gdutruy

These motorcycles are so cool. I'd like one so bad. Is the first motorcycle mounted with the Rotec engine as the second is ?

Gilles

the Gnome

Gilles, I think You are right, may be the Rotec is the only engine that will work because it is "only" about 2000cc, on a swap market last month I saw a cylinder of a wright 14 cyl. radial, that had about 2000cc for its own...

What about this? It's a Chech MEGOLA, about 1922, more than 2000 motorcycles were built. Top speed could be chosen by the front wheel size, 1923, with a 29'' wheel, a MEGOLA made 150Km/h, about 95mph! Nearly every museum in eastern germany has one, and I'm really looking for one!

gnome

Holm und Rippenbruch

gdutruy

Rotec engines are really good looking. The 7 cylinder does 2800cc (172 ci) 110 HP, and the 9 cylinder does 3600cc (220 ci) 150 HP. The megola is really nice too, that may be on the list for some day.

Gilles

the Gnome

Aha, so then they "supersized" their engines, last time I visited the ROTEC website, I think, they only had a seven cylinder with 2000cc. Does anybody know what's the actual price for the ROTEC radials? When I visited the website last time it was about 6000,- Australian Dollars for the seven cylinder.


gnome

Holm und Rippenbruch

Kmot

My Feedback: (24)

Rotec R2800 Price List:



Standard Package: $12,500 US*

R2800 engine including starter, alternator, carburator, stub exhaust

& engine mounts.



Oil Tank Accessories Package: Add $750 US*

Aluminum fabricated 8 litre oil tank, hoses, filter, fittings, and filler cap.



VDO Engine Gauge Package: Add $1750 US*

includes engine instruments and all relevant electrical sender units inc.

Tachometer, Oil pressure gauge, Oil temperature gauge, Cylinder head

temperature gauge, Voltmeter, Exhaust gas temperature gauge EGT, Fuel

pressure gauge. Rotec application manual included.



R2800 Performance Propellers: Add $750 US*

A range of magnificently presented hand crafted wood propellers

specifically designed and tuned for the R2800 ranging in diameters from

68" to 76". Contact us for the right prop for you.



R2800 Exhaust Collector Ring: Add $2,750 US*

Superbly hand crafted stainless steel exhaust system. Outlet pipe exit

positioned to your requirement.



* All above prices are calculated on current Australian exchange rates and thus subject to variation without notice.

Prices do NOT include shipping.

the Gnome

Well, let's dream on...

gnome

Holm und Rippenbruch

Aluminum Overcast

Makes the cash we spend on our hobby seem like a bargain!

chasrb

Don't you just enjoy these radials!!!!

Here is the link to a review of the radial motorcycle, very cool...
[link]http://www.motorcycle-usa.com/Article_Page.aspx?ArticleID=4609&Page=1[/link]

gdutruy

I've never been reall y interested into motorcycle, but this one is really cool, even more than a Harley ...

Gilles

the Gnome

Hey everybody,

I'm short with money at the moment, so, if anybody has interrest, here is a three cylinder TECHNOPOWER on ebay germany:

http://cgi.ebay.de/4-Takt-Sternmotor...QQcmdZViewItem


gnome

Holm und Rippenbruch

gdutruy

Gnome, or anyone,

I heard that thechnopower engines are not really powerfull, and that their name schould be pronounced thech - no - power, is that true ?

Gilles

the Gnome

Well, Gilles, I am flying models with Technopowers for several years now, and to my oppinion this was said by somebody, who was expecting the same power as from a single cylinder and did no further experiments after the first disappointment. The 7A Technopower with 22cc for instance delivers power between an OS FS70 and OS FS 90. My first test flights with this engine were with a trainer model with about 4Kg weight and 69'' span, and power was very adequate.

The only thing to put attention on is, that normally and to get all the power out of the Technopower, one must heat the plugs all the time, right up to full throttle. This point is very important, because especially my 7A looses cylinders at full throttle without heated plugs. If one cylinder does not work correctly, this drops power dramattically. Important is also, that 10% nitro is needed.

However, I am very satisfied with my technopowers!

gdutruy

Gnome,

Thanks for your quick answer, did you check the seidel 770 (you'll find it under st-710), the sailer say he was turning 26x8 prop @ 5500), my 770 turn a 22x10 @ 5600-5700, this is hard to believe for me. His the guy a lyer ?, has he a good engine ? or mine is bad ???

