Fuel Hose Size?????

[DansBlown73Nordic]

I have this Blown 454 in my Nordic. Im wondering if my 3/8 fuel line is big enough? Or should I go with the #8?
http://www.***boat.com/image_center/data/520/76Nordic_Cayuga_1-med.jpg

[sanger mike]

dan, 3/8 is not big enough. you need to go with #8. and make sure you go all the way with #8 including the pick up in the tanks. if your tanks have 3/8 you need to put in #8 weld in bungs.:)

[058]

It wouldn't hurt to run #10 line from the tank to the pump.

[DansBlown73Nordic]

How to clean a Imco fuel tank pick-up? I figured out last night that my pick-up must be plugged. If I nail it from a dead stop it runs great for maybe 15 seconds then it starts to break up. With my other fuel tank set-up.....6 gallon can:wink: I was tuirning 6,000 and it never skipped a beat.

[burtandnancy]

The suction side, from the fuel tank to the first pump, should always be larger than the discharge side. #8 from the pump(s) to the T, then 3/8 may be OK to the bowls. The absolultely worst thing that can happen is an air leak on the suction side. You can't find it and it can cause a lean condition.

[revndave]

I have #10 to regulator and #8 to each Dominator.

[VD CRUISER]

On my blown 547, I come out of the tanks with a -8 , then thru 1/2" ball valves screwed into a 1/2 tee. I come out of the tee with -10 to the filter,-10 to the Clay Smith mechanical pump and -10 to a fuel log. Out of the log with -6 to each carb bowl, then a by pass regulator feeds back to the filter inlet. This works great and allows me to run from either tank or both tanks. Pressure is set at 7 psi at idle and maintains 6.5 psi at wot.

[Infomaniac]

Originally posted by VD CRUISER
On my blown 547, I come out of the tanks with a -8 , then thru 1/2" ball valves screwed into a 1/2 tee. I come out of the tee with -10 to the filter,-10 to the Clay Smith mechanical pump and -10 to a fuel log. Out of the log with -6 to each carb bowl, then a by pass regulator feeds back to the filter inlet. This works great and allows me to run from either tank or both tanks. Pressure is set at 7 psi at idle and maintains 6.5 psi at wot.
Excellent fuel system :)

[VD CRUISER]

Thanks Info, I made this setup based on your input in a thread we had going a while back about by pass set ups. Do you think I have the pressure set high enough?

[Infomaniac]

I try and run 7.5 but if it works for you no need to change.
Not that big of a deal when the fuel system is engineered properly.

[burtandnancy]

VD, now I know why I was a salesman and not a mechanic. But logic says to me, how can pulling from the tank with #8 feed the #10 out of the pump and to the two #6 at the carb. I am under the impression that you have to have the larger lines for the feed and step down as you get to the carb T's. I like your fuel pressure but where do you take it off? Of course the real answer is; no blown motors, good EGT's and spark plugs, and to hell with all this theoritical BS...right?

[superdave013]

Burt, sounds like he is pulling from both tanks at the same time.

[burtandnancy]

Oh. Thanks Dave, sounds like that would work...

[VD CRUISER]

My plan was to pull from both tanks when running hard, but it doesn't seem to be necessary. I couldn't get any bigger than -8 from the tanks without major surgery.
Yea Burt the real proof is that the ends are staying on the spark plugs with 11 lbs of boost and 93 octane.
Pressure is taken at the carb bowl. You can see the -3 line coming off the rear bowl.

[Dimarco21]

http://www.***boat.com/image_center/data/500/1693DSC02966-med.JPG
I run -10 from each tank to fuel switch, -10 to aeromotive fuel pump(fixed at 45 lbs.), -10 to fuel log on the front of the blower, -6 from log to carbs, -8 return line from log to aeromotive bypass regulator (set at 7.5 lbs.), -8 from bypass regulator into "Y" fitting between fuel switch and fuel pump.
I've tried to put a "Y" after the bypass regulator and return back to the tanks (like Aeromotive suggests). No luck, I couldn't regulate where the fuel went and over filled the tanks in minuets. I've tried lots of different combinations, This one works for me with no fuel surge at idle or drop at boost.

[VD CRUISER]

Damn Dimarco, thats what I call Bitchen. That looks like it should be on a fighter jet.

[Dimarco21]

Originally posted by VD CRUISER
Damn Dimarco, thats what I call Bitchen. That looks like it should be on a fighter jet.
It is......isn't it?:D

[VD CRUISER]

Yeh,Jet Fighter, I didn't mean it that way, but it fits

[MKEELINE]

Dimarco,
Clean setup you got there! I'm running the same pump and regulator, except i'm returning to the tanks. I run the return to a ball valve that can be swithed.

[Dimarco21]

MKEELINE, That was my next step if returning it to the fuel supply did not work. I thought I could install another electric fuel valve(for return back to tanks) and have it tied into existing one. Flip the switch on the dash then draw and return from the same tank.

[MKEELINE]

Why on earth would you want to make it easy with the electric valve, when you could crawl under a hot engine cover and switch it by hand?:rolleyes: Actually, i really like the valve your using, what is it?

[Dimarco21]

the only markings on the fuel valve is a Rex Marine stamp on the bottom.

[ssmike]

Originally posted by VD CRUISER
Damn Dimarco, thats what I call Bitchen. That looks like it should be on a fighter jet.
Dang!
Where is the BBC???:D

[Dimarco21]

Originally posted by ssmike
Dang!
Where is the BBC???:D
Hey Mike, 2 more weeks I should be running.:D I traded the GenV for a GenIV to make life a little easier.

[ssmike]

Smart move on the switch. Good luck getting that thing going again.
ss