Zephyr's got the percolation blues (HELP!) (link)
- Thread starter Tom Wells
- Start date
) for a carb'd engine. Their ad says
Tom, it's not the PSI,,,, I'm talking about GPH.. gallon per hour. My boat used to use over 60 GPH at wide open throttle, but that was with twin 502's.. now do you think your engine can eat that much fuel... so how many GPH is your pump rated at ???
czarsmith
Member
Tom / Don...
I don't believe that the pump is the problem though my preference would have been for one with 8-9 psi and still run a regulator. The regulator you're using with it with should handle the PSI fine and if it shuts off flow it doesn't really matter how many free flow GPH the pump can do. Now, having a return line will be good because it will limit the time that fuel is in proximity to high heat (it will actually cool the regulator and feed line) and take some of the load off the pump. I don't know how much heat, if any, the pump generates and transfers to the fuel when it's generally "backed up" because of no return line. Other than when you have your foot firmly planted on the floor (which being a responsible adult you'd never do) you'll never even begin to use that pump's capacity.
Herb...
I don't believe that the pump is the problem though my preference would have been for one with 8-9 psi and still run a regulator. The regulator you're using with it with should handle the PSI fine and if it shuts off flow it doesn't really matter how many free flow GPH the pump can do. Now, having a return line will be good because it will limit the time that fuel is in proximity to high heat (it will actually cool the regulator and feed line) and take some of the load off the pump. I don't know how much heat, if any, the pump generates and transfers to the fuel when it's generally "backed up" because of no return line. Other than when you have your foot firmly planted on the floor (which being a responsible adult you'd never do) you'll never even begin to use that pump's capacity.
Herb...
I'm an injection kind of guy, but if float bowl boiling is the issue, then it seems like a flow of fuel THROUGH the bowl would be the solution. Plumb a return line and I'll bet a beer that percolating will stop. As long as fuel keeps moving around the system (tank - pump - hot pipes - carb - pipes - tank) you can rely on the heat sink of the tank of gas - I bet that the tank won't warm up appreciably even without insulated / relocated lines.
Scott "Elder" Harrison
"Growing old is mandatory, growing up is optional"
Staff member
Contributing Member
That pump is flowing enough to fill bathtubs....and certainly helping to heat the fuel.
Hey Tim...that was a novel idea.
Hey Tim...that was a novel idea.
OK.
My pump's maybe too big?
A 10AN feed line and an 8AN return will be going in.
The reg will be relocated to the top center of the firewall.
The scoop will be opened up.
If these don't work there's always a Viking funeral for the banana.
Next week may tell the story if I can find enough time to work on it. As Elder can attest, grandkids have priority!
Tom
My pump's maybe too big?
A 10AN feed line and an 8AN return will be going in.
The reg will be relocated to the top center of the firewall.
The scoop will be opened up.
If these don't work there's always a Viking funeral for the banana.
Next week may tell the story if I can find enough time to work on it. As Elder can attest, grandkids have priority!
Tom
czarsmith
Member
Tom... Interesting, very interesting. Have you figured out what will happen on a nice 100 degree day when you're stuck in traffic and the asphalt starts melting under the car? The "LaZephyer" Tar Pits... In a couple of million years some archeologist will dig you and the banana out of the tar.
Herb
Herb
Do you know the temp under the hood while driving???? sitting at a light??? or are you guessing that it's HOT.. Do you know the temp of the fuel line going to the reg.??? or are you guessing??? When you are pumping a lot of fuel and it goes nowhere it get's hot, real hot. If the pump free flows it stays cool.
I remenber back in the old days big block cars had 2 fours and only had a factory fuel pump, never seen one run out of fuel, althought I was on a few rides where I wished they would..
I didn't look at Scott's reply until now 150 GPH !!!!! Also I don't think you need a bigger line once you reduce the flow, that motor can't burn 1/3 of 150.....
I remenber back in the old days big block cars had 2 fours and only had a factory fuel pump, never seen one run out of fuel, althought I was on a few rides where I wished they would..
I didn't look at Scott's reply until now 150 GPH !!!!! Also I don't think you need a bigger line once you reduce the flow, that motor can't burn 1/3 of 150.....
Doc,
The reg itself was hotter than 143*F. Fuel going in was over 130*F.
You're probably right!
In addition to the re-routed 10AN feed and the new 8AN return, I'm relocating the reg higher on the firewall and near the center. I'm putting a Derale 13252 cooler in the return line and opening the hood scoop which is now fake.
Since I have grandpa duty coming up, there will be a pause until I can get it done...
Tom
The reg itself was hotter than 143*F. Fuel going in was over 130*F.
You're probably right!
In addition to the re-routed 10AN feed and the new 8AN return, I'm relocating the reg higher on the firewall and near the center. I'm putting a Derale 13252 cooler in the return line and opening the hood scoop which is now fake.
Since I have grandpa duty coming up, there will be a pause until I can get it done...
Tom
Scott "Elder" Harrison
"Growing old is mandatory, growing up is optional"
Staff member
Contributing Member
One more suggestion.....
