kolorzcars

what kinda valve lift and duration are you guys getting away with stock piston(and no fly cutting)

RamAir95TA

iTrader: (2)

Enough where it's hardly a concern. It's not like other engines - there's a ton in an LT1. A friend of mine is using a 25x/26x .640"+ lift on a 107 lobe with enough room to spare.

And FYI, duration is far more important than lift when it comes to determining PTVC. If you have any doubts, the tootsie roll/clay method is your best bet.

kolorzcars

Yea I kinda was thinking that too, I have a tpis zz409 cam now, and have a buddy that has some 1.65 roller rockers for dirt cheap. I was just thinking if there was were getting away with a lot more lift and duration, then I would snap them up, then check it, I just don't want to waste cash.

gregrob

iTrader: (8)

That cam will be nowhere near having PTV issues.

kolorzcars

My only concern would be the lobe sep and duration, but I think there are guys running wider on both accounts with out issues

hitmanws6

iTrader: (20)

The rockers mostly change lift, not duration. Duration is affected but the main purpose of going with a higher ratio is to increase lift for a few ponies

gregrob

iTrader: (8)

Yes... there are people running much more than that cam without PTV issues.

FWIW you can do MUCH MUCH better in the cam department than that grind.

gregrob

iTrader: (8)

Actually they do increase duration as well. Albeit slightly

hitmanws6

iTrader: (20)

Yes slightly, i remember the multi page discussion on this. But OP im running essentially a stock bottom end (stock heads were only milled .005 and I have Mahle stock replacement pistons in a 4.030 bore) with my cam and no issues.

Wicked94Z

iTrader: (26)

please delete this post...

hitmanws6

iTrader: (20)

Fixed

kolorzcars

yea, i want a le2 set of heads and his cam.... but im planing a single turbo build for that engine......plus the tpis cam was $00, my car has been sort of a budget build, i have $7500 invested(including the purches price of the car).

I actualy talked to Lloyed Elliot after i got the cam, but he said to hold off on his stuff(for after headers, and stall, and gear....wich i have done since then) he is like the most honest guy i have ever talked to.

TABBED 5.3

iTrader: (1)

236/242 550/560 110 lsa here, no issues.