Fuel feed issues
#21
Registered
iTrader: (3)
I agree that you may want to upgrade the pump itself. However, if the engine was able to pull 5500 with a 28p prop, then only able to pull 5000 with a 26p prop, you had more going on, than simply a insufficient fuel pump size. I think you may be on to something, as far as the pickup being clogged, a fuel line that collapsed internally, or some junk in the carb. Junk in the carb though, wont show a loss of fuel pressure, where as a clogged screen, filter, line, etc, will.
What I would do, is try to rig up a mechanical gauge, to where someone can see it while you run, temporarily. Forget those electric pieces of crap. Ideally, if you have 6.5-7psi at idle, you dont want to see it drop to 3-4psi at wot. You wanna see it stay around 6 or more at speed. Even most of the mechanical gauges arent very accurate as far as they go. You can take 1 gauge, install it, and see 7psi at idle. Remove it and install another one, and see 8psi at idle. But what you wanna watch is for the pressure drop at high load/speed. If it drops more than 1-2psi say from 3000-5000, you prob have a supply issue.
Your typical holley needle and seat cant take 9psi without being pushed open. The CV product pumps are nice, but, they are not gonna help if the pickup is clogged, lines to small, etc. Also, make sure the tank vent isnt clogged with spider webs.
What I would do, is try to rig up a mechanical gauge, to where someone can see it while you run, temporarily. Forget those electric pieces of crap. Ideally, if you have 6.5-7psi at idle, you dont want to see it drop to 3-4psi at wot. You wanna see it stay around 6 or more at speed. Even most of the mechanical gauges arent very accurate as far as they go. You can take 1 gauge, install it, and see 7psi at idle. Remove it and install another one, and see 8psi at idle. But what you wanna watch is for the pressure drop at high load/speed. If it drops more than 1-2psi say from 3000-5000, you prob have a supply issue.
Your typical holley needle and seat cant take 9psi without being pushed open. The CV product pumps are nice, but, they are not gonna help if the pickup is clogged, lines to small, etc. Also, make sure the tank vent isnt clogged with spider webs.
#23
Registered
Join Date: Jul 2014
Location: Northern Indiana
Posts: 376
Likes: 0
Received 0 Likes
on
0 Posts
Is there a reasonably priced pump that will support my HP level? It is Gen6 sea pump mounted.
http://www.cvproducts.com/ProdDet.aspx?PN=SPIN-MP-2630
http://www.cvproducts.com/ProdDet.aspx?PN=SPIN-MP-2630
#25
Platinum Member
Platinum Member
iTrader: (6)
Its always something with these things, good luck
#27
Registered
iTrader: (1)
#28
Registered
def get a high flow water/fuel filter.... 3/8 line is way undersized... I would say 600HP max with that.... I built my 509 and guess its around 575HP and it does OK with a stock pump and larger lines. I also installed a wide band air/fuel ratio gauge to monitor everything in real time and it is really the way to go to dial in your carb. If you are leaning out and I bet you are, you are running the risk of frying your nice, new motor..... I am running aluminum heads and high compression so I have to run 93 octane from the pump and I am always afraid of the alcohol in the gas creating crud in my fuel system.....
I would also get an AFR gauge, I look at mine all the time. the only thing is you need is to weld an exhaust bung for the O2 sensor. I use a plate with mine as I have the 496 style dry joint exhaust.
I would say going with electric is a good idea. I am going to install an electric setup as a backup just in case my mech pump craps out......
I would also get an AFR gauge, I look at mine all the time. the only thing is you need is to weld an exhaust bung for the O2 sensor. I use a plate with mine as I have the 496 style dry joint exhaust.
I would say going with electric is a good idea. I am going to install an electric setup as a backup just in case my mech pump craps out......
#30
Registered
iTrader: (1)
Don't tell'm, but my question remains the same..maybe even more so since so anal.
Oh well. Others can learn from this. If you can stay mechanical : ie, you have carb(s) vs EFI, stay mechanical.
My Dirty Floored Shop Opinion. . LOL.
Oh well. Others can learn from this. If you can stay mechanical : ie, you have carb(s) vs EFI, stay mechanical.
My Dirty Floored Shop Opinion. . LOL.