Biggest engine for a U-Can-Do 40 size?
 

I'm planning on getting one of these in the next few days. I have a spare OS .65LA laying around. Is this too big? I like my planes to run pretty hot - but will this be too heavy? I'm just asking because I don't want to buy more stuff really. I have everything and this spare engine. If this is too big, what is a good 3D ARF that will accept this motor and have hovering/punchout power? The 60 size UCD I'm afraid will lack power with this setup.

Any help is appreciated.

Thansk

RE: Biggest engine for a U-Can-Do 40 size?
 

I ran a Satio 100 in one...but we fly at high altitude, so power is needed...

Mark

RE: Biggest engine for a U-Can-Do 40 size?
 

I have a ucd 46 and a os fs 70 in it. It can hover at half throttle and sounds sweet. The best engine I have ever ran. A perfect match for the ucd. It can idle so slow you can actually see the blades and throttle resonse is great

RE: Biggest engine for a U-Can-Do 40 size?
 

First of all the UCD is not ment to be hot. Its ment to be slow and limber. I had one with a saito 72 and a OS 50SX both were great motors. The 65 should be fine. Trust me you dont want a hot rod.

RE: Biggest engine for a U-Can-Do 40 size?
 

What about a Tower .75 on one?

RE: Biggest engine for a U-Can-Do 40 size?
 

tower 75 would be better if proped right ULTRA LOW PITCH. i broke my ys 110 in on mine so nothing is to over kill.

RE: Biggest engine for a U-Can-Do 40 size?
 

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RE: Biggest engine for a U-Can-Do 40 size?
 

I started with a Saito 100 in my UCD 46 and didn't like it. Plenty of power but too much vibration. Went to a Saito 82A, the new 82, and like it a bunch for sea level flying. Power is just right, still experimenting with props. Presently using APC 15x4 but think its over-propped. Gets hot on hot days - 90+ and high NJ humidity. Will try Zinger 14x6 next time out.

RE: Biggest engine for a U-Can-Do 40 size?
 

See.. Now I'm confused :)

Hegasis says that the FS .70 runs good. The FS 70 is 1.1hp and weighs 22.1oz with muffler. My OS .65LA is 1.7hp and 18.9oz. Shouldn't the 65 LA be a better choice? It's $100 cheaper too.

Or is there a super secret about 4cycles that I don't know about?! I've never had one, so forgive my ignorance on that subject!

Thanks

RE: Biggest engine for a U-Can-Do 40 size?
 

Your 65LA weights 23.8 oz with muffler . Put a 13x4 or 13x5 prop on it and have fun . I have a Magnum .91 four stroke on mine now that weights about the same and the plane flies good . I have thought about putting my Saito .72 on it just to see how much difference there is .

Barry

RE: Biggest engine for a U-Can-Do 40 size?
 

Ok, thanks for the help. I will do that then, and see how it flies, then go from there.

Thanks for the prop reccommendation too - I'm never good at figuring that out :)

Thanks
Jeff

RE: Biggest engine for a U-Can-Do 40 size?
 

There IS a big difference between 2 stroke and 4 stroke on a 3D machine. The 4 stroke swings a large diameter, low pitch prop with peak power at low RPM. The 4 stroke responds instantly to throttle changes. The 2 stroke swings a smaller diameter, higher pitch prop and power peaks at max RPM. The 2 stroke takes greater RPM and larger throttle changes to get the same thrust as a 4 stroke. I had to see it to believe it.

RE: Biggest engine for a U-Can-Do 40 size?
 

well you can put a larger diameter smaller pitch prop an a 2 stroke and it will give a bit more low end power. i have a 13x4w turning 11,800 rpm on my tt61pro and it does great. it does better with the regular 13x4 at 12000 rpm and quicker spool up, but the LHS didnt have any last i bought.

this set up is on my UCD46. and i love it. although the 4stroke arguement is a good one. having an engine that will work well. is better than buying an expensive 4stroke, just to say you did.