Drivend
Probationary Member
- 15
- 0
- Jul 5, 2004
-
Palmyra,
Virginia
I bought a 91 GSX about six months ago. It had lots of aftermarket goodies on it. I paid 3K, thought I got a good deal. It ran well in first, second, and fifth, but had a bad trans. Since then I've gotten a used trans, and been waiting on my Hotbits coilovers(which look pretty nice, by the way 
). I was changing the balance shaft belt, trying to get the crank timing gear loose. It seemed to be moving back and forth. Upon closer inspection it seemed like a massive case of crankwalk(about 1/8th inch movement. Today, I pulled the oil pan to see what things looked like. I pulled all the main caps. The thrust bearing cap told the story. The crank is chewed up like mad on the rearward face of the bearing. The bearing doesn't look so hot either, but the other two/or four(depending how you look at it ) caps showed no sign of abnormal wear, and I couldn't see any substantial damage to the crank other then in the thrust bearing cap area. On this cap, the rear face is just slightly scared to the outside of the bearing seat. The bearing can be removed from the cap with the typical amount of effort, the bearing seat is undamaged. I wonder if this block is still usable, provided it's not cracked, or out of spec in some other area? I'm hoping it is, mind as well do a stroker being that the crank, rods and pistons need to be replaced. A little missing metal shouldn't hurt anything, should it? I wouldn't think so, but some of you may have first hand experience with these kind of issues.
As to why it walked, I found that the balance shafts(which were supposed to have been removed
) were timed out of phase, and the motor appears as if it was the victim of a shade tree mechanic rebuild. One rod was replaced, a re-ring, and new bearings and I believe they called it good, from the looks of it.
I've also got a line on a g4cs motor, the guy said the motor is bad, but I don't know exactly what went on it, yet. I'll have to call him back Monday. Does a broken timing belt typically require a replacement of the crank?
Any advise would be greatly appreciated.
Dan
). I was changing the balance shaft belt, trying to get the crank timing gear loose. It seemed to be moving back and forth. Upon closer inspection it seemed like a massive case of crankwalk(about 1/8th inch movement. Today, I pulled the oil pan to see what things looked like. I pulled all the main caps. The thrust bearing cap told the story. The crank is chewed up like mad on the rearward face of the bearing. The bearing doesn't look so hot either, but the other two/or four(depending how you look at it ) caps showed no sign of abnormal wear, and I couldn't see any substantial damage to the crank other then in the thrust bearing cap area. On this cap, the rear face is just slightly scared to the outside of the bearing seat. The bearing can be removed from the cap with the typical amount of effort, the bearing seat is undamaged. I wonder if this block is still usable, provided it's not cracked, or out of spec in some other area? I'm hoping it is, mind as well do a stroker being that the crank, rods and pistons need to be replaced. A little missing metal shouldn't hurt anything, should it? I wouldn't think so, but some of you may have first hand experience with these kind of issues. As to why it walked, I found that the balance shafts(which were supposed to have been removed
) were timed out of phase, and the motor appears as if it was the victim of a shade tree mechanic rebuild. One rod was replaced, a re-ring, and new bearings and I believe they called it good, from the looks of it. I've also got a line on a g4cs motor, the guy said the motor is bad, but I don't know exactly what went on it, yet. I'll have to call him back Monday. Does a broken timing belt typically require a replacement of the crank?
Any advise would be greatly appreciated.
Dan
