30-U Firewall

Frank2 · April 23, 2018, 03:26:56 PM

Soup, When you remove the inner tank, you will see the "flap valve" on the bottom. If this does not open, gas will continually be drawn into the inner tank, unless it doesn't seal. The fuel is only shut off when there is no vacuum created in the tank. The washer is a stop.

My tank is using the same cork from 1965 that came on the car. It has not been coated with any thing by me. I understand the "dope" paint used on gas powered models works, but have no experience. Since you have used synthetic material in carbs, you know what your doing! frank

Soup · April 23, 2018, 01:34:39 PM

You are probably right about the check valve idea. I have never taken a Kingston vacuum tank apart but I assume the gas gets into the oil because the float level gets too high. If that is true, does the washer Frank is referring to act as the stop for the float that causes the fuel supply to shut off before it reaches the level of the vacuum line. I wonder if ethanol gas will affect the cork float and cause the same problem if the cork gets gas soaked. Is the cork sealed with something that is impervious to alcohol? I believe corks were coated with varnish or shellac years ago and I don't think either of those sealants are alcohol resistant. I have replaced cork floats in a few early carburetors with a synthetic material because they were soaked with gas.

chetbrz · April 23, 2018, 09:32:47 AM

Quote from: Soup on April 03, 2018, 10:21:38 PM
... I plan to put a check valve in the line from the oil pump to the vaccum tank just in case....

Soup,

I don't think that will work in that the vacuum and the fuel would both be traveling in the same direction.

I too have not used the vacuum tank because I thought it was missing a check valve assembly when I first took it apart. I have since then realized that Chrysler used the consistent vacuum produced by the oil pump as the regulating mechanism for fuel usage. I think Frank found the key to help prevent the fuel from back feeding to the engine.

If you find a way to check the gas flow, please let us know.

Tks, Chet...

Frank2 · April 18, 2018, 10:06:07 AM

My Kingston is run from oil pump vacuum and it broke and sucked gas into the oil, too. Here was my problem.

In the inner tank, the 2 corks are on a brass shaft and they are secured in place by brass washers on the bottom and top of the shaft. The solder on the top washer had broken and allowed the corks to rise on the shaft. I re-soldered the top washer and have had no problems since. The corks should be tight on the shaft with no movement on the shaft. Corks rise and fall, so does the shaft.

It was frustrating to identify, but easy fix once discovered. I hope this helps and you get your tank repaired.

frank

28 Ply.cpe · April 04, 2018, 08:06:11 AM

My car has been running since 1961 with a Stewart Warner Vacuum tank. I have rebuilt it twice which just includes a couple gaskets. But when I show the car at a National Plymouth meet questions arise why it doesn't have the original kingston tank. First of all it has taken 40 years to find one and now that I have one I find out that they were problematic because of the gas getting into the oil. I could just put the kingston on to show it. thanks for the reply.

Soup · April 03, 2018, 10:21:38 PM

Bill, my car had an electric fuel pump on it when I got it from the original owner. He said the vacuum tank was always a problem so he took it off in the mid 30's and went with the electric fuel pump. I searched for many years until I found the right Kingston. If I am not mistaken, the oil pump provides the vacuum which is the reason for the possibility of gas getting into the oil. I plan to put a check valve in the line from the oil pump to the vaccum tank just in case. I am in the process of restoring my car now and the vacuum tank has never been installed so I can't speak to how well it works or wheather my plan is even feasible but I plan to find out.

28 Ply.cpe · April 01, 2018, 08:56:27 PM

Nice picture Frank. My 28 has another brand vacuum tank on it and I found a Kingston. Not in too bad of shape but I don't think it works the way it is. I have been told that this brand of tank had issues which could possibly back feed gasoline through the vac/pump and put gasoline into the oil pan. Have you ever experienced an issue like that. I am going to rebuild this pump and see if it holds gas without leaking. The top doesn't seem to fit very well and the inspection cover just bounces around on top. I would like the car to be using the original vacuum tank. thanks Bill

Soup · March 24, 2018, 02:22:38 PM

Thanks Frank. That is what I was looking for. I think my early 30-U is the same.

Frank2 · March 23, 2018, 10:02:52 PM

Soup, This is my 29U Kingston tank on the firewall. frank

Soup · February 27, 2018, 06:34:38 PM

I am looking for pictures of the firewall from the engine compartment on an early 30-U with vacuum tank. I am tryting to figure out what holes need to be closed up as over the years there seem to have been several extra holes made in the firewall to accomodate modifications that were made to keep the car running. Thanks.