The point I'm trying to make is, a lot of unanswered questions yet so eager to throw the machinist under the bus. Did I miss something?
what happened to these main bearings?
- Thread starter ryan319
- Start date
Lack of lube. Or in simpler wording the engine ran without oil pressure at some point. Could have been on initial startup or for a couple seconds under power. Fwiw the rods typically wont show the same wear as the mains since they require a lot less oil.
Could it be that
Your oil filter is the problem? Been following this thread and to my suprise no one has mentioned oil filter. Either one without anti-drain back provisions or not functioning giving you dry startups. I was involved with an engine that the mains were identical to these--rods were not near as bad (caught it early). These bearings have definately been run a short period without oil pressure.
Your oil filter is the problem? Been following this thread and to my suprise no one has mentioned oil filter. Either one without anti-drain back provisions or not functioning giving you dry startups. I was involved with an engine that the mains were identical to these--rods were not near as bad (caught it early). These bearings have definately been run a short period without oil pressure.
My vote goes to the previous detonation damage knocking the main bore out of round, as Chuck said. Machine the caps and align hone or bore/hone the block - it is very, very difficult to "check" if a block needs at least an align hone without just going ahead and honing it and seeing how much material comes off and where. Plus, with the fretting on those caps they won't seat as tightly in the registers and will be more prone to keep moving around, until you machine off all that damage. You might think about going ahead and stepping up to two center billet caps since you already need all the machining anyway, so the cost difference would just be the caps.
ok, last post until i get the parts to a machine shop. i was in the garage last night and noticed that the front galley plugs are threaded, and the passenger plug is sunk into the block a little. i shined a light through the #1 main passage and i could see a few threads of the plug in the oil passage. it wasn't completely blocked but i probably shouldn't be able to see any of that plug in the oil passage right? could that be enough to restrict the oil flow to the mains? i'm not real clear on how the oil travels through this engine.
everything on the oil pump checked out. i blueprinted it using the instructions on vortexbuick.
i'm hoping to get it back to the machine shop after labor day.
everything on the oil pump checked out. i blueprinted it using the instructions on vortexbuick.
i'm hoping to get it back to the machine shop after labor day.
- Joined
- May 28, 2001
Many yrs ago..
Jim Ruggles did my 109. The screw in plugs were a pet peeve of his. He said many do the mod, but don't machine the plugs to prevent blockage. The plugs he used were THIN!
He also described problems w/ the line hone process. Due to the short length of the block, the line hone bar can "flop around", and make the end bores bigger than the centers... He claimed that Sunnen had a trik to prevent this. Never did say what it was....
Jim Ruggles did my 109. The screw in plugs were a pet peeve of his. He said many do the mod, but don't machine the plugs to prevent blockage. The plugs he used were THIN!
He also described problems w/ the line hone process. Due to the short length of the block, the line hone bar can "flop around", and make the end bores bigger than the centers... He claimed that Sunnen had a trik to prevent this. Never did say what it was....
also
He also said to do a line bore right--need to torque heads with gasket on.
Jim Ruggles did my 109. The screw in plugs were a pet peeve of his. He said many do the mod, but don't machine the plugs to prevent blockage. The plugs he used were THIN!
He also described problems w/ the line hone process. Due to the short length of the block, the line hone bar can "flop around", and make the end bores bigger than the centers... He claimed that Sunnen had a trik to prevent this. Never did say what it was....
He also said to do a line bore right--need to torque heads with gasket on.
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
I had bearings like that once!
was because I didnt wash out the oil galleys after machining the crank before assembling. crank was full of shavings.
A.j.
was because I didnt wash out the oil galleys after machining the crank before assembling. crank was full of shavings.
A.j.
- Joined
- May 28, 2001
Yep..
I've been on both sides of the fence...
B4 I became a mechanic, I was a brain surgeon..
The ONLY problem I have w/ this particular shop is, they decided it was a problem based on what they were told during a fone call...
look how many "opinions" that have been offered here, and we can at least see some pictures.
I've been on both sides of the fence...
B4 I became a mechanic, I was a brain surgeon..
The ONLY problem I have w/ this particular shop is, they decided it was a problem based on what they were told during a fone call...
look how many "opinions" that have been offered here, and we can at least see some pictures.
I think that the HV pump did contribute to this problem. Mainly the cold start pressure being too high. My shop mentioned that when oil pressure is too high it can actually push the crank down into the main bearings in the cap.
I talked to the local GN expert, JaysGN, and he strongly advised against the high volume pump. A lot of people talk bad about the oiling systems in these cars but there are a lot of stock shortblock turbo 3.8's running around with well over 100K miles. The oil system only seems to be a problem when people start messing with it. I will for sure be setting my clearances around .002 (again) and running a stock oil pump.
Other than that, my block, pistons, and 5 rods look OK. I should only need to cut the crank .010, size a rod, and bore the line with some billet caps to be back in business. I sent the turbo back to Limit just to check it. It only has 800 miles on it but a lot of material could have gone through it. I'm also going to eliminate the stock oil cooler.
I talked to the local GN expert, JaysGN, and he strongly advised against the high volume pump. A lot of people talk bad about the oiling systems in these cars but there are a lot of stock shortblock turbo 3.8's running around with well over 100K miles. The oil system only seems to be a problem when people start messing with it. I will for sure be setting my clearances around .002 (again) and running a stock oil pump.
Other than that, my block, pistons, and 5 rods look OK. I should only need to cut the crank .010, size a rod, and bore the line with some billet caps to be back in business. I sent the turbo back to Limit just to check it. It only has 800 miles on it but a lot of material could have gone through it. I'm also going to eliminate the stock oil cooler.
[QUOTE=ryan319;2585836. My shop mentioned that when oil pressure is too high it can actually push the crank down into the main bearings in the cap. I can buy this cause my main bearings in the cap where a lot worse than the ones in the block.
Another case of the shop telling you anything. Think about it. Why would the bearings in the block ever show wear? ALL the load is on the cap bearing--always trying to push the crank out the bottom.
Another case of the shop telling you anything. Think about it. Why would the bearings in the block ever show wear? ALL the load is on the cap bearing--always trying to push the crank out the bottom.
Lol. Thats some funny chit
