Carb'd 347 Fuel System Setup Questions

[Daddy O]

Hello All,

Hoping you guys can share your thoughts on my fuel system plans and recent input I received from Aeromotive.

Currently have:
- Pro M Hanger
- 265LPH in tank pump
- 45 micron post pump filter canister

Engine plan:
Carb'd BPE 347

3/8" Nicopp feed and return lines

None of the above installed yet.

Planning a return style system. Called Aeromotive to see what regulator they recommend. The tech guy said the X1 regulator is a good choice but said I need to run 1/2" feed and return lines because the 3/8" lines I was planning would bump the pressure up coming out of the pump. Did not think to ask him at the time why this is a problem. Maybe concern the regulator will not be able to drop the pressure enough? The Pro M hanger has -6 fittings so running 1/2" fuel lines seems kinda pointless since the feed is already starting with 3/8" in the hanger. But, I am a total noob so this is new territory for me.

Any help is most appreciated.

Thanks!

[edwardb]

Maybe I'm missing something. This seems like massive overkill for a carb'd 347. I've run a similar setup (Pro-M hangar, 255LPH pump, 3/8" lines, Aeromotive regulator) in a couple Coyote builds. Works great BTW. But for a carb'd 347? Blueprint builds a good engine but shouldn't need that much. Quick search shows that regulator can only be turned down to 35 PSI. Still way too much for a carb. Not even sure why you'd have a return line if plan to stay with a carb. 1/2" lines for a carb'd 347 is way out there too. You have an opportunity to simplify this greatly IMO.

[NAZ]

A -6 (3/8") fuel line on supply & return will be plenty but you will need to limit pressure to the carb to 5-7 PSI and a filter before the regulator & carb should be maximum of 10 micron and 5 micron is better. https://www.dragzine.com/news/filtering-facts-the-lowdown-on-high-performance-fuel-filters/

[Daddy O]

Thanks for the input guys.

The Aeromotive 13304 X1 regulator is for carbs and outputs 3-20psi. If going with an efi style in tank pump and dropping the pressure with a regulator is overkill, what are my options? I am trying to avoid an external pump.

[skidd]

You could do something similar to what I did. I plumbed for a return style fuel system, just in case one day I switch to EFI. But, I run an in thank low pressure fuel pump, dead headed at the carb. My return fuel line is just capped off.

It makes about 6psi at my carb... And I think something like 60GPH.
https://www.amazon.com/gp/aw/d/B008M4R69E/

[Daddy O]

Thanks Skidd. Did you use the Pro M hanger?

[edwardb]

Thanks for the input guys.

The Aeromotive 13304 X1 regulator is for carbs and outputs 3-20psi. If going with an efi style in tank pump and dropping the pressure with a regulator is overkill, what are my options? I am trying to avoid an external pump.

That's better. I just did a generic search on Aeromotive X1. What does Blueprint recommend? They've done a ton of these. There's nothing wrong with what you specified. It just flows way more fuel than you need unless you have big power plans for the future.

[Olli]

When I converted from EFI to carb I used this Aeromotive regulator. It allowed me to retain the intank pump. https://www.summitracing.com/parts/aei-13220

[FLPBFoot]

That's better. I just did a generic search on Aeromotive X1. What does Blueprint recommend? They've done a ton of these. There's nothing wrong with what you specified. It just flows way more fuel than you need unless you have big power plans for the future.

Blue Print provides an external pump with their engines. I think DaddyO wants to stay away from the external pump. I did too but finding a low pressure in tank pump that flows 125 gph at 7 psi is the issue. So I went with BP's recommendation and I hung mine on the passenger side down tube just above the 4 inch main and ran the fuel line along the outside of the 4 in tube. With my 427 they provided a Holley Red pump. They are loud and I upgraded to a HP 125 that is almost silent.

[CaptB]

Blue Print provides an external pump with their engines. I think DaddyO wants to stay away from the external pump. I did too but finding a low pressure in tank pump that flows 125 gph at 7 psi is the issue. So I went with BP's recommendation and I hung mine on the passenger side down tube just above the 4 inch main and ran the fuel line along the outside of the 4 in tube. With my 427 they provided a Holley Red pump. They are loud and I upgraded to a HP 125 that is almost silent.

I haven't installed yet, what's wrong with using the Holley FP that's delivered with your engine? I mean why sell us a very expensive engine and include a FP that wouldn't do the job?

