Pick the Right Camshaft Using
HTML-код
- Опубликовано: 7 авг 2024
- Today on Unity Motorsports Garage I pickup where we left off on the "Untold Truth about Camshaft LSA" video. DV's 128 cam formula has been beaten up by the internet but has stood the test of time. Using your engine specs you can determine the perfect Lobe Separation Angle and when used in conjunction with the Overlap needed for your given combination you will find the intake lobe duration that is needed to achieve your goals! make sure you subscribe to @DavidVizard and we will keep the videos coming!
Thanks for watching
Andy
#ford #chevy #mopar #camshaft 
Авто/Мото
I am so amazed at David Vizard's knowledge and so grateful that he is willing to share it with the world. Those who give him a hard time should leave him alone and learn it the hard way. Of coarse that will be the expensive way too. It's hard to find good information on difficult subjects. Bad information witch seems to be in abundance can really steer you the wrong way. I can clearly see that David thinks at a higher level than most of us out here, and to share it with us makes him a very special person. Keep up the good work David! Thank you Andy for this video and believing in David.
I've been reading his books for a decade. Awesome part is they're mostly about low bucks budget builds, step by step. Definitely recommend all his books
I have learned a lot from David through out the years. I remember the book I had read many years ago when I was still in high school on how to build small block horsepower on a budget. I have alot of respect for David. Growing up as child, my father owned an automotive shop and my father taught me so much about building race engines but he passed away a few years ago so I'm not able to ask him a question anymore when I am needing an answer on any given situation. I am able to find those answers to those situations through David's videos. I can't thank him enough for the knowledge! Knowledge is power and as my father always told me "never stop learning" and "speed costs money, how fast you want to go?" Keep on keeping on David Vizard and I will never stop learning from your knowledge passed along through all your videos. 👍🤙✌️
Your channel is growing , you went from 20,000 to 31,300 as of August 16 2023 .....
Keep 'em coming !!!!!!!
Thank you David and Andy
I’m sorry to hear that your friend passed away. I look forward to you and DV teaming up on future videos. I learn a good amount from the both of you. Thanks for sharing this formula.
Thank you so much. spent years doing engine simulations to pick the cams for my 76 K20 tow vehicle and 69 Nova 440 hp 327. my numers came up very close to these recomendations. the truck 206/214 .461/483 at 38 deg overlap and pulls like a tractor. About to start putting the Nova motor together, Dart block, Diamond pistons, Jesel lifters, solid roller 224 deg and .525 lift. Car is my daily driver and comes in at 48 deg overlap. The 327 simulates at 1.4 ft-lb per inch at 110 seperation
Andy I love it when you and David work together, the best of both worlds in one. Would you be able to do a video on how to accurately work out dynamic compression? Some online calculators use @.050” duration and some use advertised. Surely it’s when the valve actually hits the seat that matters?
I really enjoy this technical gold and best of all learn from you guys. Stick together guys, it makes you both better. Both of you have different skills that work good together... Thanks for doing this fellows.
Always watching you and DV.. brings back memories from the late 80’s/early 90’s, all the testing we did to find the right combo, I hope this generation of builders listen to us old timers
THey dont...they want a chop, stage xx cam they know nothing about.
Then refuse to regear, upgrade converter etc.
They gotta learn their lesson that more isnt better and chop doesnt mean fast.
Andy and David, I am soaking up all this great info and expertise. Already applying it to my 355 sbc, 108 LSA and the torque is awesome! Thanks for the great work
I like your videos and DV’s as well. This is stuff I have in his books but it’s nice hearing it explained. It help give you a better understanding of the information. Thanks.
I like the content. Both yours and David’s. So glad you’re ready and able to help David with his work. If I were you I’d try to sponge as much of his knowledge as my head could absorb.
Another great video, and of course I went right over and subscribed to DV's new channel. I have read his books and been applying his lessons for decades and with great results.
Awesome video here. I'll be applying this for my next build. Thank you for sharing your knowledge guys!
I have very expensive simulation software that I use. I input every bit of data I have on my engine, then run through many different cam profiles until I find the one that works for what my intended purposes for that engine. So far, it's worked out very well. The one item I find that makes the biggest difference is head selection. You can't make a decision without knowing what your heads breath! Well, you can, but it may not work out so well for you. If you try running an 8000RPM cam on a set of stock heads, good luck making that work for you.
