FULL RESULTS-CHANGE ONLY LSA-LS CAM TEST. What happens when you change ONLY the LSA of the cam and keep the lift and duration the same? Does LSA change power? Do LS motors like narrow (108-degree) LSA or wide (120-degree) LSA?
Пікірлер: 1 000
@Co-xm1nt4 жыл бұрын
My guy in 3 months has proved more combinations than ls1tech has for the past 12 years
@n5yiz4 жыл бұрын
Agreed!
@crw36734 жыл бұрын
Sad but true!
@RumblestripDotNet4 жыл бұрын
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.
@JunkGaragehome4 жыл бұрын
@@RumblestripDotNet yup amazing the information people have forgotten or ignored
@jefflowry41124 жыл бұрын
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
@pauldulworth27684 жыл бұрын
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.
@escuelaviejafarms4 жыл бұрын
Please, pass the knowledge along and share the crap out of his content!
@kevinwest36893 жыл бұрын
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, 😏
@UnityMotorSportsGarage4 жыл бұрын
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!
@richardholdener17274 жыл бұрын
David's has done a lot of crazy and cool stuff over the years
@UnityMotorSportsGarage4 жыл бұрын
@@richardholdener1727 you sir are correct! I know that he is impressed with the work you have done as well... Keep up the great work!
@Warloch1 Жыл бұрын
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.
@darrinstone49 Жыл бұрын
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.
@darrinstone49 Жыл бұрын
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.
@chandannel4 жыл бұрын
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.
@chandannel4 жыл бұрын
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.
@shelbyavant50814 жыл бұрын
@@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.
@shelbyavant50814 жыл бұрын
@@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?
@dburkh914 жыл бұрын
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. 🤷🏽♂️
@jaredfarney6754 жыл бұрын
@@bigboreracing356 I really enjoyed CT magazine growing up !
@r.d.riddle2068 Жыл бұрын
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.
@GregHuston Жыл бұрын
I think I need to dump the 112 in my Olds 350 for a 108!
@shotamakarashvili37144 жыл бұрын
David Vizard published very good book with great explanation on LSA and how t choose best one for particular application.
@jaredfarney6754 жыл бұрын
Great book!
@adamsweet35874 жыл бұрын
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.
@jaredfarney6754 жыл бұрын
@@adamsweet3587 I really enjoyed his how to port and flow test. Also how to build horsepower. Really great stuff!
@frankrizzo27244 жыл бұрын
Shota Makarashvili whatever happened to him?
@jaredfarney6754 жыл бұрын
@@frankrizzo2724 he has a KZfaq channel to promote his lectures and books.
@MasterWitchDoctor Жыл бұрын
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.
@brianmeyer55354 жыл бұрын
Richard giving the people what they wanted. Awesome. Patiently awaiting SBF combos.
@aaronford71244 жыл бұрын
Brian Meyer Cleveland’s forever!!! J/k. Me 2.
@iamblamb5014 жыл бұрын
Yes, it would be cool to see this test done on a 5.3L and 5.7L
@rongravel45854 жыл бұрын
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.
@msk3905 Жыл бұрын
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
@davidreed6070 Жыл бұрын
Vizard is up to something He has been DYNO testing for 40 years
@petercermak40955 ай бұрын
Me too. 128 sb chevy formula
@lacboiatl2 жыл бұрын
Truck norris cam makes sense now. I just revisited this video and glad I did. Truck norris is what I'm rolling with. Thanks
@BlueMountainRacingEngines4 жыл бұрын
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!
@dennisrobinson8008 Жыл бұрын
Excellent. Richard test gives the explanation point. I wonder about 104 or 106. I've even seen people run 102.
@MWR-lg9qp4 жыл бұрын
You run tests I've always wanted to see. Thank you again for the awesome data you create and provide. Great job!
@brianbrigg57 Жыл бұрын
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.
@timseely24223 жыл бұрын
Great job explaining LSA. Tighter more chop & more bottom end, wider less chop more on the top ! Thanks Richard!
@edpetrocelli263311 ай бұрын
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
@AB-80X8 ай бұрын
That really depends. If you have high compression, you need more LSA
@axlegrind42124 жыл бұрын
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.
@dreece20002 жыл бұрын
Good point, I hope most people can understand that.
@slow5oh894 жыл бұрын
Was just trying to choose lsa for my new tsp cam last night! Thanks for the test Richard, you're the man!
