised) and overlap. I think Isky was one of the first guys to start tightening up the LSA and he made a high mark to reach for
I have been reading and have David Vizards books from the early 80s and have built numerous engines on his specs, they have never failed to impress, starting on the Mini A series, Ford Pinto, Chev 350 and now finally the LS series.
Around 50 years ago I was taught to run narrow LSAs as much as conceivable to help capture cylinder pressure at higher elevations like in Denver. We were always happy when we got cams at 110, and really happy at 108.
Been watching david vizzard lately and he has a formula that puts this engine’s ideal lsa right around the 108 that made the most power, maybe he is on to something. Oh yeah and as always another great video by richard
What do I think? Hell, I don't know anymore...between you and Engine Masters everything I learned as a kid was false. Can't wait for the next installment.
I understand physics... and english. My point is, all the hearsay and conjecture are being disproved through a scientific method and theory to practice. Sorry, I didn't have all this information available so easily at a younger age. Thank you, Mr. Holdner for sharing.
@@bigboreracing356 All he said was that he was taught some things as a young person that wound up being inaccurate. No need to be a jerk, I'm sure you have fallen prey to misinformation at least a time or two. We all have. Some of us are man enough to admit it. They knew everything in the 1930s that we know now? You're out of your fucking mind.
@@bigboreracing356 The truth about what? That you're a keyboard warrior who thinks he's "the bad man"? How would I have your comment removed? It's not my video. I'm a commenter just like you, but with some substance. You talk about safe spaces, but probably drive a mustang. Kill any bystanders lately?
STREET RACER what’s your point in trashing someone for something they learned or were told wrong when they were young? Don’t be a douche, we all have been told things that were wrong. Doesn’t give you the right to jump all over someone. 🤷🏽♂️
Good video - people are realizing the tighter LSA means more acceleration torque AND NO LOSS upstairs- bigger displacement responds even better, of course vacuum drops due to more overlap and worse throttle response below 1500 to 1800, so an automatic and smaller engine should use a somewhat looser converter, BUT make sure converter stall speed is below top gear or overdrive RPM at highway cruising speeds.
That last part is basically impossible for a good street car. Cruising RPM in top gear at highway speeds needs to be under 3000 for anything approaching acceptable fuel efficiency. Most underpowered ecoboxes and sport compacts (the normal ones, not the extra weak ones under 130hp) run 3000rpm at 75mph in last gear. The way I spec it is roughly 1/3 redline should be your normal cruise RPM, and that should match up with 0-10mph over your local hwy limits. Or if you have an abundance of torque and/or enough gears that they don't feel too long, 2000rpm cruise no matter what, and between 60-80mph
Very interesting. I run in a tightly-regulated race club where LSA is basically all we have to play with (DOHC, adjusting stock cams) and we are typically living in the realm of 103-105 LSA. Our duration numbers are pretty high (streetbike engines) and we operate around 6000-12000 rpm. There is definitely a point of diminishing returns in wide LSA for top end! This is why we test!
Welp, I'm seeing this two years hence, but of course it's still very interesting. I've wondered the same thing about LSA for many years now. I'm positing the lower numbers at lower RPM for a wider LSA have to do with how the wider LSA bleeds off more cylinder pressure. Both valves are still open for several degrees of rotation, and you can't build cylinder pressure until they are both shut. My bit of homework on the newish cams sold for use on low compression engines run in line with this. Comp Cams' Thumper series, Hughes Engines' Whiplash cams, all have very tight LSA numbers. As you say, they give the hot rod guy the lope he likes, but the smooth out early. And they actually make more cylinder pressure than an OEM cam. The lope isn't desirable for an OEM for sale to the general public. All in all, very interesting and thanks for taking the time and effort to do it. One other factor I've wondered about for years, how about the installed angle of the cam? Would installing the 112 LSA piece, maybe even the longer one, make these valve events soon enough to compensate? Thanks!
Back in the70's Isky and Clay Smith had a bunch of cams at 108, they were ahead of the curve compared to most cams. They also made very good power through out the rpm range. Nice test
Wow! Great video Richard! Had no idea that a tighter LSA (with choppy idle) would make more low end power!?!?! NOW.....I can have the best of both worlds!!! I can put a 108 LSA cam in my work truck, have a bada$$ idle and tow my trailers (enclosed tool trailer, 6T flatbed and my I/O boat trailer) all day! ALL your videos have awesome content and enjoy the heck out of them. I watched several of them more than once to make sure I'm absorbing the content for my LS/OBS swap coming up.
Don't get too excited... If that were the case, all cams would be ground on a 100 degree LSA. You get more low end to a point, and then, nothing... Makes your power-band more like a two-stroke.
Nice this is a topic iv always thought about. Few things I knew for sure was the lower the LSA = more chop @ idle but also slightly more difficult too tune. Now we need the results on smaller cube, less radical builds like your budget 5.3 & 6.0.
@@richardholdener1727 the idle is car porn, yes. I've got to get a better tune though. Still dealing with vacuum issues and the brake booster since it's a high lift cam.
Good one thanks. That's what I wanted to know and that was my hope that tighter lobe separation will give me better low-end power and a wild chop without increasing lift and duration.
Exactly what I was saying on a different video about the intake tests. Just because you have a long runner intake you don’t need to run a wider lsa. The reality is that tighter lsa cams tend to make more power even more so when naturally aspirated. Thanks for the video!
my take away: don't rush out and buy a camshaft on a 108 degree lsa. the 112 degree lsa cam is so close to the same power numbers it makes more sense to use it in a speed density fuel injection system because it gives better vacuum at idle and allows the map sensor to work correctly.
Nice I loved my Lunati Bootlegger in my sbc 406. 108LSA nice chop great power band. Running a Summit cam in my budget junkyard 307 build, 106lsa, gm 601 heads that I cleaned up a bit. Fun little mighty mouse motor. Going to build the 406 right and put a forged rotating assembly in.
The L.S motors are a whole different animal than the old small block when it comes to cams and l.s.a it seems to me they can do so much more with the l.s cams as far as all of the numbers more lift and longer duration and thus not needing to tighten the lsa as much and fight with the choppy idle and vacuum issues like in the past if I understand right it's due to the cam actually being moved up and ,made larger is this correct ? I'm interested in anything I can. Learn. Pls
Awesome, awesome video Rich... Guess I now know what to expect when I install that Truck Norris cam into my Pontiac LS2... More chop, and more down low-mid range, and hell maybe even more up top as well
Hey Richard, camshaft theory is fascinating to me and watch this video often. In fact, I had a custom Bullet Cam for my 454 ground partially based on this video. Theorizing here, a tighter LSA generally increases cylinder psi, because it increases the dynamic compression, which may have contributed to not only the expected bump in low speed torque but also the power across the board.
GREAT test Richard! This test repeats ALL other dynos I've seen where only LSAs are changed. Yet you read all the tech info they say the reverse. Well done.
I've had the opportunity to work with a few engines using a 108LSA over the normal off the shelf selection. Two 347 SBF's and a 388 LT1. All engines were amazing street strip combos. Still had manners down low, came on strong in the middle and ripped up top. For the 330 to 400ci range, I don't think it can be beat.
