Stock fuel pump limit

[SUX2BU99]

What's a stock pump good up to in terms of HP? Just wondering if I should consider a performance pump or not.

[Captkaos]

Carb'd?  If so, stock should be fine.

[SUX2BU99]

Yep, carb'd. Estimated flywheel HP to be between 350-375.

[VileZambonie]

Unless you are having a problem with fuel volume, just keep your stocker on there.

[SUX2BU99]

For sure. And without a fuel pressure gauge in the cab, I guess I may not know if I'm fuel starved or not, besides leaning out and hearing detonation. But I might attribute that to timing. Anyway, I don't think I've ever seen a chart listing fuel flow vs. pressure vs. HP. For example, 400 HP at 6 PSI requires ____ GPH. And then that asks the question of what is the stock pump sized at? Probably too many questions to ask but I'm a designer of mechanical systems for buildings so flow, pressure and load are always key items  lol

[VileZambonie]

Almost all manufacturers give a fuel volume specification for carbureted systems. It's job is to keep the fuel bowl full and you have to be sucking some serious fuel to empty the bowl and not have the ability to keep it full. If you are concerned about it though, go for a high volume pump but just make sure you install a regulator.

[SUX2BU99]

True, any aftermarket manf. does list the flow at a certain pressure. I'd like to know though what's actually required for a certain HP. I thought I had read that a 110 GPH pump can supply up to something big like 700 HP, so they do know flow vs HP. I'd just like to see a chart for my own interest. On the other hand, no one publishes specs for stock stuff which kinda sux. I had also heard though that the stock pump can be pretty good, so I'm not too terribly worried but I was curious.

[Captkaos]

It should be no less than 3lbs at WOT or something like that..

[VileZambonie]

It'd be a huge guestimate for rating it by HP rather than by volume. The stock specs are 1/2 pint or more within 15 seconds of cranking. 4-6.5psi

[SUX2BU99]

Interesting. Are there electric fuel pressure gauges available? Or are they just mechanical? I was thinking of what to have in the cab for extra gauges and trans temp and fuel pressure came to mind.

[VileZambonie]

What are you building an airplane cockpit?

yes there are electric fuel pressure gauges
http://www.egauges.com/pdf/AutoMeter/571.pdf

[SUX2BU99]

Sure, then I can be like all those Civic owners with 3 unconnected boost gauges up their a-pillar! 

One part that is missing from those instructions is how exactly to get the sender into the fuel system. My first thought would be to get a 3/8x1/8x3/8" metal tee to insert into the rubber fuel line coming from my fuel pump to the carb. Not exactly stealth or tidy though. And why would they recommend to use teflon compound on the threads but not teflon tape?

[VileZambonie]

Well a pressure tap at the outlet of the fuel pump or inside the pressure regulator would work. I prefer pipe thread sealant also. Many people end up with pieces of teflon inside the system because they don't know how to wrap threads correctly...