starved for fuel on incline

[gusbratz]

This has happened a couple times. Get out in the woods into an extreme incline and the truck acts like it is out of fuel. I top up the gas tank and choke it and finally get it going and back to level ground but I need to figure out why. It started doing this since I put the real gas tank back in. I had it stuck really badly this winter in a ditch and it was about on its side and ran fine with the old 5 gal can so I am leaning toward fuel delivery not float level. Could a weak fuel pump could have more trouble picking up fuel at an angle. Or at an angle the fuel could slosh over to the filler neck and somehow cause a vapor lock? I have never been satisfied with the filler neck as I had to lower it when I installed the dump bed to get it to clear and I have issues with the vent not letting air out when I fill up. It takes forever to fill up but I have blown air into the vent line on top the tank and it is clear. I have a feeling all these events are related. Maybe I can put an electric pump on it and see if that helps. It is stuck down in the woods now dead in the water and I am just getting to work for the night. Guess I will fight with it tomorrow.

[MoparFreak69]

Carbs to have a tendency to want to crap out and not work properly when at extreme angles. When you had it almost on its side you may have been in the one angle where it would run at quite an extreme. Usually what happens is you either wind up sloshing the fuel directly into the venturis or the angle makes the gas flow away from the jets which are usually on the side of the bowl going into the venturis. This is a big reason why a lot of the Jeep guys toss the carbs in the can and go with a fuel injection system. They just dont work well at angles.
I would think that as long as your fuel pickup is at the very bottom of your fuel tank, and approximately in the center of it that you are providing it with the best chance of pumping fuel in pretty much all situations. If it isnt sitting at the bottom of the tank this could lead to some fuel starvation problems as well.

[gusbratz]

I guess the incline is not relly extreme but it was idleing on this hill waiting for these kids to hook up a chain so i could pull them out when it died. so today the first thing i did was pull the line off the carb and roll it over and sure enough no fuel. i found the tank is full. so i put a funnel in the inlet line to the carb and filled it up she fired right up and that got me up to level ground where it started pumping again(and pumped gas all over the place).
When i put that tank together it was missing the big cover on top so i made one and built a little stinger out of 1/4 inch stainless for it that is stuffed to within about 3/8" of the bottome. i would think the fuel pump would be able to suck up and out the top so I am thinking i need a new fuel pump or a rebuild kit. well on the count of 3 every body together now "I HATE THIS ETENOL FUEL" lol

[gusbratz]

oh i almost forgot the question! can i call napa and just ask for a fuel pump for say a 1955 dodge power wagon 230ci flathed and will it fit?

[Tom Petroff]

Try Napa AFP587 pump.
I don't think that is the dual pump for M 37 but will work, just no vacuum. for wiper assist.
TGP

[maineSS]

Some carbs work very well at angles, many do not. A lot of this has to do with the design of the float chamber. The Samuraii crowd that has modified Harley and GSXR motorcycle carbs have no trouble running upside down- bad news for engine oiling, though. Military aircraft ran carburetors til the end of WW II, and civilian aircraft ran them decades afterwards, even in aerobatic use- just a matter of design.

[gusbratz]

do they not have float chamber? like chainsaw carb? maybe i should make a custom flathead with 6 weed wacker carbs on it. :)

[Kaiser2boy]

Some carbs work very well at angles, many do not. A lot of this has to do with the design of the float chamber. The Samuraii crowd that has modified Harley and GSXR motorcycle carbs have no trouble running upside down- bad news for engine oiling, though. Military aircraft ran carburetors til the end of WW II, and civilian aircraft ran them decades afterwards, even in aerobatic use- just a matter of design.

The Mustang P51 was still using carburetors as did all American planes. This caused them to have to slide off to the side to make a quick dive. If they just went nose down there was a good chance of staling the engine.
The German Messerschmit BF109 and the Focke Wulf 190 all had fuel injection and could just jump right into a dive with no problems.

[maineSS]

If you watch old war movie footage, you'll see Allied aircraft roll upside down before diving, which prevented the fuel droplets in the air/fuel mixture from rising out of the carb throat due to inertia. The British incorporated a special butterfly with a hole to lessen this effect in their carburetor for the Hurricane & Spitfire based on work done by a female motorcycle racer named Tillotsen, who worked for Rolls Royce during WW II.

The Germans used a modified aircraft diesel engine, the Daimler Benz 605, which featured in-cylinder fuel injection (Today's Next Big Thing for auto manufacturers). This engine kept them flying after 1942, when supplies of high octane gas became very scarce in Germany. The DB 605 could use 87 octane fuel, where the Allies needed 110/120, especially for heavily loaded bombers on hot days. Along with better aerobatic performance, it also gave German aircraft more mileage, which initially gave the Brits a surprise during the Battle of Britain, as they expected the Germans would be at the very edge of their range, based on carbureted engine performance. The U.S. considered TetraEthyl Lead, the octane enhancer, to be an absolutely vital War material- a barrel (42 Gal) cost $5000 during WW II, (over $100,000 in todays dollars).

The Harley CVK 40 Kehein and GSXR carbs have floats- they just happen to handle off-camber much better. I'm working (slowly) on a triple Harley setup for the flathead.

[gusbratz]

thanks for that info. very interesting!