Chris Harris & GT PORSCHE
12-26-2007, 09:22 PM
#47
Nordschleife Master
I bought a car that had a 4.7L with a cracked cylinder liner, this was caused by a failed HG and hydrolocked the cylinder. The entire block cracking though. nope.
12-26-2007, 09:34 PM
#48
928 OB-Wan
Rennlist Member
Rennlist Member
GTPP has been back and forth on 928s since they started... nothing surprises me with them anymore, the main reason I won't buy their rag
blown hg turned this 79 engine into a coffee table... literally
blown hg turned this 79 engine into a coffee table... literally
12-26-2007, 09:50 PM
#49
Race Director
okay this guy is totally clueless....... Now if he said "prone to timing belt failure" (which is due to a lack or servicing) then I might think he know 5% about 928's......
I would venture a guess that this guy only knows of 1 928 owner (possibly himself) that had a cracked block (how I dunno).....
I would venture a guess that this guy only knows of 1 928 owner (possibly himself) that had a cracked block (how I dunno).....
12-27-2007, 01:11 AM
#50
Addict
Rennlist Member
Rennlist Member
I have two 928 blocks in garage which suffered serious cracking problems. At least one was caused by head gasket failure. This allowed water to leak into combustion chamber and was away oil film from cylinder wall. This in turn heated up piston which then cracked cylinder in nice straight vertical line either at 12 o'clock, 6 o'clock or both when looking cylinder from above on exhaust side. It seems on at least one cylinder crack started in middle of cylinder tower but did not reach all the way to the top. On other cylinders crack lower end is about same position while they get to all the way to top.
If he is worried about cracking block because of head gasket failure perhaps he better leanr to look for signs if this problem. Exact same thing will happen in 944 and 968 if they are abused same way. Especially in 3L blocks it might take more abuse as blocks are better designed but it really doesn't change the fact that root cause is head gasket failure which should be seen much sooner than block has any possiblity to crack.
If he is worried about cracking block because of head gasket failure perhaps he better leanr to look for signs if this problem. Exact same thing will happen in 944 and 968 if they are abused same way. Especially in 3L blocks it might take more abuse as blocks are better designed but it really doesn't change the fact that root cause is head gasket failure which should be seen much sooner than block has any possiblity to crack.
12-27-2007, 06:58 AM
#51
Rennlist Member
