Fuel pump interchange
 

I'm having issues with my 36 LB engine regarding fuel. There is no fuel filter so I want to add one. I have a fuel pump from a 51 truck motor with the built-in glass bowl filter. It will physically bolt up, but my concern is it having the correct "throw", that is enough to actuate the pump but not so much as to cause it to bottom out or jamb/bend or break anything. I can use the original "tower" with the oil fill cap and the original pump shaft. Am I setting myself up for failure or disappointment? Thanks in advance!

Re: Fuel pump interchange
 

Yes, it will interchange with the earlier pump without damage. It may not be clocked to the same position as your current pump, but you should also know that if you are careful to preserve the gasket, you can remove the top and clock it to the new position without issue. Just know that even if in perfect working order, this change may not cure your stated fuel problem.
Tell us what that problem is, maybe we can suggest a solution that is meaningful.

Re: Fuel pump interchange
 

The original pump would have a screen for a filter under the top cover and a sediment drain on the side of the pump

Re: Fuel pump interchange
 

Alan, I did clock it over 1 click and it sits nice and close to the firewall now. Kurt, I didn't know about the screen in the original pump and I was wondering what that petcock was for. This is a car I just bought and I am in the early stages of sorting it out. I has been sitting for 4 or 5 years. The seller told me he replaced the tank but it has that varnish smell. She will fire right up and idle beautifully, but is hesitant to take gas when you step on it. It has a model 59 Holley on it and I have had it apart twice now. I pumped out what gas I could (a couple of gallons) and put some fresh in it. Thank you for your replies.

Re: Fuel pump interchange
 

The 51 fuel pump is not the same as the 47-48 fuel pump with sediment bowl. The later pumps have a flange that hangs down lower below the hold down bolts. I haven't tried the later pump on an earlier engine but apparently it works. The earlier pump on a later engine is a poor idea.


Pamlico, have you checked that the accelerator pump is working properly? You should have two streams of gasoline in the carburetor when you open the throttle, one for each barrel.

Re: Fuel pump interchange
 

38 coupe, yes I have checked the accelerator pump and had the little check ball out(it was stuck both times). I will take it apart again and do a more thorough cleaning. I will probably end up taking the tank off for cleaning and to blow out the line to the front.

Re: Fuel pump interchange
 

After the tank and lines are cleaned out with fresh fuel it wouldn't hurt to use some seafoam or MMO for awhile.

Re: Fuel pump interchange
 

The later fuel pump may not have the correct threaded openings for input and output. They went to NPT thread the slightly earlier pump with the filter does have the correct threaded openings with seats and will work properly if in good condition. Both pumps are identical in outward appearance.

Re: Fuel pump interchange
 

Terry, you are right. I had to use some adapters to go from NPT to compression fittings. Luckily, I had two. Thanks for the heads up.