Pleass critique my planned fuel sysytem
- Thread starter rbsWELDER
- Start date
Mike
Well-Known Member
+1. Servicing your initial filter will be simplified by placing the shut-off upstream, rather than down-stream.
No real need for the second shut-off in the system. That just amounts to two more connections with potential for leaks and one more component with potential for failure. Keep it simple.
If you are using the Holley 'blue' pump, I am assuming (dangerous territory, I know) you are going to also use the 12-803 Holley regulator. If that is the case, then I recommend getting the regulator directly connected to the fuel log and making sure the runs from the fuel log to the carbs are as short as possible. Mind that particular regulator has a .220" restriction, so everything downstream from the regulator is not going to see the volume you are supplying to the upstream side of the regulator. You can run as big a supply line as you choose, but once you get to that regulator, you are strangling the volume. The 12-704 regulator has a .437" restriction, so it will flow more fuel.
No real need for the second shut-off in the system. That just amounts to two more connections with potential for leaks and one more component with potential for failure. Keep it simple.
If you are using the Holley 'blue' pump, I am assuming (dangerous territory, I know) you are going to also use the 12-803 Holley regulator. If that is the case, then I recommend getting the regulator directly connected to the fuel log and making sure the runs from the fuel log to the carbs are as short as possible. Mind that particular regulator has a .220" restriction, so everything downstream from the regulator is not going to see the volume you are supplying to the upstream side of the regulator. You can run as big a supply line as you choose, but once you get to that regulator, you are strangling the volume. The 12-704 regulator has a .437" restriction, so it will flow more fuel.
I would put the first shut off right at the tank as others have said. Omit the second shut off. The first filter will be right after the shut off, before the pump. The second filter I would put right before your fuel log. You will have flex connections in this system and they tend to break down internally. That is small pieces of rubber line will be stopped by that second filter.
Screaming Metal
Active Member
What they said....I've seen setups like your describing....only reason for the 2nd shutoff was to work on the carbs while not emptying the whole line....like you are being told, theres a shutoff switch.
While the fuel pressure is more critical in a blown setup, I used to use the Carter 4070 or a Sun SuperPump back in the day alot, and would regulate it right before the log. But, with a really hi pressure/vol. pump like the blue, from your pump and filter back by your tank, your gonna want a hardline under your car from the tank up to the firewall, you don't want to have a rubber line nicked, scraped with a potental for leaking or bursting from a cut.
But, on a street car, all that pressure isn't needed to fight G forces from a launch.
If your worried about fuel starvation, a hi pressure/volumn pump isn't gonna change alot, you'd also need to also run the bowl baffles along with the vent hoses, too.
You don't need 20+ psi line presure, just a pump that'll get you some pressure to your carb, then regulate it down to where the carbs can use it, if theres any starvation in the line, thats what the log is for, and to also mount a fuel gauge to and/or a regulator.
....just my 2 pecos....
While the fuel pressure is more critical in a blown setup, I used to use the Carter 4070 or a Sun SuperPump back in the day alot, and would regulate it right before the log. But, with a really hi pressure/vol. pump like the blue, from your pump and filter back by your tank, your gonna want a hardline under your car from the tank up to the firewall, you don't want to have a rubber line nicked, scraped with a potental for leaking or bursting from a cut.
But, on a street car, all that pressure isn't needed to fight G forces from a launch.
If your worried about fuel starvation, a hi pressure/volumn pump isn't gonna change alot, you'd also need to also run the bowl baffles along with the vent hoses, too.
You don't need 20+ psi line presure, just a pump that'll get you some pressure to your carb, then regulate it down to where the carbs can use it, if theres any starvation in the line, thats what the log is for, and to also mount a fuel gauge to and/or a regulator.
....just my 2 pecos....
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Screaming Metal
Active Member
You need to run a filter before your pump, the good pumps are expensive and don't really like alot of the water laden E85 crap thats at the cheap places. The Mallory spin-on filters are nice, not super expensive. I use a waterblock filter that restricts fuel flow as it sucks up water, so I carry a couple of spares....it filters dirt also.
On my car, I gave a spin-on just before the pump. All I have to do is slide under it with a new filter and change it out, no need for a screwdriver to loosen clamps and all that mess.
They also have liquid filled gauges that are nice for mounting on the logs if theres alot of motor vibration or dancing from a hot cam in a nat. aspirated motor.
On my car, I gave a spin-on just before the pump. All I have to do is slide under it with a new filter and change it out, no need for a screwdriver to loosen clamps and all that mess.
They also have liquid filled gauges that are nice for mounting on the logs if theres alot of motor vibration or dancing from a hot cam in a nat. aspirated motor.
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TriodeLuvr
Member
Indycars
Well-Known Member
This is pretty close to what I did for my fuel system for 500 HP. There are few things that are different from the drawing, mostly the two tee fittings at the carburetor are now completely AN with them being -8 x-8 x-6, with -6AN going to the carburetor. You have two choices for placing the fuel pressure regulator, before or after the carburetor. My understanding is it works better when placed after.
I also went with this SS ball valve for my shutoff just before the 100 micron filter as the input to the fuel pump.
1/2" NPT 316 Stainless Steel Valve - Full Port 1000 WOG - $9.99
I found a lot of people that didn’t like aluminum fuel line and I could not find anyone that sold 1/2 inch steel line, so I bought this SS fuel line after already buying the aluminum.
Stainless Steel 316L Seamless Round Tubing, 1/2" OD, 0.444" ID, 0.028" Wall, 72" Length-$37.48
I started out configuring three systems and deciding on the least expensive, but I tried not to sacrifice too much in quality to just get by, but this shit is expensive.
