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Is My Crank Finished (or where did my oil pressure go)

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Blown&Injected

Active Member
Joined
May 31, 2001
Messages
3,721
Had an oil pressure problem so I started on an oil pump and front cover replacement. Pulled the oil pan to Plastigauge the center mains and perhaps some rods.
Well
The second from the back, main cap comes off and the bearing is showing some scoring and there is some copper showing.

I knew I was in trouble as I could see a gold sparkle like ribbon in the oil when the last few ounces drained from the pan.

The main crank journal looks dirty.

The engine was running great when I took it off the road for repair. No knocking from the engine and since I use GT-100, I was getting no KR on my scan tool so I do not think I beat it up to bad.

What should I do?
I guess I should inspect more of the main and rod journals.
Would it be a rotten thing to just put new bearings in and keep an eye on the oil pressure?
 
Steve, you're almost halfway there. Install new bearings. Get Clevite MS-960P. Easy to do. Mains only cost a few dollars. Rod bearings, if you're changing them, are CB-1443P....wider style. Better than a total rebuild which takes time and quite a few dollars more. You'll be back to new. Enjoy your car. Drill out the upper main bearing shell oil holes to 9/32" for more oil flow. "Dirty" sounds like oil starvation". If you have any questions, let me know. ;)
 
Cool.
Thanks John.
I failed to mention that when I did a rebuild the crank was turned 10/10 so are the part numbers you listed the still ones I need based on the 10/10 I just mentioned?
Thanks again.
 
Steve, they would be the same numbers but would read like this......MS-1443P-10 & CB-1443P-10. Changing the bearings in the car is not hard and by enlarging the oiling holes may prevent this from happening again. If the crank has any slight imperfections from bearing debree, just polish it up with some crocus cloth or 600 grit or finer wet or dry sandpaper. IMO, things aren't perfect anymore, so need going crazy measuring your clearances. You'll be happy to have great oil pressure again when you've completed the bearing change. ;)
 
>>Get Clevite MS-960P. Easy to do. Mains only cost a few dollars. Rod bearings, if you're changing them, are CB-1443P....wider style.<<
>>but would read like this......MS-1443P-10 & CB-1443P-10.<<

Thanks for the tip about polishing the journals with 600 or finer sand paper. I was thinking about doing just that.

The first part number appears to differ from the other numbers. Are the last two, 10 thousandths over sized, the correct numbers for both the rod and main journals?

Also, will this do just the two center main journals? What about the front and rear journals? I would like to get it all while I'm in there.
 
Yeah, I messed up on the numbers.........forgot the mains. Mains would be MS 960P-10. The 10 applies to .010 under cranks. This is a complete main bearing set........all 4. No problem changing them all. Front is easily assessable by turning the crank for better view. Don't change the rear main seal but you'll have to fill the rear main cap grooves again with sealer.
 
Red Regal T's right on the money...I just wanted to chime in on another point...

While you have the pan off, BE SURE to inspect the oil pickup. It's easily covered/partially covered with debris over the years. Since you're in this far, remove it and thoroughly clean and inspect it to make sure the screen is free of foreign objects. A replacement for the small gasket can be easily found. When re-attaching the pickup, be SURE to use LocTite on the two small bolts.

BTW, how did the front cover/oil pump look?
 
Local parts place says MS 960 P-10 is for a carburetor engine, says his book shows 1747 P-10 for the mains, and lists CB 1228 P-10 for the rods.

Yeah, I did pull the pick up. Not to much stuff on the screen for all the chips I found in the pan.

The front cover had some scoring but I had a hard time getting a .002 feeler gauge in-between the tips of the gears and the side of the cavity in the front cover where the gears sit in. The edge of the gears are dead even with the surface of the cover - there is some scoring on the oil filter plate too.
 
First of all, I didn't put out the wrong Clevite numbers. Your parts guy is wrong. MS-960P is for the turbocharged 231 and the CB 1443P is the wider rod bearing. If you don't want the wider bearing for more bearing area, 1228P would be the number. Numbers are correct as I designated. If you don't want to have a problem, such as, wrong bearings, use the bearings I suggested.
 
Thanks John, just wanted to be sure I got the right stuff and the guy at the parts store was so sure - he double checked :rolleyes:

I'll take your word on the numbers.
 
The MS 960P is the first bearing listed in the book for turbocharged motors. It can also be used for carbeurated versions. I've used these numbers numerous times. The book also shows the 1747P main bearings for turbocharged motors. I guess both numbers are good. The rod bearings are as I explained. ;)
 
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