Rookie with an engine problem

[Shelby1962]

Just bought a '31 Deluxe that was well restored. When I checked it out everything was fine. Now after the first drive it is pumping oil out of the rear main area and coming out of the hole in the bell housing. The inspection plate was almost dry. I pulled the pan and saw the drain pipe is in place and the engine was just redone. It has a new forged crank,cam, pistons, etc....my question is how can i determine where the leak is? I did not see any gasket cement on the oil pan gasket corners or the main cap. Could it be leaking between the cap and block by the shims? Is it possible pull the cap with the bellhousing in place so I can check the bearing clearance? If it is the rear cam gasket is there a way to check this?
Lastly how do I re-install the oil pump and pan at the same time? is something supposed to hold it in place? it just fell off with the pan.
I'm used to my model T and not this newfangled modern stuff......

[colin1928]

Hi and welcome
Check that you have not over filled
these engines like to be under the full mark on dip stick
mine likes to be just above 1/2 between F and L
Colin

[Kohnke Rebabbitting]

If you can't run a Model A engine with the oil on the full mark, you have got something wrong!

[Great Lakes Greg]

In the side of the block next to the oil pump is a pipe plug. If you pull that, you can stick a bolt in there and hold the oil pump in place. Be advised that it is a pipe thread. Or a buddy can hold the pump up through that hole with the tip of a screw driver while you put the pan back up. Don't forget to replace the plug.

[tbirdtbird]

take a 3/8 fine thread bolt. grind off the threads about 3/8 of an inch. Carefully screw this bolt in where the pipe plug is that was mentioned above. Just snug. Don't forget to replace the pipe plug when done.

GET the manuals for the car!!

[James Rogers]

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Originally Posted by Shelby1962

Just bought a '31 Deluxe that was well restored. When I checked it out everything was fine. Now after the first drive it is pumping oil out of the rear main area and coming out of the hole in the bell housing. The inspection plate was almost dry. I pulled the pan and saw the drain pipe is in place and the engine was just redone. It has a new forged crank,cam, pistons, etc....my question is how can i determine where the leak is? I did not see any gasket cement on the oil pan gasket corners or the main cap. Could it be leaking between the cap and block by the shims? Is it possible pull the cap with the bellhousing in place so I can check the bearing clearance? If it is the rear cam gasket is there a way to check this?
Lastly how do I re-install the oil pump and pan at the same time? is something supposed to hold it in place? it just fell off with the pan.
I'm used to my model T and not this newfangled modern stuff......

First, what do you mean by a "new forged crank"? Second, is it babbitt or inserts? Only way to help is to know what the engine consists of in the way of parts. If it has a Burlington crank, you cannot remove the rear cap while the motor is in the car unless the flywheel housing has been modified. Pictures will help bunches.

[700rpm]

I use a tapered wooden dowel to hold the pump up while installing a pan from underneath, then remove and replace the plug. No danger of damaging the pipe thread this way.

[ctlikon0712]

If the oil fill cap is plugged or put to far down on the fill tube the crankcase might pressurize and force oil up the rear tube and then out the rear main.

[H. L. Chauvin]

Hi Shelby,

All good comments.

In Mr. Rogers's reply no. 6, he knows ................. pictures would help.

Some cranks had modifications machined for new seals, & some not ........ then some seals were entirely different from others

[George Miller]

Most likely to much clearance in rear main, or to much end play, or plugged oil passage through the main cap. You see this all the time. Some have babbitt in the hole, plus sludge. Also could be the bottom of the cap is not flat. Could be oil coming from the rear of the cam shaft.

[Shelby1962]

Here are a few pictures of the engine. The crank appears to be new but might be stock (i'm used to the little thing in my T).
I used a mirror in the bellhousing and the back of the cam gasket is dry. Oil drain tube is clear. The only thing I noticed is there was no permatex use don the gasket or cap. My thought it was leaking where the pan and main cap gasket went together.
Did not leak at idle, only after a few mile drive, dripped heavily and left a large puddle after i shut it off.

[Tom Wesenberg]

In your first picture The center main bolt heads are turned from the factory position. Each bolt head has a tiny bump sticking up to indicate the alignment for the cotter pin at the other end of the bolt. The bumps should either face straight in or straight out so the cotter hole is perpendicular to the crankshaft. As long as the cotters are installed, it's not a big deal, but I'd guess most Model A engine builders would know this.

[Duffy1]

Drain tube could be stuck to far in the oil return channel not allowing the oil to move out of the channel into the return tube. The new return tube I put in had a notch in the end of the tube to further facilitate oil moving out of the channel into the tube .Oil can also leak around the main cap bolts . I put a little silicone around the bolts and along the edge of the main cap. My oil leak was caused by the oil channels being stopped up. Cleaned out the channels ,put in new return tube and applied silicone as mentioned . No leaks . Mine was a major leak .