If you download the Excel files you see all three fuel systems, it has links to each part, mostly at Summit. The text for the links is really small, but you don’t need to read them, just click on them. I ended up purchasing the 3rd system. You will notice that I estimated $100 for AN fittings, should have been $200. Wishful thinking I guess!
Below is everything I purchased in the first order. I’ve bought more AN fitting since, but that’s minor, except for the cost.
I also went with this SS ball valve for my shutoff just before the 100 micron filter as the input to the fuel pump.
1/2" NPT 316 Stainless Steel Valve - Full Port 1000 WOG - $9.99
I found a lot of people that didn’t like aluminum fuel line and I could not find anyone that sold 1/2 inch steel line, so I bought this SS fuel line after already buying the aluminum.
Stainless Steel 316L Seamless Round Tubing, 1/2" OD, 0.444" ID, 0.028" Wall, 72" Length-$37.48
I started out configuring three systems and deciding on the least expensive, but I tried not to sacrifice too much in quality to just get by, but this shit is expensive.
If you download the Excel files you see all three fuel systems, it has links to each part, mostly at Summit. The text for the links is really small, but you don’t need to read them, just click on them. I ended up purchasing the 3rd system. You will notice that I estimated $100 for AN fittings, should have been $200. Wishful thinking I guess!
Below is everything I purchased in the first order. I’ve bought more AN fitting since, but that’s minor, except for the cost.
Indycars
Well-Known Member
Thanks Keeper!
I just got the Coors beer keg back from the machine shop with the new fittings welded in. He wants me to grind and polish the welds, then bring it back for another pressure test at no additional charge.
I had three bungs and a new cap welded. I've got it ground down and started polishing, that should be good enough to pressure test again. Anything I can do after that by hand should not effect the welds.
Sorry didn't mean to highjack the thread, so lets get back to the original question. If I can help by creating a new drawing for you (rbsWelder) let me know.
I just got the Coors beer keg back from the machine shop with the new fittings welded in. He wants me to grind and polish the welds, then bring it back for another pressure test at no additional charge.
I had three bungs and a new cap welded. I've got it ground down and started polishing, that should be good enough to pressure test again. Anything I can do after that by hand should not effect the welds.
Sorry didn't mean to highjack the thread, so lets get back to the original question. If I can help by creating a new drawing for you (rbsWelder) let me know.
I agree with a few of the others, I'd lose the first filter and just run the Fram one before the pump and leave it at that. Those Edelbrock carbs would not be my first choice for a blown motor, but they are good on a mild street motor. They tend to be a set up a bit lean from the factory, so get a proper tune up done. Looks like you're going about this the right way first time, which is nice.
PS those Holley blue pumps cost $330 in New Zealand and the Fram filters are around $150!
PS those Holley blue pumps cost $330 in New Zealand and the Fram filters are around $150!
I agree, No need for the second shut off
TriodeLuvr
Member
Nearly all the Mr. Gasket parts are Chinese now, so I don't buy them. What are you guys seeing from Holley and K&N on these types of components? Are they still U.S. made?
Jack
Jack
rbsWELDER
Active Member
All – Fantastic feedback!!
Ben - Removing second shut-off.
Mike – I had not even thought about the regulator. For my set-up do you recommend the .220 or the .437 restriction?
Keeper – This is only a concept, if you think the sock and the Fram are adequate, that is less expensive. BUT, I see that Indycars runs both for carburetors.
RPM – Shut off moved next to tank
2old2fast & Indycars – I thought that you only needed a return line with fuel injection???
Screaming Metal – Do you have a part number for the waterblock filter? Would that replace the Fram?
Triodeluvr – Thanks for the reminder on not running the fuel lines on the bottom of the frame!
Indycars – Thanks for the spreadsheet // What is the restriction on the Mallory 4307M? // The Fuel gage that you spec'ed does not appear to be liquid filled //Where does the Vent Filter attach?
Golly – What would you recommend for carbs?
Thanks again, all! I will modify my drawing and repost after the above questions are answered.
Mark
Ben - Removing second shut-off.
Mike – I had not even thought about the regulator. For my set-up do you recommend the .220 or the .437 restriction?
Keeper – This is only a concept, if you think the sock and the Fram are adequate, that is less expensive. BUT, I see that Indycars runs both for carburetors.
RPM – Shut off moved next to tank
2old2fast & Indycars – I thought that you only needed a return line with fuel injection???
Screaming Metal – Do you have a part number for the waterblock filter? Would that replace the Fram?
Triodeluvr – Thanks for the reminder on not running the fuel lines on the bottom of the frame!
Indycars – Thanks for the spreadsheet // What is the restriction on the Mallory 4307M? // The Fuel gage that you spec'ed does not appear to be liquid filled //Where does the Vent Filter attach?
Golly – What would you recommend for carbs?
Thanks again, all! I will modify my drawing and repost after the above questions are answered.
Mark
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2old2fast
Active Member
Using a bypass reg. w/ a return line is not absolute ... the thinking is by keeping the fuel moving there is less chance of vapor-lock , the pump will run cooler [less back pressure] , and it reduces the risk of "pressure creep" that sometimes occurs w/a deadhead reg. .... just a different way of doing it... research the subject & make your own decision ....
dave
dave
fordsbyjay
Active Member
These cars are so short that I ran my Holley regulator right on the pump. I had it at the carb before and have not noticed any change. Magnafuel has been doing it like this for years and it seems to work fine for them as well. Now I'm not saying there is anything wrong with putting the regulator right by the carbs but I was trying to clean things up a bunch.
Tank -- Fram fuel filter -- Pump -- regulator -- 1/2" aluminum line -- carb line.
Tank -- Fram fuel filter -- Pump -- regulator -- 1/2" aluminum line -- carb line.
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