F'in RUclips, I have many of your books, they are priceless even today, years after they were published. Now I discover your RUclips channel, really? You are a hero to many of us. Thank you.
I do! Thank you Mr Vizard, here's the funny thing, you would know better than I. All I can say is, many of us are still using carburetors and older ignition systems, that book you wrote, "how to build horsepower;" it's still very relevant to many of us. I'd say anything that you can entertain us with from that book is a sure win. I like stories, like the ones you tell in this video-None of us would know this without 30+ years experience, like you have. Keep it up!
🔔You mentioned the vibration harmonics transmitted from the crank to the cam and dampers. Years ago I saw a back to back dyno tests of SBC aftermarket dampers. Large diameter heavy factory one won.😱 What a surprise.
So having a little more slack allows for a little more clearance for oil to ride between the chain rollers and the sprocket teeth hence reducing friction and drag, makes perfect sense. Kinda like that boundary layer affect that we also see with air flowing through a port, so what David is talking about here is fluid dynamics as much as chain tension.
For anyone that rides motorcycles, that resistance is a noticeable quantity when pushing your motocross bike after putting a new chain and sprockets on. It's takes a good month before it really rolls freely. It's slightly better after a few runs but will glide almost effortlessly right before it's getting worn out.
The problem is more than likely O-ring (or X-ring) chain, often run too tight plus whatever grease is in it from new.(often too heavy) Even though they wear much faster, a non-o-ring chain on a 125 or even 250 will give noticeably better acceleration as long as it's lubed. Fitting a chain oiler with a non o-ring chain extends chain life dramatically. Non o-ring chains are also cheaper so you buy 2 chains and a set of sprockets (and a handful of connecting links) I rode open class (490 Maico Alpha 1), it was a long time ago but I also worked at a dealers with everything from RM and YZ 80's to RM500 and YZ490
Depends. My bike stetches the chain every ride but any bike rider knows not to have the chain tight. Did david deed to make everyone feel dumb when we allready know.
@@michaelgiglio1571 You may be surprised how many people don't know how to correctly adjust a motorcycle chain or even ignore factory spec as they don't want any drive line 'snatch' when posing around town (even worse with the swing arm extensions on pseudo drag bikes) Common fallacy. The side plates don't stretch (at least not at any rate you or I can measure ) Chains WEAR. There are a lot of parts, inner and outer side plates, rollers, bushings, pins, multiply that by the amount of links and even a small amount of wear or poor construction/materials can be noticeable. It's why cheap chains don't last long o matter how careful you are. There are a few solid roller chains made with sintered metal and oil impregnated, when under pressure the oil comes to the surface ( IZUMI used to make them, substantially more expensive than 'conventional' roller chain.) Reynolds in England invented the 'white high pressure grease that comes on OEM DID chains, Reynolds never invented a way to mass produce the chains with it though so they licenced it to DID
Loose is fast ,same with piston rings if you replace them ever 2 or 3 rounds there not ment to last more then a few seconds ,oil pumps too always use a standard pump with a bigger spring a hi volume pump eats up horse power
Back in the 80’s running the 010 4bolt Chevy truck engines ran good with loose chains, you always heard someone saying: that thing runs better than it did when it was new
Brands of products are also a big reason. I also have run into gears that had tapered wholes and sloppy key ways. They also sent me plastic cam walk buttons. You really have to watch what your buying. Inspection everything to fit as it should.