[nucjd19]

I haven't installed yet, what's wrong with using the Holley FP that's delivered with your engine? I mean why sell us a very expensive engine and include a FP that wouldn't do the job?

Nothing is wrong with it IMO. I am running the Holley that came with my BPE 347 and mounted it also to the rear passenger 4" tube. It works perfectly. ILB is correct though, you can hear it before you start your engine when you turn on the ignition. But once the engine fires...... the pump is whisper quiet :)

[skidd]

Thanks Skidd. Did you use the Pro M hanger?

Stock Hanger. My 302 isn't starved for fuel with the 5/16 outlet.
I did mistakenly plumb a 1/4 return line though. Which is going to be totally useless if I do ever switch over to EFI (not planning to though).

[rich grsc]

Stock Hanger. My 302 isn't starved for fuel with the 5/16 outlet.
I did mistakenly plumb a 1/4 return line though. Which is going to be totally useless if I do ever switch over to EFI (not planning to though).
There are hundreds of these cars using the 5/16-1/4" fuel lines without issue, it's the same size the Fox body Mustangs used. Until you get over about 350hp, no concerns.

[Jim1855]

I've run an Aeromotive bypass regulator and return system for my mechanical fuel pump and carb'd 427. Perhaps not necessary but had issues with underhood temps boiling fuel and over pressuring the needles. The bypass system gave the fuel someplace to go. Worked well and I will do the same for the current build.
Jim

[Daddy O]

Thanks for all the great insight. I am leaning towards an external pump. I really liked the idea of having pump and pre filter in the tank to simplify and make for a clean install but there does not seem to be a clear path to achieve that without creating a high pressure efi type system.

[CaptB]

Thanks for all the great insight. I am leaning towards an external pump. I really liked the idea of having pump and pre filter in the tank to simplify and make for a clean install but there does not seem to be a clear path to achieve that without creating a high pressure efi type system.

I'll go get the part number for the external carb that BPE puts into the crate when they ship. I know it's Holley.

[Daddy O]

Thanks but no need, its a Holley red head.

[FLPBFoot]

Nothing is wrong with it IMO. I am running the Holley that came with my BPE 347 and mounted it also to the rear passenger 4" tube. It works perfectly. ILB is correct though, you can hear it before you start your engine when you turn on the ignition. But once the engine fires...... the pump is whisper quiet :)

Mine started out noisy when the engine was off and then could not hear it with the engine running and after about 2,000 miles it got so I could hear the pump with the engine idling. That's when I went with the HP125.

[skidd]

There are hundreds of these cars using the 5/16-1/4" fuel lines without issue, it's the same size the Fox body Mustangs used. Until you get over about 350hp, no concerns.

Totally agree.
The only issue is the 1/4 return capacity when used with a higher volume pump than a typical OEM pump.
Anecdotally, I had a Walbro 255 in my 2000 Subaru, hooked up to a Vortech RRFPR and a 6:1 plate. that raised the pressure from a OEM level of 30(ish) psi, up to nearly 70psi at full boost. (It was a custom M62 Supercharged Scoob)
I always wondered if at idle when the least amount of fuel is needed, and the most fuel is being bypassed, if the OEM 1/4" return line was too small. After driving that car supercharged for 12+ years, the fuel pressure was never an issue.
If I ever do go EFI one day, I'd almost certainly chose a Holey Sniper system. Then, just a matter of picking a pump that can produce 60psi, and the minimum flow needed for a 350hp 302.
I would not be surprised if the little 1/4 return line was easily able to handle the demands of a system like that.

[Tony_G]

Thanks for all the great insight. I am leaning towards an external pump. I really liked the idea of having pump and pre filter in the tank to simplify and make for a clean install but there does not seem to be a clear path to achieve that without creating a high pressure efi type system.

It is possible to do the internal pump and a carb. I have a 427w with a 750 quick fuel carb. Areomotive 340 in tank pump and Pro M hanger. 3/8 supply and return lines. Edelbrock return style regulator. Works great.
https://www.summitracing.com/parts/edl-174133?utm_source=bing&utm_medium=cpc&utm_term=%2bedelbrock+%2b174133&utm_content=Edelbrock&utm_campaign=Part+Number+Ad+Groups

[Daddy O]

Thanks Tony, I have heard from CV2065 too saying his similar setup also works great. Having the option to easily switch to a Sniper later if I wanted would also be a plus. I have not returned the Pro M hanger or pump yet so I may still go that route.