Me to, I build Harley engine's for a living, I use that software also and sometimes I'll spend an entire evening going through cams until I find something that does what I want and it almost never is what the cam manufacturer's recommend for the application, but I wind up with better results than the other engine builders around my area, and no one can figure it out, as far as required flow I don't pay any attention to that until I get the results on that software I want and then I look at the required flow to get there then do what I have to do to get it, a big mistake is guy's will over flow heads thinking bigger is better but they'll lose that all important velocity because they don't understand how important it is, I have a math formula I used to determine the size of the ports I need to achieve that flow and don't exceed the size even the least bit, that's another thing about Harley's that make them easy is our ports are round so it's easy to do the math because it's just a simple diameter calculation, you don't need a degree in geometry to figure out the optimal port size, and we don't have push rod area's and water jackets to worry about breaking into.
I'm all the time picking bolt in cams for performance applications and vice versa, one thing I have to deal with that car guys don't is the varying weights between different models of Harley's that use the same engine, some models weigh almost twice as much as another model with the same engine, that changes things more than people realize, and that's why the cam makers recommendations don't always work, I can hot rod a lighter bike and get away with keeping compression down so I don't get detonation pulling away from a stop but it still won't be a low end dog because it's lighter, then when the rev's go up it comes on the cam it feels like someone hit the back of the bike with a giant sledgehammer, I'll also shorten up the timing throw so it doesn't retard so much at an idle and that'll replace a lot of the lost bottom end, I'll shorten it up just to where it starts flirting with detonation then give it a couple more degrees of throw just to be safe.
I also play around with gearing a lot to get what I want, Harley transmissions are easy to work with especially pre 04 Sportsters and fortunately through the aftermarket we've got a huge selection of ratios for the different gear positions to choose from, one of my Sportsters I put a close ratio 1st gear in that's actually for getting more dig out of the hole by lowering the final drive ratio (at the rear wheel), but I left that stock, as a result it'll exceed 65 MPH in first gear, when I tell people I have a Sportster that'll do that they say "It's impossible", I've won more 20 dollar bills off of people with that thing then you'd imagine, I didn't do it just for the the sake of it going over 65 MPH in first gear that's just a byproduct, I did it because we've got some very sharp curves in the mountains where I live and I'm into road racing, with that tall first gear I can hit a hairpin turn that's too sharp for 2nd gear and throw it into 1st and the power is exactly where I want it instead of the RPM's going through the roof causing my rear wheel to break traction and the engine being over revved, I'm right in the power and can slingshot out of the corner hard, since it's a solo bike I can get away with pulling out from a stop even on a steep hill because the weights down.
People can never figure out how I do what I do because I think outside of the box and all they do is follow the manufacturers suggestions, I'm always using cams and gear ratios for what they're not intended for, that's why I get the kind of results I do and do it running on pump gas at that.
@@dukecraig2402 @Anarchy Is Freedom. If is not a secret, can you say what software do you use? Cheers.
No matter how expensive a software is, still someone’s creation based on his assumptions to sell it and make money,… the question is… do you trust that software 100%? are you racing softwares or cars?
@@tjed1071
That's not how the software works and until you learn how to use the information it gives you you're still in the dark, it's not like it says "Pick that cam instead of that one" or actually design a cam for you.
It really doesn't do anything I can't do with a calculator and 20 to 30 minutes of my time, what it does is instantly crunch the numbers and shows you corrected compression, percentage of camshaft occupying the cylinder, lobe separation angle among other useful information and tells you which category of cam it is, ie street, hot street, street/strip and race only.
They usually already have a cam library full of existing cams saving you the time from having to program in all the specs like intake and exhaust opening and closing in degrees, max lift etc etc, or you can design your own and see where all the values fall into without once again having to spend 20 to 30 minutes with a calculator figuring things out like corrected compression and everything else.
Like any other tool if you don't know how to use it it's not going to do you any good, but if you do it give you more insight than someone who wets their finger and sticks it in the air saying "I've got years experience at this, yeeee hawwww".
It's all about the math and how it crunches number's instantaneously speeding things up and giving you better insight, I love it because it saves me all kinds of time from having to make all the calculations myself.
