i bought a 25% extra setup for a ZDZ 40 ..I plan on using a 2.1 glow engine and was wondering if the fuel lines that were set up for gas will work ok with glow fuel. The clunk in the tank says WALBRO and has a cotton filter attached....can i use it with glow fuel ?

John:

The only parts you can use from the gasoline system that will work with alcohol fuels are the body of the fuel tank, and the clunk. The tank stopper and all the hoses will have to be changed. Might well be simpler just to get a new tank for glow fuel when you get the new hoses.

Bill.

Hmm, Thanks Bill.
I was led to believe that a certain type of fuel line was compatible with both types of fuel. Like glow fuel could be used in both type lines but not the other way around. Leave it to my "know-it-all" flying buddies to feed me misinformation (i'm not in a club).

Another concern is that cotton filter on the clunk, is that OK to use with glow fuel ?

Like you stated... I might be better off just getting a new tank and saving this one for when the time comes when I go to a gasser.

John:

The common "Gas" fuel hose is Tygon, and while it will work with the alcohol fuels, it gets hard in a hurry. Best to use the silicone hose. You don't really have much choice for the clunk line inside the tank, when it gets hard the clunk can't clunk anymore. The tank stopper I'm not sure about - it seems to me it disintegrates using alcohol.

A real life example. When Archer Daniels Midland and the other eco-Nazis pushed hard and got alcohol blended gasoline fairly common, I was working for the importer of an up-scale European car. We started having problems with our fuel injection hoses, the alcohol was causing them to disintegrate from the inside. And the bits of hose were clogging control regulators, filling nozzle filters, and generally causing mayhem. We replaced several thousand sets of hoses (wasn't just one year model that was affected) and a few hundred complete fuel systems. All because some uneducated asses decided to yell about gasohol, and ADM wanted to increase profits. Didn't matter that gasohol is more expensive as well as being less efficient. Sounds good for the eco-freaks.

Anyway, play it safe. Replace everything. It's a lot better to do it now than later, while you're repairing the damage from the dead stick landing.

Bill.

Sorry John, forgot to comment on the cotton filter. I don't think it's worth bothering with. You can leave it if you wish, but the fuel flow will establish channels through it, and then it wont even be much of a strainer. Just use an external in-line filter and be done with it.

Bill.

Thanks again Bill. Your right ..for the price of a new tank its not worth crashing my extra. One other thing. Do they sell heavier fuel clunks or is the one that comes with say a 24 oz tank good enough ?

John:

I've never seen the need to use a clunk different from the one that comes with the tank.

I do look at it, some aren't drilled straight through. When I see that I will make it's hole the same size all the way. Probably doesn't make any real difference, but at high flow the sudden increase in diameter could cause turbulence there, and restrict the flow somewhat.

Bill.