Now I know why I have always ran a 112 LSA advanced 4 degrees. Intake is always more critical than the exhaust. Also with a 10 - 12 degrees more on the exhaust duration. This is what I have found to work best in the vast majority of cases, over the last 45+ years. What we also found was that a 108 LSA, (MPG) suffered on the street. It was not worth the loss of gas mileage for the little HP that was gained. That was why we started advancing the camshaft, and it worked...
literally all wrong, you change the DURATION to bring the overlap down, you do not change the LSA to help with drivability, having too much duration and then widening the LSA to help drivability is all wrong, if you need to do that you have way too much duration for your application
@@danawilkes6174 Yeah, but I think we'd all like to see a direct comparison of a 112+4 adv vs a 108 with reduced duration to have the same overlap (both advertised and at .050) with the same lift, too.
@@RadRidesByCru I run a 228/234 .614 lift in/exh, 108 LSA in a 355 CI gen II SBC (LT1) and my vacuum at 825 RPM is 13.5 to 14 In/hg. So vacuum in that engine was likely similar given more duration and more CI @volvospede it really depends if you plan on running an auto or manual? As I just pointed out my engine doesn't produce a ton of vacuum at idle, but since I have a manual and a working checkvalve on my vacuum canister my brakes are no different than stock because on decel at cruising RPM my engine will easily produce 25 in/hg at about 2000 rpm with the throttle closed of course. This is plenty of vacuum to charge the canister, and have never noticed a change in my brakes. An auto would obviously be a whole different game though.
I have an LM7 5.3L Gen 3 bored 30 over. I have watched a lot of your videos and love them. My cam and engine spec are: Custom grind. Cam Motion - 210 int/ 218 exhaust/ 570 int and 570 exh lift with a 110 LSA +2. PAC 625 springs. Stock heads with a 3 angle valve job. I will be adding Long tubes and a full 3" exhaust with a cut out for fun.
It looks like the rest of my comment did not go through. 10.3 compression with flat top forged summit pistons with valve reliefs. Was wondering what you though how this will perform and what rpm range it will perform the best and how high it will rev before falling off. I have the new rockers with upgraded trunion kit. Stock truck intake. Thanks for any advice. .007 shaved off heads and about the same shaved of the deck to make true. I will have long tube headers and 3" exhaust all the way back. Any advice would be appreciated. Thanks and love the videos. Piston are on average about .004 - .005 out the hole. Stock bottom end. I will be rebuilding my 4L60 and keeping the stock converter if possible. I hope the trans shop can build it to hold 600Hp because I want to add nitrous in the future. Thanks a lot. Love the videos.
How about some lsa +0 vs +2, +4, +6 intake lobe advance. That type of data would help understand ground in advance a bit more while helping with camshaft selection.
I feel honored. I think my dumb question yesterday motivated you to make/post this video. Thank you! I most definitely learned something from this video. I personally envisioned the LSA effect backwards figuring less overlap would help low-end. So glad you post these educational videos.
Yep-your question yesterday motivated me to go back in time to 2014 to run this test, lol. Seriously, make sure to post requests-I read them all and love the ideas
another way of seeing this for someone with a DOHC engine. Is the stock camshaft timing, then advancing the exhaust camshaft 4 degrees. then another 2 more degrees. ( however because everything has an equal and opposite reaction this is Also decreasing the overlap period by closing the exhaust valves that many more degrees before. Thus decreasing the overall amount that both intake and exhaust are open together at the same time.)
I would like to see this test run again, but this time with the icl set to 108 for every cam. 12 degrees advanced for the 120lsa, 4 degrees for the 112 lsa, and straight up for the 108 lsa.
this....if they were all installed straight up, then the 120LSA cam's intake valve is opening much later on the intake stroke.....would like to see them all installed on the same ICL, too. would be interesting to see idle vacuum and manners for each, as well as maybe some part throttle fuel consumption (say, 40HP load at 2000 RPM, about what running down the freeway at 75MPH in OD would be)....more than just power to consider with a street car
all that would change is make the wider LSA even worse as it would then open their exhausts even earlier, kill off all low speed torque and still make less HP up top, The low LSA would just make more power everywhere
YOUR VIDEOS ARE GETTING BETTER AND BETTER. I LIKE THAT YOUR PUTTING MORE TECH DATA . I WOULD LIKE TO SEE A TEST ON HYDRAULIC LIFTERS VS LIFTERS LIKE RHOADS.
Was the cam advance changed for each cam to keep intake valve closing the same? I have to wonder how much of the low end power was from the earlier IVC of the 108LSA cam then just LSA (or overlap) by itself. Obviously changing LSA moves all the valve events, but keeping the IVC the same might be more of an accurate test of LSA? Especially since IVC is considered the most important. Great vids btw.
Intake Valve Closing is becoming earlier when LSA tightens. An interesting test would be to install the 112LSA cam 4 degrees advance. This would have the IVC point the same as the 108LSA. However, the difference would be that the exhaust would open and close 8 degreese advanced, as the intake would be 108 Lobe Center Angle and the exhaust would be 116.
I find it super interesting. Well done sourcing exact same spec cams other than LSA. If any cam had even a slight duration or lift difference, results would be controversial. Power increase up top with 108 lsa cam is confusing. Could it be due some kind of harmonics? Matching with Intake runner length or something like that? I’d love to see a test with same cams on different displacement Ls motors. Thanks for sharing. Love the content you putting out.
I am leaning towards exhaust scavenging as well. As for the increase in low end torque with tighter LSA’s, this occurs due to earlier IVC which increases the dynamic compression. That’s the whole premise behind variable valve timing. Advance the intake cam down low for higher dynamic compression (tighter LSA) then retard the intake cam up top to take advantage of port velocity cylinder filling (wider LSA).
GM uses the ASA cam to increase performance in several of it's crate motors, i.e the 525 hp 6.2. This cam has a lsa of 110 and you can use stock ls3 springs. I'm currently running this ASA cam in a 6.0 with ls3 cylinder heads. great videos
I’d definitely like to see this on a smaller displacement engines possibly comparing the 4.8L/5.3L to the bigger 6.0L is also be interested as to how the LSA can affect specific boost pressure
it would be very interesting to see this on the 4.8L/5.3L, as well as comparing, for example, what BTR did with their truck cams between V1 and V2 where what used to be 113+3 LSA is now 110 LSA.
Have you not watched his videos? The difference it makes na will be the same under boost. Almost every time he tests a motor na vs boosted the curve is the same just higher up the graph obviously.
More awesome work Richard, you're cranking out the best content on YT right now! Now can we see the 108 LSA vs the 120 LSA with turbos? Maybe even SC? I know you saw it's the same, but we'd love to see it proven!
From what I understand, which ain't much, it's all about the EVC point. Start there, and adjust the rest. This is per the great Harold Brookshire, and Mike Jones, and even David Vizard. It would be interesting to see that installed +4.
Lobe profile helps with valve tran stability and longevity allowing the lifter to follow the lobe more accurately hopefully without bounce. Possibly allowing larger cams with less negatives towards the valve train.
You said you did this in a reply to my comment on an old video and I looked a couple of times to find it, but now I see why I didn't find it. Now take the 112 and change only lift. Then do the same with the duration would be awesome.
