Cam Question...pushrod/valve springs
 

Hey guys n gals,

So im almost ready to get the cam swap goin on the 4.8. Got a VHP #62.

210/218 112LSA .551/.551


VHP won't get back to me...so i figured i'd toss this up here and see if anyone could help me out.

I'm callin bs, but according to the card, it says the VHP dual springs are required, figure this is probably a move to get more money from an unknowing consumer. I was planning to run yellow LS6 springs...couldn't find exact numbers but i've read anywhere from .560-.570 lift for them? can anyone actually verify that?


Also..are the stock pushrod lengths fine?



Thanks in Advance,

Dave

Dave, the stock length pushrod 7.400 should be fine, provided the base circle of the cam is the same as your stocker. most aftermarket grind cams for these motors are the same base circle, but a lot of the ls6 and z06 cams have a smaller base circle. call the manufacturer of that cam and ask what BC the cam is, and cross reference.

springs.... LS6 and z06 springs are rated ~.550 as far as i know, so you may want to step up to some dual springs for insurance....although you may find some cheaper dual springs from someone else.... i think i saw some in the classified section on here. comp 918's ? i cant remember for sure....but i would do a search for dual springs and see what your most reasonable option is.

and being that that cam is on a 112 LSA...i would line up a good tuner.

LS6 yellow springs are good for that .551 lift, Lingenfelter sales their cam package with .57x lift... so dont sweat it, I ran my cam with .558/.563 lift with the LS6 yellow springs with no problem... and stock push rod length is also fine....

get r done!!

what is the factory BC if you know off hand? i dont have a micrometer to measure out...

i don't plan on takin the little motor above 5500 often (pullin DD) so i don't think the springs would be hurtin that much, lol. Should also add thats the gross lift.

I have Justin (blackbear performance) lined up for my tune...i don't really like the prices SpeedINC or Outlaw Perf. (juicin) gave me for a dyno tune price and there's no others in state as far as i know. So i just got a base tune so it'll run and the cables to log on the laptop and send them to him so he can re-tune it for the best of the motor.

Lotta people say a 4.8L aint shit...but im gonna try my hardest to A. beat thunder's 13.2 record, and B. find a way to magically hit a 12.999999 n/a :P since it pulls daily duty and occassionally hauls 3000lb worth of seed corn in the bed.

So youre going to use your stock pushrods? Also from what I've read I'd go with the yellow ls6 springs like suggested above.

i will until i feel like takin the motor higher in the revs, then i'll swap em out for comp hardened ones. I need another vehicle to drive just in case first though.

Go for it :) I don't think the crane/vinci cams have an aggressive enough ramp on their lobes to "loft" the lifter off the lobe with the Z06 springs. If it were a Thunder cam I would think twice about it but I think you're on the right track. I am taking out my 4.8L that had a Z06 cam with Z06 springs and would run it up to 6200 RPM's on a daily basis without problems. You will like that cam and Vinci's service is crap so don't expect to hear back anytime soon as I never could get ahold of them. That's why I'm not buying one of their cams. Good luck and I think you chose wisely with your cam selection :)

thanks man, i've had a couple of my tech advisors (lol) over on gmfs help me pick the cam. One is HitmanX on pretty much every lsx based board, and the other was the clutch tech for ronn capps who has a 370ci turbo truck so i figured they knew what was up.

I'm pretty disappointed with VHP's customer/tech support as well, i mean i understand there busy with crane testing and stuff, but when your own phone line says all tech calls returned at 7-10pm EST, you should deliver. I was pretty close to going with the new LS based trickflow cams, but got a good deal on this one and its still brand new.

I def. liked the lope it had on vinci's vette soundclip. Im just hoping to set the new n/a 4.8 record, but i need to lose driver weight im 3 tenths :( :P

Vinci had these 062 cams on sale a couple of months ago for $289 a piece only. I was going to buy one but the cust serv at the time frusterated me to the point where I didn't want to purchase the cam. I was also considering getting the trickflow Stage 1cam such as yourself, but decided against it when I got the advertised duration numbers. The trickflow cams must have a very poor idle (lope a lot) for a given size. Looking at cams at .050 duration is only half the picture of what's going on, it's the area before hand that determine's the aggressiveness of the ramps. Slow ramps mean long valvetrain life but at the cost of torque, performance and gas mileage (lazy port velocities). Whereas a more aggressive lobe is going to provide you with a noisier valvetrain, shorter lived valve springs, but better torque curve and more responsive better running engine that van deliver the power you want along with gas mileage. At the expense of changing valve springs every 50K miles or so.