Whose making the most power with Factory GM casting heads?
We did 1132rwhp on the dyno at right around 25-26 psi.
S88 Turbo,370ci motor, stock crank, Ported 317's, MLS Gaskets,Patriot double springs, 224/220 cam. Thru a Powerglide and S60 rearend and 325/50's.
At the track it would run all day with out pushing water ie(lifting the heads, preasurizing coolant system) at 20psi. It ran a 6.27 1/8 @ 119, 9.26@150 like that.
On the 1132rwhp pull it pushed water on the dyno.
Ran it at the track like that... 5.89 1/8 @ 127 and popped the head gasket and rolled to a 9.7 @137. Race weight was around 3350#
Kyle
S88 Turbo,370ci motor, stock crank, Ported 317's, MLS Gaskets,Patriot double springs, 224/220 cam. Thru a Powerglide and S60 rearend and 325/50's.
At the track it would run all day with out pushing water ie(lifting the heads, preasurizing coolant system) at 20psi. It ran a 6.27 1/8 @ 119, 9.26@150 like that.
On the 1132rwhp pull it pushed water on the dyno.
Ran it at the track like that... 5.89 1/8 @ 127 and popped the head gasket and rolled to a 9.7 @137. Race weight was around 3350#
Kyle
Damn thats impressive! Knowing what you know now about the GM MLS stuff would you continue to use them or consider a aftermarket set like Cometic?
I run Cometics under my ported 317s with Pat Gold Ext springs & have never pushed any water, but I've never pushed my setup to the limit like some of these guys do. The secret to MLS gaskets seems to be throwing in a tube of alumiseal & re-torquing the heads after you heat cycle it. I've run a 100 mile open road race, making 1000 fwhp at 15 psi, run 9s, etc & never had a gasket issue.
but you will be changing your head gaskets at 1000whp mark pretty often, especially if you use a cylinder head with a thin deck, like the stock casting
i am not doubting you that your car made 920whp and did not blow a head gasket, but i am sure the car does not see WOT on a daily basis
but o ringing the block or using fire rings have proven well to keep the heads down
yea i did hit the zero too many times there
but you will be changing your head gaskets at 1000whp mark pretty often, especially if you use a cylinder head with a thin deck, like the stock casting
i am not doubting you that your car made 920whp and did not blow a head gasket, but i am sure the car does not see WOT on a daily basis
but o ringing the block or using fire rings have proven well to keep the heads down
but you will be changing your head gaskets at 1000whp mark pretty often, especially if you use a cylinder head with a thin deck, like the stock casting
i am not doubting you that your car made 920whp and did not blow a head gasket, but i am sure the car does not see WOT on a daily basis
but o ringing the block or using fire rings have proven well to keep the heads down
Teching In
Joined: Jun 2009
Posts: 32
Likes: 0
From: Camarillo
Any thoughts on the RHS 6 bolt heads
We were at the track this weekend with the GTO, and it would move some water on every pass at 19psi. Although the engine has 100k on it now and utilizes stock bolts and gaskets. Went 9.92@141 @4000lbs race weight.
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Thread Starter
9 Second Truck Club
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Joined: Sep 2006
Posts: 3,672
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From: Colorado Springs, Co/ Central, Ca
Is the water pushing out of the head gasket, or overflow tanke? I wonder how much of this they will take before the gasket blows.
I have some stock 241's with some dual springs/hardened pushrods in them and a small cam 214/224. The other day in 99 degree heat I made 550rwhp/505 lb ft of tq through a non-lockup th-400. Not super high but I was impressed since the car only made 566/510 with the M6. I also have used the GM MLS gaskets since 2003 in my car and they work great!
I have the LS9 Head Gaskets On My S10 and I plan to run 18-20 psi regularly when the engine is broken in, also running ARP Studs and Stock 317 Heads, I am having it tuned this afternoon so I can drive enough to break in the engine!
Is that track known for having a high MPH or did you have a really really bad 60'? I wonder why my car won't MPH like others do. I've run 6.3's in the 1/8 but only trap 109mph and my 60's are high 1.4's low 1.5's. In the 1/4 I run 10.0's to 10.2's @ 134-136mph and my car weighs 3850 with me in it. Only makes around 520 rwhp on the dyno too.
Is that track known for having a high MPH or did you have a really really bad 60'? I wonder why my car won't MPH like others do. I've run 6.3's in the 1/8 but only trap 109mph and my 60's are high 1.4's low 1.5's. In the 1/4 I run 10.0's to 10.2's @ 134-136mph and my car weighs 3850 with me in it. Only makes around 520 rwhp on the dyno too.
My setup made 840 rwhp on a mustang dyno through a 4L60E, a pig *** rich tune, and very low timing. We where starting to make the tune more aggressive when the reluctor wheel slipped. Almost 27 degrees 
Basic setup is: 402CID, 317 heads( o-ringed ), F1-R.
Basic setup is: 402CID, 317 heads( o-ringed ), F1-R.
Teching In
Joined: Jun 2009
Posts: 32
Likes: 0
From: Camarillo
I saw a 2009 twin turbo Caddy 6.3 punched to 6.8 making 1147hp on the engine dyno. Stock heads ported by GMS in Oxnard. Motor was running 18.5 psi. Began to lift head and weap. GMS is working on a TT system pushing through a TVS2300. I was inquiring about doing 1 myself - they said I should wait for the new RHS 6 bolt heads so I can run like 22psi
Any thoughts on the RHS 6 bolt heads
Any thoughts on the RHS 6 bolt heads
