fuel pump removal?

[derek costello]

When I removed my pump and installed an electric unit I had also upgraded my oiling system to 95% filtered.
This left me with no pushrod in the pump bushing, with the engine turning rapidly
on the starter (no plugs, 6volt starter on 12) It shows 25psi..With the plug I made from a 7/16" bolt an O ring and spring I now have 80psi !!
see pictures............

[flatjack9]

What year engine? Did it have a bushing in the pump rod hole?

[derek costello]

1952 mercury truck 255 cid it has factory bushing in fuel pump push rod hole.....

[flatjack9]

I can't believe that it would make that much difference. What sort of gauge are you using?

[JSeery]

I have never measured it, but the claim has been that it allows a pressure drop. It would sure be a big drop with the bushing out! I even plug the 59a blocks just for the heck of it.

[ford38v8]

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You might consider adding a new flywheel gear ring and Bendix to your parts shelf... Just for the hell of it.

[derek costello]

New gage and sender, The guy I bought the engine from started it up for me on an engine stand with a mechanical gage and it read 80psi. I has heavy oil in it and it is cold!

[Tinker]

Maybe check the "gauge" again? Not sure also how your starter would turn faster with the modification. But it's the internet. Think there is more to the story.

[derek costello]

The gage has been verified by a mechanical gage and it read 82 psi! the starter turns much faster on 12volts and even faster with the plugs out but I have run flatheads in the past with 12 volt batteries and no problems. I would think that my engine would be doing 300 RPM
on the starter.........

[derek costello]

There is some talk about pre 1949 engines having a thin-wall bronze fuel pump bushing versus late engines with a thick wall steel bushing with a groove around the outside to let oil pass by. any thoughts ???

[JSeery]

Later bushing. If the bushing was missing you would give you a large oil pressure drop. If the bushing is in place and the fuel pump rod removed you should get an oil leak seemlier to the oil filter restrictor.

The second bushing is 32-48.

[derek costello]

OK, that is the later bushing that I have in my engine, and with the 1/2'' bolt "plug"
in place I read 80psi on the starter, so is that OK??

[19Fordy]

According to other replies on the Fordbarn, 80 PSI can damage bearings.

[JSeery]

Originally Posted by derek costello

OK, that is the later bushing that I have in my engine, and with the 1/2'' bolt "plug"
in place I read 80psi on the starter, so is that OK??

It depends how long you have the 80 psi and with what viscosity of oil. If it is maintaining that high a pressure after it warms up I would take steps to get it lower. One approach would be a lower viscosity oil.

[JSeery]

Originally Posted by derek costello

...The guy I bought the engine from started it up for me on an engine stand with a mechanical gage and it read 80psi. I has heavy oil in it and it is cold!

Why does it have "heavy" oil in it? Sounds like you my be restricting the flow with a high viscosity oil. The flow is what is important!

[derek costello]

I am just trying it with the oil that came in it (thick stuff).
I will switch to 20/40 when I change it

[JSeery]

Originally Posted by derek costello

I am just trying it with the oil that came in it (thick stuff).
I will switch to 20/40 when I change it

If it were mine I would stop trying it with the oil that is in it and get it changed ASAP. Cheap thing to do and much better for the engine. And if it is in a cold area might want even a lower viscosity. The original Ford recommendations might be a good starting point.

Just checked 8ba recommendations (F1).

above 32 deg - SAE 30
32 to 10 deg - SAE 20
10 to -10 deg - SAE 10
below -10 deg - SAE 5

So, 20w/40 should be good as long as it's above 10 deg.

[derek costello]

So I will drain the oil and refill it with 20/40 the truck is in a home shop where it never gets lower than 55degrees F

[JSeery]

Be interesting to see how much the oil pressure changes.

[Tinker]

I used to only use straight 30 diesel in florida. Mn I use 10-40. When it's hot you see a bit of drop. But nothing like going from 80 to 20. Or an increase really that drastic either. Maybe with the thicker oil overall over 5-10 psi. Hot.


Standard Flatheads are a low oil pressure system. If you are above 0 hot you are okay really, 10+ better. Ya high pressures rush oil over bearings to my understanding. Old oil can be abrasive.