Pressurized center main bearing?

[BRENT in 10-uh-C]

[ModelA29;2289017]Jim Brierley's book 4 Bangers and me has a photo on page 39 where the tube is feeding all 3 mains. I'd think an orifice in the line would be desired to make sure the other areas still get enough oil.]

I have a few questions about this thread.
If you pressurize the center main bearing why not all three?
Is there any advantage or disadvantage to doing all three?
Would the oil tubes in the valve chamber going to the bearings need to be plugged? Or could the pressurized oil be run through the valve chamber tubes?
How would either affect the oiling to the camshaft.
I have not had a Model A engine apart in 30 or so years so I am a little rusty on the internal workings.
Sorry if I ask stupid or too many questions.
Thanks

In a nutshell, there really isn't a need to pressurize all three. The size of the rear main bearing is WAY more adequate than needed, and it receives plenty of oil thru gravity. If you were to pressurize the rear main, then you must figure out how to effectively, -and reliably seal the rear of the rear main to keep it from leaking oil out into the flywheel housing. The tubes that feed the mains are the same tubes as used for the horn rod and the center hood rod. They are a rolled tube that will leak if pressure is added. The camshaft oiling is not compromised.

 

[alexiskai]

I guess I should start by saying these aren't my design. I have been purchasing these from Ron's Machine over the years.

If anyone's interested, I called Ron's and they said the kits are available for general purchase for $45 plus shipping.

 

[duke36]

Piriano's doesn't sell the kits now. What are the exact dim.'s for the drill/tap ?
How about steel carb.gas line or brake line tubing ?

 

[Bruce of MN]

The fitting you use determines the tap spec.

 

[duke36]

Piriano's doesn't sell the kits now. What are the exact dim.'s for the drill/tap ?
How about steel carb.gas line or brake line tubing ?

The photo shows the location dim's needed for placing the drill/tap, not the tap size. I should have made the wording clearer.

 

[Bruce of MN]

Post #20 sort of addresses that. I don't think that the photo in your post is a literal depiction of a connection point. I am rebuilding my engine now and there isn't anything below that spot on the rail for the oil to come from. I have decided to stick with the original design and drive the car a lot to keep the valve chamber flooded. That will wear out the center main sooner, but at 77 yo, I think it will outlast me.

 

[BRENT in 10-uh-C]

The photo shows the location dim's needed for placing the drill/tap, not the tap size. I should have made the wording clearer.

Likely you are overthinking this. I'm sure we rarely drill & tap in the same exact location from engine to engine. Don't fret over getting it precisely located because the tube will adjust for slight differences in fitting locations.