What is your evaluation of, Chevrolet factory original gear drive camshaft on a Chevrolet 427 Big Block industrial engine ( grain truck on a farm) ( reverse rotation camshaft, factory original). Would a reverse rotation camshaft & gear drive "FIX" the chain problems? Thank you for the Professional training & education. Why are the camshaft companies NOT making reverse rotation camshafts and gear drive???? Can you test reverse camshaft & gear drive VS chain drive??? Using a Big Block Chevrolet (or small block) gear drive VS chain, using a electric motor to drive (power) a crankshaft ( without rods or pistons). Also test, does high spring pressure require more horsepower???? Does roller lifter use more or less horsepower??? Does roller rocker arms use more or less horsepower??? Yes I know the crankshaft oil passages will spray oil, so a crankshaft without rod passages drilled out. Just ask a crankshaft manufacturing to Not drill out the rod passages. Thanks
David vizard tech. explanationss unlike so many youitube videos . while watching ,"I'm thinking to myself what language or combination of languages is the presenters peaking in" , are so informational & mind powering . My only complaint is my mind is thirsting for part 2 that in most cases never appears. Because of part 2 which would be a accumulative summary of part 1 fallow up that is usually missing I don't know wether to give David A A+ for what I just watched or thumbs down because I'm left hanging waiting , [ & I have searched youtube for part 2 ] looking forward to part 2, the accumilation to every thing presented in part 1
Sir, your knowledge is well earned, and eagerly needed to be learned. It’s what I call Raw Wisdom. There’s a book that makes this very plain that we don’t learn from. With age comes much wisdom. We appreciate what you have to teach, and thank you.
Timing chains have always been one of my pet peeves. It’s always hard to get one that fits correctly, I have a huge selection of new and used to find one that’s just right.
Thanks, David! Did you investigate the condition of the cam bearings and main upper bearing shells after that tight chain was used for dyno tests? Just wondering if it was tight enough to cause metal-to-metal at the forward cam bearing and front upper main.
Thanks again David. I've learned several things from this one video, not the least of which is the guy showing the chain tension. Always wondered what was right. And I bet I'm not the only one who said to himself "why have I been prying off the cam gear all these years" when that man drove the cam rearward with a drift and the cam gear just fell off. Maybe I overlooked that tip when I read one of your books.
Love the advice on avoiding HP losing too tight timing chains. Any chance you can do a video on Ford FE head porting, FE heads, FE rods and FE blocks? Their is such a resurgence in the original BBF with vintage Cobra, Mustang, Cougar, Galaxie and Fairlane restorations and hot rodding that the old FE engine family has gained a new life and quite a following of late. Keep the great videos coming as they are most appreciated and cherished! Great info there, keep educating the masses.
My brother and I run something called a Cam Correct. Made by Roger Hurst marketed through Competition Products. I run a chain with 4 deg of stretch, on purpose! Lol. It's supposed to advance valve timing every time you let off the throttle. Its mostly aimed at the circle track community but we ve used it for mud racing.
Excellent video with Dyno-proven results. My question is what is the measure of a chain that is too tight or too loose? How much range of deflection is preferred between the cam and crank gear and how many pounds of force are required as a standard to impose the deflection? 10, 25, or 50 lbs? What is the maximum “allowable wear” measured in deflection typically? Also, I realize this would be a variable on all different engine types as the cam and crank gears vary in spacing and chain length.
Dave. have you ever drilled the oil galley plug with a .030 oil feed hole to oil the chain?? I've done it for years and have seen timing chain stretch over 20k miles almost completely disappear to the point that I have used the same chain and gear on several motors.. what are your thoughts?
I've got the really expensive Milodon single idler on my street 350 (don't ask me why lol) and it is *completely silent* in case anybody was wondering. I did spend a lot of time setting it up EXACTLY as per the instructions though. I was shocked at how quiet it is when I first started it. It's as quiet as the crappy stock Morse set.
Very interesting video! Was that block align honed? Lineboring & honing can move the crankshaft location , which typically would decrease chain tension. A Sunnen line hone cabinet has the weight of the mandrel on the block . I built my own line hone machine (with a sunnen mandrel) where I can rotate the block to put the weight of the mandrel on the caps instead of the block , which in theory should reduce the amount that the main bores are moved towards the cam tunnel. I may have to rethink my method especially on a virgin block that just needs cleaned up with minimal effort.
Went through 3 cloyes timing sets. All of them loose. Contacted manufacturer, was told they are not matched sets but if i sent it back they would replace it. Set was true double roller street/strip.
Hi Mr Vizards ..I watch all your stuff ..absolutely priceless knowledge!! Any chance you can do a video on Porting for VELOCITY an Port speed..? Hope so ok have good night!
