7Bolt Rebuild Question

[G9S1X]

Hey, my friend bought a 1995 GSX for 3,500 with a blown headgasket. ARP head and bottom end hardware, not sure what type of rods, and 9.5:1 JE .20 pistons. I took off the head and sent it out for a complete rebuild, checked for block deck warpage and its fine. Looked a the head gasket and saw that the lip of the CC area of it is a little deteriorated.

Now heres where it gets ugly. Dropped the oil pan and I see a tangled bearing in the oil pan WTF . I can tell its a balance shaft bearing so I tried to wiggle the balance shafts and sure enough they both have tons of play. Bottom of the pan was all silver. So were gunna eliminate the balanceshafts. Then were taking out the pistons and honing the bores and check for cracks / pits because there is rust in there. My question is do you think the block is trashed? Looks like it lost oil pressure from the balanceshafts and just took a dump. I took a look at one rod bearing and it didn't look bad.

I will take pictures of all the rod & main bearings and see what you guys have to say. But is there anything else that needs to be checked on the block for wear?

 

[skier_du]

If you're going to have problems with anything on a 7bolt rebuild, it will be the thrust bearing. The thrust is especially susseptible to low oil pressure. Make sure that the thrust is not worn from the low oil pressure and that there is addequite pressure after you put it back together. Allso check to make sure the thrust is not only centered, but is flat. I have seen more than one 7bolt rebuild have the problem of the thrust being centered, but not even, and crankwalk was shortly followed.

 

[Big Woo]

If you want to check the crankshaft endplay, you will need a dial indicator and a means to mount it such as a magnetic stand. Place the indicator so that it is parallel to the long axis of the crank, lightly hold the crank in either the full forward (drivers side) or rearward (passanger side) position and zero the indicator. Then move the crankshaft in the opposite direction and read the amount of travel on the dial indicator. compare this number with the specifications found in the manual.

The block may or may not be junk, you will need to install some new bearings (rotated so the the oil passages do not line up) or block-off bearings in two of the balance shaft bearing housings, if doing the balance shaft removal. Make sure these bearing press firmly into place.