25lbs of boost
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Stock head gaskets hold fine..bad main bearings..sounds like there are other problems..examine your tune..if it detonates..you can arc weld the heads to the block..and still blow.
Detonation is what blows HG's..unless your running upwards of 30 PSI and the heads are lifting..but this doesnt cuase defective MB's.
HTH
Stock GM head gaskets torqued to 85#, and using ARP bolts.
29.5# boost through the traps. I run 23-25# on the street
I'm no professional, but I did the work myself and think good prep, proper torque & torque sequence, and NO KNOCK is the key to having the stock gaskets hold.
-Banning.
29.5# boost through the traps. I run 23-25# on the street
I'm no professional, but I did the work myself and think good prep, proper torque & torque sequence, and NO KNOCK is the key to having the stock gaskets hold.
-Banning.
TT/Ameasap
The White Blur
- Joined
- Jan 31, 2002
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- 5,374
Originally posted by V6Power87
I run up to 32psi of boost with the stock head gaskets. (from 1987)
With what turbo?
Im expecting to run 9's with a juliotune.
Bo
Boost is a restriction..the smaller the cam and head flow..the more boost you will make to achieve a certain HP level.
And the better the heads and cam flows..the more detonation it will be likely to see.. Look at the TSM cars running low 10's high 9's..talk bout heads and cam..and OCTANE
And the better the heads and cam flows..the more detonation it will be likely to see.. Look at the TSM cars running low 10's high 9's..talk bout heads and cam..and OCTANE
i run about 25 lbs of boost on a TE-44 turbo on a BONE STOCK UNOPENED MOTOR...stock headgaskets from 87...about 10 years of storage and never racing the car up until the last two years helps keep the gaskets almost permanently attached to the heads
Same with me. I run 27# of boost and 28º of timing at the track on stock head gaskets.
As you can see the main theme of this is NO KNOCK!! You cannot allow any knock or detonation to occur at those boost levels!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Any that does will take out the best of head gaskets.
This means real good race gas (nothing less than 114 octane), no playing around with exotic mixtures, octane boosters, etc.
Good race gas, sneak up on the safest boost level, allow no knock.
I also do my own work, and whole heartedly agree with J Banning "I'm no professional, but I did the work myself and think good prep, proper torque & torque sequence, and NO KNOCK is the key to having the stock gaskets hold."
As you can see the main theme of this is NO KNOCK!! You cannot allow any knock or detonation to occur at those boost levels!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Any that does will take out the best of head gaskets.
This means real good race gas (nothing less than 114 octane), no playing around with exotic mixtures, octane boosters, etc.
Good race gas, sneak up on the safest boost level, allow no knock.
I also do my own work, and whole heartedly agree with J Banning "I'm no professional, but I did the work myself and think good prep, proper torque & torque sequence, and NO KNOCK is the key to having the stock gaskets hold."
machinegun
Active Member
- Joined
- May 25, 2001
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I run 25 PSI and will be going higher. Stock heads and GM stock head gaskets with ARP head bolts. All is good so far. Of course no knock although we are going to turn it up a little. I put in a pair of billet mains in the center, and used ARP stud kit on the bottom end. Many people running 10's on this and that is where I will be going next year.
25 PSI is only part of the story.
25 PSI at 300dF MAT, is very different from 25 PSI at a 110dF MAT.
A small turbo and stock intercooler running 25 PSI, is always going to borderline on detonation. The Knock Sensor is not a perfect devise, so even a track undetected can cause problems.
25 PSI with a 60 turbo and huge front mount is alot more forgiving, and less likely to detonate.
I routinely run over 25 PSI with mine and it has over 140K miles on it. Thou, I have replaced the rods and mains. Even lifted a head one time from a steady diet of 28 PSI with too small of injector. No trace of detonation, but with larger injectors have lots of miles on dem old stock GM headgaskets, now.
The cruise tune has a HUGE effect on things also.
You spend a vast majority of time at cruise and few people really tune for it. Done right you can keep the oil temps down, and preserve the bottom end life.
boostcreep
New Member
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- Nov 30, 2001
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So how much of an oil temp drop did you see?? 10*?,20*?,30* or more?
Nick
Nick
I wound up seeing the difference in pressure. On a long cruise now on a hot day, I carry right at 10 PSI more oil pressure.
I had been playing around with the lean cruise stuff, and had broken 30 MPG, and just on a whim, tried backing way done on the timing to see the effect. ie I had been at 46d and dropped back to 28. MPG dropped instantly to just over 25.
I'd rather trade the difference in gas for longer engine life.
Plus the car can be tuned differently since it not so borderline on being in detonation.
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