L20B (L16/L18/etc.) Fuel Pump thread sizes?

[kidatari]

Fello datnuts,

 

Looking for details on the thread sizes on the inlet and outlet for the L20B stock fuel pump, and/or if anyone has details on the thread pitch/count on the other fuel pumps it would be greatly appreciated for those of us attempting to change the fittings on them.

 

I've searched about everywhere I could find, but no luck. Anyone?

 

Thanks in advance-

 

Josh

[banzai510(hainz)]

L series fuel pumps are the same build type but are specific if you want inlet outlet locations.

510 /521s are the same inlet/outlet locations.

 

620 trucks have different inlet/outlet locations.

[kidatari]

Well, my specific application is on an L20B in my 1970 521. Not sure what the engine was originally from.

 

I'd be happy to provide photos if it'd help.

[banzai510(hainz)]

order a 510 or 521 specific pump to have the correct inlet outlet location.

other wise most 620 L20b pumps I see the inlet faces the firewall. On 510/521 the inlet comes from the passemger side by the battery

 

Or get soem copper tube and make some bends and hook the fuel hose up to it. Its low pressure so shouldnt be to muck of proplem leaking

[kidatari]

Hainz-

 

The intent is to replace the lines with hard lines to my Weber, and if possible I wanted to just swap the fittings on the pump with correctly-sized adapter to AN fittings. I used to be an aircraft mechanic, and I hate having rubber lines snaking all over the engine bay, so I try to use hard lines for a clean and reliable install.

 

On my pump, the inlet faces the firewall and the outlet faces the head.

 

It still leaves the questions of thread sizes of the inlet/outlet, as they appear to be brass fittings threaded into the aluminum body of the fuel pump.

[DanielC]

This is just an educated guess. The oil fitting on the block is a British pipe size, on my 1971 521 truck. I would kind of expect that the threads on the fuel pump are, also.

however, since the fuel pumps are not manufactured by Nissan, but I think by Nikki, and Hitachi, is is possible the fuel pump threads could be either an American standard, like the body bolts on a 521, or is is possible that they are metric.

I also would kind of expect the L-20B fuel pump to be metric.

 

Sorry, I really did not help much. In fact, I probably just made you aware of a third choice you were not considering.

 

If I remember correctly, the top half of the fuel pump is held with six screws. It might be possible to reclock the top half. Be careful you could rip the fuel pump diaphragm really easily, on a pump that has been together for 40 years.

[banzai510(hainz)]

as they appear to be brass fittings threaded into the aluminum body of the fuel pump.

 

Yes your correct. best guess is pull them off and go to a fitting place.

 

as for hard lines I guess you could find some later L motors as they have more hardlines and even return lines and make something work

 

But 510/521 is pretty basic from the fuel filter left to the inlet. then the outlet goes right to the weber. use short rubber hoses and it will be a clean look.

 

 

goodluck