I had that problem with my timing chain. I tore an engine apart, after 4 years. Note, that it only ran a couple hundred miles a year. The timing chain had about less than 3/16 “ play, but I changed it again after a little more than 2 years of about the same usage. At that point I had lost a love on the cam, and I’m guessing it was from running Mobile One without a zinc additive. Upon disassembly I noticed that the cam was worn, and the cam bearings had worn more towards the right side. I can only imagine that it was caused by the tight timing chain
Hi Mr Vizard, how does this relate to an engine with a tensioner. I have a toyota 3t it's a 4 cylinder OHV 8valve Hemi. Would also like to see how you modify Hemi heads. Thanx for great content
David love your videos.. looking for a 383 ultimate street stroker combo..500+HP and crazy torque 88 Chevy Silverado short bed..hope you can help.. thank you
The rubber belt drives stops harmonics affecting the top end and causing valve bounce or chatter. thats why nascar and top fuelers started using them 30 years ago
great video. Curious- are the crankshaft harmonics not detectable via spark/timing scatter? you mentioned the tight chain did not have scatter, but may have transferred harmonics. I would think that should be visible but maybe not? the harmful harmonics, if not detected thru scatter, i guess would affect valvespring stability.
Fascinating as always, I wonder if a thermal sensor in the housing would reveal a much higher temperature, 7.5kW in a confined space is not a marginal effect. (Dangerously assuming that it is frictional loss)
You mentioned transmission of crank harmonics into the timing chain and cam, so I was curious what your thoughts were on this issue. It seems like most people don't rev AMC inline 6s past around 5200 rpm, as they have issues throwing timing chains. People have tried gear drives, belt drives, etc as solutions, but to me it seems that the issue could be caused by the fairly common crank harmonics present in many of the long crank American inline 6s. I imagine an upgraded damper, which unfortunately is currently not a normal production part could be a potential solution to this issue as there's nothing otherwise bad or remarkable about the AMC I6 timing chain. Certainly it would be something that could only be speculated on, but I guess the question is have you seen timing chain failures increase with poor harmonic damping?
As a diesel mechanic I was always amazed that the Isky 2 gear setup wasn't more widely used. I know reverse ground cam's are few, but in these high dollar builds it doesn't seem like it would be that big a deal, or am I missing something?
David, I will only be assembling my engine once (383 Chrysler, '67, stock bottom end). One cam, no Dyno. Do you have a preferred brand of timing chain? For a street engine, does it matter? I don't have a degree wheel or fancy tools, so I'm not gonna degree it even if I knew how. Just line up the dots.
I have read the double roller chains cost hp as compared to the stock type chains. Is there any truth to this? What type of chain would yiu recommend for a street engine?
I was looking through the comments to see if anyone asked this question. For engines that don’t have crazy high valve spring pressure, I would think a single roller chain would be a better choice. Less friction.
11 Hp is a lot to loose. Has to be more going on there than we are understanding. A duplex 3/8 pitch chain would not last long if it were asked to transmit 11hp. A 50cc moped is only 3.5 hp Puts it into perspective .
The problem isn't really the chain as that is a standard size between pins and usually made very accurately. (even cheap chains start very accurate just have poorer quality material and heat treat) Production tolerance between crank centreline and cam centreline is really the issue. . Some engines are quite 'loose' particularly if mains are line bored, in fact, isn't there a difference in Pitch Circle Diameter of sprockets for line bored blocks (I know there used to be 20~30 years ago or more?) I remember seeing 0.005" and 0.010" sprocket advertised (to compensate for crank getting closer to cam) The 'correct' thing to do is get sprockets with smaller PCD. and not fit a worn chain. Did you monitor oil temperature? I would expect things to run quite a bit 'warmer' as your also 'pulling' the cam down into bearings and crank up into mains so friction will be a lot higher than anticipated.
