Screwed up! Now what?

Lower End Assembly

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Schwee
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Screwed up! Now what?

#1

Post by Schwee » Mon Oct 08, 2018 3:01 pm

I screwed up a couple of years ago when I put my WLA lower end back together.
I didn't seal the cases with anything.

The motor runs so well that I hate to take it all the way back down, although I plan to pull it to do some painting.
It's has less than 1000 miles on the rebuild, but it's seeping oil.

Any way to seal the motor cases from the outside?



liberator
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Re: Screwed up! Now what?

#2

Post by liberator » Mon Oct 08, 2018 3:36 pm

As you mention yourself: to do things right you have to pull the cases apart.
You can seal/ smear some sealant on the outer seam, but that won't look nice and probably won't last too..

If you have the motor out, just loosen the basenuts from the cilinders and remove the casebolts.
You should be able to pull the cases apart just a bit (a few millimeters or thou) without loosing parts.
Just enough to degrease and seal the seams.

RUBONE
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Re: Screwed up! Now what?

#3

Post by RUBONE » Mon Oct 08, 2018 4:08 pm

If you have the motor out, just loosen the basenuts from the cilinders and remove the casebolts.
You should be able to pull the cases apart just a bit (a few millimeters or thou) without loosing parts.
Just enough to degrease and seal the seams.
If you attempt this be aware that if the crank thrust washers come off the locating pins (one or both can occur) they will seize the crank when the cases are bolted back tight. Personally I would not take the chance.

guppymech
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Re: Screwed up! Now what?

#4

Post by guppymech » Tue Oct 09, 2018 12:29 am

Schwee wrote:
Mon Oct 08, 2018 3:01 pm
I screwed up a couple of years ago when I put my WLA lower end back together.
I didn't seal the cases with anything.

The motor runs so well that I hate to take it all the way back down, although I plan to pull it to do some painting.
It's has less than 1000 miles on the rebuild, but it's seeping oil.

Any way to seal the motor cases from the outside?
I have sealed minor leaks at seams on the outside with success. Get some Pematex Ultra Black (or Gray if they make it) and clean the cases very good and apply the RTV in a flat band over the case seam extending 1/4-5/16 on each side and about 1/8 inch thick. Let it dry overnight. Hopefully it won't show too much. What have you got to loose?
You can smooth RTV without it sticking to your finger or a tool if you put some oil or petrolatum on whatever you are using to smooth it with and it won't interfere with the cure.

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