The formula does use valve size as a variable. Head flow is important. Most aftermarket 2.02 heads flow extremely well. They flow so well that the engine may run out of cam or have valve float before it runs out of air. Sure, some freak may run 2.02 valves in a TBI swirl port head but that's rare and a bit silly.
I just watched the LSA video and this one. Great work! Thanks for sharing!
Thank you for trying to help us. Even those that are less willing to except the help that they need.
I done the math on my 6ltr LS and I got 108.8 LSA..108 to 114 are common numbers for an LS cam 👍, using 108 as LSA I plugged in 50 for overlap and got 266 duration and 70 and got 286 thumbs up again IMO 👍👍 I'm runnin 232/234 (282/284) on a 110 currently on a Auto with 2500 converter..so I'm sayin the formula is a good thing.👍👍👍
Thanks Dave! Hopefully it can help folks.. DV is the man
Andy
Do you know what rpm your hp peaks at? I have an ls7 it revs to 7000 and the popular cams have wide lsa. Tighten the lsa it will have more overlap for the same duration possibly compromising idle and drivability
@@slick408 Carbs arent as sensitive to tight lsa, overlap
Sequential like an LS is pretty sensitive thus less overlap keeps them happy.
@@slick408you'll have to shorten the duration
I another excellent video Andy, fascinating, now I’ll have to go back and watch it again to ponder those statements and formula. I’m always open to clearing the fog and learning something new.
Great video! Thanks to both of you guys!
giving out and sharing these valuable information for orientation is so awesome!
is there a way to align this equation with changes in compression points?
Good Video Andy! I'm looking to spec a flat tappet billet camshaft for my Ford FE and I think that this formula will certainly come in handy.
Thanks, Andy. I subbed to DV's "new" channel a couple of days ago, and also purchased the TorqueMaster cam program.
Awesome vid Andy . Great info . Thankx
Great video Andy. I purchased DV's Torque Master and IOP software. Both are great programs. Like all new software it took a little to get my head around them, but I would highly recommend them to other viewers. As well as DV's books. Regards Greg
Thanks for the input! I feel exactly the same.. the 128 formula is just a snap shot of what the Torquemaster program actually does.. Thanks for watching,
Andy
For the formula noted at 5:51, is the divided overlap based on 0.006" lift or 0.050" lift?
For anyone interested, I found a similar question posted a month ago and Andy responded that it (the duration) is based on 0.006" lift.
"split" overlap is at the same place regardless of .006 or .050 being the lift number used. Split overlap is when the cam installed at 0*, not advanced or retarded. Most cams today are ground to be installed 4* or more advanced. Install using .050" to degree the cam is because .006 at the lifter is too small of a lift number to be accurate.
I had David spec a cam for me years ago through Motor Machine for a 350 Chevy build that went in a 74 Impala that car went 12.70 @ 106 mph at IRP 1/4 mile and I was asked by a bunch of people what I had done to make it run like that so I told them but they didn’t seem to believe me all I can say is David’s cam program absolutely works and was well worth the money to have him spec it out and you just don’t get these kind of results from the cam tech line I really appreciate the great work you do David.
Awesome video and Congratulations on the 20,000! Looking forward to to the next installment!
Thanks Brother! I'm glad you enjoyed it
Andy
I am seeing this for the first time as a retired dealer repair tech. I understand that software is complicated but I wish this small part could be used on a fictional engine in a brief explanation. I guess I can search for it, wait for that video or go to David V's channel that I subscribed to. I just want to understand but it takes one part at a time to build an entire understanding. Thanks.
I would have been that guy who goes with the Information the Camshaft manufacturer would either recommend or advertise. Fantastic information on Camshafts " The Brain of an Engine" as I like to call it.. Great Stuff Brother!!
I recently got build up my new Pontiac engine where I used DVs 128 formula. I also used his overlap chart, the very same you showed us all. It feels and sounds pretty healthy and crisp.
So, I think the 128 formula work also with Pontiac engines.
I also bought the Progression Ignition distributor in it cause YOU encouraged me.
Keep up the good work and let the know-how grow!!
So what was your LSA? For my 400, I get 102 degrees LSA. This seems really tight. Most street Ponchos are running 110-112.