Question. So what do you suggest to do to increase pulse which provokes ramjet of flow. So far I have cam and best with a RV cam to give a quick open and shut Them 1:7 rockers for even quicker off the seat to create a pulse
Mr. Vizard, I've heard that the '70s Ford 351M/400 had, to crutch emissions, a camshaft ground 8 degrees retarded. If I was to get a multi-keyway timing set, would I install it using the 8-degrees-advanced keyway? Would that make the cam effectively "straight up"? Thanks.
I would love to port a head an send it to you an You give me an honest grade..mind you my only tool is my grinder an my memory..I try as hard as possible to memorize what finished port jobs look like
🔔Normally gear wear gets 2*+ (slack/retard) fairly soon. Would it be advisable on a street driven engine to start out with an "extra" 2* cam advance?? I've noticed the SBF 5.0 HO likes more advance than factory spec. Thanks DV 👍😁
I saw this happen at a friend of mines shop building a Kawasaki ZX7R motor for an AMA event....The motor was down 7-8HP from the previous records. My friend was checking things knowing it shouldn't be down on power....Looked and looked....Then the lightbulb went off in his head....I know what it is! He backed off the manual timing chain tensioning screw....Warmed the motor up for another pull on the dyno....INSTANT 10HP! no other changes....Winking at me he said....That works on Chevies too!
Maybe for fanatics going racing but not for everyday use since those chains will stretch with use to the point of jumping timing and eventually it will not run! Please do not become a liberal! :)
Michael, If you did not like what you saw and continued watching then it's you that is wasting your time not me!! Try using the time you save to learn some better manners!
Hi Mr Vizard, how does this relate to an engine with a tensioner. I have a toyota 3t it's a 4 cylinder OHV 8valve Hemi. Would also like to see how you modify Hemi heads. Thanx for great content
![Noob To Max With DRAGON REWORK In Blox Fruits [FULL MOVIE]](http://i.ytimg.com/vi/LnBMOinoOvA/mqdefault.jpg)
F'in RUclips, I have many of your books, they are priceless even today, years after they were published. Now I discover your RUclips channel, really?
You are a hero to many of us. Thank you.
Well Stephen I hope you like what you see. Got any general topic subject suggestions that would apply to a wide audience??
I do! Thank you Mr Vizard, here's the funny thing, you would know better than I.
All I can say is, many of us are still using carburetors and older ignition systems, that book you wrote, "how to build horsepower;" it's still very relevant to many of us. I'd say anything that you can entertain us with from that book is a sure win.
I like stories, like the ones you tell in this video-None of us would know this without 30+ years experience, like you have. Keep it up!
🔔You mentioned the vibration harmonics transmitted from the crank to the cam and dampers.
Years ago I saw a back to back dyno tests of SBC aftermarket dampers. Large diameter heavy factory one won.😱 What a surprise.
So having a little more slack allows for a little more clearance for oil to ride between the chain rollers and the sprocket teeth hence reducing friction and drag, makes perfect sense. Kinda like that boundary layer affect that we also see with air flowing through a port, so what David is talking about here is fluid dynamics as much as chain tension.
Love the frequent uploads, these videos are fantastic for us with above average interest in engine building 👍👍👍
i remember way back also mate, you are as young as you feel! well thats what i tell myself! cheers.
Hopefully he'll keep going for another 10 years at least 👍
For anyone that rides motorcycles, that resistance is a noticeable quantity when pushing your motocross bike after putting a new chain and sprockets on. It's takes a good month before it really rolls freely. It's slightly better after a few runs but will glide almost effortlessly right before it's getting worn out.
The problem is more than likely O-ring (or X-ring) chain, often run too tight plus whatever grease is in it from new.(often too heavy) Even though they wear much faster, a non-o-ring chain on a 125 or even 250 will give noticeably better acceleration as long as it's lubed. Fitting a chain oiler with a non o-ring chain extends chain life dramatically. Non o-ring chains are also cheaper so you buy 2 chains and a set of sprockets (and a handful of connecting links) I rode open class (490 Maico Alpha 1), it was a long time ago but I also worked at a dealers with everything from RM and YZ 80's to RM500 and YZ490
Depends. My bike stetches the chain every ride but any bike rider knows not to have the chain tight. Did david deed to make everyone feel dumb when we allready know.
