1999TransamWs6

iTrader: (21)

What is the largest cam with a ls1 stock shortblock with 66cc AFR 205 heads unmilled and cometic gasket with an .030 gasket that I wont run into piston to valve clearnce issues? Thanks.

PREDATOR-Z

I would not run .030 gasket. that is a .025 quench at best with stock block.

1999TransamWs6

iTrader: (21)

what is ideal quench?

PREDATOR-Z

Street is .033>.040
Race , I've seen as much as .027 but that is tight IMO.

Spinmonster

My C5 has .027 gaskets for 11k miles now.

PREDATOR-Z

That is not the norm Spin, on the street you'll get more carbon buildup.
And Spin, why don't you tell him what setup you have and why you're running such a tight gasket!

Spinmonster

The .021 quench was definitelt not the norm. The motor is all forged 348 and N20. It is a max effort motor and I wind it to just under 7K.

Input came from my uncle on the build as he is an engine bulder for over 30 years.

When you say 'the norm', it is generally accepted outside the LSX forums that .020 is the minimum but on these forums a few builders got it in their heads that .030 is the minimum and is law. Who is to say. My 11k on this build is a very abusive 11k and there is definitely not any carbon build-up in there like the stock set-up had...maybe from the nitrous?

Anyway, just offering what I have for statistical referece or you can just discard it as useless. A properly built motor can do things a patchwork motor can't.

It is my understanding that cometic no longer makes the .027 gasket since no one uses it. I asked why they made it in the first place and they said .020 was acceptable. The minimum is now .033 which is fine with the stock.006-.008 out of the hole piston.

If my set-up didn't blow up by now it is fine. I had the heads off twice to do some head work and all is fine in there.

I went with .040 on my C6 since the displacemnt put me at 11.4:1 and that is where I wanted to be.

PREDATOR-Z

Oh yeah, nitrous will clean things up pretty well.

BTW, let me emphasise that tight quench will not produce more carbon, but i mean't street driving with stop and go and lots of idling. This in turn, at the long run might cause some clearance issues from carbon buildup.

And Spin, You said nothing wrong, I just wanted the guy to get a clear picture on why you would run such a tight gasket.

orangeapeel

iTrader: (18)

What is a stock gasket quench?

PREDATOR-Z

It depends on the piston to deck position.
mine stock is .007 out of hole so
.054-.007= .047

moeZ28

iTrader: (7)

now back on topic, the g5x4 clears stock heads, the trex is made for stock heads, the magic stick is big, f15 ron jeremy is big, my cam in sig is big. there are many big cams out there that clear the stock heads. if you want a bigger cam that still makes a little power down low, a g5x2 is great, and so is an f13, or f14.

LSXRX7

So does any one know what's the most lift you can go with on a LS1 or LS6 with stock heads? just wondering...

kenp

iTrader: (9)

The original question was with AFR heads which have valves larger in diameter than OEM.

ArKay99

iTrader: (1)

Unfortunately there is no 'correct' answer to your question. A lot of variables come into play and they all stem from valve event timing. Lift and duration play a part for sure, but LSA and advance/retard also play a big part. I have read that if installed correctly you can put a G5X3 on a 114LSA into an LS1 with stock unaltered heads on stock gaskets. I also have read here that you can install a TReX in the same motor under the same conditions. Thos are pretty big cams. The G5X3's specs are 'proprietary' sort of, but you probably can find it if you look around, and the TRex's specs are on Thunder Racing's site.

1999TransamWs6

iTrader: (21)

Thanks for all the information however I am running the AFR 205 with a 66cc chamber and the 2.02 valves. I understand it is hard to give a "this is how big you can go" so is there anyone with this set-up running a big cam on stock pistons? and if so what cam? Thanks.