'37 vs '38 LaSalle 322 rear oil seal question

[Joe G 12138]

     I recently acquired a 1937 LaSalle. I knew it had a rear oil leak, but figured on going after it and fixing it as I've dealt with this sort of thing before on the overhead valve engines. Not fun, but do-able. I've read about sucess with the Mercedes seal on flatheads, so I figured I'd line up parts (including the original style) to have on hand before the job started. I'd use what worked best after seeing both types.
     While looking at "Best Gasket" parts, they're listing a '38-'48 rear main seal. They state that "37 Didn't use a main seal. WHAT? If not, what did they do? I sure don't want to pull that engine if there's nothing to replace! Is this true? Or is there some sort of packing or something?
     It appears to be the correct original engine. The number is in the right sequence for 1937 (224XXXX) and matces the chassis and Title VIN. However , there is a star after the stamped number on the block. Does this signify a possible replacement motor( Hopefully WITH a seal) or do they all have stars after the engine number?
    New to the world of Flatheads....Joe Gibeault

[Tom Beaver]

Joe,  The Best Gaskets parts listing is correct.  The 37 engines had no oil seal, they used an oil slinger and relied on the fact that the crankcase operates at a slight vacuum when the engine is running to keep most of the oil in the engine.  However, if you were to stand the engine on end, either end, the oil would all be gone inside fifteen minutes. 

There was a post in this forum on 9/5/02 by Robert LeCoque explaining how the existing 1937 system works (no seal) and his method for converting to a modern seal, as follows: "The seal I use is a National #457294. Its dimensions are: Shaft size-4.000", OD-4.756",Width-.562". The crankshaft will require the removal of the slinger ridge and resizing of the rear flange, by precision grinding to 4.000". The back of the block has to be counterbored to a diameter of 4.750"X.562" deep. This effectively removes the entire oil groove. (A slight witness of the bottom of the oil groove may be visible. Won't hurt anything) When setting up to bore the block, it is important to set up to the bearing bore, not the groove bore. If the bearing bores have ever been trued, they are no longer concentric with the oil groove bore."

Tom Beaver

[Steve Passmore]

After Toms very good explanation of the replacement I wouldn't think that was something you intended to undertake Joe, it requires complete dismantling of the engine and specialized machining. Could the leak be caused by the car being parked always on a gradient? or too much oil?  I have always found the slinger to work well under normal conditions but some oil may escape if doing a lot of hill work or parking on one.

[Jeff Hansen]

Regarding the star after the engine number on the block, I'd always assumed the presence of the star on either end of the stamped number preventing people from stamping in addtional numbers before or after to effectively change the engine number.

Don't know whether that is accurate or not, but seems to make sense to me.

Jeff

[Joe G 12138]

     Try as I may, I have not been able to pull up the original 09/05/2002 by Robert LeCoque. My searches do bring up some 2006 posts that essentially say the same thing (to see Mr. LeCoques 2002 post), also a referral to an old Self-Starter. What a coincidence! This Spring I went through my files, needing space, and took out all my old Self-Starters that I didn't need and gave them away at a car show to prospective CLC members. That issue was probably in there!
     Without reading the original post or article, it seems as if he's turning down the crankshaft flange, and installing the National seal EXTERNAL to seal the engine on the flange, given the stated dimensions of the seal. The crankshaft itself only has a 2.50 or so diameter.  Unusual.( But I'm open to anything.) If I'm reading that right, If the sealing is done on the turned down crank flange, then why would one remove the Slinger? I'm not sure I'm understanding the details. I think I'm missing something.
    Another poster (guest) tried removing the drain tube at the rear main, and was succesful in the garage. He was going to try it on the road and get back: but he never did. Success? Failure? (and sell the car to Joe?) Don't know!
    Steve: It's not an uphill park, hill or overfill problem. More like driving and speed. 40 mile drive @ 45-55 MPH leaves a 3/4' stripe up the driveway. I'm sure these cars were expected to do that type of duty when new. Getting oil on the clutch too; somewhat inconsistant operation after she's wet.

Joe Gibeault

[harry s]

Joe, Here is a copy of the modifications done by Bill Harper from Feb 2004 SS. I have rebuilt my '37 engine using the modifications described. I just got the exhaust manifolds back from porcelain coating and hope to have the engine assembly finished and started in about a week or so. Before the rebuild I was adding one quart of oil every 200 miles. A lot of leaking and burning. Harry

[Steve Passmore]

That almost sounds Joe as if the engine is over pressurizing, the engine vent on the earlier motors recirculated through the intake, later years discharged down the back of the engine, I wonder if you have the breather pipes blocked?