@@michaelgiglio1571 You may be surprised how many people don't know how to correctly adjust a motorcycle chain or even ignore factory spec as they don't want any drive line 'snatch' when posing around town (even worse with the swing arm extensions on pseudo drag bikes)
Common fallacy. The side plates don't stretch (at least not at any rate you or I can measure )
Chains WEAR.
There are a lot of parts, inner and outer side plates, rollers, bushings, pins, multiply that by the amount of links and even a small amount of wear or poor construction/materials can be noticeable.
It's why cheap chains don't last long o matter how careful you are.
There are a few solid roller chains made with sintered metal and oil impregnated, when under pressure the oil comes to the surface ( IZUMI used to make them, substantially more expensive than 'conventional' roller chain.)
Reynolds in England invented the 'white high pressure grease that comes on OEM DID chains, Reynolds never invented a way to mass produce the chains with it though so they licenced it to DID
Agreed same thing with bicycles when I was a kid I adjusted my chain to tight and it took a lot more effort to peddle
Loose is fast ,same with piston rings if you replace them ever 2 or 3 rounds there not ment to last more then a few seconds ,oil pumps too always use a standard pump with a bigger spring a hi volume pump eats up horse power
Back in the 80’s running the 010 4bolt Chevy truck engines ran good with loose chains, you always heard someone saying: that thing runs better than it did when it was new
Thank You Mr. Vizard.
Exacty! The slack and oil cushion helps to isolate the cam from the crank. Hence a belt does an even better job.
David growing old brings more knowledge and wisdom of which you are generous enough to share with us. Thank you very much.
David, it's amazing to see you outside of the pages of my favourite sbc building books! Love the tips and the knowledge you're sharing..
Brands of products are also a big reason. I also have run into gears that had tapered wholes and sloppy key ways. They also sent me plastic cam walk buttons. You really have to watch what your buying. Inspection everything to fit as it should.
What is your evaluation of, Chevrolet factory original gear drive camshaft on a Chevrolet 427 Big Block industrial engine ( grain truck on a farm) ( reverse rotation camshaft, factory original).
Would a reverse rotation camshaft & gear drive "FIX" the chain problems?
Thank you for the Professional training & education.
Why are the camshaft companies NOT making reverse rotation camshafts and gear drive????
Can you test reverse camshaft & gear drive VS chain drive???
Using a Big Block Chevrolet (or small block) gear drive VS chain, using a electric motor to drive (power) a crankshaft ( without rods or pistons).
Also test, does high spring pressure require more horsepower????
Does roller lifter use more or less horsepower???
Does roller rocker arms use more or less horsepower???
Yes I know the crankshaft oil passages will spray oil, so a crankshaft without rod passages drilled out. Just ask a crankshaft manufacturing to Not drill out the rod passages.
Thanks
David vizard tech. explanationss unlike so many youitube videos . while watching ,"I'm thinking to myself what language or combination of languages is the presenters peaking in" , are so informational & mind powering . My only complaint is my mind is thirsting for part 2 that in most cases never appears. Because of part 2 which would be a accumulative summary of part 1 fallow up that is usually missing I don't know wether to give David A A+ for what I just watched or thumbs down because I'm left hanging waiting , [ & I have searched youtube for part 2 ] looking forward to part 2, the accumilation to every thing presented in part 1
Sir, your knowledge is well earned, and eagerly needed to be learned. It’s what I call Raw Wisdom. There’s a book that makes this very plain that we don’t learn from. With age comes much wisdom. We appreciate what you have to teach, and thank you.
I had a Cloyes on my 351C which was very tight. And I thought this was the way a new chain should be. Than you for your experience DV!
Timing chains have always been one of my pet peeves. It’s always hard to get one that fits correctly, I have a huge selection of new and used to find one that’s just right.
Love your tips David, Thanks.
Thanks, David! Did you investigate the condition of the cam bearings and main upper bearing shells after that tight chain was used for dyno tests? Just wondering if it was tight enough to cause metal-to-metal at the forward cam bearing and front upper main.
