MTK

Exactly right but there a bit more detail that may be useful. The Tech Aero IBEC also has a built in Vreg. I typically will set mine for about 5.8 Volts, well inside the limits of any CDI, which means the input voltage to the CDI is 5.8 volts. But, Anything from 4.8 to about 6.8 is doable. My airborne battery has 2000 ma capacity and I get about 75 minutes of flying before I have to charge. I use a lithium 2S battery so my voltage is higher than needed.

If you use a NiMH you should use 5 cell pack. Remember that this will be the supply to theradio and the IBEC. Li-Ion and LiPo will need to have the voltage dropped to maybe 6.5 volts OR one can use LiFe battery without dropping the voltage first. Regardless of the voltage supply, once the IBEC output voltage is set, that's what the CDI will see.

The IBEC installs in a spare channel in the RX. The retract channel is one convenient spot. The TECH AERO unit has advanced filtering so RFI noise simply can't get through to the RX from the engine or CDI.

buzzard bait

Not a non-believer, but I did enjoy your video. Especially the effortless land launch; the flight and landing looked good too. I have a couple Irvine 36s and 39s, so I know not to underestimate the power of those little gems. The OS 35 AX I imagine is if anything even a little stronger, but I don't have one.

Jim

ETpilot

I'm scratch building a Kadet LT-40. I have debated going gas or glow for a while. I have decide to go with my OS .55 AX. I have this engine and would have to buy the smaller gas engine.

I have a Valley View 21cc gas engine for another model. But I have yet to start the learning curve for gas engines. It should be interesting.

michaelnel

Don't go gas unless you have a pickup or trailer to haul it in. I had my first gas experience last week (Giant Big Stik with OS GT33). Driving home with the thing in the back of my Xterra I was getting nauseated from the gas smell. I actually LIKE the smell of glow fuel, but being cooped up with that gasoline smell sucked, bigtime.

SIX GUNS

ET pilot , the switch from glow to gas is nice no glow driver no 20 + $ for glow
fuel as far as tuning the carb the needles are the same ( high & low) high for
wide open and low for idle and mid range the only thing that I found I needed was a tach

MTK

Autogas smells lousy I agree. Let me recommend you use Avgas 100LL. No smell to speak of and what little there is is actually pleasant. Carb Settings need no significant changes. Is what I use in my GT33 powered models. Grandson's T-Clips is powered with the OS GT15 and we use the same Avgas mix in the 15. Oh and BTW- measure shelf life in years not weeks. Buy Avgas at the local muny airport. The one I go to let's me drive up and fill my 5 gallon can and the pump allows credit card use. It costs about 50% more than autogas or around 3.60 in today's marketplace.

There is also puregas. New Jersey doesn't have any stations that sell it, but many other states do.

michaelnel

Thanks, good tip! I will go get some at the local airport.

JohnBuckner

My Feedback: (1)

Hi michaelnel I also love the smell of glow fuel and I admit I transport with both a covered pickup and or my trailer so I do not know how to offer solutions if you transport in a SUV (sorry I guess that is what an Xterra is).

However I just wanted you to know depending upon your local fixed based operator or who ever operates the fuel consesion at your local airport may refuse to sell you 100LL or Jet A into a can. This is quite worse since 9/11 and the ability to buy it in small quantities can range from refusal to open purchase. So best to inquire at your local FBO first with out a can and explain why you want to purchase it.

Most recently here, while we have been able to buy 100LL but unfortunately the same operators will not sell us Jet A for certain of our turbines into small containers.

On the original question of this thread my somewhat enlarged Senior Cadet float plane has proven ideal with the spark ignition version of the OS 15 cc gas engine.

John

michaelnel

My club tells me our local airport mgr will sell us avgas. She is a heck of a nice gal with a gorgeous Taylorcraft, and she lets us use the airport office afterhours for our club meetings.

JohnBuckner

My Feedback: (1)

You are fortunate so do take advantage of that. At one airport where I formerly kept a full scale airplane post 9/11 they would only sell 100LL or Jet A to you in a can, if you provided a full scale tail number of an aircraft that was listed as being based there.

So michaelnel , not sure how long you have been into the hobby/sport but let me suggest a simple point. That is after a period of time as this hobby/sport become more important to one, The type of vehicle/transport we tend to choose is more a choice driven by the types of models airplane we tend to fly, rather than the other way around where the type of models we tend to fly is driven by the type of transport we have.

John

MTK

Note that Avgas is LL meaning low lead. The spark plug will need cleaning every 10-15 gallons or so. You may also want to open the engine up at that time and check for cleanliness/build up. With good carb settings it should be clean inside.