[Joe G 12138]

           Harry: A million thanks for digging up and scanning that Bill Harper article from the Self-Starter!!!! THAT is the information I'd been hoping for! A friend of mine said he'd look through his spare parts; he may have a '38-'48 bearing cap I can measure up to make the changes.
          Steve: You may be onto something regarding vent tube problems or over pressurization too. I've got to do some research now on what those tubes look like and how they're routed. I'm wondering if mine is not there. Looking at the Bill Harper article, he mentions cleaning the vent holes in the intake manifold. That means that the vapors enter upstream of that point. I'm not seeing a tube. What I do have is a pipe plug near the base of the front of the Stromberg Carb. Could that be the suction point for the tube? If that's it, where would the other end come from?
           The previous owner gave me a two piece tube assembly, along with a broken speedometer cable. At the time, he said the speedometer cable broke, and the mechanic forgot to re-install this "Guide Tube" for it "so here it is if you want to put it on". Looking at the Speedo cable ends, they're to large to fit through the tube. I'm guessing this tube is something to do with the engine, as one end is cleaner and the other more blackened. Could this be a missing breather tube? It's about 1/2" diameter and has a slip joint for swiveling or adjustment. Also, looking at the top or valley cover of the engine, slightly behind the carb, there is a hole, although larger than the tube. Could this be the pickup point? By itself, the tube won't make the distance between holes without a hose or extension. If this is it, What's the routing?
         Sorry about the out of focus second picture. That's showing a 1/8" pipe plug on the intake manifold as well as the 1/4" pipe plug on the base of the front of the carb.
          It's great to be making progress. Thanks again all!
                       Joe Gibeault
         

[Steve Passmore]

That looks like one of the vent pipes to me Joe, one attach's to the underside of the intake manifold and the other(the one you have) clamps to the back of the air cleaner, if you have the correct air cleaner. You must also ensure the screened intake on the top of the oil filler tube is clean.
Hers a picture of the vent system.
The hole on the valley cover rear takes a large grommet, the extra holes in the carb tell me its a later carb for auto advance and retard, earlier engines didn't have this feature.

[Joe G 12138]

       Hello Steve! I see now your from the U.K.! The internet is a WONDERFUL thing. 25 years ago we'd be writing letters and it would take 6 weeks to get this far, if we would have gotten connected at all!
       That drawing is spot on! There IS a hole in the back of the air cleaner assembly. It appears there may have been an extension or nipple crimped onto the air cleaner backside at on time which the pipe may have slipped on. The blackened short elbow probably was in the hole in the valley cover, hence the larger hole to get the radius of the elbow through. A grommet could make up the difference after it's pushed in. The clamp would limit it from falling into the motor if it got loose. The downpipe is a little short to reach the short elbow, but there are remnants of a shallow thread on the one in the photo earlier. An extension may have been lost; but easy to fabricate.
       I took some pictures with the pipe loosely in place. The ruler tip shows the pipe.
       Earlier in this chain I mentioned that the problem was more speed related than parking angle. The sketch even notes that the rear tube is effective at higher speeds. 
       THANKS a LOT!

[Joe G 12138]

Another picture

[Joe G 12138]

The front pipe is in place, and has the loop just like in Steve's sketch. As shown, right behind generator. Smaller tube, about 5/16".

      It looks like Cadillac was 30 years ahead of it's time with a primitive PCV system! (but lacking in crankshaft sealing technology). I'm still planning on doing that job too.

[Tom Beaver]

Joe,  With Steve's diagram it looks like you have the vent tubing figured out.  The plumbing is almost identical to what is on my 38.  I can relate one modification I made to the rear J shaped metal tubing to make things a little safer, i Think.  I cut off the J tube a little short of the valley cover and then purchased a "modern" or relatively modern PCV valve and sealing gromet.  I found a PCV valve designed to connect to the size rubber hose that would also just fit over the shortened end of the J tube.  I placed the PVC valve in the valley cover and coupled the J tube to it with a short piece of rubber hose.  I had to bore out the hole in the valley cover sheet metal slightly so that it would except the rubber gromet for the PCV valve.  The installation is hidden down below the intake manifold and crossover pipe so the modification is not at all obvious.  But now there is a PCV valve between the crankcase and the air filter to prevent an engine backfire from possibly igniting the crankcase fumes, I've seen it happen.

Tom Beaver

[Joe G 12138]

The PCV grommet and valve sounds like it could be a pluseven if used as a transition. At this point I'm still guessing as to how to orient the piping, as I DO have to make up some pieces. I could run forward or back of the intake manifold runner, depending on how I bend the lowest piece. Anybody got a picture of a genuine original '37 LaSalle rear vent pipe behind the carb?

Joe Gibeault