@bruceleroybell81393 жыл бұрын
Thanks Richard, you have answered my next cam choice. This info is priceless and worth gold.
@drakeolson25394 жыл бұрын
Man, I have always wondered what the change in LSA would affect!!! Thank you for the information!!!!
@RAZER1RR4 жыл бұрын
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
@darrellsomers5427 Жыл бұрын
Racer brown made good cams too back in the day
@Freebaggin4 жыл бұрын
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.
@johnagreen883 Жыл бұрын
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!
@ORego-em8yf4 жыл бұрын
Just subbed, you really get to the point without unneeded banter! Thank you for an informative video
@richardholdener17274 жыл бұрын
Welcome aboard and thnx for the support
@jnieto4904 жыл бұрын
Gotta have that chop! Besides power down low with good torque is what I need!
@pandora18754 жыл бұрын
I am learning so much from your videos! Thank you and keep them coming!
@bobryan64744 жыл бұрын
Another great informative video Richard. Thanks for showing what’s behind the curtain when it comes to making power.
@velr50gt4 жыл бұрын
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!
@arthurrose6473 Жыл бұрын
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.
@Drunken_Hamster17 күн бұрын
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
@mathewboyd37463 жыл бұрын
Thank you! I only just discovered this vid of yours and I been looking for this test and demonstration for a long time. Now I'm really interested how this would apply to other smaller NA engines such as 6 & 4 cylinder engines which are not just V8's. Thanks again. Really like how you conducted this test in a real objective way.
@antipasinchrist4 жыл бұрын
Just installed a Mutha Thumpr (109 LSA) in my LQ9 swap. This videos gives me hope.
@richardholdener17274 жыл бұрын
The success of the cam is more than LSA but my guess is you are happy with the Thumpr
@antipasinchrist4 жыл бұрын
@@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.
@RunningJoe4 жыл бұрын
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
@monsterzard14 жыл бұрын
THIS IS WHAT IVE BEEN WAITING FOR!!!
@johnhazel99864 жыл бұрын
Thankyou! These dyno tests where you change one thing are the cool ones!
@V12LS4 жыл бұрын
Thanks for doing this test Richard, really interesting.
@TheSteve11754 жыл бұрын
Tell em what happens to the vacuum. The brakes 😁 Great video 108 centers rock ⚔
@volvospede4 жыл бұрын
Do you think vacuum suffers much with smaller LSA? I need good vacuum for the brakes or need to go hydroboost.
@ttank944 жыл бұрын
@@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.
@jgkk58623 жыл бұрын
I have run as big as 266@50 on a 99LSA and still had enough vacuum for brakes...
@Ginofia4 жыл бұрын
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.
@jerrymurphy2474 жыл бұрын
A lot of great info on this channel. Clearing up a lot of misconceptions. Keep doing what your doing brother!! We appreciate you!
@bowhite12934 жыл бұрын
One of your best tests. Great job
@bigal8784 жыл бұрын
Great test 👍🏻 Would be great to see these exact three combos now fitted with a blower. Richard keep up the great work
@richardholdener17274 жыл бұрын
same
@notme81212 жыл бұрын
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.
@frtaylor294 жыл бұрын
Great video! Highly appreciate this one.
@carbf19424 жыл бұрын
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.
@Sir_Theodore_Wigglesworth4 жыл бұрын
The work never ends... Same test with turbo, supercharger and nitrous. Thanks for everything you do Richard!
@richardholdener17274 жыл бұрын
it's the same with boost
@rayjon2374 жыл бұрын
Every cam is a turbo cam.. lol
@jackpinnell32044 жыл бұрын
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.
@michaelangelo80014 жыл бұрын
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.
@EGGINFOOLS4 жыл бұрын
It has to be sized to the motor properly. In this case the 402 just happened to like the 108
@marcstlaurent37194 жыл бұрын
Great test , another always asked question answered
@GreatLakesLogger4 жыл бұрын
Hey I stayed up late enough to catch the upload! BTW, awesome video Richard!
@TheTmshuman4 жыл бұрын
I feel like a certificate is in order after watching all of your videos.
@ShawnDickens4 жыл бұрын
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.
@BLUUCIFUR2 жыл бұрын
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
@mannypantoja82524 жыл бұрын
This channel rocks!! Very very informative!
@Hitman-ds1ei4 жыл бұрын
Nice, separating fact from fiction as usual top stuff,
@crash58114 жыл бұрын
There is an exception to every rule, with a few exceptions.