@@kellynestegard5208 106* LSA
Good info. I'm working on an old school build, a 1972 455H.O, 30 over, trw L2394 pistons, 7f6 heads. The cam in it now is 110 as far as I remember. Can't wait to use DVs formula on my build👍👍🏁🏁
@@kellynestegard5208 - Curious too as i just ran a quick calc using 128 for my BB Olds and it came up with 103!! haha
Thank You David for all the Knowledge and Wisdom You share. It'll Truly Help Me in the Very near Future. And Thank You Andy, for if it wasn't for You, None of Us would even know David.✌️
Called Hughes engines in Illinois years back for a cam recommendation for my 440 build. Was not disappointed! He asked me if I'm going to drive it around on streets but also like to burn the tires off and have fun? And said, it's a moderate cam but 440 is big cubes. I got the Hughes "Real Mopar cam" BL232. Flat hydraulic. 232@50 110. Had very noticeable idle but not rough at all. Ran super great with 10" 3000 stall and 3.91. Matching valve springs etc. Crane gold 1.6 race rockers. Engine would just keep pulling hard. 👍
DV , in one of his books (I can't remember which one, It's been a while - give me a break!) published a carburetor venturi to cylinder size graph. And after trying 4 pairs of carbs on a Suzuki 1100cc GSXR, I told my friend he had nothing to lose by at least trying 'what the book' said , so the 32mm carbs ended up being spot on for the bike to hit peak power at 11000rpm or so , and it was only after going through 20 carbs (4 cylinder bike don't forget) lol .. I don;t know what type of carb it was, motorbike carb, flatsides, pumper / non, etc that's a whole other rabbithole in itself
DV is the #1 engine engineer in the WORLD.
Damn good chassis engineer too.
👍👍👍😎
I subscribed to DV new site a while back, and your site months ago, maybe a year + I have used DV's information and my own experience for the last 15 years or so. In most cases I spec my own cams. I use Bulletcams and Jones cams in most applications. Getting ready to install a Jones cam in my 408w next month. You might even be able to tell what it's in. I like the T shirt.
I understand just glad to know there are a few ford guys out there. Love your truck and the video on the c-4 you did a while back.
Thanks David and Andy.
Awesome video..the math i was looking for..thank you
If you have to call a cam company for recommendations they figure your not experienced and will sell you a baby cam
God bless you guys for supporting each other and us. Take care of each other.
Fascinating life study. Thank you for sharing. The pursuit of excellence. Studying to know. Listening and learning from the truly bright among us. Let us celebrate them. The amazing world of optimizing air flow 🏁🏁👌👌
Well Done! Thank you.
My first SBF hot rod build back in 1981 made 1.17ftlbs/cuin. I am sure had we used the correct 110LSA instead of the company suggested 112LSA we would have had seen better results. Prof Vizard teachings have yet to fail me. I dont know why so many regard them with suspicion. Thank you for stepping in Andy. Continue the great work. Blessings to you and Prof DV.
He's not a professor of anything.
Your giving out my speed secrets . lol Thanks Andy & David
This is all great info I like it and bet it helps a lot of people
Great content, love both your, and DV's channel. Question I have: Would this formula work with Buick engines? No special difference for this formula? I assume not, but always good to double check. Great content, the both of you!
Thanks Andy and thank you DV.
I appreciate all of your help.
Take care, Ed.
Thanks for watching Ed! hope all is well your way..
Anytime,
Andy
DV is the HP and Torque man! Thanks Dave for all the past, present and future awesome tire 🛞 burnouts. 😊
Good stuff as usual, Andy!
I really like your videos and Mr. Vizards videos. I am so happy to see he is doing well. I don't talk to many people anymore... they know too much
I have learned a LOT from you, and David. Thank You.
Thanks Alexander! Im glad you enjoy it.
Andy
Best wishes from the Florida Keys!
I have used a combination of previous experience, Engine Jr. parameters, and further refinement using Engine Analyzer Pro. These are heads up circle track race engines. They have won many races using these techniques.
I was once challenged to select a camshaft for a 383 Chevy that would allow a full bodied El Camino to run 11.50’s on pump gas running less than 6,200 rpm. It took quite a bit of analysis to develop the proper cam. In the end we were successful with runs at 11.53 in the quarter mile on 91 octane pump gas. He won his bet.
Keep up the videos!
Good video. Between you and DV there is always something to be learned on your videos.
Thanks Bill! we are glad you enjoy them and get something from them..
