1941 distributor drive length and diameter re oil pump drive?

[Chris Bamford]

Hello â€" new member here, not an owner but helping a car club friend get his long-term 1941 Series 62 Coupe project running and finished this winter.

Tomorrow we anticipate starting the engine for the first time in seven years. The engine is apparently a NOS tank engine with approximately 20 hours service some 10-15 years ago.

I plan to to take a 1/2" drill over to his garage tomorrow, pull the distributor, and spin the oil pump to build up initial pressure and circulation.

To save time I would like to take the pump drive with me, but it would be helpful to know ahead of time what would be best to use â€" lacking any more concrete suggestions, I would take a 1/2" shaft about 15" long with the lower end cut 1/2 away about 1/2" up from the end.

Can someone familiar with this engine confirm this sizing or suggest a better approach?

Many thanks!

[Brett Baird]

You can't prime the oil pump/system that way on the 346 flathead. The distributor shaft is driven by and sits in a slot in a bronze gear that is in mesh with the cam shaft gear.  The oil pump is also driven by the bronze gear which will not rotate independently from the camshaft. 

I have primed oil pumps and galleries by using a pressurized tank with oil in it and attaching its supply line to the fitting that feeds the oil pressure gauge.

[Chris Bamford]

Thank you Brett, much appreciated.

[Bobby B]

You can't prime the oil pump/system that way on the 346 flathead. The distributor shaft is driven by and sits in a slot in a bronze gear that is in mesh with the cam shaft gear.

Brett,
  A 346 Flathead can be primed by a long shaft with a slot cut in it or by using an old distributor shaft and removing the gear. A electric drill works best but you need to hold a rag around the opening or go slow. I took a whole distributor base minus the gear and fabricated it so I get no splash back of the oil. I've done a few engines, so I'm not getting why you feel that this can't be done. Also while doing this, it's a good idea to have someone turn the crank over 90 degrees at a time, for at least a few complete cycles so you can check every lifter block and lifter for oil dribbling out. I use a remote gauge which I made an adapter fitting for, so I can monitor the pressure while I'm doing it. Should be between 15-30 PSI. Good Luck!
                                                                                                                                       Bobby

[Tom Beaver]

Chris,

As Bobby said if you just drive the oil pump with the distributor tower off the engine you will have a big oil spill in fairly short order.  However, if you have another tower that you are willing to sacrifice you can cut it in two just above the upper bearing, plug the oil feed hole in the bottom end and then mount that on the engine along with with your drive shaft and electric drill.  This will keep oil from overflowing all over the back of the engine and allow you to pressurize everything else.  Here is a picture of the setup I have used.

Tom Beaver

[The Tassie Devil(le)]

I made this one for my Sons' Oldsmobile.

Trimmed down an old distributor I had laying around, and machined off the gear driven gear, gutting the rest, and use battery drill to spin the shaft.

Bruce.

[Steve Passmore]

Second what Bobby said. The oil pump on the 346 is driven by the distributor shaft not by the intermediate gear so you can spin it independently, but as he said, that oil will come out of the tower hole real fast.  Do not attempt to just remove the distributor and leave the tower on to spin its shaft. Its locked by the intermediate bronze gear.

[Chris Bamford]

Thanks to everyone for the additional info and suggestions.

I hadn't checked back on the forum until we finished work on the project today, so with the understanding that we couldn't pre-lube through the distributor tower we instead spun the engine with the plugs out.

We probably ran the starter for two minutes in 10-15 second bursts, and were pleased to see 20 psi on the oil pressure gauge each time. We were even more pleased to have the engine start right up with some gas in the carb and run smooth and ever so quiet! We have a fuel pump issue â€" new thread starting soon about that â€" but otherwise everything else looks positive.

Photos: The happy owner; I took the original owner of my '26 Model T along today, he seemed to enjoy the ride.

[Steve Passmore]

When they start up like that it is most satisfying. Congratulations.