@rifleman73132 жыл бұрын
Great video, very informative as before watching your videos I did not know much about LS engines except for basic generalities.
@mikie90774 жыл бұрын
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.
@TheSlim93gt4 жыл бұрын
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.
@JACB0063 жыл бұрын
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.
@jimmy_olds9 ай бұрын
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.
@tc6hp4 жыл бұрын
Thank you I been asking you to do this for 6 years!
@richardholdener17274 жыл бұрын
this was done long ago
@ssoffshore51114 жыл бұрын
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!
Exhaust scavenging induction event. The fifth cycle.
@autobodyspecialistsinc.43974 жыл бұрын
all those number can change with different grind timing ...
@n5yiz4 жыл бұрын
@@autobodyspecialistsinc.4397 If I hand you a cam with 10 degrees of overlap, you can change that?
@autobodyspecialistsinc.43974 жыл бұрын
Yes, I agree. for some reason i was thinking in terms of the timing events in relation to crank position...
@glennmanchester15684 жыл бұрын
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
@scrapmetal_sleepers4 жыл бұрын
Yessssss I've been waiting for this one!
@johnhazel99863 жыл бұрын
This is another great post by RH. That 210/218 duration cam might really wake things up with 102-106 LSA
@jonathanposs44484 жыл бұрын
I don’t think the smaller engines will have such a dramatic change as the test engine you used. Prove me wrong😏
@tiitsaul90364 жыл бұрын
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.
@indyrock81484 жыл бұрын
I'm thinking it's from extra exhaust scavenging during overlap. Starts air in runner moving more, sooner.
@meetthecarolinas96384 жыл бұрын
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).
@zachganoe3 жыл бұрын
Love your videos Richard keep testing
@ELIRMN4 жыл бұрын
Very good experiment, thanks Richard
@bartpang4 жыл бұрын
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.
@michaelangelo80014 жыл бұрын
Good Point...
@jeffwooton71384 жыл бұрын
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.
@poncoolride4 жыл бұрын
IVC, is the most critical event.
@100amps3 жыл бұрын
At first I was wondering why you were on one knee in front of the truck. Then I noticed the nearly perfect Rembrandt lighting profile on your face. Well done. Oh yeah, the cam LSA info was great too. 👍
@creepycrawler432 жыл бұрын
Thanks so much for answering my exact question is a very easy to understand format
@shannonsisk4 жыл бұрын
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 👍
@strong_voice_of_truth Жыл бұрын
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.
@86chrysler5thave8 ай бұрын
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
@strong_voice_of_truth8 ай бұрын
@@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.
@ezmny13877 ай бұрын
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
@thebedtimeranger35882 жыл бұрын
Great Job Richard! I learned something!
@frankrenda25194 жыл бұрын
great job richard. your engine tech vids are great and so are your books.
@billythebake4 жыл бұрын
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...
@richardholdener17274 жыл бұрын
Glad you like them!
@ElPants214 жыл бұрын
Would love to see this focusing on higher rpms on a 4 cam mod motor. Would be super easy to change only LSA without even pulling the cams
@danawilkes61744 жыл бұрын
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...
@alphaghost16337 ай бұрын
Fool - that does not change the LSA - you need to go back and study
@ezmny13877 ай бұрын
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
@danawilkes61747 ай бұрын
@@alphaghost1633 Really. If I advance a 112 LSA camshaft 4 degrees. Then the Intake would be 108 and the exhaust 116.
@Drunken_Hamster17 күн бұрын
@@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.
@michaelangelo80014 жыл бұрын
Richard, you say the dynamometer won't measure the entire operational rpm range. But last year when I was building my Cadillac stroker, I spoke with the engineer at "The Cad Company" extensively. He brought this very subject up in our conversation. Oddly enough he mentioned Westech specifically. He said: "Westech says their dyno won't measure across the whole rpm range, and that's just BS". Said: "we have the exact same dyno, and we had the factory come out and did a add on modification that allows us to do the entire sweep from idle to redline accurately. They could easily do the same" So, maybe this is something you'd want to have Westech look into? If they aren't interested in cooperating, you could still do both a low, and high sweep. At least then we could compare the relative low and high characteristics of the different cams, or whatever you are testing at the time. I think the duration on these cams was too long for your rpm cutoff point. Like you, I would expect to see a sharper drop off in the curve for the shorter LSA cams on top. I think you would see an even more dramatic drop on the low end, also. My experience has been that a closer LSA tends to concentrate the power in a tighter rpm band. Thanks for this data, though. Anything at all in this regard is helpful.