[James Rogers]

First, you can remove the cap without any problems. The best way to check the clearance is with aluminum foil when the engine is in the car. The rear cap is a forged cap which has to be tinned before pouring and with the inability of many modern builders to properly tin the cap, that could be the problem. First thing I would do is to use a screwdriver to pry the crank forward and measure the clearance between the thrust surface on the crank and the thrust of the bearing. The clearance should be between .004 and .012. Any more than that and you will have the beginnings of a leak to a massive leak when running. I check the bearing clearance by removing the cap and cutting a piece of heavy duty aluminum foil to a size of 2" X 1". Fold the foil in half to make a 1"X1" piece.Insert the starter crank in the front of the engine. Lay the foil in the bottom of the cap on the bearing surface and replace the cap. Torque to 60-80# and try to turn the crank. If you can turn the crank you need to remove the cap and peel one shim off one of the shim packs. This is done with a very sharp knife by picking at one corner and peeling one off when it is lifted on the corner. Replace the cap with the foil still in place and try to turn the crank. If you can still turn it go through the process again removing a shim from the other pack. This is done till the crank gets very hard to turn or won't turn at all with moderately heavy pull on the hand crank. Once you get it to lock up or very hard to turn, remove the cap and take the foil out of the cap and replace it, torque it and, replace the cotters. Reinstall the pan and this should take care of the oil problem. I do know of more than one builder that does not check the clearance of the bearings when fresh. No machinist is so good that he does not ever need to check his work. If you have any questions about this procedure, please ask. Either I or someone here will be sure to help you.

BTW, I don't use or suggest any sealer of any kind on the mating surfaces. When the cap is tightened down, that stuff will squeeze into places that should never have sealer and can stop up channels that can damage the engine.

[Duffy1]

James ;
Glad you clarified this as it relates to using silicone on the mating surface of the main cap. I did not put the silicone on the mating surfaces.

[PC/SR]

Another leaking rear main problem. Leaking rear mains are a regular topic here and it is kind of disheartening. People pay good money for rebuilds and are entitled to better results.

Kohnke quote: "If you can't run a Model A engine with the oil on the full mark, you have got something wrong!"

That's it in a nutshell. When some rebuilder trys to sell you a "modern" seal, or some other gimmick, go elsewhere. A properly restored rear main will not leak, no more than the proverbial few spots "to mark it territory" and that bit of leakage lubricates the rear thrust face, and the wishbone ball as well.

James quote (I don't know how to capture his comments in a box) "I do know of more than one builder that does not check the clearance of the bearings when fresh. No machinist is so good that he does not ever need to check his work."

I became convinced a long time ago that the only way to be sure it was right was to learn about how to do the assembly myself (I am not a machinist) and measure everything. This is not a knock on the pros here. If you do not do it yourself, you want the guy who will do the assembly measurements. It may cost you extra, but their time, knowledge and expertise is worth it. Someone (Tbird?) a few days ago who said that fixing the mistakes of the rebuilders of "moderns" was his stock in trade. That's a lesson. I am sometimes amused by folks who say their rebuilder was great, but, Oh Yeh, I have a leak.
We should all become "informed consumers", learn what is needed and ask questions, and pass along the knowledge to others. There is no reason for a leaking rear main.
Edit added: I hope too that Shelby's experience might be a lesson to learn. If the engine runs when you buy it, run it and see if it leaks before you write the check.

[James Rogers]

PC, I check all clearances as I assemble the engine, no matter what the micrometer read when I cut it or what a supplier suggests. My rod supplier furnishes a 3/4" piece of plasti-gauge with his rods to check one with. This assumes the rest are correct because one is. I don't subscribe to this line of thought and use a 1" piece on EVERY rod for a check. I have found rods that were cut wrong, even just one in a set.

The person who said fixing the mistakes of other rebuilders and mechanics is his stock in trade does this because today's mechanics are little more than parts changers with no diagnostic skills for the most part. This line of thought has projected into the restorer rebuilders of our hobby and many don't know the intricacies of such a simple motor. I agree with that person whole heartedly. Herm is right about the full pan. These motors have run for 85 years with the pan filled to full. The only time the pan will leak profusely when full if done right is when the car is driven or parked on a steep hill. Even a perfect stock original motor will leak in this instance. This is the only reason I suggest running the oil slightly low.

[Shelby1962]

Mr. Rogers...Thanks for the suggestions on the tinfoil and everyone else that replied. As you can see from the photos the engine maybe fresh but whoever did the babbit work should be banned from doing this kind of work! The clearance was .006 but the thrust was good at .004. Had a friend come over with Les Andrews book and he helped with the main clearance. It's now within spec. Put it all back together and ran it for 45 minutes and no leaks yet. Not sure how long it will live but it appears to be OK for now. Not the most confident on the engine but it sure is a pretty thing.

[Tom Wesenberg]

While the cap was off you should have filed an oil pocket in the parting edge of the babbit. I don't have any pictures handy, but Herm has posted pictures of what a good babbit job should look like with oil pockets. And make sure the oil pockets stop before the ends of the babbit.

Maybe James or Herm will post a picture of the cap with good oil pockets.

[Bob C]

Is that a piece of babbit missing near the front of that cap?

Bob