Damacman

I want to make 500 at the flywheel out of stock bottom end 6.0, gonna change camshaft, do lil work on the 317's. The question is can I mill the block and heads to get around 10.5 compression and get the best quench possible. Its been a few years since I built a motor so is Cometic still the go to to get the best quench? Do I need to even worry about milling the block? How much can be taken off the 317's safely without worrying about intake sealing issues. I have a stock LS1 intake and have a truck intake setup laying around also. I also ended up with a custom grind camshaft but not sure any of the numbers on it so gotta do some digging to get more info. Is 500 realistic with the right cam and the rest of my combo?

Thanks for reading.
Joe

G Atsma

Not sure how a rock buggy likes to run. Got a feeling idling and low end is important?
Fill us non-rock buggy dweebs in on how they have to behave and you WILL get some guidance on your build! This should be interesting to many!

Damacman

So yes idle is a must lol, I will have a turbo 400 with about a 2800 converter in it. Yes I would like to have some low end power. You have never seen rock crawlers, rock bouncers?

G Atsma

Only pictures and VERY short video. 500HP from a 6.0 while retaining good idle is a tall order unless you turbocharge, and then you do very little to the long block and let the turbo(s) do the work. The stock bottom end will handle 500HP easily. Use the truck intake manifold as it will help the bottom end power. Will this engine be built from scratch or are you using an existing long block?

Damacman

Existing long block that's apart. New rings, bearings, hone, and that's it on short block.

G Atsma

Nice! Might as well freshen things up while it's apart. Do a good valve job on the heads, and you're set.

tech@WS6store

iTrader: (2)

420 rwhp is 513 crank at 20% loss.
So with better heads and a mid range cam youre there.

G Atsma

He mentioned good off-idle power. Will a mid-range cam provide this? I agree better heads are needed too.

tech@WS6store

iTrader: (2)

Just some 243s or l92 heads prob. A full flat top 370 with those heads and a mid 220s cam would ge there but not with a stock intake prob. need a ported ls3 or a fast to bring it up.

Damacman

317's cleaned up and milled won't get it done? I was inder the impression that they were as good as 243's just bigger combustion chamber.

KCS

iTrader: (20)

It's that lack of compression that's going to hinder your off idle and bottom end power. Selling the 317's for a head with smaller chambers will be well worth it. If it were me, I'd go right to a 862/706 head with the 61cc chambers and cut a valve job for 2.00" valves.

Damacman

I have a set of 241's on my LS1 I could use. Would I not be better milling the 317's and use a thinner Cometic gasket to maintain compression and tighten the quench?

KCS

iTrader: (20)

Milling and using a thinner gasket will hurt PTV which is really going to limit the camshaft you can use. Like I said before, I'd go straight to a small chamber head.

Coincidentally, this was just recently posted:

706 vs 317 Head Dyno Test

Damacman

I did see that on Tooleys post.