Who is running one? Where do you have it degreed? What RPM do you shift at? Mine is degreed 6* advanced on a 107* CenterLine. It runs out of steam at 5100-5200 RPM. Even the engine dyno sheet shows that. Just wondering...
I have the 413 cam in my '71 350 GS dont know if mine will have much relevance to a big block installation, but I have mine degreed to 108.5 deg. The cam card says to degree intake lobe to 109 for 4 deg. advance. 108.5 was as close as I could get using the TA billet gears and chain. Mine will pull to 6000 rpm, but I have the governor set to shift at 5500 rpm. The additional 500 rpm to 6000 rpm seems like the engine was outta steam, so I set it to shift at 5500.
*bump* I'm interested in this thread as I have a 413 cam sitting in a box waiting to go into a 455. Yes, Yards is running a fuel pressure regulator, and although he had trouble earlier in the year with pressure, he's fine now all the way to at least 5k RPM according to an inline gage he had mounted.
Why is the cam so advanced? Is that as close as you could get with your timing chain or ? Have you tried another tach?
When you say "run out of steam" does that mean it stops reving higher?, flattens out?, or starts loosing power quick/breaking up? Does it do it in every gear? or only at top end of track? It could be: Valve float Ignition related, do you have rev limiter? Fuel related Double check cam timing
"Running outta steam" in my case means it will pull to 6 grand, but it pulls hard to 55 to 5800 rpm, the last 500 rpm to 6000 it doesnt pull as hard it makes it to 6 grand but the rpm rise to 6000 is slower. Hope that makes sense.
It levels out. It will rev higher but you can feel that it stops pulling. I only seem to notice it at the top of 1st gear. I run 2nd gear to 5000 and don't notice it leveling off. But that could be because you sneak up on it in 2nd gear as oppossed to snapping up to it in 1st. The rev limiter is set to 6000. It doesn't break up, just stops pulling. It doesn't lay over, like running out of gas. Jim Weis and Mike TA advised me to install it 6* to 8* advanced because of the weight of my car. Anyone have a 413 in a car that weighs ~4500 pounds with driver? I'm running new TA dual valve springs with 1.6 TA roller rockers. The cam is degreed spot on @ 6* advanced. Would installing it straight help or hurt my 1/4 mile times? I know I'd probably suffer a loss of 60' times with less torque, but would moving the power to the HP side by advancing it gain me more on the top end than I'm losing on the bottom end?
Coming from a tuning point of view, as opposed to trouble shooting, I would ask: Do you have more than enough bottom end power? If you have low end torque to spare then I would see no reason not to retard the cam to a 108 to 110 degree intake centerline.
Yards, Haven't you been chasing this problem for awhile now? Didn't it do this with the other cam too? Seems me the only real unknown with your combination is the HEADS. I know they are supposed to be some Super Whammer Jammer Kenney Bell heads, but what if it has something to do with the head flow. If it was me, I'd want to pull those heads off and Have Greg go through them and flow them to see what they actually do. Port match them to your intake while he's at it too. If those heads were as good as you think they are, shouldn't that motor make at least 475 HP with that 413 cam. Something to think about.
Just another thought........ My 510 cam motor fell on its face with Kenne-belle roller rockers. It did much better with stock arms. I don't know about the TA rockers - but think some cams don't respond well to rollers.
I think Yards is comparing old motor to new motor build - same heads, same roller rockers, not sure but I think same pistons, same intake. only real difference is the cam ... and he's lost at least 3/10ths with the new build
DINGDINGDINGDING WE HAVE A WINNER! I spoke with Jim Weis this evening and he said the exact same thing. I will be swapping in stock stamped steel rockers and see if it makes a difference.
My question is why have we never heard of this to this point, and what the hell is making it happen? I flushed $700+ down the toilet?
Just use the rocker arm retainers that are used on the roller shafts and you should be good to go..................but I am sure ole Jim told you.......... I suspect there are many big blocks, that were never dynoed, built with roller rockers that are not seeing there full potential......... I think my motor was about 40 hp short with the rollers................still powerfull enough to get me well into the 11's............but no where near its potential... Good Luck!
