So just had thoughts flying around in my head and reading a few posts that are out there by Mr. Hanson.

Why has the RCS 140 not been targeted as a potential pattern gasser?

The engine has a rear exhaust and likes to be setup on a tuned pipe. It weighs only 2.8 lbs with a 1200mah NICAD and ignition.

Any thoughts? Has anyone tried this? Could an airframe similiar to the "lightened" carden be assembled to come in under 11 lbs. A

smaller 10 OZ tank could be used saving weight. I figure the weight difference between an OS 160 and the RCS!$) to be 10 oz but i

believe a smaller lighter ignition pack could be used and make that smaller.

In regards to engine performance, if it could swing a larger prop at say 7200 RPM, maybe a 3 blade carbon prop, would this help

in more consistent speed and more downline breaking?

Just looking for peoples thoughts and opinions.


Chuck

Chuck,

I never have seen the RSC 140 in a pattern plane. However, I have the wonderful opportunity to put together a pattern plane is called Abbra in three version. Electric, glow and gas. The glow (mine) uses the OS 160 with perry pump. I have well over 300 flights in this version which is my plane. I fly Master and the OS 160 is powerful enough to move the plane in any wind conditions. This glow version is 9 lbs 15 oz.

The gas versions has the ZDZ 40 engine with carbon pipe. It has plenty of power to do the Master schedule but it is a little sluggish in the up lines compared with the glow version. Down line breaking is great but not too much difference with the glow version. The plane lands a lot heavier than the glow (higher stall speed) but this is not a problem. Base on my experince using this airframe, it is a lot more difficult to make the weight wiht the gasoline engine. Assuming that the gas engine power is linear to the displacement, I will predict that the RSC 1.4 (23 cc) won't have enough power to do the Master schedule unless you get a plane that weights a lot less than 11 lbs. or the RSC 1.4 is turbocharged. Again this is a conclusion base on my experience using the Abbra with gas and glow engines. Your results could change a lot depending on your actual conditions. I saw that ZDZ is coming with a ZDZ 40 F3A that is lighter but I have not seen actual information.

The electric version is 10 lbs 6 oz. I haven't had chance to do the Master schedule Wilt this version. However, we saw this version getting a second place at the Nats last year so there is no problem in regard electric power.

I hope this help.

Regards,

Vicente Bortone

Thanks Vicente, i too had the pleasure of seeing the ABBRA flwon by Earl Haury in the FAI schedule and it had NO PROBLEM inn 15+ MPH winds performing the maneuvers.

I appreciate the info and am surprised that the zdz40 could not perfrom any better than you describe. I wonder if you could use an E-APC prop on a Gasser to slow the RPMs down and get better performance because of the effiency of the prop.

Course i have no idea of the safety factor here, just a crazy thought, i would never try it.

Chuck, I'm currently using an MVVS 1.60 gasser in a Tojeiro 140. With a Mac's 1092 tuned pipe and APC 16 x 11 (or Mejzlik 17 x 10) it is fully capable at 11lbs even. Although I don't have a lot of time on it yet, it is clearly capable of FAI sequence work. The real advantage is energy management through dynamic braking. I believe the ignition system contributes to this, but Brian Young flies with me, and says the braking is as good as the three-bladers that we all know and love.

Although I won't be doing much competing, you may be able to see it around somewhere this season. It is a viable platform, of that I have no doubt.

Chuck.

I don't think the E-props are any more efficient for a given diameter/pitch, but they are significantly lighter. (Electric props are more efficient because they generally are bigger) Less material is used on the E-props, because less strength is required. With a IC engine, you get a hammer knock every revolution (2C) or every second revolution (4C), while with the electric motor you get an (almost) even torque.

I would not stand anywhere near an IC engine with an E-prop!!!

Magne

I agree Magne, just a crazy thought...

Bob, miss you at the contests, hope maybe next year you find your way back down south or maybe to Dallas at the end of the year.

