av8tor1977

My Feedback: (6)

Looks good! I have considered cutting the fins down on some of mine. Might get around to it one of these days... I want to pick up those exhaust pipe expanders from Harbor Freight to use to chuck cylinders in my lathe easily. (Don't have a mill yet.)

I meant to mention this earlier. If you don't let them warm up sufficiently and take off, the engine can cool itself down to the point where it will be lean; like a cold engine needing choke. Kind of puzzled me the first time I had it happen until I figured out what was going on. I have never had this problem if I just let them warm up good on the ground before taking off.

Take care and have fun!
AV8TOR

travisback

I did ruin one cylinder from excessive clamping force so I have learned to take the time for propper fixturing. I have access to a mill at work that I use during lunch. I am surprised that anyone would not do this and choose to use a spark plug.

nitro joe

My Feedback: (2)

Quote:
“I did ruin one cylinder from excessive clamping force so…�

Very good advice.I can see how that could happen. Locating, and driving the cylinder in a lathe using an exhaust pipe expander as a mandrel begs for serious caution .Consider what might happen if the cutting tool digs in,and hangs up a bit for any reason? If tightened up enough to prevent this,what happens to the the bore concentrity/ring seal if even only a few tenths distortion?

Some kind of “dog� to transmit the driving torque into a mounting bolt hole(s) with the auto tool expanded just enough to do the centering might be worth looking into.

Maybe experiment with a cylinder that are not too dear first.Of course,your milage may vary...[8D]

av8tor1977

My Feedback: (6)

Yeah, I think I would give the "mandrel" (exhaust pipe expander) a wrap of thin, soft aluminum, and not tighten it very much in the cylinder. Then use a dog as you mentioned and take light cuts.

I have some aluminum roof flashing that I use for things like this. It is very soft aluminum, and can be cut with a scissors. I use it to protect prop hubs, etc., when I chuck them up to finish sand/polish them, etc. Home Depot "hobby shop" at work again!

AV8TOR

clocknut

My Feedback: (6)

I sold A G62 to A friend and he gave me A used one in on trade that had A twisted crank and bad ign.Guess what I'm doing yes your are right I straightened the crank and cut off all the ign stuff cleaned it up,turn down the fly wheel(7 Oz. down to 3 oz.), put in new rings and my gasket set just came in so I will be bench testing this week I think when the guys see A G62 Zenoah on gas/glow that might turn few heads .Has any one else set up one of these on gas/glow and if so how did it do? does any one know what temp that they run on gas? I would like to find out if it runs hotter or colder on gas/glow. Of course I know it will run hotter until it gets broke in.I plann on putting this in my Sig Bravo which has A conope And want to make sure it stays cool.I will let you know how it did when I get it fired up.
Thanks Av8tor for the great thread.

av8tor1977

My Feedback: (6)

Your welcome!!

While I can't provide actual temp numbers, the engines do run cooler on Gas/Glow than pure gasoline.

AV8TOR

clocknut

My Feedback: (6)

That is good to know so now I won't worry as much about putting the G62 in the Bravo.
I need to get some time this week to get it fired up.

rangerfredbob

My Feedback: (13)

I picked up one of the expanders at HF, you need the small one. what I did to protect the bore was to put electrical tape down the fingers (easier than flashing, which I didn't have). when they heat treat the threaded portion they bend it, so it's not exactly straight... but I used it as is anyway (the jug doesn't spin in that direction, no one will notice). I had alaready trimmed my jug with a dremel and hack saw so I only needed light cuts, and the engine ran fine afterwards.

once I get the dang thing maidened (had a few radio issues and then weather issues) I'll get pictures up.

proptop

My Feedback: (8)

Would a Supertigre 3000/3250 be a potential candidate for gas/glow?
I recently aquired one of each at a pretty fair price...but...the thought of running them on glow fuel makes me wonder if that's why the other guy sold 'em so cheap.
One is NIB (3000 ) and the 3250 only has a few test runs on it, so they're in good shape.

I'm mainly wondering about the rod, and the carb...

captinjohn

I am sure it would run on a mix of Gas/Glow fuel. You would have to have about 12% oil. for lubrication of the big Tiger. You will not save any using gas/glow, over the use of a Mix of strait mentanol acohol because the Nitro in the glow fuel causes the fuel to burn faster. The big Tigers they say run better with no Nitro at all. I can buy very good mentanol for $3.75 or less per gallon. All you need then is enough Klotz(or any good lube that mixes with acohol) in mix to end up with 12% lube. Total cost per gallon...maybe just over $4. Not bad at all. Best Regards Capt,n

Down and Locked

Is it possible to run a glow engine with this set up of gas and glow mix at a 32-1 oil mixture thanks.


flyingdragracer

clocknut

My Feedback: (6)

You have to covert it to gas first by installing A walbro carb and having the rod bearing on the crank changed form bushing to needle bearing .There was a old post on here all about it.Try typing in converting A super tygre to gas the guy that does some conversions is Kenneth lambert you might also try typing in his name? I have a 2000 being converted by him right now.

