ZONES89RS

iTrader: (25)

Ok, i completely forgot those heads have big block valves in them, LOL.

ZONES89RS

iTrader: (25)

Man, i have some TEA heads line up, i was not going to the LS3 heads, just wanted to see what folks had to say on the topic.

But, the 5.3 heads i should be buying soon....i dont know if i will have PTV issues with them, i know they have a smaller chamber and the fact that the compression will help allot but man, i i just dont know if the valves sit lower than the 317s or not, i have been told the 243/799 casting would be the same as my 317s and need no PTV clearance, but the 5.3 TEA heads, i really would not want to have to clearance the piston for the valves if i dont have to, they have 2.02 valves, and that would be near the limitation if they are unmilled, i had .110 with my .030 milled 317s, i will have to check anyway when i do the swap, but it would **** me off no to be able to just put my **** back together.

ThunderStruk

iTrader: (1)

100% correct on this

ThunderStruk

iTrader: (1)

That cam like to make peak around 6300rpms and will carry out past 6800 if needed.

99 Blue Bird

iTrader: (3)

i thought the large split in duration was irrelevant for LS3/ L92 headed cars running a single plane CARB setup?

ZONES89RS

iTrader: (25)

Well ****, looks like i might have to fly cut if i was to get the TEA 5.3 heads, that makes me want to hold out for ported 243s since it seems they wont require fly cutting.

ZONES89RS

iTrader: (25)

Anyone know if there is somewhere i can get information to how much further down a set of TEA heads valves might be?

speedtigger

iTrader: (16)

Hmmm. Well, I would say this has to do more with them being 5.3 heads than ported by TEA. Now if TEA put larger valves in the heads, then they may have moved the final installed height. I hate to be captain obvious, but I would say TEA would be the ones to answer that question if the heads were part of a standard production performance head that they offer. If it is a "one-off" custom pair of heads, I would doubt they could tell you. Then there is the variable of have they been modified, milled or valve job since they left TEA.

There are many variables here. So, as unappealing as this answer is, the only sure fire way is to bolt em' on and check the actual clearances.

ZONES89RS

iTrader: (25)

Well, one said they his machine shop told him that anything above 228 duration would probably require cutting, but then again, i am sure this was probably a FT LS1, not a dish piston motor, so really, that is the issue for me, i know the only way to tell is to bolt them down and check, but that is a turn off if i can get away with 243/799s that are ported and not have to fly cut.

speedtigger

iTrader: (16)

I have thought many times about ordering some CNC 243s. The idea of cracking 500HP is just so tempting. Unfortunately, I am running close to budget if not over. So, if I do it, it will have to be down the road after everything running and sorted out.

DMMizell

iTrader: (1)

The dished LQ4 pistons give at best 10/1 with milled L92's.
With a carb and single plane and enough duration and lift to make power up around 6800-7000 you need an early ICL like 106.
If this causes you to have PTV issues then make the clearance!
I went 137-138 mph at 2900 lbs with an LQ4 and stock unported l92's with 9.8/1 on pump gas.
The Rapid Motorsports dominator 2X required flycutting for intake clearance.
It was well worth the effort..This engine is still going strong in a '57 Vette.
Running 9's on 93 pump, shifting at 7000.
Put the right cam in, make the clearance and don't look back.

Dave

DMMizell

iTrader: (1)

some older video of the 6.0 with the Rapid cam...
http://www.youtube.com/watch?v=fn719sol8hE

DMMizell

iTrader: (1)

Of course the new smaller 346 runs better....
http://www.youtube.com/watch?v=bqSf4FDf8MU

again, pick the right cam timing events, and if this causes clearance issues,
make the needed clearance... it will be worth it!

99 Blue Bird

iTrader: (3)

same cam in that motor? or did u go with another cut?

DMMizell

iTrader: (1)

The cam has more duration/lift with a wider LSA and later ICL.
Higher compression, more total intake volume, higher rod ratio needs the above.

Dave

ZONES89RS

iTrader: (25)

I am worrying that spraying a motor with stock pistons that are fly cut might cause an issue and damage/burn through the piston, seems it would be a weak spot...

What is the thickest head gasket i can find? The TEA heads are already .01 less with the 2.02 valves, but i cannot seem to find out how low the valve is to get a better idea, if i can use a ticker gasket and my dish pistons help me get away with it, that would be sweet. Otherwise, i dont have the monster L92 intake valves, LOL. Sticking wit the Trex.

NoMoreFWD

iTrader: (1)

Dave, I have been inspired by what you have done. I am building an LS2/L92 motor for a 2000 Camaro. My combo is very similar to yours, just don't think I can get the weight down quite as low.

yfzduner

Adding a thicker head gasket would also loose compression and quench. Probly loose what you would gain with the new heads flowing better.

ZONES89RS

iTrader: (25)

They already have smaller chambers, so they would still be gaining compression.

NemeSS

iTrader: (127)

sounds like a very well thought out combo that works for that lower scr and l92 heads.
i personally would go with milled/worked 243/799 to raise scr/dcr as much as possible for use with the trex cam and still run 93.
similar higher scr trex cathedral port heads combos have worked well for me in the past on pump gas.
running any kind of cam without valve relives makes me nervous. i just cut them in any build now and keep use the thinnest compressed gasket i can find. usually the ls2 .053 compressed gasket.
i shoot for a .035-.040 quench area. most oe ls are around .008-.010 out the bore stock