63 backfiring, question about carburetor spacer plate

[BP63]

Hi, I've read previous threads about ethanol boiling and engine backfiring issues. I haven't located a source of non-ethanol gas near me, and I have added the enzyme additive that's supposed to fix that issue. I also asked tbirdparts.com about the spacer plate that has been discussed, and they reminded me that the 390 comes with a cooled spacer, which I confirmed is present. They did not have any additional spacers in their inventory. With the recent heat in the northeast, the car just started to have the backfiring problem again, even with super premium gas and the enzyme additive.

Does anyone have experience adding a different spacer than the one originally supplied by Ford? Any sources that are recommended?

thanks very much

 

[Gary Tayman]

I've never had a backfiring problem related to the gas or carb issue. The problem I've had was a gas smell when the car is hot, followed by hard starting and bad idle until the car has moved a bit -- in other words, trouble getting out of the parking space. Once moving the car runs fine.

This happened AFTER replacing the manifold and carburetor with an Edelbrock. Basically I bought a replacement motor, and boy what a mess it has been and still is, with these components on it. I called Edelbrock and they said it needs a spacer plate. I put it on, huge improvement.

I don't want to dwell on this motor -- it has blow-by issues, leaks oil everywhere, and has had problems with manifold gasket (used RTV and no gasket!) -- I can go on and on, and will eventually rebuild or replace it. but the spacer helped with the hot gas issue. How it compares with the original, I suppose they ran coolant through it to help with the problem, that would be my guess.