#3 Cylinder problems

[turboh224g]

I am relatively new to sr's but have pretty much general engine knowledge. I have built several turbo honda setups for myself and friends. I have recently picked up 3 cheap sr blocks that all need rebuilding. On all three the problem was in #3 cylinder. I have also read about several other people having problems and is seems to be the #3 cylinder most of the time. I am curious to know why this is? More importantly what can be done to keep this from hapening and result in a reliable rebuilt sr? Any help would be greatly appreciated. Thanks,
JKP

[Suk02Si]

What's the problem, low compression, spun bearing? If its low compression, maybe its because of the garbage head gasket that Nissan throws on there.

[turboh224g]

two of the blocks have scored cylinder walls and the third has a spun bearing. I also have a fourth that threw a rod, #3 cylinder, really wondering why #3? And what to do to keep it from happening in the future. Thanks,
JKP

[RedtopTech]

i lost fuel pressure while running a 75 shot of nitrous. The only damage occured on cylinder three where the piston got burned right past the rings and the sleeve got trashed. No other cylinders showed any sign of detenation. I stepped out as soon as it occured and putted 1.5 miles back home. My theory is that there is some design aspect that causes higher EGT on cylinder 3 compared to the others such as coolant routing, airflow through the manifold, or heat soak.
At first i was upset at myself for not keeping an eye on the wideband and fuel pressure(which i always check before using the nitrous) but then i looked on the bright side....time for forged internals!

[slim]

i know someone that melted the side of the #3 piston. the car always smoked a little then one day it finally became a smokescreen. we ripped it apart and found one side scored really bad and that side of the piston was melted. sounds kind of like the same problem.
lack of oil to that piston?

[turboh224g]

I tend to agree that there is some design flaw that causes cylinder #3 to be weak. You are all confirming this by listing your problems with the same cylinder. Does anyone know what the actual problem is and how it can be fixed? If it is an oiling problem does higher volume pan and seperate oil cooler do it. Or if it is a cooling problem, a larger volume radiator with a higher pressure cap? Someone has to know. Thanks,
JKP

[georgesal]

no #3 cylinder tends to go bad because the turbo sits right next to it. more heat soak in the area of cylindr #3 so more wear.

[bardabe]

^^^^^ DING DING DING He's right on the money, its also where the water lines are for the turbo off the cylinder 3 sleeve. so its definetly running hotter more prone to detonation it happened ot me with 2 SR's =)

[turboh224g]

That makes a lot of sense. If that is the case does going to a top mount manifold solve this? Should I also switch to just an oil cooled turbo so I am not heating up the coolant even more? Thanks,
JKP

[Dream240]

I am relatively new to sr's but have pretty much general engine knowledge. I have built several turbo honda setups for myself and friends. I have recently picked up 3 cheap sr blocks that all need rebuilding. On all three the problem was in #3 cylinder. I have also read about several other people having problems and is seems to be the #3 cylinder most of the time. I am curious to know why this is? More importantly what can be done to keep this from hapening and result in a reliable rebuilt sr? Any help would be greatly appreciated. Thanks,
JKP

3 engines....3 problems....in the 3rd cylinder....

You're halfway to hell.....have fun. :o