E9 Questions

[Superdog]

My son just bought a '88 Superliner with a "blown"E9-500.He got it home Friday and tore it down and found the problem was a spun rod bearing.What would be the best cost effective fix?Having the crank turned and go with oversize bearings,or have it built up then turned?I suggested pulliing it out and putting a 6 cylinder in but he wants to keep the V8.

[Rob]

My son just bought a '88 Superliner with a "blown"E9-500.He got it home Friday and tore it down and found the problem was a spun rod bearing.What would be the best cost effective fix?Having the crank turned and go with oversize bearings,or have it built up then turned?I suggested pulliing it out and putting a 6 cylinder in but he wants to keep the V8.

Also have the block "align honed" through the main saddles when it is apart. A good portion of the time with a "spun" rod bearing the main saddles are out of alignment from the torsional stress placed through the block.

I've had crankshafts "spray welded" and conventional welding for building up a journal for the same reason. I've found you need to ensure the magnaflux capability is closely scrutinized and not just glazed over. Small fatique cracks in crankshafts can come back to haunt at a later time.

I've gone .030/.030 on rods and mains undersize with inline diesel engines, but have never been into a Mack V8, no matter the series.

Rob

[b61fred]

Mike,

Is the engine completely removed and tore down or is the low end removed in chassis? I would have the crank turned down, If you think about it if it is turned down .020 thats only 0.010 on each side, less than the thickness of a finger nail of materal will be removed. Plastgage the crank to make sure all the clearance is correct. If the engine is out I would have it line-honed just for safety. I have been told these engine are a joy to run untill you have to work on it.

B61fred

[Superdog]

Mike,

Is the engine completely removed and tore down or is the low end removed in chassis? I would have the crank turned down, If you think about it if it is turned down .020 thats only 0.010 on each side, less than the thickness of a finger nail of materal will be removed. Plastgage the crank to make sure all the clearance is correct. If the engine is out I would have it line-honed just for safety. I have been told these engine are a joy to run untill you have to work on it.

B61fred

It's still in the truck right now,he just dropped the pan to find the problem.Was trying to decide on the best method to repair.I'm with you on having it turned down.

[b61fred]

Mike,

It was a rod bearing and not a main, and you are trying to get by as cheap as possible, I would say your block is OK for now. The rod is more than likely trashed, The thing to look for is why she spun. There's usualy a few things that can take out a bearing, antifreeze contamination, lack of lube, or cavitation. Check the other bearings and see if the brass is shown, could be that the bearing was starved of oil because the oil clearance was to great causing the oil to leak out of the gap between the crank and rod bearing. Cavitation will look like little craters in the rod bearing surface, with the displaced metal imbeded into the lead of rest of the bearing. This is the final stages before the bearing fails. You will see this on the other bearings in the engine. This is caused by excessive oil clearance. Contamination will look like the bearing metal is flaking off. I guess the min. work would be to pull the head, remove the damaged rod/piston assy, replace rod, remove crank and have it machined and check the condition of all the other bearings, check the condition of the oil pump and reassemble. As much as that would cost I think it would be good sence to remove the engine, re ring, and check it all out. You really don't know much about the truck at this point. I would hate to see someone throw good money at a totally worn out engine.

b61fred

[fjh]

Mike,

It was a rod bearing and not a main, and you are trying to get by as cheap as possible, I would say your block is OK for now. The rod is more than likely trashed, The thing to look for is why she spun. There's usualy a few things that can take out a bearing, antifreeze contamination, lack of lube, or cavitation. Check the other bearings and see if the brass is shown, could be that the bearing was starved of oil because the oil clearance was to great causing the oil to leak out of the gap between the crank and rod bearing. Cavitation will look like little craters in the rod bearing surface, with the displaced metal imbeded into the lead of rest of the bearing. This is the final stages before the bearing fails. You will see this on the other bearings in the engine. This is caused by excessive oil clearance. Contamination will look like the bearing metal is flaking off. I guess the min. work would be to pull the head, remove the damaged rod/piston assy, replace rod, remove crank and have it machined and check the condition of all the other bearings, check the condition of the oil pump and reassemble. As much as that would cost I think it would be good sence to remove the engine, re ring, and check it all out. You really don't know much about the truck at this point. I would hate to see someone throw good money at a totally worn out engine.

b61fred

Which bearing failed #1 And Number 8 the rod can be removed from the bottom with out disturbing the heads! pull the crank and have it checked and ground 20 under get 20 over bearings and your good to go as long as you can varifiy you have no leaky liners! Have done this a few times.