When my engine was first rebuilt the heads had to be redone. The valve seals let go and the high oil consumption cause the valvestems to become coated w/carbon and that wore out the valve springs. Now my engine has a bad rear mainseal. Since I have to drop the pan anyway, should I pull a piston and see it rings are frozen? I want this engine to be 100% before I make any more changes/improvements. Any thoughts? TIA

Rick west

 

Let me get this straight!:) Did you just have the heads refreshed and you left the short block in tact?

A piston can feasably come out the bottom, but your never going to be able to put it back in because the ring compressor won't fit up to the bottom of the bores with the main caps in the way.

Th other thing is I wouldn't even attemp a rear main seal with the motor in a car. You have to separate the flex plate/ tranny

 

Having a 4 speed doesn't really matter. You would have to separate the tranny from the motor. So if you pulled the tranny out and down. Then you remove the starter motor and the flywheel. It's also best to support the rear of the block with a crane type hoist. So you can move the motor rear up and down and take less of a chance breaking a rubber motor mount.

Once you got the pan off - Then oil pump - then rear crank shaft main cap.

It would be feasable to push or pick the upper half of the seal out from between the crank and the block. Then just read the directions on how to position it when installing the new one.
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The more I think about it the less I'd try even want to try a rear seal in a car. I'd leave the tranny in and supported by a floor jack and just pull the motor and flywheel as a unit first.


Two things that I do to knock sludge and carbon out of an old motor is. With the motor hot and running at 2500 rpm slowly start pouring a gallon jug of distilled water down the carb. Just pour at a rate that doesn't kill the motor.

2. Drain the oil and replace the filter with a cheap one while the motor is still hot. Then I dump in a 6 quarts of diesel fuel in the crank case and fire it up and let it idle for about 2 minutes. Shut it down and you wouldn't believe the black scum the comes pouring out. Let it drip and dry till cool and refill with what ever oil weight and new filter you use.

The water knocks nearly all of the carbon out of the top of the chamber and the diesel acts like a solvent to clean out every thing below the rings. I've done that to old motors before tearing them down and they are just like they came out of a solvent tank wash on the inside.

 

I had oil leakge from the bottom of my intake into the cylinders on my new engine and when the engine was pulled after 1300 miles, the engine builder said the pistons looked like they were out of a 70kmile engine, too much oil in the cylinders is bad for the rings and it polishes the cylinder walls to be really slick too.