How long is fuel pump stroke?

[Car #4]

How long is the fuel pump stroke on a 440? My Edelbrock pump is 1/4” by hand. Is that all it is or is it just too stiff to push full stroke by hand. My push rod is worn down about 9/32” which would mean it wouldn’t be stoking the pump at all.

 

[Car #4]

 

[BeepBeepRR]

How long is the fuel pump stroke on a 440? My Edelbrock pump is 1/4” by hand. Is that all it is or is it just too stiff to push full stroke by hand. My push rod is worn down about 9/32” which would mean it wouldn’t be stoking the pump at all.

There is an epidemic of bad pump push rods. Just look on this site for fuel pump push rods and you will find a massive amount of threads about the failure of these push rods.

 

[toolmanmike]

There is an epidemic of bad pump push rods. Just look on this site for fuel pump push rods and you will find a massive amount of threads about the failure of these push rods.

Thank God the pushrods are wearing and not the cam lobe. That wouldn't be fun or cheap to fix.

 

[R/T Boy 67]

That 1/4" movement is just taking up the slack. I don't know for Sure who makes a good pushrod, but hughes makes one, which you would think would be be good.

 

[steve340]

I have never actually measured it but from memory you are about right 1/4 inch or slightly less.
The pump should have more movement than the lift of the eccentric on the camshaft or you would get mechanical damage.
The diaphragm of the pump only needs to "flex" to operate.

 

[khryslerkid]

If not using a Billet/roller camshaft find a nos pushrod or even a used one that measures 3.220. Installed a Howard's in my 440 and it didn't last 500 miles. Took a used one out of my 361 and it still measured within specs. That's what's in it now.

 

[turbine68rt]

Almost every original pushrod I find in yards is still within a few thousandths of the original length of 3.22".
I wouldn't hesitate to use a good original over a new one. Are you using oil with a sufficient amount of zinc?

 

[Car #4]

I add STP oil treatment to Castrol 10W30