NorthernBoy

My Feedback: (1)

I am getting ready for my first 50cc gas engine and I have a few questions:

- Will a 1100maH pack be good enough for the ignition, how long will it last?

- What type of fuel filter do you use with gas, is it the same as glow?

- What type of manual fueling pumps are available?

Thanks
NB

buck1856

My Feedback: (49)

#1--yes,a lot longer than your TX battery,by hours.
#2---use gas filters like the ones on motorcycles to fuel up,then a brass one in tank if ya want.i dont use any in tank because i have on one on my gas can, jug.
#3---you can get electric or manual GAS pumps designed for gas at your LHS,internet(horizon,tower,ect...)use a 12 volt automobile electric pump from your local supply store with a motorcycle or your feild battery.

The Raven

I've only built one gasser but will soon start a further 3 gassers of various styles.

Having run only magneto engines my guess is that 1100mAh will depend a lot on the ignition module itself. Some modules will run on 4.8-6V while some must have 6V. Given that large capacity battery packs are so cheap now I'd just buy the largest I could. For me the practical limit is 2500mAh NiMh (freshly charged before use) AA cell pack, which I'd buy in 5 cell configuration for a gasser ignition. 1100mAh should give you an easy hour of operation (at least 4 flights) but I'd do some battery checks after some ground runs to see how much the ignition draws.

I haven't used a filter but have seriously considered it, however; I note that most gassers don't have filters. Glow filters probably won't handle gas but, perhaps the alloy cased ones with the brass filter would work (check the O-ring doesn't melt).

The gas rated pump I bought is a standard grey hand cranked unit from China/ROC which came with a basic mesh filter. Most pumps will be labelled as for which fuel they are suited. Use gas rated fuel line from your LHS. They will tell you whats suitable AND, in case no-ones mentioned it, also change the fuel tank stopper to a gas rated one (otherwise it will melt quickly).

NorthernBoy

My Feedback: (1)

Thanks for your quick replies.

I guess I will try the 1100 and see how long it lasts & if I need to go bigger I'll upgrade an old reciever pack.

I'll install a fuel filter on my pump only.

I ordered a six shooter pump for gas.

Thanks Again.

ram3500-RCU

My Feedback: (221)

I have run gas engines for almost two decades now.

1. 1100 will work (you don't need 6v) and it will last for a day of flying, for a single cylinder. That is, however, the smallest I would use. I go from 1100 to 2400, depending on how much the plane will fly, and the size of the engine.

2. I too do not use an on-board filter. I carefully filter the gas as it is dispenced. I do however use an air filter.

3. I have used the hand crank pump by Dubro for years. Just install gas type fuel line on it and it will last several seasons. I don't like the Six Shooter. They come apart inturnally too often.

karolh

Yes, an 1100 mAh battery pack will do quite nicely, just do a voltage checks after a couple of flights to be safe.

It is quite the norm to use a felt filtered clunk in the tank with suitable gas tubing and stopper. Dubro brand tanks and their brown gas stopper work well.

Gas engines carbs are fitted with internal filters and have much smaller passageways than glow motors, so it is imperative that the fuel be free from all debris. The use of an automotive type paper filter on the fuel jugs feed line and a clunk type filter on the pick line is a good method of filtering.

I use a Hangar 9 manual pump which works well for me.

Karol

BaldEagel

NB

Read your manufactures instructions on your ignition unit, contrary to some I have one that needs between 11 & 13volts but only uses approximatly 500Mah during a flying session of four flights.

Use a felt clunk in your storage container and maybe a felt clunk in your tank and just keep everything clean, if dirt gets into your tank you have already lost. Manual pumps seem to be more realiable, the 12volts things sold in your LHS are generally car windscreen washer pumps, a car fuel pump will work, but its just more junk to carry, with a manual pump you don't need the battery at all, just a can of mixed gas attached pump, your plane and TX.

Have fun
Mike

3d-aholic

My Feedback: (7)

-4 flights..last one needs a check.
I would go with 1500....it will give you the same 4-5 flight but comfortably. Thats what I use.

-No, you really need a finer filter than glow... Most glow filters are just screens...you need felt or very fine screen.

-Get a Jersey Modeler...its got everything ready to go...

ram3500-RCU

My Feedback: (221)

I like the observation, "if dirt gets in your tank, you already lost". As noted, carburators have inturnal filters. I clean mine once a year, and they are usually 90% open when checked. I use NO other onboard filter but am careful with the fuel I load onboard. I don't like to create more possible restrictions in the system. This has been debated, but in my experiance, the small fibers of felt often break free and find their way to the caburator filter, clogging it. I have seen this personally and that is the reason I no longer use them. IMO, clean fuel in the tank needs no additional filtering.

The Raven

I have one glow filter that uses what appears to be a brass filtering mechanism. The outer housing is alloy and the filter is made of very small brass balls molded into a cylindrical shape (presumably some form of gluing or sintering).

You can use it either direction but basically the fuel flows into a center cavity of the brass element and then passes out through the minute spaces between the 'brass balls'. I imagine this to be quite efficient as the size of the balls are quite small and the spaces between them would be very very small and quite convoluted....making it hard for any rubbish to make it's way through.

It's better than a conventional glow filter (cheap mesh) and probably as good as the old superfine mesh filters you used to find on automotive carbs (remember those).

From memory most walbro carbs have internal filter so, provided one handles their gasoline carefully to keep dirt out, it's probably more than enough. Still there is a valid argument for a second filter (costs little, could save a lot).

Tired Old Man

My Feedback: (1)

I'm going to argue the filter side of this. Two filters are much better than one. The one in you gas can is good place to have one but is often forgotten and left in place for months too long. You can say you'll replace it regularly but most don't. The one in your tank should be nbetter than the one in the gas can. It's really you last defense. The so called "filters" inside your carb are nothing more that a small screen and clog often. Generally when they do there will be a long thread asking why someone's engine is running like crap. Walbro makes an excellent felt clunk that used in many extremely high end UAV's and serves the purpose well. It also acts as a heavier clunk which you will need anyway.

As for the felt filters clogging anything, Myself and many others change out header tanks with 100 or more flight hours on them several times every week and none of the engines have clogged anything in them. They go right back into service. All Walbro felt clunks.

As for the battery, depending on your ignition type it should last about 8-10 good flights. Figure 125 to 250 milliamps per flight. Most of the 4.8 volt ignition systems draw between 250 to 400 mAh/hour of use. If the ignition does not require 6 volts it's pointless to use a 6 volt battery.

Hanger 9 is another company that makes a gas compatible hand crank fuel pump. I've been using the same one for the last 4 years.