Thanks again David. I've learned several things from this one video, not the least of which is the guy showing the chain tension. Always wondered what was right. And I bet I'm not the only one who said to himself "why have I been prying off the cam gear all these years" when that man drove the cam rearward with a drift and the cam gear just fell off. Maybe I overlooked that tip when I read one of your books.
Great tip as usual. Please keep them coming, Thank you
Thanks for showing telling, and all that good info about the chain well see ya next time see ya bye bye.
So is there a power difference between a double roller style and a multi link style? What about those crazy noisy timing gear sets?
I’m also interested in gear drive setups and your expert opinion. Thank you sir.
Love the advice on avoiding HP losing too tight timing chains. Any chance you can do a video on Ford FE head porting, FE heads, FE rods and FE blocks? Their is such a resurgence in the original BBF with vintage Cobra, Mustang, Cougar, Galaxie and Fairlane restorations and hot rodding that the old FE engine family has gained a new life and quite a following of late. Keep the great videos coming as they are most appreciated and cherished! Great info there, keep educating the masses.
Hi David, what is your take on belt drive timing kits
Another great video! I really look forward to seeing more. There’s so much information that you present, that makes great sense!
My brother and I run something called a Cam Correct. Made by Roger Hurst marketed through Competition Products. I run a chain with 4 deg of stretch, on purpose! Lol. It's supposed to advance valve timing every time you let off the throttle. Its mostly aimed at the circle track community but we ve used it for mud racing.
www.competitionproducts.com/mobile/Cam-Correct-Variable-Valve-Timing-Kit-Chev-BB-Standard/productinfo/CAM8272-1/#.YOJW9WllAzY
Oh and BTW, thanks again David! Your videos are always very helpful and looked forward to watching.....;)
Can you do an episode on how to properly break in a bbc or a sbc and any differences with different procedures ?
Excellent video with Dyno-proven results. My question is what is the measure of a chain that is too tight or too loose? How much range of deflection is preferred between the cam and crank gear and how many pounds of force are required as a standard to impose the deflection? 10, 25, or 50 lbs? What is the maximum “allowable wear” measured in deflection typically? Also, I realize this would be a variable on all different engine types as the cam and crank gears vary in spacing and chain length.
Thank for the tips, what a wealth of knowledge David.
Dave. have you ever drilled the oil galley plug with a .030 oil feed hole to oil the chain?? I've done it for years and have seen timing chain stretch over 20k miles almost completely disappear to the point that I have used the same chain and gear on several motors.. what are your thoughts?
I believe this is mentioned the the Chevy Power Manual. It defiantly will help lubricate and cool the chain.
Thank you David
What's your thoughts on gear drives? Like the Pete Jackson, with double idlers?
You read my thoughts...I hate the noisy things and where do all those harmonics go.?..Can't be good for the valve train.
@@ziggassedup 👍😎
Yeah I have the quiet one can’t really hear it but it’s been in for 21 years
Definitely an interesting question !
They are fine. I like them better than chains. If you dont like the noise you can get a quiet one.
I've got the really expensive Milodon single idler on my street 350 (don't ask me why lol) and it is *completely silent* in case anybody was wondering.
I did spend a lot of time setting it up EXACTLY as per the instructions though. I was shocked at how quiet it is when I first started it. It's as quiet as the crappy stock Morse set.
Very interesting video! Was that block align honed? Lineboring & honing can move the crankshaft location , which typically would decrease chain tension. A Sunnen line hone cabinet has the weight of the mandrel on the block . I built my own line hone machine (with a sunnen mandrel) where I can rotate the block to put the weight of the mandrel on the caps instead of the block , which in theory should reduce the amount that the main bores are moved towards the cam tunnel. I may have to rethink my method especially on a virgin block that just needs cleaned up with minimal effort.
Went through 3 cloyes timing sets. All of them loose. Contacted manufacturer, was told they are not matched sets but if i sent it back they would replace it. Set was true double roller street/strip.