Andy
@@Roxx______________ LCA and LSA are the same... You are referring to Intake centerline!
@@ViewThis. we will let DV settle it.. how's that
He is in the video with me! In fact I'm in his best selling Cylinder head book and have worked with him for nearly 20 years... Have a nice night
Thank you for this video! I learned a ton! Subscribes to DV's new channel. I met him back in the 80's at Westech! At the time, he was developing an intake valve that had a spring loaded mini-valve, and would open slightly to allow a small jet of fuel before the valve opened completely. It was a pretty interesting concept!
Great video as usual. I'm glad to hear that you and DV will be creating more content together. This is going to be great!👍
Thanks Brother! Im looking forward to it. Im at his house a couple times a week anyways.. might as well do videos on what we have going on!
Andy
@@N-Lee LSA is the term commonly used in the US in other countries it is often referred to LCA...
@@UnityMotorSportsGarage He's right and you won't admit you screw'd up. LCA and LSA aren't the same. You probably lie that you know David Vizard too. I'll encourage people to stay away from your channel.
@@First_______ well I can tell you haven't watched the video! David Vizard is in the Video with me.. what says you now?
@@UnityMotorSportsGarage You're right I didn't watch the Video. I saw you didn't know the difference between LSA and LCA and didn't bother to explain it, your video is misinformation
I enjoy your videos. I have wondered for a long time about something that I believe to be true. I would love to see a comparison between identical cams with different lobe separation angles. However, I would like them advanced so that the intake lobe centreline on all the cams are the same. Example: a 114 lsa advanced 8 degrees, vs a 110 lsa advanced 4 degrees, vs a 106 lsa straight up. This only moves around the exhaust centreline angles. Test them all with open headers and with a slightly restrictive typical street exhaust system. With an exhaust system in place I find that wide lsa cams run advanced work better. Move only the exhaust centreline and see what the results are. Thanks
I bought and read DV’s books back in the late 1980s and the information in them was so far ahead of it’s time. I had just graduated as a mechanical engineer and it really opened my mind’s eye on how to assess and view such things. Which I benefited for a lifetime with. I trust his methods completely and without question.
So this wasn’t clear in the video; when doing the intake lobe duration calculation is the result for the advertised or 0.050” value?
Because I’m trying to assess a SBF 347 stroker build on the Powernation channel for a sleeper Granada build. They chose a 110° LSA when the SBF 127 formula suggests 104°.
Which on the dyno it only made 1.277 lb-ft/ci using AFR Renegade 205 heads w/Jesel 1.6 shaft rollers, Vic Jr intake, 950 cfm 4-bbl, and Comp Cams High-Torque 406 MechRoller cam; 280/292 adv. duration, 110°LSA, 4.5° advanced, 0.650 lift, 46° overlap (by my calcs).
Which at 1.4x would yield about a 10% increase in peak torque. It would be interesting to see a projection on what the program might suggest the outputs to be using the preferred 104° LSA instead.
.
Dude that is so weird, on Tuesday I asked in a text "how do you calculate the RPM of peak torque and peak power based on camshaft, bore and stroke. The Thursday you published this info. Awesome thanks
I'm glad you enjoyed it
Andy
I’ve heard of the 128 but never used the formula. I’m at the middle of number four. I’m running a mild mechanical flat tappet in my 0.060 over Windsor. Stock crank with forged rods and pistons. This engine has way exceeded my expectations. Of course the reason why is circled on the valve covers.
Keep up the Good work Guys!
wonderful stuff guys
Andy guys like us have to have guys like David or this home shop and teaching our children will disappear brother. I’d give almost anything in the world to stills have my ole mentor. But I’ll settle for you and David. Thanks for all you guys do
Great tech. Over the years I've used the a hobbyist level of educated guess. Only made 1 bad choice and one mehh. In a mild 355 a comp 292 magnum way to much and a Saturday night special undesirable powerband, both had roudy idle so wasn't total loss! Lol
great info ... great channel had to sub to keep updated
David you are the best. Keep it up. Thank you.
love all your content!
Thanks Stephen, that means alot to me
Andy
The DV 128 LCA Formula is interesting.
One Old Time Mechanical Engineer introduced us to the Formula a small group of us back in 2011 on his closed Forum.
LS Was just getting Hot.
Most of us into Old School SBC, Big Chevy, Ford 302 , Pontiac V8.
