Freakinhobo

So after ordering a couple pumps that were wrong I finally decided to pull the leaky pump to see exactly what it is. Seems to be an AC Delco 40083....? For some reason I thought I had put a high volume holley on when I put the motor in 8 years back. Any idea what this is exactly? From the pic you can see the warped garket which I assume is where the fuel leak comes from. Would it be easier to replace this pump or just that gasket?

DUB

If you are not worried about judging...I would replace it and move on. I just put one on a 1966 that looked like the one you posted a photo of.

OR...if you want to tinker with it..then mess with the gaskets.

DUB

leif.anderson93

The 40083 pump was used on the L79 engine.

mrnisguy

Call Claude @ Fuel Pumps A2Z. Fast service. Fair pricing. 618 842-6130

Freakinhobo

I'm not worried about judging at all. The orig motor (327/300) is sitting on a stand in the garage. I'm looking to start driving the vette as soon as I can with the good weather here. So I was wondering first if this pump is sufficient for a 450hp 383..? If so, I'll simply replace it for now.

Jackfit

I would get a Napa replacement , will last forever...

66jack

You got it out already, just get a rebuild kit....also get rid of that rubber line....

Tampa Jerry

Hemmings Muscle Machines published an article with pictures outlining how to rebuild a fuel pump for a GTO. It is essentially the same pump. I believe it was within the past 4 months. Jerry

Freakinhobo

I'll most likely do that.. I'd like to drive it this weekend. Looking up the specs for this pump it looks to be 45gph. It seems to have worked fine for the most part.. but what is the difference between a 45/80/110 gph pump? Is this enough to supply a 450hp motor?

Target Hp * B.S.F.C. = Fuel required in lbs/hr
450 *.6 = 270 lbs/hr
270 / 6.34 = 42.6 gal/hr

Another forum suggested this:
But remember pump losses, and a fuel pressure regulator and a return line fuel feed system designs flow requirements ?
well on a mechanical fuel pump that supplies about 7psi at the pump, getting more than 4-5 psi at the carb, under hard acceleration is going to be a challenge, due to flow restrictions, pumping losses, etc. youll find that the 80 gallon pump matched to a quality fuel pressure regulator,is about the minimum required, and a 100-110 gallon flow at 7 psi would be a nice option...

I actually already have a pressure regulator on it..

DUB

And then there is another thought on this.

When the fuel pump I installed and NOT attached to the carb...spin the engine over and make sure you kill the ignition so no power to the coil...and with the fuel line off the carb spin it over and capture the fuel in a good container and see how much it is pumping at every 'squirt'.

Then look at that..and ask yourself. "Am I going to be on the throttle that much and for such a long period of time that I really need to worry about fuel starvation?"...especially when you are actually seeing how much the pump is providing.

I understand if you are racing it...but on the road...how often do you stand on the accelerator and HOLD IT there??? If you do that a lot...then taking the fuel starvation issue into consideration is important.

AS for installing fuel return line...that would NOT be a picnic.

DUB

Freakinhobo

Good info thanks.. I'll stick with what I have.. easy plumbing.. and seemed to work fine anyways. Thanks.

Frankie the Fink

The success of your rebuild is dependent on the quality of the parts...stiffer diaphragms and springs can cause excessive pressure. Here is how to do it (a 1960 fuel pump but the procedure for yours is identical)...

65tripleblack

Here is the draft from my Restorer article Summer 2010. It explains how to rebuild the 40083 pump:

Frankie the Fink

Nicely done!