New type of 4-stroke engine ?

[First time Juke]

I just got a RCV .90SP four stroke model engine.

It is very interesting looking. Take a look !

http://www.hobby-warehouse.com/rcv90sp4cyce.html

What do you make of it...could be hot for a racer ?

I will build a 1/6 scale Svensson Fieseler Fi-156 STORCH for it which I also just purchased.

[First time Juke]

Re: New type of 4-stroke engine ?

Here is an outstanding story of the 1/6 scale Fieseler Storch model:

http://www.fly-imaa.org/imaa/hfarticles/plans/v3-2-55.html

[Wild Bill Kelso]

Re: New type of 4-stroke engine ?

I am running an RCV 91 CD in my 1/8 Rare Bear. The CD is good for racing but the SP turns too slow for any speed use. I do plan on a DO-335 in the future using two of those SP's. Great engine so far.

[First time Juke]

Re: New type of 4-stroke engine ?

Ok FNG,

I appreciate your reply. So after all RCV is a good engine..and possibly just the right one for the Storch !

Someone said it sounds little too metallic ?

rgds,

Juke

[Wild Bill Kelso]

Re: New type of 4-stroke engine ?

Ok FNG,

I appreciate your reply. So after all RCV is a good engine..and possibly just the right one for the Storch !

Someone said it sounds little too metallic ?

rgds,

Juke

Mine makes a little gear noise at low RPM, but it sounds super cool. Doing the run-in was a pain. Super tight engine, and it took almost a gallon to run in. Once it was it swung a 14/8 with no issues. It has a ton of torque so you can swing big props. Even in the engine without the reducton drive. I think the SP will do great in the Storch because it was such a slow flyer, and you can get it all in the cowl.

[First time Juke]

Re: New type of 4-stroke engine ?

It has a ton of torque so you can swing big props. Even in the engine without the reducton drive. I think the SP will do great in the Storch because it was such a slow flyer, and you can get it all in the cowl.

So that makes it awesome for scale issues !

Also the Storch cowl will provide good cooling for the engine.

[Wild Bill Kelso]

Re: New type of 4-stroke engine ?

So that makes it awesome for scale issues !

Also the Storch cowl will provide good cooling for the engine.

Yeah on the SP(reduction drive) you can swing a 18/10 prop. HUGE for that sized engine. Customer service is awesome too.

[First time Juke]

Re: New type of 4-stroke engine ?

Will this 18/10 prop make my Storch more like the real ones to fly with sizeable torque effect and all ?
I have to be really gentle with the throttle I assume.

[DPK2]

Re: New type of 4-stroke engine ?

Juke,

I have that exact model Storch built from plans. It is covered in coverite and dope. Detailed interior/pilot etc. In other words it is very heavy. It does fly very well. The slats and flaps work great. Originally I flew it with a OS 72 fourstroke which was ok but a little marginal on power. Now I have a Magnum 91 fourstroke in it and is perfect.

With the 91 it will take off in less than 10 feet (no wind) and climb at about a 60 degree angle with about half flaps. Full flap landings are cool. You can either bring it in with a little power for an almost zero ground roll or my favorite is to come over the end of the runway at about 200 altitude, announce "coming in" (your flying buddies will think you are crazy) pull the power to idle, dump full flaps and drop the nose to about a 50 degree dive. The Storch will descend almost straight down without picking up much airspeed. At about 5 foot altitude begin flare and land still at about the same spot on the runway you started your decent. Do be careful in crosswinds because as soon as the tail drops the into the wind wing will increase its lift do to the more positive angle of attack. No amount of aileron will hold that wing down and you will drag a wingtip. It really is not a problem because you are going so slow at the time but on a hardsurface you could damage a tip. Takeoffs in crosswinds require hard aileron into the wind. Also the Storch requires lots of rudder to keep turns coordinated.

I hope you enjoy your Storch as much as I have. It is a lot to build but well worth it.

David

[First time Juke]

Re: New type of 4-stroke engine ?

David,

Exellent to hear this. I expect something like this from the landing and take off caracteristics as well. How many hours have you logged so far with your Storch ?

Also the Storch requires lots of rudder to keep turns coordinated.

I expected this too to happen...so I have to practise with it in calm windcondititions.


rgds,

Juke

[DPK2]

Re: New type of 4-stroke engine ?

Juke,

I don't know how many hours I have on the Storch. I have had it for 7 or 8 years now. It has been crashed once due to someone turning on their radio on the same frequency as mine. It was too neat of a model not to rebuild.

The Storch will handle high winds once you get accustomed to its charactertics. Don't expect it to fly like a trainer.

One more thing. With the tall forward main gear the Storch has lots of weight on the tail. I first had a full castering tailwheel on mine but it always gave me trouble. In the rebuild I changed to a skid with scale shock. I like this much better. It is much stronger.

David

[First time Juke]

Re: New type of 4-stroke engine ?

One more thing. With the tall forward main gear the Storch has lots of weight on the tail. I first had a full castering tailwheel on mine but it always gave me trouble. In the rebuild I changed to a skid with scale shock. I like this much better. It is much stronger.

Dave,

I see also the original Fieseler Fi-156s seemed to have both tail assemblies...with and without a wheel. Skid seems/sounds to be ok...so I'll do it with a skid.

Thanks Dave once more.

rgds,

Juke

[AirDOGGe]

Re: New type of 4-stroke engine ?

Until today I had not heard of this engine (I haven't been participating in the RC plane hobby since '92), and I have been banging my head on the wall trying to figure out how it worked.

I finally located a website that had a cut-away and clear explanation of the concept....very clever and very imaginative.

I suppose with a small planetary gear drive on the front they could increase prop-shaft RPM and make a speed version someday, or with a 1:1 ratio crank to cylinder geartrain it might be possible to make a 2-stroke version for racing.

Here's the website with the engine description information for anyone else who is curious. Scroll down the page to find it:

http://www.rcuniverse.com/magazine/article_display.cfm?article_id=68&CFID=18675032&CFTOKEN=76942141

.

[First time Juke]

Re: New type of 4-stroke engine ?

As I see it it saves space...and I think a rotary engine with revolver type layout with the cylinders and pistons....and prop axis between them, could save space...maybe enough to reduce frontal drag about 20-30% ?

Could that make any difference in AIR RACING ?

[First time Juke]

Re: New type of 4-stroke engine ?

I found a 49 years old magazine in an antique boutik and they had in 1958 issue of Technics World ( Tekniikan Maailma ) and this type of engine called X375 had in fact already been built and tested for aeroplane use. It had 6 double cylinders and a weird uneven crankshaft bores throught the engine.

To me the engine seemed the most simple aviation engine I ever did see. It was really sleek too ( ideal for a racer perhaps ? ).

Designer was Karl Herrmann of the Herrmann Engineering Co. in California.

It also introduces the fiberclass...which it says is ideal for boats and car chassis + bathtubes.

Same magazine introduced also nuclear powered pusherprop bomber.