Belt drive fuel pump plumbing question

[andrewb]

I’ll be running a belt drive fuel pump with limited space. What is the best pump/plumbing setup for this? How close to the pump does the fuel shutoff valve need to be or does it matter. How about the primary bypass valve? I was thinking about picking up an Enderle 80A-1 pump, which only has one outlet, then route that up a foot or so to a 4-way shutoff valve and plumb in the primary bypass there.

Any suggestions on this?

Thanks,
Andrew

[Spud Miller]

 Hi Andrew,

 The main bypass can be anywhere in the system...doesn't matter too much. If it's real low on the car and set up very light, sometimes the weight of the fuel in the line above it can cause it to bleed down. It'll also lose a bunch more fuel when you change the pill if it's low. The 4-way shut-off idea is a good one! For just a few bucks more, you get an extra port that is always open on the shut-off for use as a main or high-speed port. If a person has to buy a new shut-off anyway, I always suggest a 4-way for that extra hole.

 Generally, because the pump is rigidly fixed and the shut-off cable needs to pull on something solid, the shut-off is mounted directly into the pump outlet using a bulkhead fitting. Also, the Enderle-type shut-offs don't have a means of attachment to the chassis or anything like that. Flopping around mid-stream in a hose might not work well. If you can come up with a creative way to mount that shut-off, it should work well where ever you put it.

I think if it's down low on the motor with the pump, it may shorten a bunch of your return lines vs. being mounted up higher on the motor.

Have fun plumbing!
Spud

[andrewb]

Thanks for the info Spud.

Regarding the Enderle 80A-1 and Hilborn PG150C-1 pumps. New, both advertise 7.0 GPM, #100 @ 4000 RPM. I've been looking at used pumps and in the case of Hilborn, I see flows range from 5.68 GPM to 6.30 GPM. At what point is the flow too low and the pump requires a rebuilt? How much variation do you see in GPM on new pumps? From your experience, which pump has the ability in delivering consistent flow over time.

Thanks,

Andrew

[Spud Miller]

Neither of those pumps make 7.0 (maybe free flow, which means nothing). A brand new -1 pump is 6.4-6.6 @ 4000 pump RPM and 100 PSI head pressure. They are all generally within a couple of tenths of a gallon when new.

As long as you're returning something to the tank, the pump isn't too small Practically speaking, once your main pill is below a .060 or so, you really are out of pump and need more flow.

Both Enderle and Hilborn pumps are equally capable and have nearly identical parts inside. A good used pump is not likely to change much over time. A brand new pump will generally lose .05-.1 or so in the first season as it breaks in. After that it won't change much unless it sees damage (dry starts, dead-headed, drive misalignment, debris through it, etc.).

 Spud

[slingshot383]

I liked staking my system, pump, cross, 3-way shutoff, line to barrel valve.  The cross would have my main, hi-speed, and converter helper coming off it, that way when I pulled the shutoff, the pump didn't overpressure as there was lot's of ways for the fuel to return.  I also had a manifold about a foot in front of the pump where all my returns went into the the spuds angled to the pump to prevent cavitation.