[68ssvelle]

489 bbc 8-71 ..set up for 7psi ..thats with pump gas ,,but going to run VP red now..need more info on it let me know fellows..

 

[69bowty]

I have ran 9 psi boost with no orings and the Fel pro performance gasket with the wire ring in the gasket. If you want to be safe run the Cometic MLS gaskets, I know people running close to 30psi of boost with these gaskets and no orings.

 

[68ssvelle]

I have ran 9 psi boost with no orings and the Fel pro performance gasket with the wire ring in the gasket. If you want to be safe run the Cometic MLS gaskets, I know people running close to 30psi of boost with these gaskets and no orings.

thats the 1027 fel pro.?

 

[68ssvelle]

dam i thought al chevelle dudes were cool....?

 

[Rogers Performance]

The v6 buick runs about 15lbs with a turbo and no o rings. And has only 4 bolts per cylinder.

So with a BBC with 5 bolts per cylinder and a set of cometic gaskets i would say you can go that high.

But when you use any type of MLS gasket the finish on the block/heads has to be real smooth RA 30 or smoother.

 

[forcd ind]

on my s/b i ran over 18 lbs with just the felpros, but i was intercooled
detonation could cause a failure in an engine with a lot less boost, good studs or headbolts help some lifting-run them rich, keep an eye on the plugs, you will prob be ok-i never had a problem with the roots, even 20 % over

 

[69bowty]

thats the 1027 fel pro.?

I was running the Fel Pro 1037.

 

[Gokou]

O-rings are becoming a thing of the past now that MLS head gaskets have the bugs worked out. I don't know anyone who bothers with O-ringing anymore, MLS gaskets will take just about anything thrown at them without a problem IF your block and head surface finishes and flatness is within spec for their use. (32RA or less surface finish, flatness of .002in/in or better per Cometic.)

Even "conventional" style head gaskets will take a lot of boost provided you have good head bolts/studs and don't detonate it (detonation will tear up a LOT of stuff besides head gaskets.) I'm running the stainless core/fire ring FelPro "Hi-Perf" gaskets (can't remember the part number right now) on my smallblock with 15psi of boost, about 7000 miles on it right now and not a whimper out of anything.

Troy

 

[68ssvelle]

how you fugure the drive ratio..i got 59 top /52 bottom ..if i was to swap them what would it be??also

 

[camcojb]

how you fugure the drive ratio..i got 59 top /52 bottom ..if i was to swap them what would it be??also

divide the two numbers, bottom pulley tooth count divided by top pulley count. 52/59 = .88 which is about 12% underdriven. The reverse case would be about 11.3% overdriven.

Jody

 

[68ssvelle]

divide the two numbers, bottom pulley tooth count divided by top pulley count. 52/59 = .88 which is about 12% underdriven. The reverse case would be about 11.3% overdriven.

Jody

thanks in terms of boost how much is that both ways ..you been great help.