How to cure vapor lock
 

Any ideas out there on best approach to stop vapor lock. Shield the gas line??, try Mystery Oil in the Gas??...
Would appreciate any feedback.
Thanks
Rick Jensen

Re: How to cure vapor lock
 

In the past when vapor lock would occur, I've upgraded to premium gas and it solved the problem.

Re: How to cure vapor lock
 

Rick . Hi . Good to see you at Reno. We ran 86mph at the salt in stock A cpe . Flathead. You may gets lots of comments on this one , I have tried along with others clipping two wooden clothes pegs on the line, If that does not work at least you can hang the washing out. Make sure you have orginal fuel line & no extra filters. Winter is coming so you will be ok. Derek from spring sunny day in NZ

Re: How to cure vapor lock
 

Thanks Derek. That's exactly what I'm doing for our little outing to Bend tomorrow. Still hot and smokey here in Reno..
Regards Rick

Re: How to cure vapor lock
 

Rick, hope to see you in Bend. Good luck with your vapor lock. The weather in Bend looks like it could be in the 80's but should be great time.

Re: How to cure vapor lock
 

the best way to help or stop vapor lock is to install an electric fuel pump

Re: How to cure vapor lock
 

Make sure the fuel line is always tilted up hill.

Re: How to cure vapor lock
 

A 1/4" bakelite spacer placed between the manifold and the carb on mine improved the situation. I got the material from McMaster-Carr (mcmaster.com). It acts an insulator to keep the carb cooler so the fuel doesn't flash into vapor when entering the carb.
Also, the addition of MMO, or 2 cycle oil will slightly raise the boiling point of the fuel and help the situation.

Re: How to cure vapor lock
 

There have been numerous long threads on this in recent years. Use Search function for key words "vapor lock". Here's one that will get you started:

https://www.fordbarn.com/forum/showth...lock&showall=1

You will find every cure under the sun, plus a host of vapor luck deniers and semantic quibblers.

Steve

Re: How to cure vapor lock
 

Another WACK to the dead Horse....:eek:

Re: How to cure vapor lock
 

I only use the good gas, no corn crap gas. This solved my vapor lock.

Re: How to cure vapor lock
 

Ditto on what Tom says. Plus, I also run MMO and I read some where that the original type (copper/filler/copper) carb to manifold gaskets.
Help with the heat problem.;)

Bob-A:D

Re: How to cure vapor lock
 

I started using Non-Ethanol gas in my 49 8N Tractor, and it cured my vapor lock problem almost immediately!
I think the ethanol lowers the flash point of the gas so it will vaporize in the lines easier causing more vapor lock. IMHO, that is...

Re: How to cure vapor lock
 

I recently found 'corn-free' gas locally and the old cars really run better. MMO does help if you must burn ethanol.

Re: How to cure vapor lock
 

You can go to Pure-Gas.org, or fuel testers.com to find listings by state of stations that sell non-corn gas.

Re: How to cure vapor lock
 

On our last Summer Tour we had about 25 Model A's traveling home from Michigan. The combination of equipment varied from close to stock to highly modified up to and including overhead set ups. Every one had vapor locking problems coming over the Continental Divide in Colorado except one car that was using ATF added to his fuel. It is pretty close to the Marvel Mystery oil and is less expensive. The ethanol added to the fuel seems to boil quicker that straight gas so that has increased the problem. Going to higher octane use to avoid the added ethanol but they now put 10-15% in all grades. So I guess my recommendation would be the ATF/Marvel Mystery Oil to solve your problem.

Re: How to cure vapor lock
 

Have any of you ever tried to the addition of Kerosine to an A that was prone to the fuel boiling problem? I can see where the addiotion of MMO would help by raising the boiling point, however MMO is not volatile as Kerosine (or Diesel) is.

it is worth noting when discussing this issue that Gasoline as we know it today is a distillate of several compounds. Some of those compounds blend at the Molecular level with the fuel and some are simply additives that will evaporate out, or settle out. In the case of fuel boiling in the Carb or Fuel lines, it is worth noting that depending on the season, and the State we live in, our fuels are different with different compounds and additives. Here in NH we have Winter Blends and Summer blends, each is different from a Volatility standpoint, volatility is a measure of the gasoline’s tendency to vaporize under a given set of conditions. So the car that is prone to fuel boiling in AZ, may not occur in NH, even if the operating condition and temperature are identical. Fuel in NH is simply not the same blend as fuel in AZ.

The low compression engines of this era run on Kerosine, many were run on it during the war because it was not rationed.

So I am wondering if any one who has the problem, has tried adding a gallon of K1 or Diesel to the tank?

Re: How to cure vapor lock
 

I didn't try a gallon, but I did try a quart or two of diesel per tank. All it did was make the exhaust smellier. Others have reported more success.

Steve

Re: How to cure vapor lock
 

Thx for the reply. A qt. In a 12 gallon tank is one 48th or about 2%. I should think one could easily go up 20% win a low compression A with no other modifications. Leaning a bit with the GAV might be in order? I have dumped up 25% old Kerosene (just to get rid of it) in my Flathead 8N. Could not tell it was in there.

Re: How to cure vapor lock
 

I've used ATF in the fuel for low use engines, enough to let them smoke a bit. I always thought it kept the carbon soft and they store fine. As far as vapor lock is concerned, I agree with Mike in keeping a good pitch on the lines as well as making sure the battery ground connections are clean and tight. But, I've never experienced vapor lock in a Model A yet, I have in other engines though.