Author Topic: The RingStreakster - Which engine to use? (Read 3234 times)

Terry Caron · « **on:** October 20, 2015, 04:24:42 PM »

I'm ready to mount an engine, either an OS .20FP or the Fox .35 on it previously.
I've read many recommendations for the newer technology over the old but no discussion of the advantages.
The OS weighs 1 oz more; other than less fuel consumption and less oil, how is it better?

Terry

Tim Wescott · « **Reply #1 on:** October 20, 2015, 05:15:54 PM »

What are the dimensions of the plane? If it's got a standard Flight Streak wing and you build lighter than I do then a 20FP ought to work well.

Terry Caron · « **Reply #2 on:** October 20, 2015, 05:34:56 PM »

It's the standard ARF Streak wing on a RM fuselage/tail feathers.
All up weight will be 31oz +/-, depending on engine.
I had the OS on the original FS and the Fox on the RingStreakster prior to a pancake.
So either will fly it just fine. The only difference I could tell was more line pull w/the Fox.
What will I get with the OS over the Fox?

Terry

kenneth cook · « **Reply #3 on:** October 20, 2015, 05:47:04 PM »

Terry, I'm a true Fox fan. However, the OS engine you want to use would do quite well. I have a FP.20 on a original Top Flite Streak which is no lightweight by any means. It flies with authority not to mention you have a short nose. The FP uses a lot less fuel which makes easy tank selections on the small real estate you have up front. The FP runs very smooth so vibrations which are a possibility if you use the Fox are a non issue. Ken

Terry Caron · « **Reply #4 on:** October 20, 2015, 06:07:58 PM »

Either will have to mount fwd on the cutout to balance CG so nose moment isn't an issue.
Lack of vibration I'd count as a definite OS +, as my Foxes are all box stock.
But surely fuel consumption and vibration aren't the only reasons for a modern engine preference.

Terry

Avaiojet · « **Reply #5 on:** October 20, 2015, 06:43:58 PM »

Terry,

Here's my Flite Streak with a Fox 35.

Brings back memories for me, my last Flite Streak before this one had a Fox 35 also, flaps and a shortened tail!

Flew great.

Charles

Chris Wilson · « **Reply #6 on:** October 20, 2015, 08:02:58 PM »

Quote from: Terry Caron on October 20, 2015, 06:07:58 PM

Either will have to mount fwd on the cutout to balance CG so nose moment isn't an issue.
Lack of vibration I'd count as a definite OS +, as my Foxes are all box stock.
But surely fuel consumption and vibration aren't the only reasons for a modern engine preference.

Terry

Terry, nice Foxy read here -

http://www.clamf.aerosports.net.au/newsletters/ACLN/Issue97.pdf

But if the engines vibrate less then a lighter airframe can be used, and if they use less fuel ditto
Fuel foaming is probably less also.

And are you sure of the 1oz weight difference of the engines without mufflers?

Terry Caron · « **Reply #7 on:** October 20, 2015, 09:04:46 PM »

Yes, quite interesting article Chris, thanks.
No argument with your comment on less vibration, but it's pretty moot for me as my airframe weighs what it weighs.
Re: engine weights, I weighed both with prop, muffler, etc. as they would be flown and to be as precise as I can the OS is 1.2 oz (33.6 grams) heavier.
So what will the OS give one beyond less vibes, less fuel, less oil?

Terry

Add: my Fox has the Fox tube muffler.

Chris Wilson · « **Reply #8 on:** October 20, 2015, 11:35:45 PM »

I was under the assumption that the Fox 35 'compares' with a good modern 25 or 20 and the modern engines add some user friendly traits.

And ............ that's it, apart from losing the 4/2 break (plus the delicious note that goes with it) and of course the right to wave the American flag on the nacelle!

Steve Helmick · « **Reply #9 on:** October 21, 2015, 05:08:56 PM »

The OS is much easier from a fuel acquisition standpoint. Plus, the muffler is easier to keep in place (depending on vintage of Fox), the crankshaft is less likely to break during flight, and the .21FP with the correct muffler is mucho quieter than the Fox with most any muffler you can put on it.

