cfaw10

Ok guys,
I'm to the point on my 4*120 where I cut it up to install my homey 33 conversion. Planning to remove the cheeks, move the firewall back, and put the radio gear in the tail. I want to hear from people with experience with this engine. Would I be better off going with a bcma 26? I would hate to cut up such a nice plane only to find out that the 33 is to much engine for it. From talking to others at my field, I think the final weight with the 33 is going to be around 12-12.5lbs. Around 11lbs with the 26cc. I read somewhere in here a guy said his 33 was too much for his 4*. What's your opinions?

arobatx

I can't speak about the 33cc Homey, i have no idea what it weighs after conversion, what prop it will spin and at what RPM, so it is hard to say. 33cc in general is not too much for a 1.20/1.40 sized plane. I can talk about two planes: Quique Somenzini Yak 54, 72", 11 lbs, Zenoah G26 converted to EI, Mezjlik 18x6 @9000, and it will do everything it did before with the YS 1.40 on it, unlimited performance. Hangar 9 Funtana X100, 69.5", 10 lbs, Zenoah G26 converted to EI, Mezjlik 18x6 @9000 and APC 17x6 @9400, again unlimited performance, the same as the YS 1.20 it replaced. Zenoahs are known for running really well at higher RPMs, where other small gassers don't love it so much. At least here you have some plane sizes, weights, rpm and prop measurements to help you decide on power for your model. Good Luck!

Chad

captinjohn

Check this out http://www.rcuniverse.com/forum/m_35...tar+120/tm.htm Capt,n

av8tor1977

My Feedback: (6)

What the #$%&# is "too much power"?? The lever that goes up and down on the left hand side of the radio is a control that moves, not a switch. You can always pull back on the power. I like to set up my planes powerwise so that half throttle is a nice comfortable cruise.... and full throttle is like shooting a bullet. Nothing like pulling to verticle, hitting full throttle, and accelerating while going vertically out of sight!

I always teach my students that the throttle is another control, not a switch to be thrown, and not to fly around at full throttle all the time.

AV8TOR

tstotts

I am flying a Ryobi 32 in my 4 star 120. I moved the firewall back 2" with the tail control servos in the back and everything else pretty well in the standard positions. The Ryobi is pretty heavy with the mag ignition system. Weight and balance was no problem. Power wise it flies pretty gentle nothing real exciting but a nice flying sunday flier. very reliable.

davewallace

My Feedback: (29)

tstotts,
The 33 will blow the Ryobi away in the power department. A Homey 33 on mag weighs the same as a Ryobi 31 on mag. About 64 oz. I have both and they are about 64 oz. ,using JAG parts on the ryobi. The plane flys OK on a 31, so a 33 has to be better. A 18x8 should deliver rpm in the 7,000 range or better. You can always add standoffs if you want to try a lighter store bought engine later.

Dave

tstotts

I totally agree. The ryobi is not a power house although it is reliable and readily available in most areas. My point was that the 120 can carry the weight with no ill effects and balance easily by moving the firewall back which I believe was the concern in the question asked. The 33 and the ryobi are fairly heavy engines so if it can support the Ryobi's weight by moving the firewall back 2" that should be in the ballpark for the 33. I used the ryobi becuase I had one sitting around not being used so the price was right. Would use the 33 over the Ryobi anytime given the choice. Long story short (to late) I think the 120 powered by the 33 will be a great flyer.

cfaw10

Thanks for the info.

Built a rolling test stand and did a little testing this morning. This thing's a brute!
Had to keep the throttle at about 85% to keep the rpms at 8000 with a MA 18/6.
I've only ran 1 tank of fuel through it, so I don't want to turn it up too high yet.
Getting 16+ lbs of thrust (on my high precision $4 fish scale). These numbers are without a muffler---I'm still working on a custom aluminum one. I guess the engine will be fine--It just looks huge hanging on the front of the plane.

----Off to work, thanks for all the replies.

av8tor1977

My Feedback: (6)

Convert it to either electronic ignition, or Gas/Glow, and lose the weight of the magneto. You will likely also gain a little power, though that's not a problem in this case.

AV8TOR

cfaw10

What ratio of gas/glow and oil do you mix. Does this ratio apply to all conversions?

tkg

My Feedback: (1)

Gee everybody here thinks its a switch. Nothing like an LT40 getting jerked around at WOT.

av8tor1977

My Feedback: (6)

That's the way my brother is.... I just can't get him to pull that throttle back for anything!!

Here's all the info, (more than you want to know...), on the Gas/Glow setup:

http://www.rcuniverse.com/forum/m_12...page_49/tm.htm

AV8TOR

Rcpilot

My Feedback: (78)

[sm=lol.gif] Thats hilarious. Too much power? Never heard of such a thing. Blasphemy!!!

av8tor1977

My Feedback: (6)

If it's not scary, it's NOWHERE NEAR powerful enough!!

AV8TOR

cfaw10

Umm.....Ok..... so thaaaaat's why that stick moves! I thought it was broken!
In my original post I wrote that there was a guy here who actually TRIED this combo and said it was too much. (can't find the thread now) Don't know if he meant too much power, too much weight, or if it just looked too big hanging on the plane. Apparantly it'll work fine though.

tkg

My Feedback: (1)

Actually there are/were a whole bunch of the 4* and the Big Bingo kits running G-38s. Shorten the nose and have fun with your Homie.

cfaw10

Thanks, tkg.

av8tor1977

My Feedback: (6)

Yeah, if I remember right the specs of the 4 Star 120 aren't much different than my Giant Big Stik, and I have a 42cc Poulan on it...

Have fun,
AV8TOR