l16 mechanical fuel pump vs electric pro's and con's?

[logan1600]

Would an electric fuel pump be better for performance?

[flatcat19]

Not on a stock motor. 

 

 

You're running carb(s). Sounds like a lot of work for 4 psi. 

[datsunaholic]

Electric fuel pumps work best with full circulation.  521s are not set up that way.  But, a quality electric pump is better than those crappy plunger-type aftermarket mech pumps you get at autozone.  As long as it's low enough pressure, that is.

[Z-train]

Electric pumps are designed to push rather than suck and REQUIRE a return line.But like someone said -a lot of work to maintain 3-4 psi.But if you want the "exercise"-by all means.

[DanielC]

From a post August 1, about fuel pumps:

There still are thousands of Datsuns running around with a stock mechanical fuel pump.  Maybe even millions.

 

The mechanical fuel pump does not use the engine cam eccentric to pump fuel.  The cam eccentric just pulls back a spring, on the fuel pump diaphragm.   The pressure on the diaphragm is held back by the needle and seat.  Only when the engine need fuel, does the fuel pump move fuel.  Both are calibrated to work with each other.  Additionally, the mechanical fuel pump pumps more gas, if needed at higher RPMS.

 

An electric fuel pump just tries to supply as much fuel at idle, as it does when the engine is running 7,000 RPM, WOT.  It does not ever "back off".

 

Most importantly, if the engine stops and the key is still on, the mechanical fuel pump stops pumping fuel.   If you get into an accident, and you forget to turn the key off, you are not continuing to pump fuel.

 

I know you can add oil pressure switches, and fuses, and other safety items to an electric fuel pump, but never forget, parts left off a car cost nothing, and cause no service problems.

 

I have found the most reliable Datsun is a pretty much stock Datsun.

• datzenmike and gords11 like this

[jwerty1]

Like Daniel said absolutely no point to switch to an electris pump. Only reason would be for a turbo blow through system or a fuel injected setup. Regular ol carb, or upgraded carb, stick with the mechanical

[datzenmike]

Here's another but not the only reason.... Easier to disable so the car can't be stolen.

[Gery]

On 8/17/2014 at 7:20 AM, datzenmike said:

Here's another but not the only reason.... Easier to disable so the car can't be stolen.

Hello-

My ‘78 truck originally had ac (but now out) so it is equipped with an electric pump.  Are mechanical ones more trustworthy?

your comment brings up an interesting alternative to a kill switch for theft deterrence.  Also, a fuel pump switch would allow having the ignition on (during diagnostics etc.) without motor running and also not having the electric pump pounding away.

Inasmuch as I prefer reliability, if an OEM mechanical pump serves that purchase, I will start scouring for one.

[datzenmike]

If they are original Nissan parts they are both good enough.  If you find a mechanical one (for a spare, I wouldn't be in a hurry to change it) get the eccentric that is under the cam securing bolt that drives the pump arm. Be sure also to get the 1/4" plastic spacer between the pump and the head. You'll need two gaskets for this.

[Gery]

Thanks.