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I have been learing a lot about cars/engines the past few years. I am wondering why so many people seem to run electric fuel pumps on street driven hot rods. I have always ran mechanical on various engines 350 and 396 up to 480 HP on the street with normal mechanical fuel pumps. These were never on the stip though.
At what point must you use an electric pump? Just looking to learn more about this area.
i have mechanical pumps on all my stuff .. just the V6 pinto did`nt have provisions for one ..( fuel injected ) originally .. now has 4 barrell carb ...i suppose there is a point in HP or rpm`s at which electrics are required to keep up with flow ..
I think the primary reason, on my car at least, is that there is no room for a mechanical fuel pump with the steering linkage to the R&P. Electric was the only option for me....Quote:
Originally Posted by bucs012
My previous car was a street/strip 65 GTO with a 389 tripower and a 4 speed.
After much fiddling I got it to run 13.30's pretty regularly. Then one Sunday , it stalled when I did the burnout. It had never done that before. It restarted and everything was fine, BUT, it got me wondering if I was running out of fuel with prolonged high RPM.I added a Carter electric pump, and the next weekend the car ran a 12.97 and speed jumped from an average of 105+ to over 107 MPH!!
Prior to stalling that one time it never displayed any symptoms of fuel starvation. It always pulled strongly all the way through the quarter.
The engine probably made an honest 340 HP.
Food for thought.:o
i always wonderd to
For street use, and a lot of the bracket cars a QUALITY mechanical fuel pump does just fine.... Edelbrock, Carter, and a number of companies have mechanical pumps flowing upwards of 110 gph and pressures up to 9 pounds.... Then there's the new style one for the chebbies, only 1 moving part!!! The majority of the good mechanical pumps have
3/8" NPT threads, which works fine for -6 or -8 hose or tubing....
When it's time to go drag racing in something running 12's and faster, I usually go to one of the good electric pumps with -8 lines and a regulator with a return line..... I just don't like them rattly old electric pumps on the street!!! The new gerotor style is considerably quieter, but they're also a whole lot more $$$$$ then one of the good mechanical pumps....
K.I.S.S----Keep It Simple Stupid! The stock (or improved) mechanical pump is the way to go until it becomes obvious that it won't do the job. Usually flow rate is not the problem, the stock pump has to "pull" the fuel against acceleration and often causes starvation. An electric pump mounted behind the tank and rear line in the tank fixes that problem. Not usually a concern on a street rod.
I would have preferred a mechanical pump, but when you pinch the frame on a '32 Ford, there is no room for a mechanical pump, hence the necessity of using an electric pump.
Good info, guys.
I have a tunnel ram set up on my Nova with (2) Edelbrock 500 cfm carbs. Again,street only and I have never had any issues or hints there of.
Now I am looking at going with a small block or big block blown engine in my Ford and really don't want to move over to an electrical pump either. Again, simply street duty with a little smoking the tires here and there. :D
IMO with aftermarket mech pumps flowing 110 gph or more @ 9# or more there's just no need for an electric pump for a carbed motor on the street.
Of course FI and limited space is another story.
I run a Holley mech. pump on my blown small block with dual Demon 650s and have never had anything close to a fuel delivery issue.
I guess the fuel starvation from G forces is why the mooneyes tank in front of the grill became popular?
I run an electric on my C-10 becuase the stock pump push rod was locking up when the motor got hot. Wierd, huh?
When there is no option for mechanical pump, electric pump is used.
Blown application, I would use an electric pump. Worst thing to happen is a lean condition in a blown motor. My .02Quote:
Originally Posted by bucs012