bmwairhead

My Feedback: (2)

You guys are the greatest. Thanks for all the input.

David

Hobbsy

My Feedback: (102)

Here is a 1.30 I used to own, what a fine engine. And my Airhead. Another dave

spaceworm

And likely should require a slight dive before a loop, although my Sig 1/4 Cub doesn't with a Zenoah G23.

Twin_Flyer

My Feedback: (4)

While the four cycles will look and sound great, have you thought of going to gas at all?

Bill S.

airraptor

My Feedback: (66)

Cub crafters makes the carbon cub and a few others are making a version of the cub. there are two regular cubs out there flying with Titan 409 stroker engines of 230 hp. The Carbon cub has the Titan 340 stroker engine. it is 180 Hp

2walla

My Feedback: (10)

Valley view sells a real nice 40cc under their name. Saw the protype a couple of years ago. Would be perfect.. Most of the glow twins i have seen end up being problematic.

SrTelemaster150

Gas 2-strokes sound like crap.


See above in regards to crappy sounding gas 2-strokes.

Why would a glow twin be problematic? I have a Saito FA300TTDP W/dual carbs & it runs great.

To the OP.

Why not just put an FA180 in it & be done W/it.

[youtube]http://www.youtube.com/watch?v=tN1_-xmVLIo[/youtube]

An OS 160 Gemini twin or Saito FA182T would have a but less power but still be adequate. I wouldn't go smaller than 160 if you want ample power.

spaceworm

SWEET!!!! I am assuming that 180 has CDI. What fuel consumption on what % nitro have you gotten with that kind of flying? I have both a 1/4 Cub and a FA180 that I would like to pair, but the fuel consumption is a concern. Thank you very much.

Twin_Flyer

My Feedback: (4)

granted gas engines (haven't heard a gas twin in person) don't sound that great, however they sip $4 a gallon fuel vs. gulping $25 (where I am in NY) fuel. While that Saito 180 9or is it a 182?) will sound awesome, so will the cost of running it!

I have an OS 300 twin sitting in a box that I will probably never use for mostly the same reason (plus the size of the plane it will need) and expect to put it on ebay soon

I am slowly migrating to gas because of that and have a Kalt G22 going into an old 1/4 scale cub now.

Bill S.

Sport_Pilot

Methanol costs only $3 to $4 per gallon. You can find castor oil for $20 a gallon and sythetic oil for little more from Fox and Morgans. You don' t need but about 12% oil in a large four stroke, so the glow fuel really isnt that much more than gas. Add CDI and you can use a mix of gas and glow.

Twin_Flyer

My Feedback: (4)

you left out the cost of Nitro at $50 a gallon. Plus the mess it leaves on the plane vs. almost zero for gas.

There are several threads on RCU about mixing your own fuel and I am following them and thinking about it...

I will agree nothing sounds as nice a four cycle, especially a twin but the cost of running them is something that has to be taken into account.

one other thing to consider is what's needed at the field to start a nitro vs. a gasser.

in the end there is no right answer, just whatever makes the pilot happy.

Bill S.

SrTelemaster150

Nope, it's just a garden variety FA180.

Sport_Pilot

You don't need nitro in a large engine. Even with no nitro, glow fuel will be more powerful than gas..

SrTelemaster150

Spend $100 & put CD I on it. Then you won't need any "starting equipment" other than what you would need for gas. CDI conversions give you all of the user friendliness of "gas" Alightly higer fuel cost when power is similar, W/higher specific power output. Yoiu also eliminate the smell & fire hazard of transporting gasoline inside a vehicle..

Get rid of glow ignition & you can eliminate the nitro entirely.

Also the fuel consumption drops by 25% W/CDI, even more when nitro is eliminated. Compare that W/the 30% wasted fuel from a 2-stroke be it gas or glow. & there isn't as much difference when the same power output is acheived. A straigh FA180 CDI conversion running 15% nitro will make 3HP.

BTW, if you plan ahead & buy a few cases of fuel when you are tarveling. I by 15% Cool Power for $68.96 a 4 gallon case from Hobbytown Usa in Indianapolis. Thats $16.99 a gallon. Even here in the boonies on the Canadian border I can buy a 4 gallon case for $80.

Personally, I would not run a glow 4-stroke engine on glow ignition if it is larger than .91 & unless they start putting 2-strokes in full sized aircraft, 2 cycles engines are not an option for me.

SrTelemaster150

Fuel & therefore oil consumption is cut by 25% W/CDI. Also, you don't need the extra oil for insurance like unstable glow ignition. Iy can be cut to 8-10% W/CDI so now we are spewing less than 1/2 as much oil as W/glow ignition.

Mix your own methanol/10% oil mix W/CDI & your fuel costs will be cut by over 80%. Much closer to "gas" when the same power is produced. You need an engine about 25% larger in displacement to make the same power W/gas as methanol on CDI.

No stinky gas & power output will be higher even W/O nitro.

Hobbsy

My Feedback: (102)

The thing we're leaving out here is that he has his mind set on a twin, if he settles for a 1.80 he will never be happy with the choice. Regretting a bad choice lasts for a long time until you correct it.

bmwairhead

My Feedback: (2)

Gentlemen!

Thank you - for what is always an education. As a hobby flyer who is not yet retired, I have limited time. Because I have two highschoolers and one in college, I have limited funds.

I will continue to monitor this thread. It is sending me to places I did not expect! I am learning about CDI, engine manufacturers new to me and being challenged to mix my own fuel! I made careful notes and someday... after graduation(s)....

My best guess is that I will end up with another twin four stroke. I have several (smaller) two stroke engines in trainers and such, but this scale Cub really needed a twin - for all the right reasons. Yes, I could have inverted a FA180 and flown the wings off the famous yellow bird, but that would kinda defeat the purpose. A similar twin, close in size will really help simplify the conversion.

I am working a lot this week, but your comments are encouraging and motivating!

Thank you,
David

airraptor

My Feedback: (66)

Before you look at another engine you really should just go buy a bottle or 35% fuel and try it in that engine. You will be very supprised by the results. You will have to run a larger prop though.

SrTelemaster150

With higher nitro content, you not only get higher fuel costs, you also get higher fuel consumpsion. Operating (fuel) costs will nearly double. If the OP flies the plane a lot, the savings in fuel by not going higher nitro content will soon pay for the new engine.

Sport_Pilot

I agree, but it depends on how much he flies, so it may still be cheaper to up the nitro. Last year I probably only used about 24 to 30 ounces of fuel.

Twin_Flyer

My Feedback: (4)

30 ounces!? I burned over two gallons of 20% nitro last year...

There is 128 ounces in a gallon so...

Bill S.

SrTelemaster150

I used to run 1 gallon a week through my Saito FA150 & that had CDI. If I had been running GI it would have used another 24oz a week.

Rudolph Hart

As you can see the op has excellent judgement of real time energy management,has a good idea of how slow he is going and how much power is available.Surely cries out for a 182 twin but if it never gets fitted thanks for the vid.Not often you get to watch a good pilot in action would you all agree? you can rave on to infinity about which engine should be in what aeroplane and who cares in the end.To see any aeroplane flown well is good and if it stinks of nitro gee whizz i hope i can stand it

SrTelemaster150

The video of the 180 combo let's the OP know what the upper power envelope is.

A 160 or 182 twin will have slightly less or similar power. The added weight of a twin will probably help achieve the correct CG W/O adding ballast.

Sport_Pilot

At the end there is a Hanger 9 Cub with a video taken from inside the plane. LOL it was real looking enough I caught myself looking down at the altimeter.