Hi Mr Vizards ..I watch all your stuff ..absolutely priceless knowledge!! Any chance you can do a video on Porting for VELOCITY an Port speed..? Hope so ok have good night!
I had that problem with my timing chain. I tore an engine apart, after 4 years. Note, that it only ran a couple hundred miles a year. The timing chain had about less than 3/16 “ play, but I changed it again after a little more than 2 years of about the same usage. At that point I had lost a love on the cam, and I’m guessing it was from running Mobile One without a zinc additive. Upon disassembly I noticed that the cam was worn, and the cam bearings had worn more towards the right side. I can only imagine that it was caused by the tight timing chain
Back in the day for dirt street stock we run plastic cam gear for less friction
Thank you Sir I appreciate the information
Good info. What about gear drives and belts? Are those better for power loss?
Hi Mr Vizard, how does this relate to an engine with a tensioner. I have a toyota 3t it's a 4 cylinder OHV 8valve Hemi. Would also like to see how you modify Hemi heads. Thanx for great content
Useful information as always. Running a factory stock dirt car motor, we gotta free all the ponies we legally can
David love your videos.. looking for a 383 ultimate street stroker combo..500+HP and crazy torque 88 Chevy Silverado
short bed..hope you can help.. thank you
The rubber belt drives stops harmonics affecting the top end and causing valve bounce or chatter. thats why nascar and top fuelers started using them 30 years ago
great video. Curious- are the crankshaft harmonics not detectable via spark/timing scatter? you mentioned the tight chain did not have scatter, but may have transferred harmonics. I would think that should be visible but maybe not? the harmful harmonics, if not detected thru scatter, i guess would affect valvespring stability.
Fascinating as always, I wonder if a thermal sensor in the housing would reveal a much higher temperature, 7.5kW in a confined space is not a marginal effect. (Dangerously assuming that it is frictional loss)
Hmmm, what was that Smokey Yunick quote about the evils of timing chains…
You mentioned transmission of crank harmonics into the timing chain and cam, so I was curious what your thoughts were on this issue. It seems like most people don't rev AMC inline 6s past around 5200 rpm, as they have issues throwing timing chains. People have tried gear drives, belt drives, etc as solutions, but to me it seems that the issue could be caused by the fairly common crank harmonics present in many of the long crank American inline 6s. I imagine an upgraded damper, which unfortunately is currently not a normal production part could be a potential solution to this issue as there's nothing otherwise bad or remarkable about the AMC I6 timing chain. Certainly it would be something that could only be speculated on, but I guess the question is have you seen timing chain failures increase with poor harmonic damping?
What's your thoughts about gear drives? Do they eat more or less HP?
They dont cost power. Its been proven. Thats an old myth. They also dont stretch, and I trust them a LOT more than chains.
Only use a 3 piece Milodon. the 4 piece are junk and will eat your front cam bearing.
What oil do you recommend for break in. Do you have a break in video coming ?
We would all love to know if David ever tested gear drives, and his thoughts on it.
This channel is dead for now, find his other channel here: www.youtube.com/@DavidVizard
As a diesel mechanic I was always amazed that the Isky 2 gear setup wasn't more widely used. I know reverse ground cam's are few, but in these high dollar builds it doesn't seem like it would be that big a deal, or am I missing something?
On a lower hp engine would a double roller chain be a consumption of power where a single roller could do the job just fine?
David, I will only be assembling my engine once (383 Chrysler, '67, stock bottom end). One cam, no Dyno. Do you have a preferred brand of timing chain? For a street engine, does it matter? I don't have a degree wheel or fancy tools, so I'm not gonna degree it even if I knew how. Just line up the dots.
How about a gear drive, is the friction way less on those?
I have read the double roller chains cost hp as compared to the stock type chains. Is there any truth to this? What type of chain would yiu recommend for a street engine?
A gear drive.
I was looking through the comments to see if anyone asked this question. For engines that don’t have crazy high valve spring pressure, I would think a single roller chain would be a better choice. Less friction.