To be sure of no build up with any gas engine, Every 10 gallons or so, you may want to run a gallon spiked with injector cleaner 2 ozs per gallon. Really keeps the heads and pistons clean.

ETpilot

Well, after more research I am back to going gas with my LT-40. I've had my eye on the new OS gas glow 10cc engine. No ignition module nor battery and a 50-1 gas mix. It is described as for a .40 size aircraft. So with some throttle management it may do well on my model. The engine mounting is the same as the .55AX. So it is a done deal I just have to wait for availability which is late May.

I have lots of Stihl equipment for tree and firewood cutting. They use the same gas mix as the OS so I already have the fuel. I know how horrible it can be to transport fuel mix in an enclosed vehicle, not good. I have done it on a few occasions. My transport will be a pickup truck if I ever transport the plane. I have a backyard runway for flying.

As for avgas, I have been using it in a power tug at the airport for years. Never a problem. I sump the fuel tanks and just dump the fuel it in the power tug fuel tank. I'll have to consider avgas for the OS engine.

Thanks for for all the tips and suggestions in this thread. Good info.

JohnBuckner

My Feedback: (1)

Cool ET, would very much like to hear of your experiences with the 10cc OS glow ignition gasser. Also anyone currently running the 15cc OS glow ignition gasser

John

MTK

It's a simple engine to run the OSGT15. Its ignition module is smaller and lighter than that of the GT33/GT60. I'm turning an apc 14x8 on mine. I'm using the same 50:1 mix as I use on all of my gassies, break in or regular running. Their instructions take you through an elaborate carb set-up which I did not use. My carb just needed about 1/8 turn leaner to both the HS and LS needles and that was it. I'm currently running the regular muffler on mine; very quiet since mine is rubber iso mounted. And it is as sweet a runner as the larger OS gas engines have been. I'm using a 240 ml bottle for the gas tank and it lasts about 20 minutes.

I plan to run a pipe on it at some point to get some reference data. The T-Clup doesn't need the power but I want to see what the mill can do.

Not much else to say about it. You have specific questions?

Wait a minute, when I re-read the post, you wanted info on the glow gassie. Can't help you there. Mine was supposed to be the glow version but Tower was taking its sweet time so I opted for the CDI version. No regrets....some comments on the glow plug have been negative but I take that with a big grain of salt since I don't know the experience levels out there playing with this technology.

michaelnel

The GT33 is my first gasser. It's a powerhouse for sure, on the maiden flight of my 80.5" Giant Big Stik it went vertical ... got so high we couldn't hear it, then so high we couldn't SEE it anymore, and it was not at full throttle.

Unfortunately, the ignition module failed just before landing and the plane was landed with a successful dead stick landing. We never got it to start again. Testing it with two different charged batteries and a plug out of the engine but plugged into the cap and the shell grounded gave not a hint of spark.

So now after one flight, the ignition module is on its way back to Hobby Services. I spent a lot of money for OS quality... not sure I got it.

JohnBuckner

My Feedback: (1)

Yes been operating for some time now OS 33 and GT55 and most recently the OS 15 spark ignition. The 15 sparker is the fourth and best engine to date in my 'Catalina Cadet' which has has done a six hour static flight and carries almost a gallon of fuel. The first engine was a OS .95AX then the second was an OS .75AX and the third a OS .65AX those of course were all glow. The wing is extended and considerably reinforced.

John

MTK

My experience with the GT33 was incredible for the first 4 flights. Then something happened which I couldn't tell without disassembly, and the engine stopped working. I sent it back to HS and it took awhile since parts had to be shipped from Japan, but after receipt, the engine has been incredible again. The backplate had cracked.

It is starting it's fourth season. I kept a log on it so I know how much flight time, etc. It has about 120 hours of operation so far, some 600 flights or about 60 gallons of avgas through it. I've cleaned the spark plug 4 times in that span, replacing the plug late last season for no other reason than the electrode was rounding off. I've looked inside twice and both times neither the head nor piston needed any special cleaning to speak of.

I commissioned a second GT33 last year and have not had any problems.

Having run glow engines for 40 years before going to gas 6 years ago, one great thing about gasoline is no more rusted bearings every season and no more blown plugs after 50 flights.

Sport_Pilot

I prefer glow for the greater power and/or lighter weight. Fuel is not expensive if you mix it yourself and keep the nitro low.

ETpilot

John, will do. I'm sure as the engine becomes available there will be many postings. I have read some threads regarding these new gas glow engines. As always some debate; positive n negative. I just have to get one, give it a try n see how it works out. Gas glow on the smaller airplanes seems like a good way to go.

michaelnel

Got confirmation from Hobby Services yesterday that yes, the O.S. GT33 ignition module is bad and they will replace it under warranty.