Let's see the same test on a 4.8 (same cam). I think the smaller displacement will emphasize the torque differences much more than the stroker, and show the curves better.
This is why i love the mod motor. you can degree lobe seperation angle, intake and exhaust centerlines, and basically tailor the specs to fit your application.
Where were the intake centerlines on each of the cams when they were installed? Was each cam installed straight up or were they all installed on the same intake centerline?
Interesting to see that most basic "Turbo cams" have a wide LSA if tighter LSA produces more power down low. I would think that's what you'd want to spool the turbo up faster on most combos. It seems like you can't go wrong with tighter LSA for a street/strip motor where you aren't worried about driveability. I guess that's why the turbo cams have wide LSA, just to help driveability. Interesting to see for the build I'm trying to piece together, looks like I might try and spec out my own cam for the fun of it and see where it takes me :)
@@TurboGreggZhow are you getting reversion when most modern turbos have a pressure ratio close to 1:1 (pressure in the exhaust equal to what's coming in the intake)
The reason I widen my LSA is to soften up the bottom end for engine longevity. I have noticed with my twin turbo 406 sbc I snapped 3 different rods before I switched from 108 to 112. Now I have had the same engine for 3 years with no noticeable change in performance down low.
The engine sees only overlap, not duration or LSA. wide duration and tight LSA will give low manifold vacuum and lopey idle. David Vizards extensive testing with LSA has proven with 2 valve motors that optimal LSA is dependent on engine size, 302ci for 110LSA, 350ci for 108LSA, 383ci for 107-106LSA.
When designing custom cams for my car, I paid no attention to LSA. My main focus was on the 4 valve event timings with some attention to overlap and the consideration of variable intake advance up to 15 cam degrees. LSA alone doesn’t matter.
Too big usually means too big for what you are doing with it. For example, street use where vacuum and driveability come into play. The engine dyno won’t show driveability.
@@chucksgarage7165 Or no engine pulls at steady Max. rpm power. Depends on trans. type/coverter, you can have more/less spread on the rpms the engine will work. Too much cam ,can easily drop power on the low side of the rpm range and make the car slower.
A cam is too big when it doesn't let the other parts in your application do what they're good at, and when the engine stops making around 1.3 foot pounds of torque per cubic inch at its torque peak. For example, an LS3 with a cam that's 260 degrees of duration at .050" of lift is too much cam if you're only gonna rev the engine to 6500 RPM with the stock intake and 52" long headers. -- A monster cam is sometimes a band-aid for certain combinations. For example, if you have 5.3 heads on an LS7 (why the hell would you do that!) A cylinder head is like a pitcher. The ability of the head to flow is the diameter of the pitcher. The slot on the side of the pitcher is kind of like your headers and intake. Some slots are wide, others are narrow, others reach the bottom of the pitcher. The lift is how far you tilt the pitcher. The duration is how long you hold the pitcher tilted. The lobe profile is how fast you tilt the pitcher. The RPM is how long someone is gonna put their glass on the counter for you to fill the glass. Some folks have a pint glass. Others slam shots. Others drink beer and they like a lot of foam on top. -- Your challenge as an engine builder is to tend the bar and do tricks while you do it. If you can tilt the pitcher and shoot a stream through the air and fill someone's glass, and you're already filling someone else's glass while that other stream is in mid air, that's one badass bar.
I would like to see 108lsa waste gate spring pressure and the 120lsa waste gate spring pressure and see who makes the most power on five pounds and 20 pounds with egt gauge hooked up
@@chomin3025 So with a smaller engine will it make hp and torque in a higher rpm than a bigger engine (lets say 305 vs 400 , or a 350 as they have the same stroke) with the same 108 lsa camshaft. Or??
@@Skoog. smaller displacement = It makes the power and torque higher in the RPM (with the same camshaft as the bigger one)(Generally , bigger CI can take more advantage and make more power throughout the whole curve. and bigger CI always means more torque with the same mods as a smaller engine)
If you listen to Dave vizard. You will find that he discusses the lobe separation angle being much narrower, especially on smaller displacement engines. The higher the displacement the less effect of changing lobe separation angle becomes. At about 400 cubic inches, it has becoming almost moot, if I'm remembering his descriptions properly turn it down about a 5.3 L engine, A 106 to 108 bulb separation angle should be fairly Optimum especially for a street engine. With higher lift and duration, it still follows. As you move up in displacement the difference in lobe separation angles tends to start to fade away and larger engines tend to like greater lobe separation because of volumetric efficiency changes. I'm doing this from memory because it's been only a few times that I've studied this, but I have always remembered what he has to say because he has the background and has done more testing than you will do unless that's all you do the rest of your existence.
Interesting how it gained without really losing anything with LSA. I guess the next thing to do like you said would be to change the engine size and test again 👍
The only thing I would like to see included in this test is Idle vacuum. Have a set rpm, 800rpm or something, and tune the idle for maximum vacuum to see how smooth they idle.
@@johncholmes643 dailys, but its not just about the idle either. Theres a reason street driven ls cams mostly use a 112lsa. Otherwise everybody would use a 106lsa in their na builds.
@@deantape2759 the factory ls9 cam has something like a 122.5 lsa. Even the ls1 cam is 117 as far as I know. With short duration and 11:1 compression, they idle really smooth with so little overlap
Richard very good video , I hope your subscribers realize how much work and effort you put forth in your videos, we use to call Bob Glidden the mad dog , cause he work continuously , my friend he has nothing on you great job, much appreciated,
Very intersting, expected more low and mid but thought there would be loss on the top. Did they sound much differant at idle? I have offten used curci track cams in my projects with sbcs with narrow lsa they work well on the street but ruff idle
Hats off to ya for another interesting vid Got to be a bunch of work, setting up on the dyno, making pulls to get the time dialed in, then swap cams, then another pull or two (or more...) getting the timing and fuel optimized, then swap cams, then... yeah, a bit of a chore, even if you hold the front cover on with Velcro And when you're done - we want more! That being said, if you want a reason to swap more cams in the dyno cell... I'd be interested in seeing u yet *another* cam comparison: this time 3 cans with different LSA, but the duration adjusted so the intake valve closed point stays the same. So, a can with (for instance) a 112° lobe spread and 230° duration would be compared to one with 238° ground 108. To try to make things as even as possible, use lobes from the same family, with as similar lift and ramp characteristics. My theories: a) the length of the header tubes and exhaust runners on this engine was tuning in make peak torque from 4200-5400 RPM where the 2 bumps in the curve are) - regardless of where you set the IVC, and b) a tighter LSA combined with more duration might allow similar cylinder filling (or maybe even slightly better) up top, and allow the harmonic tuning of the intake & exhaust to make a bigger bump in the middle of the torque curve. Some of the tests you've run with larger duration cans, that didn't seem to pick up much top with long runner intakes made me kinda' think this may be the case Then again in theory, theory is as good as practice...
@Hakimbo Bola Maybe he wants something that sounds cool and helps performance? Lets say you only get 2 degrees difference in LSA and it doesn't make much of a difference in power, but sounds cooler, why not get it if that's what you are looking for.