We usually came up with very Tight LCA Profiles called for.
Most of the Old Timers wanted to Street drive cruise with Overdrive at 70 mph steady.
Younger guys wanted To Street Race like myself .
We mostly applied the DV 128 Forumula for 454 & 496 stroker BBC.
Then EFI and Boost psi wanted wide LCA preferred for ease and 100% stable intake manifold Vacuum so the MAP Sensor wouldn't go berserk.
Back then I was on The Corvette Forums and all Generation EFI Corvette owners stated it was impossible to proper tune a Radical Lopey Camshaft Tight LCA with burning chips or Hp Tuners used.
Only if you used a dedicated stand alone EFI Alpha Numeric Tuning software that is only good typical for WOT.
BBC and Cleveland uses 132 not 128 like SBC and Mopar engines
I agree with what you say from personal experience . I like how you pointed out that wider lsa on a ls isn"t always correct , I went from a 116 lsa to a 112 and it gave me more torque at a lower Rpm and this gave me more of where I wanted the power as I don't race .
This video is by far the best you and DV have done yet!!! Thanks a ton. I will never buy a camshaft from comp ever again. I am also not happy with howards. I have the TMC program and my engine wants, needs a 106 LCA. I haven’t found anyone who will grind it. Howards said all they can do is 108. It’s frustrating because when you give them your specks they laugh. I know you guys are right i am convinced. Please give me a place to buy a custom grind. I also have a big FE ford engine that needs a cam. Thanks again you guys are the best.
Thanks Mark! It depends on the cam core itself if they can grind on a 106. Im glad you enjoyed it!
Andy
Try camcraft I have never had a problem getting them to grind anything I ask for.
@@bcbloc02 thanks i will do that monday. Dont you just love these guys
Thanks for the info. I'm saving this video to look at the formulas tonight when I get some time to work with them. Maybe I can compare to the cam that's already in my 470 Mopar. It runs good but I'm always curious and question my choices.
How do you like your 470 BBM? I have the 400 block and I'm saving up for the rotating assembly. I keep going back and forth between making it a 451 and a 470.
@@Scarlet_1971_cuda It seems great. I've been told the 451 is very free reving but I have to say this it too. Got rev limit set a at 6700 and will bump that in nothing flat. I've got a Hughes 3236 hydraulic cam in it with Eddy heads and performer rpm intake on it. It makes enough vacuum for power brakes pretty easy with that cam. I figured I'm probably giving up some HP with it but it's very streetable. The torque is crazy but it's only in an A body. Probably about the only difference between a 451 and 470 is more torque and power band a little lower using the same parts on both. Desktop Dyno says 551 HP and 628 TQ for mine. I put in head flow #s detailed cam specs and everything to make it as accurate as I could. Not sure how close those things really are. Some day I'll do a chassis Dyno but I'm definitely happy how it runs on the street.
Well done Andy and thanks to DV and you for teaching us this formula, may I ask you if its the same formula for a turbo engine? Thank you
Played around with the DV 128 Formula today again.
Reading Comments for 132 substitute for Big Chevy,
I worked out my Pontiac V8s 400 and 455.
Came up with LCA that I use that delivered best Torque and Hp for myself many times.
I rounded up.
Substituted 133 and it's dead nuts on for My Pontiac V8s.
So what's the cam specs on that poncho ?
@@darrellsomers5427 ruclips.net/video/vHRTq081s2s/видео.html
Just a little cam by todays Racing Standards. This cam is Similar to the Pontiac Ram Air 4. Single pattern.
.530 inch lift with Factory NOS RAIV 1.65:1 Rockers. Revised LCA & ICA.
True 455 cubic inches 1976 Pontiac 455. 1971 GTO #66 Heads I ported myself to 270 cfm @ 28 inches intake and 202 cfm Exhaust @ 28 inches. Static compression ratio just 8.4:1 sane as SD455 Trans Am used.
1085 cfm Annular Booster Double pumper Carburetor Custom built for me to my Specs my BLP Racing Bo Laws.
Racing again in 2023 #nonamenationals event with my 1970-1/2 Trans Am RAIV 4-speed and other Events to Win Money $$$$$. Sorry Can't disclose exact Cam Events. If Build you a Pontiac V8 or other Brand Engine Be Happy disclose IVO, IVC, EVO, EVC @.050.
