Fastsky

Ok, I decided to jump into the twin game. I bought the Super Sportser 40 kit and started building and the plans just arrived. The guy that did the plans says that two 25 engines supply about the same power as the original 40 sized engine. I want good engines so I am looking at the OS 25FX series. So do I stick with the 25FX or do I up the performance (and $$) and go with 32SX engines. Is there any advantage to choosing one size over another?? Appreciate all opinions. [8D]

jrf

My Feedback: (551)

For what it's worth, the 32s are 1.5 oz heavier (each) and you won't get a lot of flight time on the tanks that will fit in the nacelles. (Don't eliminate the tank padding. Fuel frothing is death to a twin.) Also, the more power you have in a twin, the more likely it will snap/spin when you lose an engine.

Actually, I would think that two 25FXs would out pull a 40 by quite a bit.

Jim

Cutlass 60

The two 25 FX's will be more than ample. Mine flew just fine with 25 FX's. I flew it for two years before I sold it in a weak moment. I may have to build another one. It's a winner.

vmsguy

I've been toying with this build, among others as well...

Does anybody know... is the Super Sportser 60 just a bigger version of the 40? Or are there a lot of differences. I'd think a pair of 25s or 32s would pull a SS-60 pretty nicely as well....

jrf

My Feedback: (551)

The 60 is just a larger version of the 40. Usually, people use two 40s for a 60 size conversion, but I guess that depends on the level of performance you are looking for. I have a 60 size trainer running two 40FPs (just slightly more power than the 25FX) and the performance is "scale-like". I believe two ball-bearing 40s would give it good performance and a pair of 46s would be even more enjoyable. The SS60 is smaller than my trainer, but about the same weight, so engine choice should be similar.

Jim

Fastsky

Thankx for the opinions. This twin is set up for 8 oz. tanks so I don't think flight time would be a problem based on my experience with my current 32SX. The difference in weight would make a difference and I wouldn't mind saving over $100.00 difference between the 2 engine sizes. [8D]

vmsguy

OK.. I give up.. I know I saw an article or something regarding this. I thought I remembered a set of plans, or an article on making this a twin.. But I can't remember where....

I looked in the August MAN. The big twin issue, and it wasn't there... So where did I see it?

Fastsky

The article was actually from RC modeller magazine which doesn't print any more but the plans are still available. Its PLAN pl-930.
The site is http://www.rcmmagazine.com/store/sto...oFngd0zDM5Y2r7
The second picture is the modern completed version that was recently built. My apologies to the builder for forgetting his name at the moment. [8D]

vmsguy

Ah yes.. I knew I saw it somewhere... I've order several plans from RCM...

I hope you post pictures and keep up informed on this build...

Fastsky

Well I jumped into it and ordered 2 OS 32SX engines for the Sportster twin. I have one on my sons LT25 and its a great engine. Its very quiet, you can hardly hear it at half throttle, it sips fuel and it puts out almost the same power as FX40 engine at full throttle. Thankx for your feedback. [8D]

vmsguy

How is this build coming along?????

I ordered/received the twin plans.. I'm thinking of scaling them up, and using them on a Sportster 60...

Got any pictures???

Fastsky

The fuselage is pretty much completed but stopped to replace my Decathlon which crashed due to a bad switch and to make new landing gear for my P47. One side snapped off when I went to straighten it. It looks like it was made out of aluminum. I replaced with music wire and now the plane doesn't wobble when you touch the plane. The weather is starting to get too crappy for flying on the weekends so my weekends will be spent on building instead of flying. [8D]