av8tor1977

My Feedback: (6)

Unless of course, it is possible to convert your glow engine to roller bearings as stated above.

captinjohn

Needle bearings and roller bearings kinda work in the same way but have different uses. The needle type are used where there is not room to use bigger bearings. Roller bearings are mostley used in more heavy applications and where room for them is not a problem. Ball bearings work good on crankshafts, that hold end-play to a minimum. There are also thrust bearings that use needle type ground pins. Also there are tapered rollar bearings like a trailer may have and can be adjusted. So for the "newbies" out there I hope that helps. Capt,n

nitro joe

My Feedback: (2)

Semantics.
Roller and needle bearings have the same function as it applies to small gassers. They both use cylindrical rolling elements, designed primarily for high radial, low axial loading.

captinjohn

Well I guess we are caught up on bearing data...so its back to Gas/glow. Very cold here but my Granson wanted to fly. Well one thing we found out is my test Gas/glow engine will start in very cold temps better than the small .46 rgular glow engine! The test engine(MB209) will stay on stand for the rest of the winter. Part of the test is to see how the internal carb parts last. So far, real good with no additves after running. Best Regards Capt,n

kevstra22

Hello All,

I wanted to start out by applauding this forum and all that contribute to it! By reading these pages I have been able to build several .40 sized SPADs and am now working on the Ultra Spad Stick. I have a 50cc Echo out of an older CS-500 EVL saw. After a lot of cutting and a few other mods the engine is about ready to go. I have decided to give GAS/GLOW a shot as the coil was bad on the saw.

The question I have is how clean do the GAS/GLOW engines burn? The oily mess is the thing I like least about Glow engines.

Thanks again for all the great posts!

Kevin

captinjohn

The mess is not nowhere as bad as with glow fuel that contains much more oil. I kinda would like to try Gas/glow on a giant profile...and fly the "pudding" out of it!!! Capt,n P.S. Welcome to our crazy engine forums!

the Wasp

My Feedback: (1)

""ONE part of the glow fuel to TWO parts of the high test, (premium) gasoline.""

av8tor1977

how about running my Super Tartan "Tartan" 44cc glow twin on Gas/Glow,,

I ask because it's such a higher compression engine than the gasoline engines, I believe it's a 11 to 1 ratio, do you think an OS F plug will be hot enough ??

(EDITED) of-course this would have to be mixed with no Nitro as this engine was designed not to run Nitro !!

yes the Super Tartan Twin has Needle Bearing Rod Ends

Jim

av8tor1977

My Feedback: (6)

Should be alright. If you have any problems with detonation or overheating, first go to a colder glow plug. If that doesn't cure it, then go up on the methanol content and down on the gasoline content, and that's correct, I would recommend no nitro in this case.

AV8TOR

the Wasp

My Feedback: (1)

thanks,, but something else I just realized,,

accordingly to my Tartan manual I need to run 10% oil a gallon in the Tartan, unlike those gasoline engines..

captinjohn

The 10% of oil should not hurt a thing....in my opinion. See what AV8TOR says. Capt,n

av8tor1977

My Feedback: (6)

This is a gray area....

A lot of people say "Don't worry about it; run the 10% oil mix in your glow engine with gasoline and it will be fine." But it worries me that because gasoline burns hotter than methanol glow fuel, that it will eventually cause carbon build up. In a glow fuel engine with it's high oil content, most of the oil is not burned, it is sprayed out the exhaust all over the plane. But a gas engine burns most of the oil. That's why there is almost no mess on the plane. (This is also due to the normally lower oil content as well.)

It also depends on the person. A gallon of fuel lasts some guys months, while others go through a gallon in one flying outing. I would recommend that if you want to try something like this, that you just keep an eye on the engine for carbon build up. At least pull the muffler every once and a while and look for carbon build up and/or the beginnings of rings started to get stuck. This is a maintenance item that we do on Ultralight Airplane engines. If you wiggle the crank back and forth while looking through the exhaust port with a flashlight, you should be able to see the rings move slightly, and perhaps ooze out a touch of oil. If it looks ok, keep flying and check it again after a few gallons of fuel.

Just my thoughts here..... I can't personally say how much carbon one would see, as I have never run an engine with a gasoline based fuel with that much oil.

AV8TOR

the Wasp

My Feedback: (1)

hey av8tor1977, Capinjohn,, very cool,, I found while Tartan recommends 10% oil for their Glow engines they recommend only 5% for their Gasser engines,, same Piston and Liner,,

so with that, for 1 part Glow and 2 parts Gasoline I would think 7% would be OK..



Glow/Gas Mix,, LOL,, I can see the guys at the field scratching their heads saying "wha-at" LOL

Jim

av8tor1977

My Feedback: (6)

I'm not personally familiar with the Tartan, but I wonder why they recommend different oil mixes. If the rod bearings are bushings, it needs the higher oil content, if they are roller bearings, then the lower oil content would be fine.

Captain John, I believe you have some experience with the Tartans don't you?

AV8TOR