Holley 12-804 Adjustable Fuel Pressure Regulator, 1-4 PSI

#42712804

Holley 12-804 Adjustable Fuel Pressure Regulator, 1-4 PSI

Name: Holley 12-804 Adjustable Fuel Pressure Regulator, 1-4 PSI
Brand: Holley
SKU: 42712804
Price: 51.95 USD
Availability: InStock
Rating: 4.6 (41 reviews)

41 Reviews

10 Questions

Designed to be used with standard pump only
Measures 2-1/2" wide and 1-1/2" tall and deep
3/8" NPT Inlet/Outlets

$51.95

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Product Summary

Universal Fit, 1-4 Fuel Pressure Rating (psi), Aluminum

Designed to be used with standard pump only
Measures 2-1/2" wide and 1-1/2" tall and deep
3/8" NPT Inlet/Outlets
This low pressure fuel regulator is factory-set to 2.7 PSI, but is fully adjustable from 1 to 4 PSI
It includes mounting bracket with 2 each self-tapping screws for regulator to bracket installation purposes and 3 screws for bracket to vehicle installation

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Key Specs

MFG. Part #	12-804
Brand	Holley
Regulator Style	Non-return
Material Type	Aluminum

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Holley 12-804 Details

This Holley universal low pressure fuel regulator is factory-set to 2.7 PSI, but is fully adjustable from 1 to 4 PSI. Use with standard pump only - not recommended for maximum pressure pumps. Fuel pressure regulator includes mounting bracket with 2 each self-tapping screws for regulator to bracket installation purposes and 3 screws for bracket to vehicle installation.

Regulator has a 3/8" NPT tapped fuel pressure gauge port and requires reducer 617-6157 to install the gauge. Fuel pump regulator has 3/8" NPT inlet/outlet ports.

Bracket Measurements:

2-1/2" wide
1-1/2" tall and deep
1-3/4" hole spacing to mount the regulator to the bracket
Chrome steel construction

Charts

427-12804 Instructions (PDF)

Guides & Documents

Fuel Pressure Regulators Installation Instructions (42712804)

CA WARNING:

Can expose you to lead, a carcinogen and reproductive toxicant. See www.P65Warnings.ca.gov

Holley 12-804 Specifications

KEY SPECS
MFG. Part #	12-804
Brand	Holley
Regulator Style	Non-return
Material Type	Aluminum

GENERAL
Fuel Pressure Rating (psi)	1-4
Pressure Regulator Inlet Size	3/8" NPT
Pressure Regulator Outlet Size	3/8" NPT
Sold in Quantity	Each
Notes	This part is flash chromed.
Overall Height	1.91"
GTIN Code	090127020234

Ratings & Reviews

4.6

41 Reviews

Overall Assessment

Customers commend this product for its high quality performance and practicality. They noticed an improvement in their car performance after replacing older and defective regulators with this one. Many found it to be the perfect solution for their vehicles, especially for certain models like the Stromberg's 97, Datsun 240z with dual SU carburetors, and others. Some experienced ease of installation and adjustments. A few customers reported pressure spikes that required a bypass creation, and one customer criticized the product for its offshore manufacturing and design. Regardless, overall, buyers considered this product to be reliable and effective.

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4.6

41 reviews

Most Liked Positive Review

5.0

Just what I needed!

I struggled with the carb on my old Willys jeep pickup for a year after I replaced all the old stuff. It made no sense, was running before I replaced everything, would not run afterwards--until I put on the simple, easy-to-install (did I mention chrome?) regulator. Now she's ready for the parades again!

Most Liked Negative Review

1.0

Don't buy it!

Very poor design and quality. The "Flash Chrome" has the appearance that it won't hold up over time. The way it attaches to the bracket was poorly thought out. Had to grind down one of the screw heads to get to clear the fitting. The attach screws are "self tapping"? The inlet/outlet threads are very rough and difficult to get to stop leaking. The instructions that come with it mainly cover installing a fuel pump, not a regulator. The regulator was supposed to be set for 2.7 psi but was actually set at 6.2 psi. It's made offshore and it shows. Do yourself a favor and keep looking.

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Sort Reviews

Too much fuel pressure

5.0

a year ago

Cud

Backwoods, Michigan

Verified

Stock 327 fuel pump was flooding my two barrel carb with over 10psi. Works much better now under 4 psi.

Would Recommend

Exactly what was needed, quickly delivered.

5.0

2 years ago

Goatgas

Venice Fl.

Verified

Used in my MG race car

Would Recommend

Great stuff!

5.0

2 years ago

The Lemming

Spokane

Verified

Top Line product for monitoring the fuel pressures!

Would Recommend

Good product

4.0

3 years ago

Bill 40

Salem Oregon

Verified

Sent back.

Would Recommend

I will buy again

5.0

4 years ago

hotrod

ohio

Verified

use with 97 Stromberg's works great

Would Recommend

Exactly what I needed

5.0

4 years ago

George

Austin, TX

Verified

Replaced a different Holley pressure regulator that did not restrict the flow to what I needed. This one dropped in and works great.

Would Recommend

I have always been happily satisfied with the parts I've rec

5.0

4 years ago

Choir Boy 50

Nor Cal

Verified

Shipped quickly

Would Recommend

I would buy this again

5.0

5 years ago

Evilrado 402

Lincoln ne

Verified

This is a dead head style i had to build in a bypass or pressure would spike

Would Recommend

Fuel Pressure Regulator

5.0

5 years ago

Chuck E

San Jose, CA

Verified

Nice compact unit. The 3/8 inch pipe fittings are oddball and the "T" configuration is a little weird, but it works well.

Would Recommend

Haven't installed it yet, seems to be exactly what I need

5.0

6 years ago

Steve

Sterling Colorado

Verified

My old Mr. Gasket regulator got to where I didn't trust it any more, so I did some research and decided this Holly sounded like the best one for not a whole lot of money. I'm setting up dual Strombergs on a rebuilt flathead, so I liked the idea of two ports on the regulator instead of using a fuel block.

Would Recommend

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Showing 10 of 41 reviews

Questions & Answers

10 Questions • 18 Answers

Sort Questions

what is this regulator pressure factory setting and how can it be adjusted without a pressure gauge? thanks,

by bubba

• 6 years ago

1 answer

View Answer

Do you need a return line back to the tank, or can you reduce the pressure without a return line.

by Kip

• 8 years ago

3 answers

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Can this be reduced foe 1/4 inch lines and still work properly? Old BobCat skid steer 2-3 psi max.

by Craig

• 9 years ago

3 answers

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I guess I may not understand why this regulator has a 3rd hole in bottom. I thought I hook up a inlet and a out line. ??? Please help. Thanks, Don

by Don

• 9 years ago

3 answers

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will this regulator work ok with a generic electric pump?

by dan

• 9 years ago

3 answers

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Will this regulator work with standard pump gas that has 10% or 15% ethanol?

by Jim

• 9 years ago

1 answer

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Do you recommend a specific pressure gauge to work with this setup?

by Danny

• 11 years ago

1 answer

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can this be used with a holley mechanical fuel pump producing 8 p.s.I. pressure

by streetrodman

• 11 years ago

1 answer

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does this regulator come with fittings for 5/16 fuel line?

by banksy

• 12 years ago

1 answer

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Does the bracket come with this regulator to attach to firewall?

by 40MercFlathead

• 14 years ago

1 answer

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