27cc stihl
 

anyone had one of these converted if so up to what weight would they have verticle? 1/4 scale too large?

RE: 27cc stihl
 

My rule of thumb is that a 25 to 31cc engine will fly a 14 to 15 pound airplane if that is the question.

Bill

RE: 27cc stihl
 

its not about what engine you pick that you will have problems putting on your cap 232, its raw power. on any conversion engine to get the kind of vertical you need to hover and such you will have to do some amount of work to get it there. look at the brillelli guys they take conversion engines and port them and tune them to get the most out of them. a standard conversion will not give you the 2:1 power ratio that you need. it will give it enough power to get off the ground and fly in a decent manor and even aerobatics. Definitely not a hover. Start off by building yourself a rig to measure static thrust. take the stihl convert it mostly un-ported, measure it on your scale. then stuff the crank case measure it again. convert it to electronic ignition which wont do anything for you except lower weight. add a slightly bigger bore carb than what is already on it. highest you can probably go on the 27cc is 15 mm. some people remove the gasket between the crank case and the cylinder which increases the compression ratio a bit.

you need to do some reading on engines here is a list of things to do to make an engine more powerful.
http://auto.howstuffworks.com/engine3.htm

some of the things on the list wont apply to you because they are for car engines but the principle applies. You are going to have to experiment a bit to get use of any conversion engine you run. the way to know is going to be ultimately based on static thrust so the best thing you can do is make a rig for yourself like i said to measure static thrust.

RE: 27cc stihl
 

Just start hear and read about what others have done.....Capt,n http://www.rcuniverse.com/forum/sear...mitbutton=+OK+

RE: 27cc stihl
 

can i get a 27 cc to hover it it weighs 12.6 lbs with everything tonight i started it it ran good what prop should i use and what do you guys ahve a 27cc on how does it do?

RE: 27cc stihl
 

icando3d2 wonders....Can a 27cc engine hover a 12.6 lb airplane? I DO NOT KNOW...but I would start with a 17x6...but that is a wild guess. Good Luck Capt,n

RE: 27cc stihl
 

its a hanger 9 cap 232 73 inch wingspan older hanger 9 version, i ran it tonight for the first time the engine has about 2 hours of run time on it in the weedeater and then it was converted it has a zamma carb on it. im posting on this site to learn because trial and error is effective but let downs suck i can put my zdz 60 on it and it would rip the wings off but it will stay on the edge, plus i want the satisfaction of converting my own enigne and having it do what i want to do for alot less money, the prop i ran on it tonight was just an older master airscrew 18-6 just to have it run on the plane ran it about 2 mins, it snowing here so i got really cold behind the prop

RE: 27cc stihl
 

That 18x6 may be a little to much for your engine as is. If it is snowy weather I would not run it too much....I would say the engine has to run warm to breake in right. Is there any way you can post a photo of your engine? That may help viewers to come up with more ideas. Capt,n

RE: 27cc stihl
 

Aeronut....If your there yet...you got any ideas? Capt,n

RE: 27cc stihl
 

yes i will post a pic on here i have it already on the plane i have dial up so ill get it goin on , thank you guys soo much

RE: 27cc stihl
 

Here is a engine size to weigt chart............................................. ............................... Around sea level with right fuel and prop, pitts ect.....

With a Moki 2.1 on pitts plane should weigh about 14 pounds or less
With OS 1.6 plane should weight about 12 pounds or less
With OS 1.08 plane should weight about 10 pounds or less
With YS110 plane should weight about 10 pounds or less
With OS .91FX plane should weigh about 8 pounds or less
With SA100 plane should weight about 7.5 pounds or less
With a ST75 plane should weight about 6.5 pounds or less
With OS46FX plane should weigh about 5 pounds or less
With OS25FX plane should weigh about 3 pounds or less

With 50cc gass/pitts plane should weigh about 18 pounds or less
With 40cc gass plane should weigh about 14 pounds or less
With 26cc 1.6 gass/pitts plane should weigh about 10 pounds or less

------------- It may help for 3d type of flying! Capt,n

RE: 27cc stihl
 

still trying to figure out how to upload pics

RE: 27cc stihl
 

humm all up weight for cap is high 12's so the wheels are tickin i wonder if it will fit the showtime hummm [>:]

RE: 27cc stihl
 

Sent you a PM on one way to upload photos. Capt,n

RE: 27cc stihl
 

one was a test fit.

RE: 27cc stihl
 

Did you get this engine already converted and on plane? Capt,n

RE: 27cc stihl
 

no i just converted it, i just finished a 3.3 but its reed valve i dont know how i feel about it. why do you ask?

RE: 27cc stihl
 

The prop hub looks like a steel one like on a Zennoah. How is the compression and does it hand start easy? Capt,n

RE: 27cc stihl
 

my father in law made the adapter for me from a sketch i gave him, compression its 2 ring engine has 3 hours of weedwacking compression is really good hand starting is a yes, but it does take some butt behind it to hand start does it look ok to you guys im going to get another muffler for it but if you guys don think its enough i may think about putting it on the showtime

RE: 27cc stihl
 

Looks like a good conversion. Like you say a different exhaust may be needed. May give it more power too. How much does your showtime weigh? Also the wing area. Its a good idea to figure wing loading. Capt,n

RE: 27cc stihl
 

im not sure about weight on the showtime, i used to fly the cap with a 1.20 surpass fourstroke engine and it had verticle but not impressive i was going to install a 1.6 glow but being newly married money doesnt allow the purchase. The 27cc is a 1.648ci give or take the last few digits so hopefully i can get a fish scale and get some numbers for you guys i have found a apc 18-6 on my 1.20 so im going to try it tomorrow if time allows

RE: 27cc stihl
 

are conversion engines allowed in anytype of fly ins or events?

RE: 27cc stihl
 

I haven't been to any functions where conversion engines are restricted.

Most gas engines are actually conversions using at least some chain saw parts

RE: 27cc stihl
 

As far as I know they are. I know I have seen all types of engines at fly-ins. Maybe of more importance is the Radio and servo instalation. I think most events have a inspector to check this out. Well I got to sut down for the nite. Take Care Capt,n

RE: 27cc stihl
 

well i flew the cap today it flew well had good power for normal aerobatics not a chance in the world on hovering or vertical pulls it weighs in at 13 lbs even going to leave it in there to have a great conversation piece, going to convert another and stick it in another plane thanks for everyones input any questions on the conversion ill try to help