High Pressure Fuel injection with carbs

High Pressure Fuel injection with carbs

Author
Discussion

Niponeoff

Original Poster:

2,411 posts

34 months

Thursday 18th May 2023
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So basically i have a fuel injection tank and pump setup in the car, but the new engine will run carbs.

However, rather than get a whole new fuel system, i want to use the same pump, but use a suitable FPR to bring the pressure down at the rail to a suitable 4psi for the carbs.

Can this be done reliably and can anyone suggest a suitable FPR that will do the trick. I understand i will need to keep the return. Whether i return from the rail or the FPR is another question.

The reason i want to do this, is in future, i may run bodies with FI, so want to keep that option on the table.

Pump is an 044.

stevieturbo

17,535 posts

254 months

Thursday 18th May 2023
quotequote all
Niponeoff said:
So basically i have a fuel injection tank and pump setup in the car, but the new engine will run carbs.

However, rather than get a whole new fuel system, i want to use the same pump, but use a suitable FPR to bring the pressure down at the rail to a suitable 4psi for the carbs.

Can this be done reliably and can anyone suggest a suitable FPR that will do the trick. I understand i will need to keep the return. Whether i return from the rail or the FPR is another question.

The reason i want to do this, is in future, i may run bodies with FI, so want to keep that option on the table.

Pump is an 044.
Easily done, although 044 is serious overkill though unless you're making 6-700hp

https://aeromotiveinc.com/product/a1000-carbureted...

https://www.turbosmart.com/product/fpr6-low-pressu...

Some of the Malpassi styles might...just might work, but given the flow of an 044, I would doubt it. They may struggle to get the pressure low enough.

And with whichever setup, your return to the tank will need to be at least the same size as the supply from the pump/tank, if not larger.

ie. this sort of thing. https://www.ebay.co.uk/itm/264433574841


And either way, I would advise a smaller pump. 044 makes no sense unless you actually need the amount of flow/pressure such a pump is capable of.

Niponeoff

Original Poster:

2,411 posts

34 months

Thursday 18th May 2023
quotequote all
Excellent, thanks for the info. 044 is what was on the car, feeding the cosworth. I'm not a fan personally, bit old hat, noisy and like a few amps, but money is better spent elsewhere if it can be reused.

stevieturbo

17,535 posts

254 months

Thursday 18th May 2023
quotequote all
Niponeoff said:
Excellent, thanks for the info. 044 is what was on the car, feeding the cosworth. I'm not a fan personally, bit old hat, noisy and like a few amps, but money is better spent elsewhere if it can be reused.
044's are superb pumps....if the application needs it. They work, they flow, they make good pressure and are ultra reliable. Few pumps today match the ancient pump in all those areas

But IMO you will need to spend more on a good FPR to cope with that flow, whereas with a smaller pump a cheaper Malpassi would definitely work.

GreenV8S

30,485 posts

291 months

Friday 19th May 2023
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I've run carbs from an 044 with no pressure regulator to prove a point, just a T piece offering a direct return to the tank with a tiny amount of ram pressure wafting fuel into the float chamber. It was fine for the 30 minutes or so I needed it to run and saved me mucking about with the pump/tank, but the pump was massive overkill and really unsuitable for that application.

Jack_and_MLE

623 posts

246 months

Friday 19th May 2023
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Hello

I have Malpassi fuel pressure regulator going spare if interested.

Jack