fuei pump

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fuei pump

Postby jim327monza » Sat Jan 21, 2017 4:32 pm

While i have the fuel tank off to replace the in tank pump for the second time, I am considering an external pump because I do not think the stock pump will support the 600 cfm carb going on the 327 that will replace the 4.3 in the car now. Can the existing wiring harness be used? The fuse block has a 10 amp fuse . Are there any issues with the pick up? relocate the filter?
As always, I greatly appreciate all the help I have recived.
Jim H.
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Re: fuei pump

Postby cjbiagi » Sat Jan 21, 2017 7:54 pm

Jim, I am not sure that the harness will support a external pump, I would check the current draw on the new pump and go from there. However, I have the stock fuel pump on my 355 with a Edelbrock 625cfm carb and never had a problem.
Clyde.........75 Monza 2+2
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1975 Chevrolet Monza

Re: fuei pump

Postby jim327monza » Sun Jan 22, 2017 8:22 am

Clyde, Thanks for your reply. I found this formula that may benefit our members. GPH = MAX HP x BSFC /6 This applies to carbs only. Max horsepower multiplied by Brake Specific Fuel Consumption divided by 6. Max HP by dyno or calculation . BSFC is rated in pounds per hour and rated at .5 for stock or near stock engines . 1 gallon of gas weights aprox 6 lbs.
My formula looks like this 350 x .5= 175 divided by 6 = 29.2 max GPH. The Airtex pump that is stock for our cars is rated at 35 gph max and 6 psi max. This formula is affected by nitrous ,turbos, and other modifications . So it looks like Clyde is correct as usually. Stock pump should be fine.
Jim H.
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Joined: Wed Sep 05, 2012 8:42 pm

Re: fuei pump

Postby MonzaRacer » Wed Jan 25, 2017 9:46 pm

So according to one person over on v8monza.com the 94 Buick Park Ave sending unit/pump work fine in our tanks. I helped one guy and we made a baffle with a sheet of fairly thick sheet metal from Lowes, used a greenlee punch to punch holes in it. The holes nearest bottom we only used 1/2 holes at base of baffle. Then we simply cut the top and bottom of tank with cut off whe tapped baffle in with allowances for sender arm, and tig welded top and bottom. also we soldered in a 1/4" pipe fitting from an old copper/brass rad tank and installed a pipe plug so we could drain tank easily. If he hadnt centered the tank to middle in back to run tail pipes on each side I might have talked him into installing regular petcock but then it would make steeling gas easier.
We smoothed top of tank where it meets body so we could center it up for tail pipe clearance. After dumping torque arm you would be surprised how much room is under a Monza for regular pipes. He also got a quick and dirty version of the rear crossmember I am trying to get finalized so I can get someone to bend me a few up to sell. It gonna go pretty much even with top of trans tunnel, allow adding upper control arms in bot 4 and 3 link versions. I am going to tie it into rear seat belt mounts in floor as trans tunnels is said to be as much as 40% of stiffness. Thus it will stiffen the rear of car, delete torque arm which eats up undercar real estate. also allow removing Panhard bar if in 4 Link mode(will have both parallel or triangulated ability. Also got plans to work with Jim Fays and make a bolt in Fays2 watts link .
My hope is to make all three models of S10/Blazer rear axles a near perfect bolt in. THUS allowing us 8.5 10 bolts as well as later 28 spline 7.5. My main reason is I just installed my 7.5 as a swing arm with cut down front of springs as swing arm and other than I should have cut loose and rewelded or replaced spring perches a 2wd slides right in.
Yes the short arms act like small ladder bars but I had 275/60s under mine.
Oh crap I got off topic.
94 Buck Park Ave with SC fuel pump/sending unit should feed most anything you need, just use good return type regulator.
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