Packard Forum Index » Pre-War (1899-1942)

I was at a small show Sun. and a fellow showed up with a 36 Jr. 120 coupe. while looking at his car I noticed a tube running from the base of his intake manifold and it had a small device on the end. When I questioned him about it he said that it was an anti puddle valve. Supposedly it's purpose was to drain any gas that percolated from the carb when the engine was shut off while hot. I gather it was some sort of check valve otherwise it would be a vac. leak. Has anybody heard of these things? My intake has a threaded hole in it's base that I have plugged.

A lot of the prewar cars had them, and I think Customs thru 50. They just have a little ball check in the end. Vaporized fuel coming from the carb has a tendency to condense when it hits any existing puddles in the manifold, that is why Packard took pains to drain them out for easier starting.

Where would one find one of these check valves?

At least on the prewar models, it's a simple steel ball kept from dropping out of a small housing at the end of the tube by a cotter pin, and when the engine is running the ball is held up against a seat by manifold vacuum. Assuming the line and end (cylinder with the seat that contains the ball) is still there, just purchase a steel ball that fits.

If the housing itself is missing and you can't find one, it's a very simple job to make one if you have a lathe.

I don't believe they were used as late as 1950.

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Yes, they were on the 356's to the end. I have one on my 1950 Custom (factory renumbered '49). Parts manual lists them for 23rd series 2306-13-33.

JD, thanks for the clarification. Can you tell me more or show a picture? I owned two of those cars, one for 20 years and can't for the life of me remember that feature.

If you don't have access or want to go to the trouble of a lathe, both McMaster-Carr and MSC have small low cost brass check valves in various styles. Depending on type, it should be fairly easy to remove the spring and just leave the ball. If you need to add a cotter key afterwards as O_D mentions, that should be easy to do.

The manifold drain was on the prewar engines. I have 3 356 cars and none has that drain, and there is no provision for it. I also have 3 pre war engines, 32 and 35 std 8 which do have it so I do know what I am looking at.

The drain was for draining fuel that had acumulated in the manifold if the car was started and then shut off before the engine and intake got up to operating temperature.

When a cold engine is started the fuel is not fully vaporized and the droplets will form puddles in the cold intake manifold, if the engine is shut down at this time the liquid fuel will drain out. If the engine is brought up to operating temperature the manifold will warm up and this puddled fuel will vaporize and be carried into the cylinders and burned. If there is any fuel coming out of the drain after the engine has been run up to temperature then carburetor has a problem as fuel should not run into the manifold when the engine is shut down.

John

Edit: The 32 doesn't have the drain as it has an up draft carb.

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OK. That's fine but I have a 356 post-war engine that does have one and the parts manual is pretty clear. I also have a 22nd series 356 in my '41 limo and it does NOT have the drain. Go figure. I'll try to crawl under the '50 tomorrow if I'm up to it and get a picture. The valve end is exactly as Owen_Dyneto described with the ball and cotter pin. While I will admit it's certainly possible that the intake manifold on the '50 may be a replacement from an earlier engine, that still doesn't explain the Parts Manual (unless I'm not interpreting it correctly).

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Here's a couple of pictures of the intake manifold drain on my '50. The length of the tube is roughly 15". The cast land on the manifold where the tube is attached is not present on my 22nd series 356.

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