914World.com [Powered by Invision Power Board]

Posted by: nycchef Oct 1 2008, 08:46 AM

i am finishing my 2.0 installation. have a cb performance fuel pump 3 1/2 lb, no regulator (maybe later) so here's the question. i will be blocking off the old 7mm return line at the tank and using the 9mm to feed the pump, which is under the tank. i still have the 7mm and 9mm lines running to the engine bay, which would be better to feed a set of dual weber 40"s?

Posted by: Mark Henry Oct 1 2008, 11:34 AM

QUOTE(nycchef @ Oct 1 2008, 10:46 AM)

i am finishing my 2.0 installation. have a cb performance fuel pump 3 1/2 lb, no regulator (maybe later) so here's the question. i will be blocking off the old 7mm return line at the tank and using the 9mm to feed the pump, which is under the tank. i still have the 7mm and 9mm lines running to the engine bay, which would be better to feed a set of dual weber 40"s?

You wan't to feed with the original feed line as it has the brass in tank screen, but I thought that was the 7mm line. I could be wrong about the 7mm line, but you do want the feed line.

A 2.0 won't have enough Hp to need a larger than 7mm line.

Posted by: r_towle Oct 1 2008, 11:37 AM

You probably want the pump in the rear so it sucks instead of pushes the fuel...
Pumps can only push so far.

Get a regulator, 3.5 lbs can be to much for carbs and you will have issues tuning them.

Rich

Posted by: URY914 Oct 1 2008, 12:14 PM

Actually fuel pumps are made to push, not pull. Pump should be near the tank.

Posted by: Joe Ricard Oct 1 2008, 12:21 PM

Word
pump under the tank, regulator in the engine compartment.
5/16" line is enough for 150 HP for sure.
I know Paul at one time had 3/8" and I will probably upgrade as well to 3/8" when the time comes to plumb the white car.

Posted by: r_towle Oct 1 2008, 12:26 PM

Considering the stock location is lower than the tank and alot easier to get to once the cheap pump dies, and it will, IMHO its the best place to put it.
Agree, the regulator should go in the engine bay in plain sight, possible with a gauge inline to verify. I have not seen alot of accurate setups so a gauge is a good way to verify everything.

Rich

Posted by: brant Oct 1 2008, 04:36 PM

circulatory fuel systems are better than non circulatory ones...

fi or carbs

I run a return on carbs

brant

Posted by: nycchef Oct 1 2008, 04:49 PM

thanks guys all done ,pump under tank 7mm line will put in a regulator when the budget allows. i left the 9mm line tucked away in case . how do you run a return anyhow?
rich

Posted by: Root_Werks Oct 1 2008, 04:56 PM

Good time to note: I thought the return line was also a tube that run up higher than the suction line anyway. So you'd still read something in the tank via the fuel gauge, but be sucking air if you used the return line? No?

Posted by: Root_Werks Oct 1 2008, 04:58 PM

QUOTE(nycchef @ Oct 1 2008, 03:49 PM)

thanks guys all done ,pump under tank 7mm line will put in a regulator when the budget allows. i left the 9mm line tucked away in case . how do you run a return anyhow?
rich

Like has been said, run pump under tank, 7mm line has supply to first carb then out to second carb, then out to pressure regulator then to 9mm return line.

Posted by: nycchef Oct 1 2008, 05:17 PM

QUOTE(Root_Werks @ Oct 1 2008, 02:56 PM)

Good time to note: I thought the return line was also a tube that run up higher than the suction line anyway. So you'd still read something in the tank via the fuel gauge, but be sucking air if you used the return line? No?

i connected the pump to the regular suction line. i was wondering about the lines that went thru the tunnel from the old fi. does anyone know where to buy an adjustable fuel pressure regulator?

Posted by: peetzinc Oct 1 2008, 05:33 PM

I am curious here as I see what, I think, is contradicotry information. The fuel pump I have says it is a pusher, so under the tank would be good but I have spoken with a few folks that say mount it where the FI pump was. Easy here as the wiring is right there.
I am in the process of doing exactly the same. 40 IDF's, fuel pump and I bought an .009 Pertronixs electronic distibutor. I have to rebuild the carbs yet and then set it all up.
I am looking for a definative on the location for the pump. The fuel pressure regulator sounds like a great idea. Where would one get an adjustable one...with a gauge would be great?

Posted by: SGB Oct 1 2008, 05:43 PM

It should be up front. There is no problem achieving the required pressure. I've had my pump in front for 20+ years, using the 9mm line. no return line, and no pressure regulator.

Posted by: nycchef Oct 1 2008, 05:46 PM

QUOTE(SGB @ Oct 1 2008, 03:43 PM)