Hakimbo Bola the sound makes all of the difference. a heathy sounding cam just makes it funner to drive even if it is little slower on the bottom. no one looks at a stock sounding cam and thinks that sounds good.
Right in this it showed the lower lsa making more power throughout, and with a lower lsa you'd have more chop chop pop pop. If that's what you're after, that'd what you'll get!
All you read/hear is tight LSA = peaky/narrow powerband that will fall off up top. Yet every dyno test ive seen they actually have more spread between between peak torque and power.
I have been running a low 230s duration cam with 108 lsa for about 7 years now. I have no idea why more people don't run them, it's that kinda situation I think where somebody on a forum said 'it's not a SBC, you can't cam it like that' so everyone is just blindly running these 113-115 LSA cams with a heap of duration so it will chop on idle still despite the broad LSA. Seems retarded to me to cam an n/a engine like that unless you want soggy midrange. That narrower or 'lower' LSA = an earlier IVC closing point, more cylinder pressure and dynamic compression. Giving up midrange on an LS is dumb af considering most running the stock plastic manifolds are going to be nosing over anyway >6500rpm so why pick the higher LSA cam that gets beaten up until that point? Not saying 108 LSA is the be all and end all.. But it's not all bad either lol. Lot of guys go for a ride in my car and comment on the strong midrange and overall performance compared with other cammed LS1s they have been in.
My guy in 3 months has proved more combinations than ls1tech has for the past 12 years
Agreed!
Sad but true!
Three months of videos but if you pay attention when he's pulling up the graphs, some of these tests go back to 2007/8 if not further. They are an amalgamation of the tests he's done in print for 20+ years.
@@RumblestripDotNet yup amazing the information people have forgotten or ignored
You have to watch generlizations. The reason this picked up so much is because the duration was so undersized to begin with. If you have much larger duration on this and do the same thing, the reverse will start to become true where a bunch more overlap kills low end
If I ever get a chance to either build or simply can swap an LS all I have to do is watch your video series, pick the combo I think will work best for my intended vehicle and just duplicate it. You’ve take all the guess work out of it for us all. What a service you’re providing. Thank you.
Please, pass the knowledge along and share the crap out of his content!
If I had Richard & Brian Tooley a large bank account a time machine a girl with a short skirt and a Long Jacket small hands...that would be all I need, ok the girl has a twin sister, That would be all I need, 😏
I did the same test on a 4.6 2v back in '09 for my buddy David Vizard... My results mirror what you came up with on the LS! David is a huge fan of tight LSA's and he even has come up with the controversial 128 rule.... Awesome job like always!
David's has done a lot of crazy and cool stuff over the years
@@richardholdener1727 you sir are correct! I know that he is impressed with the work you have done as well... Keep up the great work!
DV's 128 formula says an LSA 107 should be ideal for this combination. I'd like to see a cam test using an LSA of 107 with duration numbers starting at 225 and increasing by 15-25 degrees. I think this could show how David's thinking works across the range of street to race cams.
Exactly! LCA is a calculated using the ci & intake valve size. AKA allowing enough time for fill. We advance the cam to help lower the rpm when it will start making power. Every 2 degrees advanced lowers it 100rpm, aka 4 deg = 200 rpm sooner. This is a total shift, top rpm is also lowered the same amount.
Crazy part is BTR thinks LCA is a mear byproduct, I don't follow that line of thinking. I have never gone as tight as 104, 106 is my tightest & I usually shoot for a 108 by using better heads. Different rocker ratios (larger) can also allow a slightly wider LCA but is limited & small. All about choosing the correct combination of parts that will all work together.
My NHRA SS/J 66 Chevy II uses a custom ground solid roller with a 109 LSA I had ground using David Vizards 128 rule. My heads are NHRA Superstock legal Edelbrock highly modified by Edelbrock to coincide with NHRA rules. I shift @ 9000 so its wound up pretty tight and pulling off a consistent 8.60s with a .060 over 327 and M22 tranny is no easy feat. Listening to David Vizard and reading his books has made not only my Superstock fast but my Stock Eliminator K/SA Monte Carlo SS (with the factory L69 305). This test Richard just run backed up the 128 rule big time. For big blocks and Fords is 127 and he has videos on it if you are wanting to learn. Thanks for this video Richard you are very entertaining and easy to listen to unlike Freiburger and Dulcich.
David Vizard been saying that for years and I believe it`s true. 106 seems to be the magic number for circle track and higher compression, 2bbl seems to like the wider LSA along with bigger CID like 454 and bigger.. There are so many contributing factors I don`t think a person could pick the perfect cam with out a dyno, back when I was a kid cams were listed by lift, duration (advertised) and overlap. I think Isky was one of the first guys to start tightening up the LSA and he made a high mark to reach for
That really depends. If you have high compression, you need more LSA
David Vizard published very good book with great explanation on LSA and how t choose best one for particular application.
Great book!
I have been reading and have David Vizards books from the early 80s and have built numerous engines on his specs, they have never failed to impress, starting on the Mini A series, Ford Pinto, Chev 350 and now finally the LS series.
@@adamsweet3587 I really enjoyed his how to port and flow test. Also how to build horsepower. Really great stuff!
Shota Makarashvili whatever happened to him?
@@frankrizzo2724 he has a RUclips channel to promote his lectures and books.
Around 50 years ago I was taught to run narrow LSAs as much as conceivable to help capture cylinder pressure at higher elevations like in Denver. We were always happy when we got cams at 110, and really happy at 108.
I think I need to dump the 112 in my Olds 350 for a 108!
Been watching david vizzard lately and he has a formula that puts this engine’s ideal lsa right around the 108 that made the most power, maybe he is on to something. Oh yeah and as always another great video by richard
Vizard is up to something
He has been DYNO testing for 40 years
Me too. 128 sb chevy formula
What do I think? Hell, I don't know anymore...between you and Engine Masters everything I learned as a kid was false. Can't wait for the next installment.
I understand physics... and english. My point is, all the hearsay and conjecture are being disproved through a scientific method and theory to practice. Sorry, I didn't have all this information available so easily at a younger age. Thank you, Mr. Holdner for sharing.
@@bigboreracing356 All he said was that he was taught some things as a young person that wound up being inaccurate. No need to be a jerk, I'm sure you have fallen prey to misinformation at least a time or two. We all have. Some of us are man enough to admit it. They knew everything in the 1930s that we know now? You're out of your fucking mind.
@@bigboreracing356 The truth about what? That you're a keyboard warrior who thinks he's "the bad man"? How would I have your comment removed? It's not my video. I'm a commenter just like you, but with some substance. You talk about safe spaces, but probably drive a mustang. Kill any bystanders lately?
STREET RACER what’s your point in trashing someone for something they learned or were told wrong when they were young? Don’t be a douche, we all have been told things that were wrong. Doesn’t give you the right to jump all over someone. 🤷🏽♂️
@@bigboreracing356 I really enjoyed CT magazine growing up !
Good video - people are realizing the tighter LSA means more acceleration torque AND NO LOSS upstairs- bigger displacement responds even better, of course vacuum drops due to more overlap and worse throttle response below 1500 to 1800, so an automatic and smaller engine should use a somewhat looser converter, BUT make sure converter stall speed is below top gear or overdrive RPM at highway cruising speeds.
