1922 McLaughlin Overheating

[BuzzW]

We've got a 1922 Mclaughlin Touring that has a substantial problem with vapor lock, driven for any period of time it simply starts burping and stops until it cools down. We feel that the problem lies in preheating the fuel from the exhaust, the manual shows two pipes running back to the carburetor but our car only has 1 and what appears to be maybe a butterfly valve in the front where it connects to the exhaust pipe. Some have thought the problem is from the copper fuel lines on the car. (they say that is not stock and may transfer more heat) Anybody out there have any ideas and what year is the single pipe if it isnt a '22. Thanks for your help BuzzW

[Mark Shaw]

Two pipes were used in the 20s. My 24 Buick has a two pipe system, and my 1931 has one pipe within a pipe to preheat the air/fuel mixture.

I used freeze plugs to plug off the exhaust preheat system in my 31. It is not necessary with modern gasoline, and caused more maintenence problems than it was worth. The outer pipe is still there just to look original.

Your problem is more likely a kink or corrosion in the fuel line from the fuel tank. You should also check to see that the fuel line is well away from the exhaust pipe and muffler.