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michael bustamante

09-14-2015 06:29 PM

fuel pressure regulator question

im using a mallory electric fuel pump for my system. engine is a pretty standard 350, hei, power pac heads. good running with a new holley 650 vacuum secondaries with a street dominator intake and a 700r trans
should i use a 1-4 psi regulator or a 4.5 to 9 psi?

michael bustamante

11-03-2015 03:02 PM

Re: fuel pressure regulator question

anyone?

leftybass209

11-03-2015 03:45 PM

Re: fuel pressure regulator question

You should use the 4.5 to 9. Up to 4 sounds really low, like for a 1 or 2bbl. carb. Anything 4 or less, or 8 and up and i'd say you're asking for trouble.

EARNHARDT#3

11-03-2015 08:47 PM

Re: fuel pressure regulator question

Pressure and flow rates are 2 totally different things. Personally I think 4psi is plenty if it's going to flow enough fuel.

engineer_gregh

11-04-2015 09:00 AM

Re: fuel pressure regulator question

I'm not sure you would need a fuel pressure regulator. With Edelbrock carbs I use an Edelbrock fuel pump because they are sensitive to pressure but everything I've read about the Holley carbs state they are not as sensitive. I would call the Holley tech support number and ask them. Just my .02 cents.

Matt Cramer

11-04-2015 09:28 AM

Re: fuel pressure regulator question

Quote:

Originally Posted by EARNHARDT#3 (Post 7364039)

Pressure and flow rates are 2 totally different things. Personally I think 4psi is plenty if it's going to flow enough fuel.

Yep, on a carb, you just need to get enough pressure to flow past the needle valve, and no more.

Fitz	11-04-2015 11:08 AM

Re: fuel pressure regulator question

Quote:

Originally Posted by michael bustamante (Post 7308839)

The sweet spot for a Holley is 7 PSI. They will run (just) at 4 but starts become hard and they tend to stumble when the pressure gets that low.

michael bustamante

11-04-2015 11:57 AM

Re: fuel pressure regulator question

well i know my engines a thirsty bastard. so 4.5 to 9 sounds like it might benefit me better.
I sweat I should just let the moths out of my wallet and buy an LS... lol

leftybass209

11-04-2015 12:43 PM

Re: fuel pressure regulator question

Quote:

Originally Posted by michael bustamante (Post 7364649)

well i know my engines a thirsty bastard. so 4.5 to 9 sounds like it might benefit me better.
I sweat I should just let the moths out of my wallet and buy an LS... lol

If ALL I had to buy was an LS, i'd be thrilled!!! Unfortunately once you total everything else you need like gauges, exhaust, motor mounts, driveshaft possibly, blah blah.... it adds up quick!!!!!

michael bustamante

11-04-2015 12:53 PM

Re: fuel pressure regulator question

i know...n my trucks all put together too.

EARNHARDT#3

11-04-2015 01:01 PM

Re: fuel pressure regulator question

Quote:

Originally Posted by leftybass209 (Post 7364699)

If ALL I had to buy was an LS, i'd be thrilled!!! Unfortunately once you total everything else you need like gauges, exhaust, motor mounts, driveshaft possibly, blah blah.... it adds up quick!!!!!

Yeah I started looking into it and I just couldn't justify all the work and money for the little bit of cruising I do in my truck. It seems so simple at first but it's really a lot of work to me.

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