rjw

iTrader: (3)

I am currently buidling a 383 ls engine.

4" stroke and 3.905" bore with cr just under 9 to 1

I have AFR 225's, but they are for a large bore engine. AFR recommends using a 4.135 to 4.165" bore gaske, but I am concerned about sealing, in that I may need to turn the boost up to 15 or 20 psi.

Looking for 800rwhp/800rwt with my 3.3 liter whipple.

Anyone used these heads on a small bore engine with lots of boost?

thanks

BLNLS1/RX7

iTrader: (2)

You need to contact Bob at Exotic Performance Plus.com.

rjw

iTrader: (3)

Can you elaborate as to why?

thx

NicD

iTrader: (7)

My current setup is close to that being a stock cube motor with the large bore AFR 225s on it. I run the AFR recommended cometic gasket and it works fine so far at 15 psi. I am going to run about 18-20 now that my fuel system is all done but just haven't had a chance to turn it up yet.

ChevyChad

iTrader: (50)

I had that same question. Well, close... Check out Tony Mamo's responses (and others) here:

https://ls1tech.com/forums/generation-iii-internal-engine/813229-afr-225-big-bore-72cc-heads-346-a.html

speedracer5532

iTrader: (8)

Talk with Tony Mamo @ AFR. I am 99% sure the AFR 225 heads he is running on his 383 are large bore ones.

rjw

iTrader: (3)

So what's the verdict on gaskets??

4.1 bore or min 4.125 as recommended by Tony?

MLS = OK....did you guys spray the gaskets with copper or install dry?

Also what do you think max boost can be....can I go to 18 -20 psi safely, if detonation is held in check?

Also, how thich are the 5 layer gm gaskets? I am looking for .041" or thereabouts. Part number?

thx

rjw

iTrader: (3)

It was Tony that recommended large bore 225's as opposed to small bore, with my setup.

Just checking to find out if anyone has had problems with boost levels near 20 psi.

kp

iTrader: (34)

I just put the GM 6.2 gaskets on mine with a 72cc AFRs, I laid them on the heads and there was no overhang in the chambers anywhere.

stevieturbo

A 6.0 gasket shows an overhang on my new Trickflow 225's. Id say the chamber is a 4.0" bore...

So thats circa 50thou overhang each side. Hopefully be up and running again before Xmas.

ChevyChad

iTrader: (50)

The GM 6.2L 5-layer gaskets are .057x4.100 IIRC. The 6.0L 3-layers are .052 thick, and the 3-layer 7.0L are 4.150x.056

ninetres

iTrader: (35)

Part #?

chuntington101

riw, bit off topic but how come you are going 383?? thought you wanted to run stock stroke??

Chris.

rjw

iTrader: (3)

I have a balanced rotating assembly (346) that I decided to keep together....higher cr, etc. May use it in another car or off it.

I got a sweet deal on a 383 rotating assembly, so I took it.

With the power level that i am looking for, I will hopefully get there without having to up the boost too much, and am using a cam that should bleed off a bunch down low....

Looking for around 600 rwt at 2k and 800 rwhp at 7k, without having to go to 20 psi.

chuntington101

should be a really nice setup! looking forward to see pics/spec of the chargercooler you are running but guess we are going to have to wait till you ahve put a 'kit' together.

still very nice work. cant wait to see final numbers.

Chris.

rjw

iTrader: (3)

Actually and surprising to me, my ic setup is almost identical to the ls9 pics floating around. Differences are copper vs alu and actual depth of ic's.

so , the cat is out of the bag....I have been running twin ic's layed down.

I guess that if GM or whoever thought it to be a decent idea, then my setup isn't too bad.

Not too many options when trying to fit it ll under ANY hood...only so many ways to configure it.

chuntington101

well if GM think its good enough! lol

are you still planning on selling kit once you have finished?? how about an 'performance' lower manifold (with your twin intercoolers) for the Magy guys?

thanks Chirs.

rjw

iTrader: (3)

Still waiting on the NEW design lower from whipple....can't go much further without an available part.

My manny is obsolete

So....when the smoke clears, I'll have to see