Can anyone give me information on the 3W-24 gas engine? I bought a SIG Rascal 110 from my LHS today and as a result of much research, it appears that this engine is about the only one that will fit on the Rascal's narrow firewall without the carb hanging too far out. I had originally planned to use the new Zenoah G-26 on it, but after checking the mounting specs, the carb will protrude almost entirely outside the cowl. This means that even the throttle linkage will be exposed. Looks like the 3W-24 will be just about a perfect fit. SIG has experimented with the new FPE 1.3 engine, but this engine does not produce as much HP as the 3W. I own an RCS 140 engine, but I have never gotten this engine to run well at all in the air. I have already lost one new airplane to this engine and do not want to lose another.
By the way, the firewall dimensions of the Rascal are 4.25 " wide by 7" high (rounded at the top).

Any help will be greatly appreciated.

Sam

another option is to look at the MVVS 1.60 gasser (26cc). The carb is in the front and will sure fit your dimensions with plenty of space to spare.
Will turn 18" props in the 7000+ rpm range depending on mufflers used.

What if you were to use something like a radial engine cowl on it and give it an entirely new look. Plus, the carb and muffler would fit pretty well too.

I have a 3W24 mounted on a plane at home. I'll try to remember to take some measurements and let you know.
DKjens

I don't know what information you want on the 3W-24. The measurements can be found on the Aircraft International web page. As for performance, this engine is the most powerful 22-24 cc engine in the class. It has the same power as a G-38 while weighting about 50% less. The preferred prop is a 18 x 10 which this engine turns in the low 7K rpms. It will turn an 18 x 8 at 8K rpms. By comparision, the RCS 140 turns a 18 x 8 in the low 7K rpms and the G-23 is weaker yet.

This engine is a great engine. I have used this engine many hours in my univ research project. At last count, I have around 15 of these engines powering research planes.

Elson

I just took an eyeball measurement on my 3W24. It looks like the header extends about 2.5" out from the centerline, and the can at the rear extends out further.
I think you should go for a twin, won't cost you mucch more than a new 3W24. RCShowcase is selling the RCS44 B2 for $475 right now and mufflers for $70.00, that is a neat little twin and would look great on that Rascall. I have one of these, but have not had a chance to run it yet.
DKjens

Thanks Guys,

bobbi, your observation on the MVVS engine is correct. I will check this engine out in more detail. Having never owned one, I do not know much about it either. I think it will fit nicely though.

Dick, this is such a pretty--no classic--looking airplane just as it comes out of the box that I feel that it would constitute some sort of crime if the lines were altered an any manner. Your idea of the radial cowl concept would certainly work and would look very nice I think. However, I just like the present cowl style even though it will be more difficult to work with. By the way--I look forward to reading your arcticles in R/C Report each month as they are well written and you always have a feel for the "pulse" of large scale R/C. Talking to you at the WMA Giant Scale Fly-in last June in Goldsboro was a real treat--I own the Giant Aeromaster and the Pacific Aero Tiger Moth you were looking at.

Elson, what I am searching for is owner/operator feed-back on the reliability and power aspect of the 3W-24. You have provided exactly the kind of information I am looking for. Thank you! With endorsements like yours, I cannot go wrong with this engine.

DKjens, thank you for your assessment of the situation. I have also considered a twin such as the RCS. Using an engine of this type would necessitate a considerable amount of cowl carving and, in some way, tend to change the aesthetic effect of the overall original "look" of the plane. The old Rascal would certainly present itself boldly with the twin, wouldn't it?

Folks, this it the kind of feed-back I need for this project. Many thanks again to all of you who have offered thoughs, comments, and suggestions. Keep 'em coming!

Sam

I seen a photo of I believe a G26. The carb was on a 90 degree elboe and it did not stick out so far. I tred to find photo but??? I will look some more for the photo. Good Luck Captinjohn

I ran my G26 and a G38 with the same 18-6..The 26 was 200 rpm faster.. And 1 lb lighter....
Both with electronic ignition....

RCIGN: How many degrees of advance are you running on that engine? If a person was to advance the timing on a mag type.... could you remove the key and use a dab of locktite to make sure the timing stays the same? How far does the offset off the keyways appear to be? Thanks Captinjohn

Looks like the width of the key..Loctite works, is not really necessary, the taper alone is good enough...Our 34 hp race engine has no key in the hub, will NOT slip....

I've been doing some reading on this Rascal 110.

Seems like most of you like the plane, plus I have a 3w-24 sitting here doing nothing...what a waste of a nice motor.

Was wondering if anyone had any pics of this motor mounted on the plane they could share with me.

Also, what type of servo's are you using in the plane.

Thanks for the info.

Eric

I have a Rascal 110 and also have a 3w-24 that I am planning on putting on it.

I am using JR 4721 servos on everything because thats what I had in the shop.

The thing that concerns me most is what muffler to use. The pits muffler that I have is wider than the cowl.

Does anyone have any ideas as to what muffle I could use that fits within the cowl width?

Todd

Todd,

Which pitts muffler do you have for the 3w.

I have the one that Cactus ships with the 24...I believe its a Johnson Peace Keeper.

Eric

I think it is a supersonic. I will have to measure the width as I do not know how wide it is. I only know it will stick out of both side of the cowl if I use it.

Todd

Todd,

What's the width of firewall? Maybe a better question is, what's the width of the cowl where the muffler is hitting.

Had my dad measure the width of the muffler at the widest point. He says it's 5 1/8".

I know you said you were using 4721's, what does the manual call for?

Thanks,
Eric

The manual calls for 60 ounce servos on ailerons, rudder, and elevator. The 4721's are overkill, but it beats buying servos when you don't need to.

The firewall is around 4 5/8" wide and the cowl is the same width.

If your muffler is 5 1/8 wide, you got 1/2" sticking out the side of the cowl, and if its the same as mine, it won't be just one side. It will be centered up so that there is about a 1/4" sticking out each side.

I am thinking about getting a small header to put on the engine and some flex pipe to run out the bottom of the cowl.

I don't know how this will affect the engine performance though and I imagine it might not get past the field noise police.

If anyone knows of a muffler that will work without butchering the cowl, please let me know.

Todd

The Mvvs is for comparison about the same size as a OS160.
I managed to fit mine inside the cowl of a H9 Edge without any difficulty.
7200 rpm with an APC 18/8 out tha box. Seems to fly the Edge just fine even runnin rich

My friend has the Rascal 110 and I have a 3W24.We took measurements and this motor is just a little too wide for the firewall.I'm sure it would fly it great,but it would stick out the sides of the cowl a hair.He decided to go a different route.

Hank

How about one of the new two-ring Ryobi conversions?

31cc

VERY narrow, not too long....

Just a thought!
Dimensions/Pics here...

http://www.theriver.com/paragonaero/ryobi.htm

CrazyHerb