@richardholdener17274 жыл бұрын
Thnx-we were past the power peak of the motor so further rpm won't any higher numbers, although possible differences, for more rpm, this motor needed a single pkane intake. Idle to redline!
@SB-vb8ch4 жыл бұрын
Awesome as ever, thanks for the data!
@l96sierra144 жыл бұрын
The stroker needed the overlap. Stock 5.3 will limit how much overlap you can throw on it I think. We need to test that!!! Title “how much overlap a 5.3 can use? How does the graph looks!!
@andrewcammer25354 жыл бұрын
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.
@ezmny13877 ай бұрын
you want tighter LSA with more cubes as it takes advantage of the larger displacement for filling sooner
@sean5comet4 жыл бұрын
Thx for the upload...look forward to your content
@dumbestoyster4 жыл бұрын
This test has always interested Me.
@awebke4 жыл бұрын
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 :)
@Tyler_Mattson4 жыл бұрын
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.
@TurboGreggZ4 жыл бұрын
Egt can sky rocket from tight lsa. Overlap causes issue due to the reversion.
@ezmny1387 Жыл бұрын
@@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)
@DavidViny4 жыл бұрын
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.
@hefftoneGA2 жыл бұрын
This is a really good point about the IVC. Changing.
@crd-nz_0012 жыл бұрын
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.
@baby-sharkgto49022 жыл бұрын
I was wondering the same thing
@FordMaverickFanatic4 жыл бұрын
Very good watch! Would be curious to see the same test on a few different engines!
@suarvemarv2 ай бұрын
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.
@bradbarnette7163 жыл бұрын
Great comparison. Can we also assume that the ICL was (obviously) different for each cam? And in addition, would you be able to test with the same installed ICL across all three cams? I know, I know, asking for the world! In addition to letting everybody see the difference in lobe separation is valuable, but (I think) more importantly, starting to understand how the ICL and intake closing event have on the actual powerband. Generally the lobe separation automatically alters this, unless advance is ground into the cam to "compensate"
@haydensmith90644 жыл бұрын
that was an awesome comparison in perfect time for me. could you do the same test on a gm lsa motor in relatively stock form? i would love to see how a cam that size goes with such a tight lsa on boost escaping
@booplesschpooples60274 жыл бұрын
Richard! People want that down low power for part throttle feeling of the motor. If you have a gutless bottom end you feel it trying to accelerate from a stop. Even though you don’t floor it there people still want to it to feel powerful everywhere. ONLY if it doesn’t have a higher stall converter
@michaelangelo80014 жыл бұрын
That's right.
@44hawk288 ай бұрын
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.
@Lokomart3 жыл бұрын
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.
@euba01493 жыл бұрын
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
@hefftoneGA2 жыл бұрын
Valve event timing is what you need to be comparing.
@bainracing6 ай бұрын
This changes everything! this test is a bit missleading without optimal intake timing.
@rideswift4 жыл бұрын
Great video, I would like to see this type of test ran on a stock 5.3 and 4.8.
@chomin30253 жыл бұрын
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.
@utahcountypicazospage54123 жыл бұрын
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
@Skoog.3 жыл бұрын
@@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??
@chomin30253 жыл бұрын
@@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)
@Skoog.3 жыл бұрын
@@chomin3025 Thankyou..!! I always thought it made power at the same rpm.
@rickyr77902 жыл бұрын
Itd definitely be interesting to see header primary length, merge choke, and LSA comparisons. I hear the larger LSA the tighter collector choke can be, and shorter primaries can be too.
@Hipsters_N_Hippies Жыл бұрын
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.)
@timothybayliss66804 жыл бұрын
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.
@johncholmes6434 жыл бұрын
Who wants a smooth idle??
@Ribbityibzki4 жыл бұрын
@@johncholmes643 certain race classes.
@deantape27594 жыл бұрын
@@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.
@timothybayliss66804 жыл бұрын
@@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
@deantape27594 жыл бұрын
@@timothybayliss6680 im talking popular aftermarket cams sorry not stock ones, i agree they do always favour a really smooth idle on stock cams.
@codyrice55914 жыл бұрын
Hey I recently bought the sum-8718 camshaft from the ls series line of cam shafts and I’m curious to see the torque gains out of a lq4 6.0 if you could maybe make a video.
@woxie49904 жыл бұрын
Thank you. Informative. Please continue!
@randallcribb6684 жыл бұрын
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,