I think that I am experiencing vapor lock in my 289. Car starts fine in the morning and gets me all the way to work on a cooler morning with no problems. Time to work is around 30 minutes. In the afternoon, however, traffic builds a little faster and it sometimes takes another 5-10 minutes to get home; most of it sitting at stop lights in traffic. Usually, I experience sputtering under acceleration and rough idle as I near the 25-30 minute mark of the home trip. I have a couple of usual safe spots to pull off of the road and there I can pop the top off of the carb if necessary to clean the little strainer going into the float bowl. I also have a glass, cleanable fuel filter b/f the mechanical fuel pump. I used to think the sputtering and other symptoms were associated with the trash and stuff that I was picking up in the filter and strainer. But I have noticed all along that we I pop the top on the carb, I see bubbles in the float bowl that appear to originating from the main jets. I also see bubbling fuel in the filter b/f the pump. The fuel line is rubber and it hugs the block pretty close from the pump all the way to the carb. Yesterday, I took an infrared thermometer and shot the fuel line near the carb and it read back around 185 F. The fuel in the float bowl was around 185 as well. The intake manifold was about 5 degrees warmer. I usually sit for a few minutes to let it cool and then stumble home. The next morning, she starts right up and goes to all the way to work with nothing done. Does this sound like vapor lock? If so, I have searched for phenolic spacers for the Autolite 2 barrel and I am coming up empty. Does anyone know where I can get a phenolic for this carb? I currently have a one inch spacer that is either aluminum or cast iron...haven't checked which b/c I know that neither are very efficient at knocking down the heat from the carb. Thanks for reading and any input.

 

Sounds to me like you should re-route that fuel line away from the block. You should be able to fine plenty of the 2 barrel spacers in a salvage yard, assuming they've bothered to keep the things.

 

did they make these phenolic spacers for the Mustang or is it a relatively new (compared to the Mustang) performance piece? I know that the phenolic compound has been around since the 60s. what is the likelyhood of finding a phenolic spacer in a junk yard?

 

where did you get your clear fuel filter at? I like the idea of seeing what kinda stuff is flowing thru the line

 

I found the filter at Autozone. It is made by Mr. Gasket. I come with everything except the pipe thread tape and I recommend using the yellow tape which will stand up to things like gas, oil and diesel. I also recommend buying the service kit for the filter which comes with a couple of extra nipples, gaskets and filter elements. This will prove useful if you have a fuel system requires occasional cleanings. Total cost for all of this was about $30. There might be some other alternatives. I know that Wix makes a clear filter element but I forget the part number.

 

The phenolic spacers are on somewhat newer cars as I recall. Cars from the smog era, such as mid 70's and newer. Most likely a smaller salvage yard would have a pile of carbs laying around, with some spacers mixed in. Be careful about your clear fuel filter. I've heard they've been known to break, assuming yours is made out of glass.

 

I don't know if just any 2 barrel phenolic spacer would work if you got one from a junk yard. I know you can get the 2 barrel phenolic spacer for a Holley, but not a Motorcraft. You might take your carb to the junk yard with you and see if one of their phenolic spacers will fit the 2100. What we did back before the plastic spacers came out, was to cut out a spacer from a piece of 3/4" plywood. They worked great and stopped the vapor locking.
Now, I have a stock intake, the aluminum spacer and the 2100 in my 65, and I don't have a vapor lock problem. As mentioned, you may want to re-route that fuel line so it is further away from the heat source.

 

I had a Ford hotrod back in the day. It was a '51 Ford flathead and I had to use a 1 inch chunk of wood under the carb to stop the vapor lock problem. I just made a template with paper and pencil on the carb, then used that template to cut out the spacer. I also added a cup to the side of the carb so I could put some chunks of ice in it to help keep the gas cool when I was racing. You guys have it made today. Just get that phenolic spacer and you will have no more gas vaporizing problems.

 

I don't think it's vapor-lock, maybe the coil getting hot and breaking down?

 

My coil is right next to my intake manifold and it doesn't break down. However, after several years of service under intense heat conditions, you could be right.