This is good info. Right away I plugged some specs for a couple engines into these formulas. It seems that the factory cam specs are almost bang on except for the lsa of the factory cam is about 5 degrees longer. For instance a factory 340 has a 114 degree lsa but should be about 109.
thats because the idle had to be pretty smooth to be sold to the masses.
Yes. I ran a stock lsa. Then 108 .?? Ran much bettr over 1/4 mile. Small cam. 230 @ .050. 280 advertised. Only 480 lift. Around 9.6 to one.
Terrific videos Andy (and David). I love your style and humility in passing on fantastic information. I have a Ford 300 six that shares the SBC 4"bore with a 1.94/1.60 valve combo. It isn't a flow through head but I'm wondering if the 128 formula would potentially work with the Ford Big Six. Thanks in advance!
Years ago, there WAS a very limited run of aftermarket aluminum cross-flow heads for the 300cid. It used the standard cam in block and had a funky shaft arrangement under the unique valve cover to actuate the valves. I don't remember what they used for headers. I wanted one but couldn't afford it. 😒
Hindsight, I should have bought one (or two)... to this day, I still think the 300 could be a killer hot rod engine with a modern head design.
Great question! I’m building a 1969 292 bore and stroke 3.875 by 4.125 Chevy straight upgraded to 1.94 valves 6 for my 56 GMC. I live at 6,500 feet elevation and my pickup is going to be carrying a slide-in camper up the passes from here. So, duration for towing and I am wondering what corrections are required for the 292?
My first engine, at age 10 was a 292. I’ve been in love with the straight six since. High altitude means more compression is possible. My Schneider cam 142F is a solid tappet 242@.050 cam but with a 112 LSA for a turbo application. I have yet to assemble it though, so no feedback at the moment. I was tempted to order a cam at 106 LSA given the parameters of the formula, hence the question
Great information I have been watching all of DV's videos I have one of his books I run a 434 SBF with a super charger does the same 127 formula work the same for picking a cam for my combo
Great information. I'm still trying to learn what all these numbers means. A brief video on LSA, / OVERLAP / LIFT AND DURATION. Would be helpful. Nothing really long going into to much detail on each Would help a lot. I'm sure DV has already made one
Forgive my ignorance, but what about the exhaust duration? Is there a seperate formula for that? Fantastic information, learning a ton!
Dave's a genius much appreciated.!
Yes he is Shawn!
Andy
@@UnityMotorSportsGarage I have a book with the DV street ram in it from 35 years ago or so ,got a wiend Stealth intake on my Elky ,but never got the DV street ram done .I actually heard about it in the army 1979 from another soldier . I met a man named Ron Shmetzler in 70s that already heard of Dave .Ron sold offenhouser the patent for the hidden nitrous manifold ,owed the high rev store by my grandma's house .
Great stuff
I just checked two custom cams I have for a couple engine builds with your formula. For my 390 and 428 and it was pretty close to what they guy sent me.
Yes Andy I’m a 68 year old man building a 1970 340 Cuda. At this age I got the street car bug again and I’m lost as far as a cam. Thank you for your videos.
Tommy that is awesome! Thank you for watching and for the kind words.. you can email me at tunnelram393w@gmail.com about the cam
I'm going to use this formula for my little 318 Magnum..the more I reduce the factory restrictions, the stronger this little thing runs. I figure out little engines are brothers so I hope it works out for you too.
Call Hughes engines. They're in Illinois. I believe it's Elgin Illinois. They are Mopar specific only. They make "Real Chrysler cams". That take advantage of the .904 tappet diameter. Not many old typical Chevrolet specs put on Chrysler cam blanks.
Thank you for taking the time to do these videos. Do you offer a service to run my engine specs through your cam calculator software? Also can you touch on how changing the lobe separation angle effects fuel efficiency?
Thanks for informing me that there had been a change in DV's channel. Wasn't aware.
Thanks for sharing this. Does using the formula to find intake duration give you advertised duration or the duration at .050 lift? The numbers I was getting for a street/strip 350 seemed too large to be duration at .050
The factory 1968 340 cam for 4 speed cars is almost the same as David Vizard's formula comes out to. Great video
275hp out of a 340 is not a ringing endorsement. Yeef
@@ZacLowing it was under rated for lower insurance rates; actual hp was 315-320. its performance on the streets is legendary.
