Homelite 25cc or 30cc?
 

Two Homelite engines were donated to me by a generous clubmember because he knew I convert them for R/C use. He said one is a 30cc and the other is a 25cc, but they both look virtually identical. How do you tell which is which?

Jim

RE: Homelite 25cc or 30cc?
 

The 30cc jug has slightly larger fins. No points for guessing which is which:). If you take off the exhaust the 30cc usually has two rings the 25cc has one and usually a bridged exhaust port.

RE: Homelite 25cc or 30cc?
 

Thanks, Rupert. I have two of the 25s in a 118" Me-110 and they fly it very well. I have one 30cc Homelite on the shelf, already converted, and it will be nice to have another one for when I build another twin.

Jim

RE: Homelite 25cc or 30cc?
 

Sounds good, my 30cc is stock with the exception of the cd ignition and turns an 18x6 300 rpm faster than the 25cc jug on the same setup. Still using the small 9mm carb and getting 7000rpm on that prop.

RE: Homelite 25cc or 30cc?
 

AH yes, the the only substitute for cubic inches is cubic money......

RE: Homelite 25cc or 30cc?
 

Hi Tim,
The displacement is cast into the cylinder flange beside the carb mount. See photo.

Dave

RE: Homelite 25cc or 30cc?
 

Jim,

I am bashing a single into a gas twin and wondered about the weight and wing loading on the 118" Me-110.

Thanks.

Bill

RE: Homelite 25cc or 30cc?
 

Interesting, I never bothered to weigh the parts like that. That shows the 30 weighing 1.6 oz. more than the 25. My complete 30 weighs two ounces less than my 25, so I guess the extra time I spent removing metal on the 30 was worth it. I recommend using the 30.

Displacement = ((bore x bore) x stroke)) x .7854

(If you measure in inches, divide by .061 to get cc)

AV8TOR

RE: Homelite 25cc or 30cc?
 

Thanks for the tip. I never noticed that before.

Jim

RE: Homelite 25cc or 30cc?
 

av8tor1977: What did yours weigh in the end?

RE: Homelite 25cc or 30cc?
 

I haven't calculated the wing loading on the 110, but the model weighs about 30 lbs. and with it's huge long wings, I think the wing loading is not very high. Takeoffs and climbouts are strong, and it does scale-like aerobatics. It will loop from level flight but slows down near the top. The 25s have the bigger carbs on them (#28)

Jim

RE: Homelite 25cc or 30cc?
 

WOW nice looking plane[8D] have you got any close up shots?

RE: Homelite 25cc or 30cc?
 

Thanks, Rupert. Here's a couple:

RE: Homelite 25cc or 30cc?
 

What did you build it from kit, plans? I have been thinking about a 25cc homie twin as a project for the distant future.

RE: Homelite 25cc or 30cc?
 

Hi,

Here's the stats and a pic of my Homelite 30cc. It turned an APC 16 x 8 prop at 8600 with only an opened up muffler and a slightly larger carb. Then I modified it...

Homelite 30cc - older design with small transfer ports.
Weight with muffler - 2 lbs. 14 oz. (More cutting/grinding on this one than my Homey 25cc, and this is with prop adapter but without prop or spinner.)
Muffler - Stock, square, gutted, with two brass 1/2" i.d. outlets added.
Carb - 11mm Walbro, manifold ported to match, external pulse line.
Ignition - CH Ignitions electronic set at about 28 degrees presently.
Cylinder - Quench or Squish band removed, cylinder to head clearance set at .020"
Port timing - Exhaust 165 degrees, Intake 148 degrees, Transfers 120 degrees (22 degrees blowdown). All ports cleaned up and entries in crankcase smoothed.
Crankcase- stuffed to .020" crankpin/backplate clearance.
Rings - FRANK BOWMAN'S!!
RPM - APC 16 x 8 = 9400 (Possibly more with tuning and more run time. Also, with this port timing, a tuned pipe would probably give 800 more.)
Test conditions - 4200 feet altitude, temperature 78 degrees, barometric pressure 29.75"

Please also note that while I did modify the transfer port timing, I did not alter the size and I think this would also help. I'll do that on the next one for sure, or use a later model cylinder with the larger transfer ports.

I like it!
AV8TOR

RE: Homelite 25cc or 30cc?
 

I built it from Don Smith plans...not real easy plans to work from, but if you're an experienced scratchbuilder you can do it. He also has plans for a Cessna Bobcat twin, which would be a good candidate for the 25s. I have his plans for the Ju-88 and I'm thinking about using the two 30s for that one in the future.

I had a Homie 30cc in my 1/4 scale Tigermoth, but the plane did not have much performance. The model is 17 lbs. and I had to bite the bullet and put a US35 in it. Now that I have two 30s, I'm reconsidering the Ju-88. I haven't done anything fancy to my Homelites...stock mag, bigger carb, that's it.

It's kind of funny when guys see the Me-110 fly and they ask me what engines are in it, and they hear the answer...Homelite leafblower engines![sm=lol.gif]

Jim