I would like to know what head gaskets are you guys using to run 15-18 psi

thanks for your time.

 

I am going with the Fel Pro 1074 gaskets.

 

I use the 1074 as well with ARP bolts.

 

I have used the FelPro without any problems. This year I am ging to try the Cometic, but you should be fine with the FelPro.

Rich Krause

 

I'm going to go with the Cometic gaskets on my build-up too. Heard great things about them, we shall see...

Marty

 

I am using the Cometics. I machined the block and heads to insure proper mating surfaces, put them on dry with studs, no problems so far.

However, I am told you will pop a piston before you blow these things. Kinda of gets rid of the fuse, make sure your tune is right on. Right Rich?

Wingnut

 

Yes, I thought about that but there was no sign of detnation on teardown this year.

Rich Krause

 

Thanks guys,
Is there a part number for the Cometics? and where can I get them?

thanks again.

 

Never mind those questions, did a search and answered myself, sorry!

 

I think the cometics may have an advantage as you can get them in any thickness.
I was looking at the srp with -31cc dish, wich they say should give 9:1 cr with 58cc chambers,
From your experience, should i look for a lower c.r. ? different pistons? Could I use the cometics in a thicker size to lower the c.r. even more?
I want to run 15-18 psi, i have 94 octane gas available at the pump.

thanks for your input and time.

 

Since you are running a 383, I am pretty sure that you will need to change you heads to get a lower comp ratio. You can go with a thicker gasket, but experience has proven to me that 1) It does not lower your compression that much 2) better performance out of a better head.

I am running about 9.2 to 1 with my 355 and had to leave pump gas at around 15 pounds of boost. But if you have a set of good ported LT1 heads with big valves, good turbo or supercharger cam, and good exhaust with ported intake, you might start with 11 to 12 pounds of boost first. With that 383, I bet you will like it a lot. If you must turn up the fun factor, you are going to have to evaluate cost vs. pleasure. In other words, things get critical north of 16 to 17 pounds of boost. High oct # fuel becomes a necessity in stead of just insurance, and long stroke engines get pushed to their max. Big HP, Huge smiles, lots of girls, but all at a cost.

Rskrause and Engineermike both have a lot of experience in this area, I bet they could throw out some numbers that might make your decision a little easier.

Do you have an HP goal instead of a boost level goal to work with?

Wingnut

 

Thanks for your input,
I didnt want to set a hp goal really because I didn't want to be disapointed once the dyno sheets print out... I do want this to be fun to drive and have a awesome seat-of-the-pants feel adn I am pretty sure 500rwhp will take care of pretty much anything I see on the street around here. I beleive that something north of 500 rwhp is realistic.

I would also like to know what kind of compression ratios guys around here run with at least 15 psi...also is my 9:1 a good start?

once again, thanks!

 

I am at ~8:1 to run 17psi on pump fuel. However, when really beating on it (at the track with nitrous plus boost) I run race unleaded (104 octane). Using a very thick gasket to lower CR is ultimately self defeating because it will prevent you from achieving an optimum "quench height". Optimum is ~0.035" to a max of 0.045". I am running 0.040" for this year (zero deck, 0.040" gasket).

Rich Krause

 

You've done your homework Rich. That is the correct range for proper quench. Don't listen to the guys who say that quench doesn't matter. By the way, isn't a Felpro 0.039?

 

I am using the Cometic 0.040" gasket this year.

Rich Krause