Eric's cam challenge
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Silence can be of substance
Turk,
You do not think Mike Jones's cams are very good? It is 'funny' you should mention that because I always wondered why he was not the go-to cam grinder for all the best engine builders in town. Reality is, one does not see a lot of his cams being used.....
You do not think Mike Jones's cams are very good? It is 'funny' you should mention that because I always wondered why he was not the go-to cam grinder for all the best engine builders in town. Reality is, one does not see a lot of his cams being used.....
TT5.9mag
Two atmospheres are better than one
Lighten up, I was speaking to no one specifically, much more generally out loud and as a response to the excuses Vizard was spouting. I know you were referring to the lobe profile, we all were, and I stand by what I said, regardless of the winner using what he called his street lobes. Oh, and I helped start this party, it came from another thread and it was moved here.
I believe it most of the cams seem inline with what people would normally pick for a build like that.
Sounds like you will have an opportunity to prove that theory in his next challenge. I will pay your hundred dollar entry fee and we'll find out if you can make the top ten.
I weigh 160lbs, if I lighten up anymore I’ll freaking blow away.
It would also be interesting to see what those cams actually do at the track as compared to the Dyno. The most “jump off the page” attribute I see with the NK Performance grind is the amount of exhaust duration compared to the intake. I miss what PBR would have had to offer on this topic, being he did more than a few LS heads for other racers.
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TT5.9mag
Two atmospheres are better than one
I really hope Eric does a few more of these. There’s talk of a small block ford cam challenge and a big block Chevy cam challenge. I’d love to see what Billy Godbold would grind for that one.
I am not an engine builder by a long shot but I have read everything I can get my hands on that has technical science behind it and built the motors for my cars using DVs methods very successfully for what I want. This seem more like a DV trashing thread but if you take time and really think about the cam specs here there is very very little (none really) that I have read from DV that was disproved in this test. What I am confused about his overlap selection. He seemed to have selected a very short overlap for a test that has peak HP as a criteria based on the methods he has published. If you follow his methods from his books the top 3 winners are _exactly_ where you would have expected the best results from... low LSA and about 30-40 degrees of overlap. His selection of 24 degrees of overlap is puzzling to me unless his real goal here was something else. He has one goal of finishing up his cam selection program for the LS. If you look carefully his is the only low LSA and short duration. I am wondering if that was a on purpose to get a data point for validating his program...... He has nothing to gain at his age buy selecting a cam that looks almost identical to 3 others.
I would really like to see the graphs, numbers never tell the whole story. Based on what I have read and simulated to me that cam he selected potentially could have the most torque at the lowest RPM, it is more of a towing cam based on his terminology. What I find interesting is the wide LSA with the low overlap doing well. I would love to know what the dynamic and cranking cylinder pressures were on those and could you really have a reliable street engine with them.
Like someone said in the thread, it was fun to watch but it really doesn't tell you much without a lot more data analysis. To me this test raises more questions than answers.
I would really like to see the graphs, numbers never tell the whole story. Based on what I have read and simulated to me that cam he selected potentially could have the most torque at the lowest RPM, it is more of a towing cam based on his terminology. What I find interesting is the wide LSA with the low overlap doing well. I would love to know what the dynamic and cranking cylinder pressures were on those and could you really have a reliable street engine with them.
Like someone said in the thread, it was fun to watch but it really doesn't tell you much without a lot more data analysis. To me this test raises more questions than answers.
The Ford one would be one I might jump into. I know some about what it takes to make a small block run. That might be fun.
He's a genius, I have no question of that. .......but anything I say sideways about him ain't directed at him, but I'm just pokin at the few here who think he's the end all be all.....because he's not. Nobody is, because nobody can really know for sure how something will actually perform in a given engine......they can only make an educated guess. I'm actually beyond surprised he didn't do better than what he did. I attribute that to maybe him being somewhat unfamiliar with the LS platform. Lord knows I know nothing about them. .....but then I don't want to. Willful ignorance. LMAO
Newbomb Turk
Well-Known Member
Do you think he did NOT use his math to chose his cam?
He knew the rules. I’m saying he used his “program” that he sells that is only sorted out for the SBC or something.
There were four metrics in the test. He wasn’t at the top in any of them. Not one.
It shows me that testing his methods with actual testing shows how lacking his math is.
That’s not bashing on the guy. That’s stating facts.
replicaracer43
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The whole entire premise of the cam challenge, was because Eric said he was tired of everyone claiming they were experts at picking camshafts, and so he set the parameters, and said "prove your the best" it's that simple. It was to separate the ones who talk the talk, from the ones who actually walk the walk. DV talks....
This engine seem to need a very large split, probably why the 1st two cams did really well.
Seem like the engine needed a lot of exhaust duration, none of the engine that made good hp had less than 250° exhaust. If you look at BTR #2 cam came in 17th, but did have 4th in hp but was fairly similar to the 2nd place cam, my guess his IVC was a little to late to make the torque like the others that were in the 41°-48° range, probably should of ground more advance in.
Also another thing to consider is this. The factory LS camshafts use a very wide LSA. SOme of them are 120 or greater. Clearly they are "different" animals than the engines before them.
I don't know what his formulas are based on, but I know it's not Mopar. Seems I have seen where it's best for the SBC.
The 128 rule is a constant and for SBC only. All other engines the constant is different. He doesn’t have a constant for LS. What he used wasn’t right and he knew that. There’s nothing wrong with the math, it just hasn’t been corrected and proven yet. It’s going to take 100’s of cams and pulls to do that.
He just used what he had.
He just used what he had.
replicaracer43
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His cams wouldn't win in a SBC application either. Unfortunately, it's not 1974 anymore, he might have been pretty good then but not these days
From watching Richard Holdener video's seem like the wide LSA's are cause of limited piston to valve clearance allows them to run decent durations.
Newbomb Turk
Well-Known Member
He claims the 128 number is for inline wedge heads. I think I have it written down somewhere but it seems to me canted valve heads use 135. Or maybe it’s 132. Something like that.
IMO if you have actually tested 19,000 cams you’d have a pretty damn good idea what cam timing should look like.
I get it’s an LS but it’s still an inline wedge. I think some guys missed because they assumed that head would need less overlap like a canted valve head.
And I think some failed on exhaust duration. Reducing pumping losses is a big deal as long as you don’t get more overlap than you need.
Newbomb Turk
Well-Known Member
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