That last part is basically impossible for a good street car. Cruising RPM in top gear at highway speeds needs to be under 3000 for anything approaching acceptable fuel efficiency. Most underpowered ecoboxes and sport compacts (the normal ones, not the extra weak ones under 130hp) run 3000rpm at 75mph in last gear.
The way I spec it is roughly 1/3 redline should be your normal cruise RPM, and that should match up with 0-10mph over your local hwy limits. Or if you have an abundance of torque and/or enough gears that they don't feel too long, 2000rpm cruise no matter what, and between 60-80mph
Very interesting. I run in a tightly-regulated race club where LSA is basically all we have to play with (DOHC, adjusting stock cams) and we are typically living in the realm of 103-105 LSA. Our duration numbers are pretty high (streetbike engines) and we operate around 6000-12000 rpm. There is definitely a point of diminishing returns in wide LSA for top end! This is why we test!
Excellent. Richard test gives the explanation point. I wonder about 104 or 106. I've even seen people run 102.
Truck norris cam makes sense now. I just revisited this video and glad I did. Truck norris is what I'm rolling with. Thanks
Richard giving the people what they wanted. Awesome. Patiently awaiting SBF combos.
Brian Meyer Cleveland’s forever!!! J/k. Me 2.
Great job explaining LSA. Tighter more chop & more bottom end, wider less chop more on the top ! Thanks Richard!
I was always told this and all our drag cars had the super tight LSA. But it was nice to see it in a graph to prove the point. Richard. Your the man.
Welp, I'm seeing this two years hence, but of course it's still very interesting. I've wondered the same thing about LSA for many years now.
I'm positing the lower numbers at lower RPM for a wider LSA have to do with how the wider LSA bleeds off more cylinder pressure. Both valves are still open for several degrees of rotation, and you can't build cylinder pressure until they are both shut.
My bit of homework on the newish cams sold for use on low compression engines run in line with this. Comp Cams' Thumper series, Hughes Engines' Whiplash cams, all have very tight LSA numbers. As you say, they give the hot rod guy the lope he likes, but the smooth out early. And they actually make more cylinder pressure than an OEM cam. The lope isn't desirable for an OEM for sale to the general public.
All in all, very interesting and thanks for taking the time and effort to do it.
One other factor I've wondered about for years, how about the installed angle of the cam? Would installing the 112 LSA piece, maybe even the longer one, make these valve events soon enough to compensate?
Thanks!
Back in the70's Isky and Clay Smith had a bunch of cams at 108, they were ahead of the curve compared to most cams. They also made very good power through out the rpm range. Nice test
Racer brown made good cams too back in the day
The work never ends... Same test with turbo, supercharger and nitrous. Thanks for everything you do Richard!
it's the same with boost
Every cam is a turbo cam.. lol
Wow! Great video Richard! Had no idea that a tighter LSA (with choppy idle) would make more low end power!?!?! NOW.....I can have the best of both worlds!!! I can put a 108 LSA cam in my work truck, have a bada$$ idle and tow my trailers (enclosed tool trailer, 6T flatbed and my I/O boat trailer) all day! ALL your videos have awesome content and enjoy the heck out of them. I watched several of them more than once to make sure I'm absorbing the content for my LS/OBS swap coming up.
Don't get too excited... If that were the case, all cams would be ground on a 100 degree LSA. You get more low end to a point, and then, nothing... Makes your power-band more like a two-stroke.
It has to be sized to the motor properly. In this case the 402 just happened to like the 108
Just subbed, you really get to the point without unneeded banter! Thank you for an informative video
Welcome aboard and thnx for the support
You run tests I've always wanted to see. Thank you again for the awesome data you create and provide. Great job!
THIS IS WHAT IVE BEEN WAITING FOR!!!
Nice this is a topic iv always thought about. Few things I knew for sure was the lower the LSA = more chop @ idle but also slightly more difficult too tune. Now we need the results on smaller cube, less radical builds like your budget 5.3 & 6.0.
Just installed a Mutha Thumpr (109 LSA) in my LQ9 swap. This videos gives me hope.
The success of the cam is more than LSA but my guess is you are happy with the Thumpr
@@richardholdener1727 the idle is car porn, yes. I've got to get a better tune though. Still dealing with vacuum issues and the brake booster since it's a high lift cam.
Good one thanks. That's what I wanted to know and that was my hope that tighter lobe separation will give me better low-end power and a wild chop without increasing lift and duration.
Exactly what I was saying on a different video about the intake tests. Just because you have a long runner intake you don’t need to run a wider lsa. The reality is that tighter lsa cams tend to make more power even more so when naturally aspirated. Thanks for the video!
Nice, separating fact from fiction as usual top stuff,
my take away: don't rush out and buy a camshaft on a 108 degree lsa. the 112 degree lsa cam is so close to the same power numbers it makes more sense to use it in a speed density fuel injection system because it gives better vacuum at idle and allows the map sensor to work correctly.
Good point, I hope most people can understand that.
Man, I have always wondered what the change in LSA would affect!!! Thank you for the information!!!!
Nice I loved my Lunati Bootlegger in my sbc 406. 108LSA nice chop great power band. Running a Summit cam in my budget junkyard 307 build, 106lsa, gm 601 heads that I cleaned up a bit. Fun little mighty mouse motor. Going to build the 406 right and put a forged rotating assembly in.
OVERLAP
Ls9 = -24.50
Crane 210/218
122.5 = -18.00
Crane 232/242 (.624/.624)
120 = -3.00
112 = 13.00
108 = 21.00
Exhaust scavenging induction event. The fifth cycle.
all those number can change with different grind timing ...
@@autobodyspecialistsinc.4397 If I hand you a cam with 10 degrees of overlap, you can change that?
Yes, I agree. for some reason i was thinking in terms of the timing events in relation to crank position...
The L.S motors are a whole different animal than the old small block when it comes to cams and l.s.a it seems to me they can do so much more with the l.s cams as far as all of the numbers more lift and longer duration and thus not needing to tighten the lsa as much and fight with the choppy idle and vacuum issues like in the past if I understand right it's due to the cam actually being moved up and ,made larger is this correct ? I'm interested in anything I can. Learn. Pls
Thanks Richard, you have answered my next cam choice. This info is priceless and worth gold.
Awesome, awesome video Rich... Guess I now know what to expect when I install that Truck Norris cam into my Pontiac LS2... More chop, and more down low-mid range, and hell maybe even more up top as well
Hey Richard, camshaft theory is fascinating to me and watch this video often. In fact, I had a custom Bullet Cam for my 454 ground partially based on this video. Theorizing here, a tighter LSA generally increases cylinder psi, because it increases the dynamic compression, which may have contributed to not only the expected bump in low speed torque but also the power across the board.
Great test but with the 108 LSA looking better all the way it would have been nice to see another with even less LSA to see what would happen.
GREAT test Richard! This test repeats ALL other dynos I've seen where only LSAs are changed. Yet you read all the tech info they say the reverse. Well done.
