Flywheel housing
 

Hi guys, I have read up on previous posts Regarding Fitting Flywheel Housing to Motor. - I have a B Pressurised motor which was leaking at the rear Camshaft.

Question -Is it best to fit the supplied Thin Gasket and use some Permatex.


Or - Just use some RTV Sealant around the Camshaft Hole.
What are peoples thoughts on this. Thankyou

Re: Flywheel housing
 

Don't know about the B, but on my A's, I use the gasket, and when it's torqued down, measure the gap between the block and the two top holes and fit shims of that thickness.

Re: Flywheel housing
 

I have had the flywheel housing machined to take an O ring. I then assemble with no gasket, just gasket silicone and no shims at the back of the block.
That has worked well for me.

Re: Flywheel housing
 

My theory is that the camshaft did not originally come into contact with the flywheel housing or its gasket. However, the thrust surface on the camshaft & block wear, so the camshaft eventually obliterates the gasket and comes into contact with the flywheel housing. Another concern is the camshaft plunger spring. Once the camshaft does come into contact with the flywheel housing, a weak plunger spring allows the camshaft to oscillate fore-aft and make a knocking sound as it slaps the flywheel housing.

Re: Flywheel housing
 

I have witnessed on pressurized motors that if there is no relief it will leak
This can be as simple as using an unmodified groove in the cam bearing or drilling a small hole to vent pressure buildup
Another point would be to reduce the amount of oil goes into the bearing at rear

J

Re: Flywheel housing
 

My own $0.02 worth - I think you would be best to not use a zero clearance fit with silicone, a bit more danger of having the silicone intrude onto the camshaft. In my experience silicone works better with something that does not need much torque to establish the bond, like an oil pan or front cover. You do want to tighten the flywheel housing to the block! I use the thin gasket with Hylomar, and shims at the upper, but Permatex #2 would work just as well. I do like Synchro's idea of the O-ring.

Re: Flywheel housing
 

I personally see no problem with Henry ford's original design but if I chose to upgrade it I would definitely set it up to use the O. ring!!!

Re: Flywheel housing
 

I second, Henry knew what the flip he was doing. If it ain't broke don't fix it

Re: Flywheel housing
 

I looked at a Ford cutaway engine drawing and it shows that the camshaft has clearance to the flywheel housing. I would shim the camshaft at its worn thrust surface with a bronze washer to get at 0.030" clearance to the flywheel housing. At the rear camshaft bearing, I would cut a shallow groove in the bottom of block's bearing journal that is blind to the flywheel housing & open to its front. The groove would give the oil at the camshaft bearing a path to escape back into the engine. In the Model A & Model B engines, the rear camshaft bearing has a voluminous oil supply.