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Discussion Starter · #1 ·
I already have 1/2 copper fuel line on my ute that the holley blue is pushing thru.
I have a bg220 pump which requires a bypass line. Have just purchased a mallory return reg #4370m which states for pumps over 200gph they need a 5/8 line? I would have thought 1/2 would be heaps?
Also the reg has a boost/vacuum port which allows you to run less pressure at idle.
Are any of you guys running a setup like this?
Any advice appreciated.
Cheers
Karl
 

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I already have 1/2 copper fuel line on my ute that the holley blue is pushing thru.
I have a bg220 pump which requires a bypass line. Have just purchased a mallory return reg #4370m which states for pumps over 200gph they need a 5/8 line? I would have thought 1/2 would be heaps?
Also the reg has a boost/vacuum port which allows you to run less pressure at idle.
Are any of you guys running a setup like this?
Any advice appreciated.
Cheers
Karl
Are you running hard line with generous radiuses for the entire length of the system? It poses much less restriction then rubber line. What fuel delivery system and pressure?
 

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Discussion Starter · #3 ·
I am a plumber so was bent with benders and then annealed before fitting. ATM holley blue @7psi. Has no dramas keeping up but the pump is starting to leak again. Hasnt done much work.
I have a brand new BG220 that I got from a friend but he used the matching reg, so I have bought the mallory to go in its place. Figure not running the pumps as dead head may extend there life expectancy some what.
I run a large paper element WIX inline filter from a track car.
A 14 gallon fuel cell under the rear of the tray.
heers
 

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What about the return, 1/2 aswell?? The installation instructions call for 5/8 for pumps over 200gph? Seriously?
I would have thought 1/2 would be heaps
1/2" should be fine for both of them, just watch your pressure gauge, I can't imagine you'd have any problems though.

Your needle and seats are likely the biggest restriction in your fuel system.
 

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1/2" should be fine for both of them, just watch your pressure gauge, I can't imagine you'd have any problems though.

Your needle and seats are likely the biggest restriction in your fuel system.
I don't mean to hijack the thread but it reminded me of this question ive been pondering for a while and figured you or someone reading this thread might know. What is the lowest recommended allowed WOT fuel pressure reading? I have heard with a carb setup you can allow it to get down to 3-4psi? or do you want it to stay at the constant 7psi all the time? .... just curious
 

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I don't mean to hijack the thread but it reminded me of this question ive been pondering for a while and figured you or someone reading this thread might know. What is the lowest recommended allowed WOT fuel pressure reading? I have heard with a carb setup you can allow it to get down to 3-4psi? or do you want it to stay at the constant 7psi all the time? .... just curious
The lowest you can go with adequate and consistent fuel delivery is best, I run mine at 2psi on one car, BUT I have large needles and seat that allow me to do that. The higher your fuel flow demands and the smaller your needle and seats are the higher the pressure you will have to run. Float height may need to be adjusted when adjusting fuel pressure, depending on how much of a change you do.
 

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I don't mean to hijack the thread but it reminded me of this question ive been pondering for a while and figured you or someone reading this thread might know. What is the lowest recommended allowed WOT fuel pressure reading? I have heard with a carb setup you can allow it to get down to 3-4psi? or do you want it to stay at the constant 7psi all the time? .... just curious
Actually the recommended pressures you hear so often should also be the pressure at peak demand. If you hear "5-7 psi", 5 psi will probably be adequate at peak, but there are formulas to figure the required capacity.

Keeping the pressure below the amount that will overpower the needle and seat that can be a problem if the pump has insufficient capacity, because when the pressure is high enough for peak demand, it may be too high when demand is low. An adequately sized fuel pump (GPH-wise) will prevent that from being a problem.
 

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I use a roundy round mechanical pump but use the regulator to also smooth out the pulses.I just use 1/2 i.d. line.I set my pressure just under 6.No problems yet and its not noisey.
 
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