Airborn

Hello all,
Well I finally got my H 30 together and got it running.. all I can say is after all the work I put into this engine I am disappointed with the power my little engine is making... or rather the lack of With an 18 x 8 prop I am getting 6300 rpm, with an 16 x 8 the results were about the same .....no big change in rpm. After reading alot of the post on engine conversion I guess I was expecting the engine to be turning around 8000 rpm. this is the newer version out of a yard broom leaf blower. This is the engine with the four small transfer ports but it does not have the hole in the exhaust port.I have done it all........big bore carb (11.11mm) bored out the hole in the intake manifold and port matched the intake side of the head, port matched the case, machined the back of the case to move the back plate as close to the crank pin as possible, machined the head to raise comp, set of rings from Frank Bowman (great rings,, make a big difference in compression) pitts muffler, CH syncro spark ignition. 30deg btdc....I have done some experimenting with the timing but this did not help. will try a different carb sometime this week and see what happens... If that doesent help I guess I am going to take the head off and machine the divider brtween the two transfer ports ( make one large port like the old style head) I havent given up yet If anyone has any Ideas pass them along....I will experiment alittle more and post the results (good or bad) latter this week.

Railridr

I have not gotten around to tinkering with the one that I have, but I would look at the exhaust port timing. To me it looks like the exhaust port opens a late, and the exhaust port is not as large as the Homelite 25cc that I have. The top of the exhust port on the 4 port cylinder is shaped like a crescent, versus straight across on the old 30cc cylinder.

w8ye

My Feedback: (16)

My older style 30cc turns a 18-8 Dyna Thrust at 7500. The only mod is a 11mm carb with a bored out insulator.

Enjoy

Jim

airbr

My Feedback: (4)

Sorry to hear of your performance issue. I got a 25cc that turn 7110 on a 18-8 prop so you should be getting at lease 8000 with the bigger piston. I would not machine the head though since there are skirts in place. What I did was deck the crank case by approx 1/32 if there is a squash ring in the top of the head or 1/16 if there is none. You may want to check your port timing and as was mention the exhaust timing. Check your squash height with some putty.

b717doc

Hey Airborn,
I've been trying to identify the engine that I have on my ULTRA STIK 120,,,I got it from the local pawn shop for $50, It came from a Homelite chainsaw, and believe it was something like a Viper Super II or something like that...I do know that it is at least a 30 cc, but not more than a 32cc. All the "experts" at the field said it would'nt work, but I still amaze them with 80+ mph fly-bys!!! It has the old contact point ignition system, so it must be pretty old. We tacked the engine at full throttle yesterday, and with it swingin a 18x10 prop, it was reading 6700 rpm or so....the airplane probably weighs at least 14 pounds, and that little engine pulls it flawlessly through the air.....check your pawn shops and start over......

smallplanes

My Feedback: (3)

b717doc,
Do you have any pics of the plane and motor? If so post them i would like to see it.



Thanks
smallplanes

b717doc

Hey Smallplanes,

I do not have any photos of the stik as of yet, but will take some tomorrow at the annual "Spring Fling" we are having. will add to this thread Saturday or Sunday (04-10-05).......

smallplanes

My Feedback: (3)

Thanks, We too are having a fly in sat.(www.flyingtigersrc.com)



Thanks
smallplanes

Volfy

My Feedback: (23)

My barely broken-in Homie 30cc turns MA 18x8 7000rpm. I've only got maybe 50 oz. of fuel run throught it, so it'll gain a few 100 rpm as it breaks in more, I'm sure.

Haven't flown it much since I got it put together last year because of the weak stock main gear and very little prop clearance even with an 16" prop. I just got these replacements on and so should be getting more airtime with it. Weighs almost exactly 16lbs dry RTF.

Craig F

Volfy, what plane is that? It looks like the 89" decathalon , is it. Thanks Craig

Volfy

My Feedback: (23)

It's the Sportsman Aviation 86" Super Decathlon. The Homie 30cc fits entirely within the cowl, except the carb velocity stack. Power is pretty decent and hauls the 16lbs plane around just fine. I thought about using my Poulan 46cc, which would also fit this airplane well. The airframe is built very stout and can easily take extra power. But I finally decide the Homie 30 should do scale aerobatics just fine, which was what I was looking for in this graceful cabin cruiser. Plus the original gears didn't offer enough clearance for 20" prop the Poulan would use. Still, I have another identical one NIB as a spare, and I may use the Poulan yet...[>:]

The Homie converted to CH elec. ign weighs about the same as the Poulan 46 - roughly 4lbs with B&B muffler and ign system. I placed two elevator servos under the stab and moved the firewall about 3/4"~1" behind what the instructions say. It balances at the forward end of the acceptable range and flew very stable. I may try to shift some weight around to get it to balance a bit further back. Still, I'm very please that, with a gas engine, I came in well within the 14-17lbs range specified in the manual for 1.20 to 1.80 glow engines.

captinjohn

Volfy....is that a ARF..or a kit. Where did you buy it. Thanks Capt,n

Volfy

My Feedback: (23)

It's an ARF that has been discontinued by Global Hobbies (HobbyPeople.net).[] I scooped up another one for spare parts when they were clearancing them out.