Mr.David, is it always in the chain? Could it be the sprockets? Could I use my sandblaster to make them smooth and deburred?
Will this also apply to chain tensioners? Like the Mopar Magnum small block.
Doesn't an overly tight chain put a lot of load stress on the front cam bearing too?
What break in oil do you recommend for a 475 hp engine
11 Hp is a lot to loose. Has to be more going on there than we are understanding. A duplex 3/8 pitch chain would not last long if it were asked to transmit 11hp. A 50cc moped is only 3.5 hp
Puts it into perspective .
The problem isn't really the chain as that is a standard size between pins and usually made very accurately. (even cheap chains start very accurate just have poorer quality material and heat treat)
Production tolerance between crank centreline and cam centreline is really the issue.
. Some engines are quite 'loose' particularly if mains are line bored, in fact, isn't there a difference in Pitch Circle Diameter of sprockets for line bored blocks (I know there used to be 20~30 years ago or more?)
I remember seeing 0.005" and 0.010" sprocket advertised (to compensate for crank getting closer to cam)
The 'correct' thing to do is get sprockets with smaller PCD. and not fit a worn chain.
Did you monitor oil temperature? I would expect things to run quite a bit 'warmer' as your also 'pulling' the cam down into bearings and crank up into mains so friction will be a lot higher than anticipated.
Question. So what do you suggest to do to increase pulse which provokes ramjet of flow.
So far I have cam and best with a RV cam to give a quick open and shut
Them 1:7 rockers for even quicker off the seat to create a pulse
Thanks for the great information! What kind of break in oil do you recommend?
My Oil Extreme 3 step formula -very good but not cheap! Go to oil extreme .com
Mr. Vizard, I've heard that the '70s Ford 351M/400 had, to crutch emissions, a camshaft ground 8 degrees retarded. If I was to get a multi-keyway timing set, would I install it using the 8-degrees-advanced keyway? Would that make the cam effectively "straight up"? Thanks.
How do you know if its too tight? Can you show us examples
Can you do a porting video on 4 valve heads
That could be why the OEMs all run chain tensioners
I would love to port a head an send it to you an You give me an honest grade..mind you my only tool is my grinder an my memory..I try as hard as possible to memorize what finished port jobs look like
Friction is a killer
Don't worry there alot of us out there that's old..everybody gets there wether they like it or not.
a 2-step makes the chain slacker. which I do not like. thanks for the movie
🔔Normally gear wear gets 2*+ (slack/retard) fairly soon. Would it be advisable on a street driven engine to start out with an "extra" 2* cam advance??
I've noticed the SBF 5.0 HO likes more advance than factory spec.
Thanks DV 👍😁
2.3 % loss is a bunch.
Bought a car with a real tight chain, took out the bottom of the front cam bearing
Wait... I can lose power via the timing chain? oh man.... :(
Thanks David JW SHOP TIME try to give my wall jeep a like and share .
🔔👍😎👍👍
I saw this happen at a friend of mines shop building a Kawasaki ZX7R motor for an AMA event....The motor was down 7-8HP from the previous records. My friend was checking things knowing it shouldn't be down on power....Looked and looked....Then the lightbulb went off in his head....I know what it is! He backed off the manual timing chain tensioning screw....Warmed the motor up for another pull on the dyno....INSTANT 10HP! no other changes....Winking at me he said....That works on Chevies too!
Maybe for fanatics going racing but not for everyday use since those chains will stretch with use to the point of jumping timing and eventually it will not run! Please do not become a liberal! :)
GET TO THE POINT. STOP WASTING OUR TIME SODI
Michael, If you did not like what you saw and continued watching then it's you that is wasting your time not me!! Try using the time you save to learn some better manners!
Michael, try Decaf.
And some respect.
It goes a long way.
Another ADHD patient commenting...
Giglio go watch something else!,
Did david take 3 months to biuld a engine
Hi Mr Vizard, how does this relate to an engine with a tensioner. I have a toyota 3t it's a 4 cylinder OHV 8valve Hemi. Would also like to see how you modify Hemi heads. Thanx for great content