Could this be the reason for low compression? [PICS]

zZsKyZz

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Dec 1, 2005
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I baught this engine with 29k on it for $150. It's stock besides maybe the camshaft. The guy told me he had it compression tested and these 2 cyl had 30. I took the head off and noticed that the metal in the head gaskets between the two cylinders was blown apart.. Here's the pics:


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the deck and head need to be checked for flatness especially in the area of blowout...can you post pics. of the bottom of the head? alot of things can cause that flatness as described above inproper torqueing,reusing old head bolts,cheap or bad head gaskets, inproper install,reusing a headgasket that was torqued loosened and retorqued..i would have a machine shop check flatness and fix if needed and reinstall...that is if bearings inside were'nt destroyed by antifreeze.
 
engine bearings, did antifreeze enter the crankcase,i dont see how it did'nt have you checked the engine oil for antifreeze oil will look like chocolate milk and leave a white foam under the oil cap..
 
Buddy of mine blew a HG like that after running dozens of bottles of n2o threw his stock 100K+ mile 87 mustang with a 150 shot on it. It didnt get any antifreeze/oil mixing or at least did not get to that point. He drove it around for a good bit too and took it to the track and ran a friggan 13.9 or some BS. The times had us thinking the problem was elsewere since he had noticed some issues. cleaned up the block really well and had the heads milled and ran fine.

BTW this car was a FREAK....bone stock (bought it off his mother) it ran a 13.9 @ 100 with everything stock...air silencer, gears, timing, air filter...it even had a role of paper towels jammed up between the airfilter and air silencer. Beat the tar out of ALOT of cars it should not have.
 
blksn955.o said:
Buddy of mine blew a HG like that after running dozens of bottles of n2o threw his stock 100K+ mile 87 mustang with a 150 shot on it. It didnt get any antifreeze/oil mixing or at least did not get to that point. He drove it around for a good bit too and took it to the track and ran a friggan 13.9 or some BS. The times had us thinking the problem was elsewere since he had noticed some issues. cleaned up the block really well and had the heads milled and ran fine.

BTW this car was a FREAK....bone stock (bought it off his mother) it ran a 13.9 @ 100 with everything stock...air silencer, gears, timing, air filter...it even had a role of paper towels jammed up between the airfilter and air silencer. Beat the tar out of ALOT of cars it should not have.

very insperational... thanks man :nice:
 
zZsKyZz said:
how would the bearing be destroyed by the antifreeze? wouldn't it just lube it?
Antifreeze is generally ethelene glycol (an alcohol) mixed with water. The bearings in your engine are hydrostatic (meaning the bearing doesn't rotate, but there is a film of oil that is what carries the load).

Basically, the antifreeze first can displace the oil at the crank, connecting rod, or whatever bearing. At that point, since the antifreeze has a lower viscocity than oil, the crank will sink and physically touch and rub the bearing. This would ruin bearings and hurt the crank. If the antifreeze goes away (my guess would be due to the heat of friction from the crank and the bearing), more heat ensues and voila, seized engine.