How bad is the vibration and knocking around idle on the 1.60 (is the evo the same?) and will your wodden airframe hold up?

Thanks

Thanks. Don't know about South travel.

Knocking about is like a smooth 2 stroke should be, with a balanced propellor. There is an 'airframe resonance' at about 3300 rpm where things get to buzzin' and hammerin' pretty good, and lots of noise at that setting... above or below, it really is very smooth.

Don't know if it will last, nor how long. It's all experimental, just like every aspect of the game.

The ignition is slightly different between the Evolution and the MVVS. Dual magnets on hub on MVVS, supposedly "reset" magnet for each pulse in their Vlach Ignition. Don't know that for sure. No clue about what is really going on; maybe Dick Hanson could shed light.

The MVVS really is very strong and solid.

Interesting

Electrics not really an option in the UK becuase a set of lipos for me is about £400 or $800 which is better spent elsewhere.

I was looking at a MVVS 1.60 Glow though not Gas, i would of thought the glow version would of produced more brake and been smoother ?

What other engine options are there with going 4stroke becuase the only option there is a YS

We have a MVVS 160 petrol which pulls a 12lb Xtra-Wot around with great authority. If you could get it under 11lb (which I think you could) then you would be onto a winner. It was very smooth as well. Turns an APC 16X11 @8800

We are (hopefully) getting the new ZDZ 40 to try as well, although no sign of it yet. Once tried I will post up thoughts/data on here.

A

The mvvs 160 glow is viable for f3a---esp. if pumped---the one in the pic has an OS pump inthe back + an OS carb---but the MV carb is so-so OK as well.
The early mv 160 glows were hampered by the original needle-roller rear bearing, but now they've gone back to a "normal" one they're OK.
The one in the pic (now in a Tunnel Vision profile) has been tried in my f3a models--it would do, but the OS160 is just overall better,IMO, so that's what I compete with.

i currently fly the os 160. awesome sick power. just too mentally activ to sit stil, i like to push the limits and try different thins and be different.

chuck

Quite simply the RCS 140 on a 12 pound sport plane is very nice but is not a viable engine for a pattern bird at that weight. A freind of mine installed his RCS 140 on a 90 Funtana, and after trying more than a few props took it off and reinstalled his glow motor. The engine makes average power. With some work it could be made to put out very good power, but is really not worth the effort. At best its a overpriced sport engine.

All of the gassers need a pipe setup for broad band running.
The ZDZ40 is easily the strongest of any of these but setup wrongly is shaky at low rpm - the new engine has a completely different timing curve. can't say anything more .
The Evolution 26 on my foavorite pipe is really good on Skorepa 18x8 for patterny stuff.
but for max power run it 9000 on the ground and then just use power as needed in th air.
weight - do not exceed 11 lbs
The RCS - you must pipe it also- and it runs well also the Roto runs extremely well and smooth but not quite the poop of the Evolution/ MVVS
Why the ZDZ "did not compare" with the glow is a mystery to me .
I fly a ZDZ40 RE with a simple JMB can - turns a Mejzlic 21x8 easily at 7200 and very quiet and smooth but not as quiet as th long cfpipesetup and larger pipe .
On my 13.25 Extra 260 H9 it will do anything any pattern setup will do extremely easily
FWIW the Showtime and the 26 Evolution is all any one could want for a good pattern practice model.

Folks should note Dick's comments - having "followed" him trying several of these setups, and actually owning some of his previous ones, he *knows* what he speaks.

I've only recently run the Mejzlik 17 x 10 on the MVVS 1.60 /Mac's 1092. Didn't tach it, too new, and who cares? It WORKS for Masters, no doubt about it. Have a 18 x 8 which will be next trying to slow it down a bit, yet still have pull...but as it is right now, I would (and probably will) use it in competition with no hesitations about it's capability.

Assuming a "gold standard" of Power to be the OS 1.60 piped, or the YS 1.60DZ on 30%, an equivalent piped gasser will HAVE TO BE a piped setup in the 40cc size. Problem there is 40cc gassers get larger, heavier crankcases, and then you have to go to exotic materials, complex constructions, and ridiculous weight conservation extremes and STILL be over 11lbs.