Steve

Terry Caron · « **Reply #10 on:** October 21, 2015, 05:55:28 PM »

I misspoke about the weight difference - i had an aluminum spinner on the Fox previously needed to balance CG.
Difference is 1.8 oz less for the Fox w/tube, and a tongue muffler would be even lighter.
But I'm inclining to the OS as 31ish oz shouldn't be problem for it.
And it has the E-2030 muffler per BBTU.
Besides, I can always mount the Fox a bit farther forward if I want to change.

Thanks for your input everyone.

Terry

Bill Little · « **Reply #11 on:** October 21, 2015, 06:08:59 PM »

Hi Terry,
The main "benefit" of the OS .20FP is the ease of getting repeatable engine runs quite a bit easier if the Fox is run in its 4-2 mode. The .20FP "BBTU" replicates a pipe run probably better than any other muffled engine. In the high rpm/low pitch mode, the FP has a bit more power than the Fox. The FP is being allowed to run up much nearer its peak for HP and torque.

I love the old Foxes but I have run the .20FP BBTU set up quite a bit, and it is much more hassle free over the long haul for true quality stunt runs. I will soon build a Super Combat Streak special cut by Walter with 4-5 lb. contest wood. The first one I had was a stock Top Flite kit with a good Fox.35 up front. This new one will get the .20FP BBTU installed from the git go.

Bill

Terry Caron · « **Reply #12 on:** October 21, 2015, 07:07:02 PM »

You've tipped the balance Bill - I'm going with the .20 FP BBTU (now that I have someone else to blame for deserting my Foxes).

Terry

Motorman · « **Reply #13 on:** October 22, 2015, 01:59:22 PM »

Quote from: Terry Caron on October 20, 2015, 06:07:58 PM

But surely fuel consumption and vibration aren't the only reasons for a modern engine preference.Terry

The way you built the nose, vibration should be a big concern, it's not for a Fox.

MM

Terry Caron · « **Reply #14 on:** October 22, 2015, 03:24:18 PM »

I was told the short bearers were Kania's original design - not so?
In any case, I've mounted the .20 FP.

Terry

Brett Buck · « **Reply #15 on:** October 22, 2015, 04:09:15 PM »

Quote from: Terry Caron on October 22, 2015, 03:24:18 PM

I was told the short bearers were Kania's original design - not so?
In any case, I've mounted the .20 FP.

Maybe they were original, but no one ever said it was designed to last a long time. This was in the era were for most people, doing a loop and a lazy 8 was still a big deal. And based on the quality of the supplied plywood doublers, you might do just as well screwing the engine to bare balsa!

You have the engine issue solved. The other issue is ensuring that the control movements are *very slow* and adjustable. The stock setup resulted in far too much motion and far too fast a response rate. The 20FP/APC 9-4 will help, but you still probably only need about 3/8" motion with full handle deflection; any more and it stalls.

Brett

Terry Caron · « **Reply #16 on:** October 22, 2015, 05:21:59 PM »

Quote from: Brett Buck on October 22, 2015, 04:09:15 PM

The stock setup resulted in far too much motion and far too fast a response rate..... but you still probably only need about 3/8" motion with full handle deflection; any more and it stalls.

Brett

I have adjustments at the bellcrank and at the elevator horn (nylon not the original ply).

Terry

ALEXANDRE TAPXURE · « **Reply #17 on:** October 22, 2015, 05:31:22 PM »

My opinion is that a classic model is for a classic engine! FOX 35 !!!
The best of the classics!!!

Terry Caron · « **Reply #18 on:** October 22, 2015, 06:58:56 PM »

You may rest easy Alexandre, as the Classics are sufficiently honored - I have a '60s Fox .35 on my Sterling Mustang and a '58 Fox .15 Rocket on my Sterling P-40.

Terry

Chris Wilson · « **Reply #19 on:** October 22, 2015, 10:58:47 PM »

Quote from: ALEXANDRE TAPXURE on October 22, 2015, 05:31:22 PM

My opinion is that a classic model is for a classic engine! FOX 35 !!!
The best of the classics!!!

Mumble, mumble "Merco 35" mumble.

GregArdill · « **Reply #20 on:** October 23, 2015, 05:38:53 AM »

Quote from: Chris Wilson on October 22, 2015, 10:58:47 PM

Mumble, mumble "Merco 35" mumble.

Got yours on the board yet Chris?