235 Vapor Lock, need advice

I run a 235 IL6. Patrick's mild cam, 848 head, Langdons 2 carb set up, Mallory dizzy. In traffic, or any time it idles for more than 10 minn it starts to vapor lock. Temp is only at 195 tops. I swaped jets, ran like shit,backed out timing and added, no good. Any ideas would be great. Thanks

 

Old timers used to put clothes pins on their fuel lines... Or clamps of some sort. I bought a ford with a six in it and noticed 4 clothes pins wooden ones.... When I asked about them he said they prevented vapor lock. I took them off thinking old wives tale, but sure enough I had to put them back on.... And it worked.

 

I know it sounds crazy.use 4 or 5 spaced about your fuel lines under the hood. They act as a heat sink.

 

I've had this happen in the past, get a hold of a fuel filter that has a extra nipple on it (79 jeep ? ) and run a return line back to the fuel tank -- gas will always be flowing & no more vapor lock . Clothes pins on fuel line-or tin foil on fuel line --never seen it work --jmho .

 

That does sound like a more sound idea... But won't it impede flow to carb ?

 

The clothespin trick works since wood is a poor conductor of anything but fire.

I'd look to route the fuel line away from anything that makes heat. I run a big Holley fuel filter along my frame rail before the fuel pump, this assists in cooling the fuel.

Other tricks, install a cool can and route the gas through that. Do you have room to add phenolic carb spacers and not disrupt your linkage? Lastly, louver the hood and inner fender wells. Looks bitchin' even if it doesn't work.

Bob

 

Timing and jetting have no effect on vapor lock.....

 

Wooden clothes pins has the traditional look and work good too!

 

electric fuel pump at the tank.

 

Blocked or obstructed fuel tank vent was my issue. Once line was purged I had no further problems.

 

Nope won't impede flow to carb--or it didn't on the times I've employed it.
Tin foil & clothes pins do look kinda neat tho , as dose a cool can -- did make one outta a Folgers can complete with plastic lid --use to put ice in it
-- to bad it didn't cure the vapor lock -- but it did look cool .

 

Make sure the fuel line isn't touching or too close to a heater hose. Routing the in line immediately away from the block and over to the frame rail can help as well as covering it with plastic wire loom.