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

In the 1939 Salesman Data Book, on page 8, it shows a drain from the carb that is supposed to drain off excess fuel and prevent flooding when restarting. The tube has a back flow preventer that closes it when the engine is running. I've had several Packards on this vintage and have never seen the drain. Does anyone have one on their car? And I guess the next question is does it make any difference on the performance of the engine?

This is based on my experience with the 356 engines and may not be the same thing. The condensation drain on the 356 is connected to the rear of the intake manifold [not the carburetor] and allows excess fuel in the manifold to drain off. The drain is closed by means of a ball bearing that is pulled up by vacuum when the engine is running.



An earlier discussion on "Anti puddle valves" can be seen here.

I have a 356 with and a 356 without and generally I don't think the valve makes any difference in engine performance.

same animal. I suspect the only thing it's good for is losing points while being judged.

The use of the intake manifold drain tubes (not carburetor drain tubes) with check valve began with the conversion from updraft to downdraft carburetion (10th series) and was a result about concerns of engine flooding with the introduction of downdraft - remember, gravity pretty much makes it impossible to flood an engine with updraft. Assuming this is what you're speaking of they are not to drain condensate but raw gasoline. My 34 Eight has one and on rare occasions it dutifully performs it's intended function. I've seen them on pre-war juniors and seniors but never on a postwar. Later ones are just a simple tube as in the photo above, the ones on the senior Eights and Super Eights (320 and 384 engines) starting in 1933 have 4 branches (one for each intake manifold branch) combining into a single downpipe with a ball check at the bottom.

Use of these devices was not particular to Packard, they were common in the industry.