Oil pump check valve

[Russ T. Fender]

I am finally getting ready to reinstall the engine in my 30-U after a complete rebuild and will be trying to use my Kingston vacuum tank instead of the electric fuel pump I used previously.  Since the vacuum tank runs off the oil pump, as opposed to drawing vacuum from the manifold, I would think that some type of check valve needs to be placed in the vacuum line to keep gas from getting into the oil pump.  Is there a check valve in the vacuum tank itself and if not has anyone added one in the line?  If so, what did you use?  Thanks.

[frankp]

To my knowledge, there is no check valve in the system.  It happened to me when the Kingston malfunctioned, but it has been very reliable.   frank

[Russ T. Fender]

Thanks Frank.  I wonder if putting a check valve in line would affect the operation of the vacuum tank.  It certainly would protect against the possible malfunction of the vacuum tank which is after all over 90 years old. 

[frankp]

Russ,
If the corks are secured on the brass shaft, there shouldn't be a problem.  Of course, if a check valve works, it would be a preventive measure and provide peace of mind.  As they say, your oil gauge is your friend.  If the oil is diluted with gas, the pressure drops.  That's how I knew I had a problem.  One whiff of the dipstick told me what it was.   frank

[Russ T. Fender]

My vacuum tank was supposed to have been totally rebuilt so I guess I will try it without a check valve and keep my eye on the oil pressure gauge.  Thanks.

[frankp]

Russ, you should be good to go then, if soldering is good when corks replaced. Other folks have had problem with valve seat at inner tank.  I've never experienced and can't describe any symptoms.  I also sealed the inside of outer tank as it was starting to weep around the bottom.

Look forward to hearing about your success.  frank

[chetbrz]

Russ,

You can't add a check valve without a major redesign of the pump.  The main thing is that Fuel line and vacuum line is sized correctly with no leaks.   With mine 6 consecutive hours of engine idling caused my pump to over fill.  This makes sense since actual driving would use more gas that just running idle.

When you first install the pump stay aware of your oil pressure.  Your car will probably take longer to pump up oil pressure with the tank installed.   If there are any problems with the vacuum line you may have problems with oil pressure.  Just an FYI... 

Chet...

[Russ T. Fender]

Thanks for the heads up.  I plan to start up initially with a simple gravity fuel feed to get oil pressure up and then connect the vacuum tank.  I will block the vacuum line to the tank for initial start up.  Did you have any trouble picking up a prime with the oil pump?  I am debating packing the pump with vaseline or at least filling it with some 90 wt. steam cylinder oil.

[chetbrz]

Initially I had lots of trouble but for other reasons.  Not connecting the vacuum pump for the initial startup of your rebuilt engine is wise.  Make sure the vacuum line is plugged.   This will bring up your oil pressure quicker actually gives an additional 5psi.    Some Vaseline or heavy oil in the oil pump to startup is a good idea. 

Good luck,  Chet

[jjohn]

 I don't know if this is useful is is from1928 Chrysler

[Russ T. Fender]

Chrysler used a Stewart tank.  The low end must have used the cheaper Kingston.  There is a big difference.  A lot of Plymouths were retrofitted for the Stewart units over the years.

[chetbrz]

How are things going.  Have you fired the engine up.

Let us know.  Chet

[Russ T. Fender]

Have not fired up yet and have run into a few other issues I am trying to sort through.  The pressure plate and clutch disc I have appear to be be the same as shown for the PA but my car is an early 30-U.  I am almost positive they are the ones I removed from the car about 15 years ago but I also found what looks like the clutch disc and pressure plate for a 30-U in my stash of parts.    Are they interchangeable?  The surface of the pressure plate for the PA is in much better shape than the other one and I would prefer to go that route if possible.  Test fitting the PA pressure plate and clutch disc, it looks like everything lines up correctly and should work.  My other question concerns the universal joint discs.   I had five NOS Fibroid discs that I got at Hersey many years ago and if I recall correctly 3 go on the rear and 2 go by the transmission but when I installed them it seemed like there was room for a third disc up front as tightening the bolts distorts the discs so the are pulling toward the rear.  Is that correct or am I short one disc?  I can't find any information on this in any of my reference material.  Once I get these issues sorted out I will be ready for a test start.  The rebuilt engine is quite stiff and I doubt the starter will be up to the task so I plan to tow start the first time.  I plan to tow in high gear with the switch off and hopefully get some oil pressure up in the process before I turn on the ignition.i

[chetbrz]

Russ,

I'm not sure about the interchangeability of the pressure plates.  28,29,30 to PA - Check the parts book. If it bolts up it might work but check it carefully prior to starting the motor.

As far as the Universal disks are concerned there are a number of threads on this topic.  Try a search in the General Discussion Category on "Universal Disks" or "Universal Joints"  BTW... You are correct, three disks in the back an two by the transmission. 

Below is a link to a long thread on the topic of disks. From 2012

http://www.1948plymouth.info/28Q29U/index.php?topic=611.msg3332#msg3332

Rich (29PlyCoop) posted this in 2009

Here are the dimensions of the discs that fit my 29 Plymouth "U",(also used on 1928, 1929, 1930) hope this helps. The discs measure 6 in. in diameter, each of the 6 holes are 2 1/4 in. apart and the center hole is 2 1/8 in. in diameter and 5/16 in. thick. The 1929 Plymouth takes 5 of these discs per car on the Plymouths, 2 at the transmission and 3 at the rear-end. Good luck with your "Q"  HAPPY MOTORING!!!! Rich

If your car is jacked up on the frame with the rear axle hanging, you might see some severe pulling of the disks.  Just a thought.

The motor.  Why is the engine so tight.  Was it put back together with assembly grease.  Can you hand crank it ?  Just wondering

[Russ T. Fender]

I can crank with the plugs out and with difficulty under compression.  The engine was put together using assembly grease and I believe rod and main clearances were set at 1.5 thousands.  Maybe the problem is that I am 75 with a bad back!  In any event the starter is even older than I am and I have almost always towed fresh rebuilds to start on my restorations, most of which have been on non-starter cars.  Never had a problem doing it and it makes things a lot easier on the back.
As far as the clutch and pressure plate are concerned I can't find anything about them being interchangeable.  I was hoping someone either has a period junkie interchange manual or has actually used the PA set up on a 30-U.  Sure looks like it should work.  I set the pressure plates together and the bolt holes align perfectly and the thickness is the same.  The throw out bearing looks like it will ride correctly on the arms so I don't know what else I can do at this point.