I've had the opportunity to work with a few engines using a 108LSA over the normal off the shelf selection. Two 347 SBF's and a 388 LT1. All engines were amazing street strip combos. Still had manners down low, came on strong in the middle and ripped up top. For the 330 to 400ci range, I don't think it can be beat.
This is another great post by RH. That 210/218 duration cam might really wake things up with 102-106 LSA
Gotta have that chop! Besides power down low with good torque is what I need!
Now I know why I have always ran a 112 LSA advanced 4 degrees. Intake is always more critical than the exhaust. Also with a 10 - 12 degrees more on the exhaust duration. This is what I have found to work best in the vast majority of cases, over the last 45+ years. What we also found was that a 108 LSA, (MPG) suffered on the street. It was not worth the loss of gas mileage for the little HP that was gained. That was why we started advancing the camshaft, and it worked...
Fool - that does not change the LSA - you need to go back and study
literally all wrong, you change the DURATION to bring the overlap down, you do not change the LSA to help with drivability, having too much duration and then widening the LSA to help drivability is all wrong, if you need to do that you have way too much duration for your application
@@alphaghost1633 Really. If I advance a 112 LSA camshaft 4 degrees. Then the Intake would be 108 and the exhaust 116.
@@danawilkes6174 Yeah, but I think we'd all like to see a direct comparison of a 112+4 adv vs a 108 with reduced duration to have the same overlap (both advertised and at .050) with the same lift, too.
Tell em what happens to the vacuum. The brakes 😁
Great video 108 centers rock ⚔
Do you think vacuum suffers much with smaller LSA? I need good vacuum for the brakes or need to go hydroboost.
@@RadRidesByCru I run a 228/234 .614 lift in/exh, 108 LSA in a 355 CI gen II SBC (LT1) and my vacuum at 825 RPM is 13.5 to 14 In/hg. So vacuum in that engine was likely similar given more duration and more CI
@volvospede it really depends if you plan on running an auto or manual? As I just pointed out my engine doesn't produce a ton of vacuum at idle, but since I have a manual and a working checkvalve on my vacuum canister my brakes are no different than stock because on decel at cruising RPM my engine will easily produce 25 in/hg at about 2000 rpm with the throttle closed of course. This is plenty of vacuum to charge the canister, and have never noticed a change in my brakes. An auto would obviously be a whole different game though.
I have run as big as 266@50 on a 99LSA and still had enough vacuum for brakes...
I have an LM7 5.3L Gen 3 bored 30 over. I have watched a lot of your videos and love them. My cam and engine spec are: Custom grind. Cam Motion - 210 int/ 218 exhaust/ 570 int and 570 exh lift with a 110 LSA +2. PAC 625 springs. Stock heads with a 3 angle valve job. I will be adding Long tubes and a full 3" exhaust with a cut out for fun.
It looks like the rest of my comment did not go through. 10.3 compression with flat top forged summit pistons with valve reliefs. Was wondering what you though how this will perform and what rpm range it will perform the best and how high it will rev before falling off. I have the new rockers with upgraded trunion kit. Stock truck intake. Thanks for any advice. .007 shaved off heads and about the same shaved of the deck to make true. I will have long tube headers and 3" exhaust all the way back. Any advice would be appreciated. Thanks and love the videos. Piston are on average about .004 - .005 out the hole. Stock bottom end. I will be rebuilding my 4L60 and keeping the stock converter if possible. I hope the trans shop can build it to hold 600Hp because I want to add nitrous in the future. Thanks a lot. Love the videos.
take a look at the btr truck cam test on the 5.3l-that should give you a very good idea
Very nice! still counts
subbed! totally explained LSA's to what I was hoping to understand on paper! also totally explains my ls swapped cruisers cam behavior now too
I am learning so much from your videos! Thank you and keep them coming!
Great test 👍🏻 Would be great to see these exact three combos now fitted with a blower. Richard keep up the great work
same
very interesting results, ill keep this in mind as are thinking of getting a custom grind for my lsx 7.0
A lot of great info on this channel. Clearing up a lot of misconceptions. Keep doing what your doing brother!! We appreciate you!
Was just trying to choose lsa for my new tsp cam last night! Thanks for the test Richard, you're the man!
How about some lsa +0 vs +2, +4, +6 intake lobe advance. That type of data would help understand ground in advance a bit more while helping with camshaft selection.
I would love some more information on this … currently trying to learn what I can and there isn’t a lot of resources I can find on ground in advance
Valve event timing is what you need to be comparing.
This changes everything! this test is a bit missleading without optimal intake timing.
I feel honored. I think my dumb question yesterday motivated you to make/post this video. Thank you! I most definitely learned something from this video. I personally envisioned the LSA effect backwards figuring less overlap would help low-end. So glad you post these educational videos.
Yep-your question yesterday motivated me to go back in time to 2014 to run this test, lol. Seriously, make sure to post requests-I read them all and love the ideas
There is an exception to every rule, with a few exceptions.
another way of seeing this for someone with a DOHC engine. Is the stock camshaft timing, then advancing the exhaust camshaft 4 degrees. then another 2 more degrees. ( however because everything has an equal and opposite reaction this is Also decreasing the overlap period by closing the exhaust valves that many more degrees before. Thus decreasing the overall amount that both intake and exhaust are open together at the same time.)
I would like to see this test run again, but this time with the icl set to 108 for every cam. 12 degrees advanced for the 120lsa, 4 degrees for the 112 lsa, and straight up for the 108 lsa.
this....if they were all installed straight up, then the 120LSA cam's intake valve is opening much later on the intake stroke.....would like to see them all installed on the same ICL, too. would be interesting to see idle vacuum and manners for each, as well as maybe some part throttle fuel consumption (say, 40HP load at 2000 RPM, about what running down the freeway at 75MPH in OD would be)....more than just power to consider with a street car
@@86chrysler5thave Also dynamic compression ratio should be the same if they're all installed on 108 icl. That would be a true comparison of lsa.
all that would change is make the wider LSA even worse as it would then open their exhausts even earlier, kill off all low speed torque and still make less HP up top, The low LSA would just make more power everywhere
YOUR VIDEOS ARE GETTING BETTER AND BETTER. I LIKE THAT YOUR PUTTING MORE TECH DATA . I WOULD LIKE TO SEE A TEST ON HYDRAULIC LIFTERS VS LIFTERS LIKE RHOADS.
Yes, it would be cool to see this test done on a 5.3L and 5.7L
Another great informative video Richard. Thanks for showing what’s behind the curtain when it comes to making power.
Was the cam advance changed for each cam to keep intake valve closing the same? I have to wonder how much of the low end power was from the earlier IVC of the 108LSA cam then just LSA (or overlap) by itself. Obviously changing LSA moves all the valve events, but keeping the IVC the same might be more of an accurate test of LSA? Especially since IVC is considered the most important. Great vids btw.
This is a really good point about the IVC. Changing.
Intake Valve Closing is becoming earlier when LSA tightens.
An interesting test would be to install the 112LSA cam 4 degrees advance. This would have the IVC point the same as the 108LSA. However, the difference would be that the exhaust would open and close 8 degreese advanced, as the intake would be 108 Lobe Center Angle and the exhaust would be 116.
I was wondering the same thing
Great video, very informative as before watching your videos I did not know much about LS engines except for basic generalities.