Set up a website with a cam calculator on it like hp or et calculators cause that is far too much math for me and i always have issues getting a correct cam
Please discuss how the tighter/wider LSA affects drivability and idle quality. Can i pull OD from 1200 RPM with a tight LSA? If i can. i may need to buy a new cam!
Thanks for the Great videos loaded with experienced professionals information and opinions. I have a LS 416 stroker I built with a forged summit Racing rotating assembly. I have factory LS3 rectangular port heads, stock LS3 intake manifold, 1 7/8 long tube headers into 3 inch collectors. I’m running 11.5:1 compression. 3000 rpm stall 4 speed automatic daily driver with 308 gears. 3000 LB car. In your profession experience….What’s the best spec camshaft for a daily driver. I’m running the Holley Terminator X max with 60LB injectors.
Thanks again
I misspoke on my 394 ci FE. I read David’s writings. I used the 128 because the engine breathes very well. I made a company grind me a 107 LSA cam straight up 107 intake 107exhaust 107 LSA I got 512 ft lbs and 503 hp with 54 degrees of overlap. I ran a 69 RA 400 GTO with a 65 Galaxie and it blew him in the weeds. That 394 has been to 7000 rpm’s and it is loud! It sounds like a hot 428SCJ that ran in C/S. I can’t find my other post. But people get sick riding in it. DV is the man. Everyone told me it would be a turd because it wasn’t a dual pattern. Why run less duration on the intake when all exhaust just wants out. FEs had the same exhaust port from LR to Tp.
i'm running a 106lsa now and really wish i had went tighter, next time i will try to go to 102
the formula says 103 is what i would need
i love that how snappy the torque is now and of course the idle
it's therapuetic
there's other factors that can determine your lsa as well.... sims/dynos/real time are all going to show different things, so use them as a tool to help you determine
it is hard to find a manufaturer that has real tight lsa's
What camshaft you recommend for GMC 06 4.3 L V6 thanks good video
Second comment.
This formula is really useful for twin cam engines, where you can use this formula to grind the '0' position. then with adjustable gears play around a little to see what's best. Gives a great starting point.
DV emphatically states the dyno testing for the proper installed angle is ABSOLUTELY NECESSARY
Ok the chevy 372CI early 262-400 indicated 107LC. With 50 OL for street it came to 280 duration is that advertised or @0.050"
That is really really big for the street 280 @ .050"
Now with vacuum breaks and a automatic that 280 @ 0.004" would be good.
Some heads flow better than others the over lap should be altered lower if the heads flow really well.
I hope you can talk about more exhaust duration and lift to maintain or fix the above 91% of exhaust to intake flows dynamics, plus extend rpm range.
Lastly, intake lobe center; it's mostlikely easier for me to find where the intake closes and keep it about 35 to 40 decrees to keep the dynamic compression ratio up and set the intake lobe center that way. You might have a better way to figure that out. Because initial timing messes with rpm range as well.
I like your channel
Thanks!
Thank you for supporting the channel!!!
Andy
Hi Andy, intake valve duration needed is based on .050" valve lift or .015" tappet lift?
I’m building a 393 Cleveland with 4V quench chamber heads. I called Bullet and got a Rep that raced Cleveland’s in the 1970s. He told me the profile to get from them for my 450 Hp application. So I feel comfortable with his recommendation based on experience. So should I be apprehensive? I thought Bullet was one of the best? My engine isn’t built yet. And fled to hear your a Ford Man!!
I’m just curious what all data is needed for DV’s cam program? Cubic inch, compression, valve size, flow numbers. Interested in trying to get the proper cam, just trying to figure out what all is needed first.
I think a big reason the 112+ LSA number have become common place is the tuning aspect. Less than that and it and the computer will freak out and see a rough idle as a misfire and try to correct it to death. Carbs dont care and can run a 106 LSA without trouble. So if you want to run a low LSA on an LS then you need to be ok with a high idle (not good for street) or run the wider LSA so its become a staple in the grind for LSs for the wrong reason. Long story short the Fuel Injection tuning aspect is the culprit for this myth.
Great info thank you. How do I get access to DV’s cam program to determine which cam will work best for my sbc 383?
great vid.
Always look forward to your notification "bell" popping up