Pressure related question

[bcgreen]

Excuse me if I have posted this question in the wrong area.
This is an old subject, #8 bearing leak, and a lot of the people who were involved in this temp. fix years ago, are no longer active on this subject. Right off the bat I want to say this type of fix is only temporary and the only true way of fixing this is just add $$$ and split the case.

Now on to my question. I am using a alum. collar with a rubber nitrile 'O' ring with a sealant. Using pressure on the ring to squeeze the rubber gasket against the block prior to tightening the set screws is important.
How much pressure?

Should I use the same pressure as one would use on torqueing down a case? It would seem to me that using a right amount of pressure should be an important part to stopping any possible leak rather than just hand pressure.

[bcgreen]

Professional opinions?

[Eagledriver]

Enough pressure to compress the oring, but not enough to squeeze it out.

[bcgreen]

I will be getting a O ring that is a 60 A diameter hardness so it will withstand a tremendous amount of pressure and it is not squishy.

[boyt911sc]

BC,

Is the contact surface area between the o-ring and the block perfectly flat? I am trying to visualize the aluminum collar with o-ring sitting flat against the crankcase to prevent seepage. Could you post a picture of the aluminum collar with o-ring? Thanks.

Tony

[bcgreen]

Originally Posted by boyt911sc

BC,

Is the contact surface area between the o-ring and the block perfectly flat? I am trying to visualize the aluminum collar with o-ring sitting flat against the crankcase to prevent seepage. Could you post a picture of the aluminum collar with o-ring? Thanks.

Tony

Yes it is perfectly flat. I haven't taken mine apart yet but this is what it would look like.

[burgermeister]

Interesting... this must be what the nitrile rubber sheet post is about as well!

What if you used a nose bearing O-ring, which will stretch over the nose bearing just fine, and cut a 45 deg chamfer in the aluminum collar so the O-ring is pressed both against the case and against the nose bearing? Use the pulley bolt to apply pressure, and then tighten the set screws.

Even more secure would be a one piece clamping collar with an M-4 or M-5 bolt to clamp it in place on the bearing. You'd need a mill & lathe to make one of those...

All of this assumes the #8 is tightly clamped by the case. The only mechanical stop keeping it from sliding out is the little pin in the RH case half.