cometic gasket failure
02-08-2006, 01:54 PM
#16
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My S4 is the best kind...UrS4! Nobody will ever get the same reliable HP per liter off a 928 motor to begin to compare to the Audi AAN's potential! Perhaps the best car I have ever owned?
You must weigh in that these are old engines we talk about...decks and heads are not perfectly flat and most are not decking their blocks anyway. I'm still considering an upgraded gasket, but I'll most likely stay stock. The stock gaskets can compensate for the small imperfections in surfaces.
I should have my motor pulled out and torn down in the next 3-4 weeks. Been fitting models of IC this week! Now if it wasn't for this pesky 4.7 liter I promised to build!!!!
You must weigh in that these are old engines we talk about...decks and heads are not perfectly flat and most are not decking their blocks anyway. I'm still considering an upgraded gasket, but I'll most likely stay stock. The stock gaskets can compensate for the small imperfections in surfaces.
I should have my motor pulled out and torn down in the next 3-4 weeks. Been fitting models of IC this week! Now if it wasn't for this pesky 4.7 liter I promised to build!!!!
02-13-2006, 01:06 AM
#17
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So, it seems that the general consensus is that:
The cometic gaskets have had issues but they have been resolved in our application up to 10lbs boost in our rear mounted turbo and.....
so long as we ensure the mounting surfaces as flat and matched, we should be ok...
Thanks everyone,
JT
89 red S-4
The cometic gaskets have had issues but they have been resolved in our application up to 10lbs boost in our rear mounted turbo and.....
so long as we ensure the mounting surfaces as flat and matched, we should be ok...
Thanks everyone,
JT
89 red S-4
02-04-2012, 04:03 AM
#18
I totally agree with you.As a matter of fact in a 3,0 s2 motor that i turbocharged 10 years ago (and still running) i enclosed a 2mm inox spacer within two reinz wide fire ring gaskets,crashed with a set of RACEWARE studs,and pushed it up to 1.6 bar and once 2.2 bar with no problem BUT, 12:1 air,fuel ratio 30% toluene in 95 octane fuel,and 15 degrees timing under boost (8,3:1 cr), no issue so far!
You know Porsche 956.,and Toleman Hart engines had no head gaskets, the heads were casted in Porsche with the barrels and in Toleman with the blocks and under detonation valves, valve seats ,pistons, liners were torched down, even con rod bearings were deformed.There is no way you can face detonation.Finally look at modern turbo engines.compared to lets say the turbo engines of 80"s are inferior check a 930 , 951 valve(sodium filled nimonic) or piston,look at an 81 928s piston ,an 85 audi 5000 turbo piston and compare it with a Subaru ,or EVO or VW group or even with a modern Porsche,The difference lies in the fact that the electronics kept the plague of detonation away.P.S back in 1986 i bought a 951 and 931 racing gaskets from Holbert Racing in P.A. The 951 was a regular wide fire ring 2mm with water passages to the exhaust ports sides only,The 931 looked regular stock but it had nitrogen filled fire rings both Porsche Racing Reinz items.
You know Porsche 956.,and Toleman Hart engines had no head gaskets, the heads were casted in Porsche with the barrels and in Toleman with the blocks and under detonation valves, valve seats ,pistons, liners were torched down, even con rod bearings were deformed.There is no way you can face detonation.Finally look at modern turbo engines.compared to lets say the turbo engines of 80"s are inferior check a 930 , 951 valve(sodium filled nimonic) or piston,look at an 81 928s piston ,an 85 audi 5000 turbo piston and compare it with a Subaru ,or EVO or VW group or even with a modern Porsche,The difference lies in the fact that the electronics kept the plague of detonation away.P.S back in 1986 i bought a 951 and 931 racing gaskets from Holbert Racing in P.A. The 951 was a regular wide fire ring 2mm with water passages to the exhaust ports sides only,The 931 looked regular stock but it had nitrogen filled fire rings both Porsche Racing Reinz items.