If there wasn't such a stinkin' bias about "you gotta have a 2M bird", the gasser 25-30 cc piped setups could make smaller airplanes perform on a par with the 2M with larger motors. Having had a Showtime - dang fine design, fully-capable, but poo-poo'ed by the masses, so therefore not "viable". A shame.

Are you talking about the showtime 4d 90 airplane with the winglets?

Yep. Minus the SFG's... the "original" Showtime from Horizon, not the new thing; I have no knowledge of it.

Something must be wrong with mine (showtime/evo26), it seems like its gonna shake it self apart around idle.

I'm holding off a 2 meter gas project until Fall when the new/lighter ZDZ 40 RE is expected to come out. Does anyone have any information as to whether this new engine is just a lighter version of the old one or have they tweaked it for more output?

OK...since BME was able to do a supertigre 90, you think they could modify the os 160 for gas???

these thoughts are the result of an idle sick mind.

chuck

CHuck, if it were POSSIBLE to do the OS 1.60 (it would need a needle bearing con rod), the power would be probably 30-40% less than we get with glow. That would make it sort of an MVVS 1.60, so why not just run one of those, as it is at least purpose-designed.

"waiting on the ZDZ" - WHY ? It will still have a Bing or Tillotson carb (both gave me enough nightmares that I swore OFF the ZDZ), and you'll need to run a hellaciously-large pipe to benefit of tuning.... Yes, you'll have gobs of power, but carving up a bird for a 28" pipe that is 2"+ in diameter.... well... I'll let someone else pilot THAT setup.

[Yes, Dick - I know you're "listening" ]

Bob, true insight into the 160 idea. thanks.

After all this brain storming, ideas, thoughts, etc... i always end up at my 160,perry pump, pipe.

My next jump will be electric. And i think haleys comet might return before then.

more ideas later.

Chuck.

btw, did you se the construction techniques on this website.. very very cool.

http://www.f3a-e-factor.de/

and. the retracts.. i would probably run retracts again but only in this format.

I'm not arguing with that, but would be grateful,as a non engineer, for more information.
As I said in an earlier post, The early MV. 160 glows had the same needle-roller conrod(big and little ends) as the petrol version.
I tried one for f3a use(Piped and pumped, APC 16/14or 17/12 from memory)
The big end failed(cage distorted,again from memory-I think that was what it was) twice in short order.
It's run OK ever since, with the factory replacement bronze bushed conrod.
It seemed that the needle-roller bearing couldn't withstand the mechanical forces from the "big glow bang".
So, why is the needle roller bearing necessary for petrol?

Wish I had the engineering background to explain it, but my understanding is that it has to do with the low oil percentages gas/ignition systems need to run properly. There is a lot of lubrication difference between 18% synthetic/castor in a methanol motor that runs cooler and a gas system running basically 2.5 - 3 % oil that runs a lot hotter overall.

I've just always been told a needle-ended con rod was essential, but I don't "know" the engineer-un reasons.

Dick / folks,

I am going to put a MVVS 160 Gasoline in an OTOP Pattern plane (because I have a bad allergy to the oil in nitro and I don;t want to spend $$$$ of dollars on batteries.) With carefull installation it should come out just under 11lbs. E-Setup's ont he OTOP come out right on 11lbs, glow at 10 or less... so I should be able to make it work. I don't think I can make 11lbs with the stock header and pipe as they are quite heavy. Is there anyone making a light wieght Alu header and a composite pipe? Anyone have contact details where to get them?

How about engine mount? Should I use a Hyde mount - and if so which one / is there one - that fits the MVVS? Or should I just hard mount?

The MVVS 160 on the Showtime with the stock pipe and manifold is excellent - that is my knock around airplane.

BTW - I will be flying Intermediate - so I think the MVVS power should be fine.