I find it super interesting. Well done sourcing exact same spec cams other than LSA. If any cam had even a slight duration or lift difference, results would be controversial.
Power increase up top with 108 lsa cam is confusing. Could it be due some kind of harmonics? Matching with Intake runner length or something like that?
I’d love to see a test with same cams on different displacement Ls motors. Thanks for sharing. Love the content you putting out.
I'm thinking it's from extra exhaust scavenging during overlap.
Starts air in runner moving more, sooner.
I am leaning towards exhaust scavenging as well. As for the increase in low end torque with tighter LSA’s, this occurs due to earlier IVC which increases the dynamic compression. That’s the whole premise behind variable valve timing. Advance the intake cam down low for higher dynamic compression (tighter LSA) then retard the intake cam up top to take advantage of port velocity cylinder filling (wider LSA).
GM uses the ASA cam to increase performance in several of it's crate motors, i.e the 525 hp 6.2. This cam has a lsa of 110 and you can use stock ls3 springs. I'm currently running this ASA cam in a 6.0 with ls3 cylinder heads. great videos
Do you have the rest of the specs?
Summit Racing Part Number:HRS-197715-10,
I’d definitely like to see this on a smaller displacement engines possibly comparing the 4.8L/5.3L to the bigger 6.0L is also be interested as to how the LSA can affect specific boost pressure
I was just thinking about making a very similar comment to this. Lol
it would be very interesting to see this on the 4.8L/5.3L, as well as comparing, for example, what BTR did with their truck cams between V1 and V2 where what used to be 113+3 LSA is now 110 LSA.
same under boost
Have you not watched his videos? The difference it makes na will be the same under boost. Almost every time he tests a motor na vs boosted the curve is the same just higher up the graph obviously.
Joe momma I wasn’t really thinking when asking my question tbh initially I was thinking about degrees of overlap
Great test , another always asked question answered
More awesome work Richard, you're cranking out the best content on YT right now! Now can we see the 108 LSA vs the 120 LSA with turbos? Maybe even SC? I know you saw it's the same, but we'd love to see it proven!
This test has always interested Me.
From what I understand, which ain't much, it's all about the EVC point. Start there, and adjust the rest. This is per the great Harold Brookshire, and Mike Jones, and even David Vizard. It would be interesting to see that installed +4.
IVC, is the most critical event.
Lobe profile helps with valve tran stability and longevity allowing the lifter to follow the lobe more accurately hopefully without bounce. Possibly allowing larger cams with less negatives towards the valve train.
You said you did this in a reply to my comment on an old video and I looked a couple of times to find it, but now I see why I didn't find it. Now take the 112 and change only lift. Then do the same with the duration would be awesome.
Thank you I been asking you to do this for 6 years!
this was done long ago
Let's see the same test on a 4.8 (same cam). I think the smaller displacement will emphasize the torque differences much more than the stroker, and show the curves better.
you want tighter LSA with more cubes as it takes advantage of the larger displacement for filling sooner
This is why i love the mod motor. you can degree lobe seperation angle, intake and exhaust centerlines, and basically tailor the specs to fit your application.
Where were the intake centerlines on each of the cams when they were installed? Was each cam installed straight up or were they all installed on the same intake centerline?
installed dot to dot-I don't have cam cards
Ask, and bald dyno Jesus will deliver... You are the man.
Interesting to see that most basic "Turbo cams" have a wide LSA if tighter LSA produces more power down low. I would think that's what you'd want to spool the turbo up faster on most combos. It seems like you can't go wrong with tighter LSA for a street/strip motor where you aren't worried about driveability. I guess that's why the turbo cams have wide LSA, just to help driveability. Interesting to see for the build I'm trying to piece together, looks like I might try and spec out my own cam for the fun of it and see where it takes me :)
awebke You’re exactly right. Back when they raced the grand nationals, Kenny duttweiler tightened the LSA on them for the very reason you stated.
Egt can sky rocket from tight lsa. Overlap causes issue due to the reversion.
@@TurboGreggZhow are you getting reversion when most modern turbos have a pressure ratio close to 1:1 (pressure in the exhaust equal to what's coming in the intake)
The reason I widen my LSA is to soften up the bottom end for engine longevity. I have noticed with my twin turbo 406 sbc I snapped 3 different rods before I switched from 108 to 112. Now I have had the same engine for 3 years with no noticeable change in performance down low.
And as for the gains up top with the 108 LSA sometimes things just click and the flow and rhythm of an engine just work right together.
Idle videos would be a nice add to these videos, LSA tends to change idle characteristics correct?
A lot...
idle is choppier with 108 as mentioned in the video, but wish I took idle vacuum and had clips
The engine sees only overlap, not duration or LSA. wide duration and tight LSA will give low manifold vacuum and lopey idle. David Vizards extensive testing with LSA has proven with 2 valve motors that optimal LSA is dependent on engine size, 302ci for 110LSA, 350ci for 108LSA, 383ci for 107-106LSA.
When designing custom cams for my car, I paid no attention to LSA. My main focus was on the 4 valve event timings with some attention to overlap and the consideration of variable intake advance up to 15 cam degrees. LSA alone doesn’t matter.
@@adamsweet3587 There are no absolutes
Thankyou! These dyno tests where you change one thing are the cool ones!
Thanks Richard, can you test a cam that is too big that's actually make less power than a smaller cam. i always hear about it but never seen it
never too big! 😎
look at the 408 (175-hp cam) video-yes you can have too much cam
Too big usually means too big for what you are doing with it. For example, street use where vacuum and driveability come into play. The engine dyno won’t show driveability.
@@chucksgarage7165 Or no engine pulls at steady Max. rpm power. Depends on trans. type/coverter, you can have more/less spread on the rpms the engine will work. Too much cam ,can easily drop power on the low side of the rpm range and make the car slower.
A cam is too big when it doesn't let the other parts in your application do what they're good at, and when the engine stops making around 1.3 foot pounds of torque per cubic inch at its torque peak. For example, an LS3 with a cam that's 260 degrees of duration at .050" of lift is too much cam if you're only gonna rev the engine to 6500 RPM with the stock intake and 52" long headers.
-- A monster cam is sometimes a band-aid for certain combinations. For example, if you have 5.3 heads on an LS7 (why the hell would you do that!)
A cylinder head is like a pitcher.
The ability of the head to flow is the diameter of the pitcher.
The slot on the side of the pitcher is kind of like your headers and intake. Some slots are wide, others are narrow, others reach the bottom of the pitcher.
The lift is how far you tilt the pitcher.
The duration is how long you hold the pitcher tilted.
The lobe profile is how fast you tilt the pitcher.
The RPM is how long someone is gonna put their glass on the counter for you to fill the glass. Some folks have a pint glass. Others slam shots. Others drink beer and they like a lot of foam on top.
-- Your challenge as an engine builder is to tend the bar and do tricks while you do it. If you can tilt the pitcher and shoot a stream through the air and fill someone's glass, and you're already filling someone else's glass while that other stream is in mid air, that's one badass bar.
Thanks so much for answering my exact question is a very easy to understand format
Great test as usual Richard, what about the ICL on those cams are they all 0 degree ground or advanced?
not sure
@@richardholdener1727 Really appreciate the amount of time and effort to provide the community with the things they love.