Gilles

Cybertom

Gdutry,

That's a big difference in performance. According to ThrustHP software a 22x10 Zinger prop at 5700rpm is 21lbs. of thrust (3.0hp). A 26x8 Zinger prop at 5500rpm is 39lbs. of thrust (4.3hp).

I would be inclinded to believe that the lower figure is typical.

gdutruy

Seidel told that the engine should thurn a 24x10 @ 5000, could you please calculate how much HP it does so we can maybye figur out what is right ?

Gilles

Cybertom

Gdutruy,


Yes I can calculate it. I can do even better than that if you send me your email address. I will send you the software compressed in a Zip format. The software is freeware created by Barry Hobson.

A 24x10 wood Zinger propeller at 5000rpm generates 23.47lbs. of static thrust. Estimated engine horsepower to turn a 24x10 wood prop at 5000rpm is 2.96hp.

SJN

I am a little disapointed in the sound it makes......but still, it is cool.

http://www.youtube.com/watch?v=GUx35zuI5GI

Aluminum Overcast

Cybertom,


Is this the software you are speaking of?

http://www.hoppenbrouwer-home.nl/ika...rusthpv20d.htm

gdutruy

Sounds better with a prop an an all in one exhaust

http://www.youtube.com/watch?v=D7t06ZMGTyY (at the end of the video)

Cybertom

Aluminum Overcast,

The very same.

the Gnome

Gilles, my ST710 swings a 24''x10'' at about 6200rpm. Mr. Seidel told me too, that with this prop it should be a minimum of 5000rpm after one hour running in. Of course he is very cautious telling this low figure, so he don't gets into warranty trouble.
The german model magazine journalist Mr. Frings claims, that the ST 710 has a much higher compression ratio compared to the ST770, this and, may be, a little hotter valve timing make the difference. it is said, that because of the compression ratio the ST710 should rev freely, so that no pinking occures.

gnome

Holm und Rippenbruch

gdutruy

Gnome,

If i could get a little bit more power, i would be able to fly my Rödel Bücker safely. I think that it's time to renovate the engine this winter, i'll maybe get a little more of it. When i increase the rpm, it goes fast and than drop of at least 500 rpm, i've never been able to fix that out. Any idea ?

Gilles

the Gnome

Gilles, that is exactly the problem that my ST540 has! I first thought, that it leans out due to the combustion temperature rising after one or two seconds. So I tried to modify the carb with a ventury, this cured the problem, but only in a way so that the rpm was emediately 500rpm less than before. With a smaller prop the problem was solved, so I think that a to early ignition point is the major cause. I then tried colder plugs which cured the effect even with the bigger prop (21''x8'').
Do You have the original owners manual? It sais that You should use ENYA 3 or KAVAN black speed plugs instead of OS F type!

Perhaps You should try this...

gnome

Holm und Rippnbruch

Sandman Norway

Hi..

I have just fired up my ST770 for the first time... Love the sound :-)..

Using a Menz Ultra 22x10, 10%syntetic oil, no Nitro. I`ve got 5800 on this prop.. Not leaned out for max RPM...

Now, I have some problem loosing a cylinder from time to time. I have a Microsense Glow7 system, but still some problems getting all of them to fire..
Could it be that I run it to ritch..? Should I lower the oil %..? New plugs will be tested as the one innstalled are proberly 10-12 years old.. But looks new, and glows
nicely.. I have set the low end correctly..

BTW, its not the same cylinder that drops out, but the lower 2 are allways lid.. Strange...

Any ideas..? Would it help to use 5% nitro...

Best regards

Sandman

gdutruy

Sandman,

Welcome to the club, it seem to me (according to Mr Seidel instructions) that 10% oil is too much. I'm using 6,16% oil and no nitro (mix of 15 liter of methanol and one of oil)

When i start mine, i follow this procedure (microsens glow 7A too)

- Full throttle, nose of the plane down, injection of 1 cl of fuel directly in the carburetor.
- Swing the propeller several time
- Plane on is wheels
- Start the engine
- 40% of throttle for about 1 minute to warm it up
- Setting of the mixture with the help of a rpm counter
- Flight
- Back to the ground, i let it turn 30 seconds at a little bit more than idle before stopping (for temperature and beauty of the sound of course )

Works good like that !


Gnome,

Thanks for you answer, i had not investigate the plugs till now, i'm gonna try this next season.

Gilles