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Discussion Starter #1
OK, I've been visiting this forum for a while now and enjoy how everyone offers up good advice when someone has a question. I'm running a 1969 Cougar 428SCJ (3:90 rear end, build Feb '69) with close ratio 4 speed (no's match). I just picked it up and thought I'd pull the pan to take a look at the bottom end.

Here's my question. The engine is still in the car. I plan to inspect the mains and rods bearings and would like to know if there are specific bearings I should look at? Should I not look at #5 (rear) so I don't have to replace seals? What about #3 thrust? Should I support the crank with a jack to prevent sag and false readings on the plastigage? Can I "over lift" the crank into the upper (block half) bearing and also create false readings? What about a tool to help remove the upper bearing? I've heard of a tool to insert into the crank oil gallery to "rotate" the upper bearing out and in. Where could I get one or has anyone fabricated a mock-up?

While I've got my hands in the bottom of the engine can anyone give any advice on what to look for in the bottom end of the cylinders? From my crude measurements it appears this block has had a 0.040 overbore. I can still see some hone marks. Cylinder #6 has a sleeve (yikes!):eek2:
 

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1. A properly done sleeve job is actually stronger than the original bore.
2. How many miles does the engine have? Is there anything to warrant inspecting the bearing (low pressure, knocks etc).
3. If warranted, do it right and pull the engine. Between the mains, rod, thrust, and miccing the crank, you need to be precise. On your back in the confines of the block is not the way to do it.

It may be fine and no doubt you'll get the "Yeah, I did it with no problem, even turned the crank .020 under while I was down there" reply, but why shadetree it to save four hours on a R&R. Besides, if it does need work, it's already out.

If it is running fine - "if it ain't broke, don;t fix it" my .02
 

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i agree pull the motor its allot easier and more precise
 

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Discussion Starter #4
Thanks guys. I agree with your thoughts on pulling the engine to replace bearings. :D I would still like to know though anyone's thoughts on checking bearing clearances (plastigage) while the engine is in the car. As well what about visually inspecting the bearing surfaces and cylinder walls? Is there anything that I should be looking for to prevent any catastrophic failures?

There is no current engine noise (not sure of the mileage from last overhaul); however, with this block and bottom end (SCJ) I dont want to take anychances! Any advice or personal experience is appreciated!
 

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Re: Replace bearings

Check #7 and 8 rod bearings. They are last to get any oil. If the motor is run low of oil, then run hard, #7-8 are usually the ones that get the "cooked bearings" or worse.

I've replaced bearings in the car, believe me, it's MUCH easier than pulling the motor and dealing with CJ manifolds.
 

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Discussion Starter #6
Thanks Art! I checked #7 and #8 bearings and they look good; there are no areas of wiped out overlay, polished sections, scoring, pockets or craters. There are a few scrathes from dirt but no imbedded dirt areas. Pretty good I'd say. Bottom line, plastigage readings are within in the tolerances (0.002-0.003).

You said you've replaced bearings with the engine in the car. How did you get the upper bearings out? Did you rotate them out with a tool in the crank oil journal?:confused: Just curious, I am. :rolleyes: For sure the CJ manifold with headers is a pain in the a$$. My headers have #1, #2, and #5 tubes come forward and down under the front linkage and all the rest out and down the back. For sure - headers removed, installed in the car!:cry:
 

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Discussion Starter #8
Calgary, Home of the greatest outdoor Stampede and Rodeo!
 

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If your going to "roll" the upper brgs out, loosen all the main caps so the crank can drop a little. Before anyone goes nuts let me say that I have done this alot and am carefull doing it. (very common on tractors where otherwise you have to split the tractor into 3 pieces to remove the engine) I use a popcycle stick to push the brg out some, and if not then I CAREFULLY use a flat blade screwdriver to get it going. Useally you can then roll it out with your fingers.

By all means if you go this route go ahead and replace the rear seal while your at it. You dont want to pull the pan and do it again later. mm
 

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Re;Re: Replace crank bearings

Cougar428scj said:
You said you've replaced bearings with the engine in the car. How did you get the upper bearings out? Did you rotate them out with a tool in the crank oil journal?
As Modified Mark says, loosen all the main caps, let the crank drop a minute amount. Push the upper shell from the opposite side of the locking tang, once it breaks free, they roll out easy.

Be extremely careful with sharp objects on the crankshaft journals. One little nick will wipe out bearings in short order! I use a paint stirring stick to start the upper shells out. Replace the rear main seal while you are there, you'll regret it if you don't!
 
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