@@richardholdener1727 were they all installed straight up ICL, or say 4 degrees adv?
Very good experiment, thanks Richard
Great video, I would like to see this type of test ran on a stock 5.3 and 4.8.
rideswift It will be pretty much the same, just shift the power curve towards the right, and it will be a more linear power band.
I would like to see 108lsa waste gate spring pressure and the 120lsa waste gate spring pressure and see who makes the most power on five pounds and 20 pounds with egt gauge hooked up
@@chomin3025 So with a smaller engine will it make hp and torque in a higher rpm than a bigger engine (lets say 305 vs 400 , or a 350 as they have the same stroke) with the same 108 lsa camshaft. Or??
@@Skoog. smaller displacement = It makes the power and torque higher in the RPM (with the same camshaft as the bigger one)(Generally , bigger CI can take more advantage and make more power throughout the whole curve. and bigger CI always means more torque with the same mods as a smaller engine)
@@chomin3025 Thankyou..!! I always thought it made power at the same rpm.
If you listen to Dave vizard. You will find that he discusses the lobe separation angle being much narrower, especially on smaller displacement engines. The higher the displacement the less effect of changing lobe separation angle becomes. At about 400 cubic inches, it has becoming almost moot, if I'm remembering his descriptions properly turn it down about a 5.3 L engine, A 106 to 108 bulb separation angle should be fairly Optimum especially for a street engine. With higher lift and duration, it still follows. As you move up in displacement the difference in lobe separation angles tends to start to fade away and larger engines tend to like greater lobe separation because of volumetric efficiency changes. I'm doing this from memory because it's been only a few times that I've studied this, but I have always remembered what he has to say because he has the background and has done more testing than you will do unless that's all you do the rest of your existence.
If you can only run a test over a limited RPM range .... Why don’t you run two tests? For a street car I would like to see what is lost low down.
Great Job Richard! I learned something!
I feel like a certificate is in order after watching all of your videos.
Great video! Highly appreciate this one.
Interesting how it gained without really losing anything with LSA. I guess the next thing to do like you said would be to change the engine size and test again 👍
Love your videos Richard keep testing
Were these cams ground with the same intake Centerline?
I'm not sure-I don't have the cam cards
@@richardholdener1727 then these tests mean nothing
Crane made the cams , I would think that they made them how he asked. With only LSA being different.
Yessssss I've been waiting for this one!
The only thing I would like to see included in this test is Idle vacuum. Have a set rpm, 800rpm or something, and tune the idle for maximum vacuum to see how smooth they idle.
Who wants a smooth idle??
@@johncholmes643 certain race classes.
@@johncholmes643 dailys, but its not just about the idle either.
Theres a reason street driven ls cams mostly use a 112lsa. Otherwise everybody would use a 106lsa in their na builds.
@@deantape2759 the factory ls9 cam has something like a 122.5 lsa. Even the ls1 cam is 117 as far as I know. With short duration and 11:1 compression, they idle really smooth with so little overlap
@@timothybayliss6680 im talking popular aftermarket cams sorry not stock ones, i agree they do always favour a really smooth idle on stock cams.
Richard very good video , I hope your subscribers realize how much work and effort you put forth in your videos, we use to call Bob Glidden the mad dog , cause he work continuously , my friend he has nothing on you great job, much appreciated,
Very intersting, expected more low and mid but thought there would be loss on the top. Did they sound much differant at idle? I have offten used curci track cams in my projects with sbcs with narrow lsa they work well on the street but ruff idle
There would have been. He just didn't take it high enough. Those cams had a lot of duration.
great job richard. your engine tech vids are great and so are your books.
Hats off to ya for another interesting vid
Got to be a bunch of work, setting up on the dyno, making pulls to get the time dialed in, then swap cams, then another pull or two (or more...) getting the timing and fuel optimized, then swap cams, then... yeah, a bit of a chore, even if you hold the front cover on with Velcro
And when you're done - we want more!
That being said, if you want a reason to swap more cams in the dyno cell... I'd be interested in seeing u yet *another* cam comparison: this time 3 cans with different LSA, but the duration adjusted so the intake valve closed point stays the same.
So, a can with (for instance) a 112° lobe spread and 230° duration would be compared to one with 238° ground 108. To try to make things as even as possible, use lobes from the same family, with as similar lift and ramp characteristics.
My theories: a) the length of the header tubes and exhaust runners on this engine was tuning in make peak torque from 4200-5400 RPM where the 2 bumps in the curve are) - regardless of where you set the IVC, and b) a tighter LSA combined with more duration might allow similar cylinder filling (or maybe even slightly better) up top, and allow the harmonic tuning of the intake & exhaust to make a bigger bump in the middle of the torque curve.
Some of the tests you've run with larger duration cans, that didn't seem to pick up much top with long runner intakes made me kinda' think this may be the case
Then again in theory, theory is as good as practice...
Glad you like them!
I want to hear the difference in the LSA of the cam
@Hakimbo Bola Maybe he wants something that sounds cool and helps performance? Lets say you only get 2 degrees difference in LSA and it doesn't make much of a difference in power, but sounds cooler, why not get it if that's what you are looking for.
Hakimbo Bola the sound makes all of the difference. a heathy sounding cam just makes it funner to drive even if it is little slower on the bottom. no one looks at a stock sounding cam and thinks that sounds good.
Lower lobe center number more choppy
@Hakimbo Bola Well considering he watched the video all the way through the choppiest cam made the most power. So STFU
Right in this it showed the lower lsa making more power throughout, and with a lower lsa you'd have more chop chop pop pop. If that's what you're after, that'd what you'll get!
All you read/hear is tight LSA = peaky/narrow powerband that will fall off up top. Yet every dyno test ive seen they actually have more spread between between peak torque and power.
Texas speed just came out with the BFD cam that has a LSA of 108. I would love to see that in a LS1
how is it that you came about this knowledge?
Because I just put it in my car and they sent the cam card with it. I'll have to look for the cam card again
I have a video of the idle on this account
@Struinzu Vaffencullo yup
I have been running a low 230s duration cam with 108 lsa for about 7 years now. I have no idea why more people don't run them, it's that kinda situation I think where somebody on a forum said 'it's not a SBC, you can't cam it like that' so everyone is just blindly running these 113-115 LSA cams with a heap of duration so it will chop on idle still despite the broad LSA. Seems retarded to me to cam an n/a engine like that unless you want soggy midrange. That narrower or 'lower' LSA = an earlier IVC closing point, more cylinder pressure and dynamic compression. Giving up midrange on an LS is dumb af considering most running the stock plastic manifolds are going to be nosing over anyway >6500rpm so why pick the higher LSA cam that gets beaten up until that point?
Not saying 108 LSA is the be all and end all.. But it's not all bad either lol. Lot of guys go for a ride in my car and comment on the strong midrange and overall performance compared with other cammed LS1s they have been in.
WoW whatta motor! Amazing engineering 👏 👌
I think you needed to go below 108 to see the drop off on the top end because 108 is about the optimum lsa for that combo.
Good Point...
Richard and project farm are bonified geniuses