The Seidel 7-70 is listed as a "methonal" engine (vs. their other engines which are "benzin"). Is methanol just ordinary glow fuel and if not, how is it different?

Pure alcohol CH3OH ... methanol. Mix in 18% oil, maybe 1% castor, and 10-15% nitromethane and you've got Wildcat or some other brand glow fuel. Leave the nitro out and you have FAI fuel.

The engine is an assembly of seven glow 4-stroke cylinders of 0.60 cuin each all connected to a common shaft.
The fuel is commercial fuel for 4-stroke glow engines.

Benzin or benzine is known as gasoline.

So this methanol-based engine is just using good old-fashioned glow fuel?

Yes, just plain ole glow fuel.

abufletcher,

I believe so, but I cannot advise about the exact fuel that the manufacturer specifies for the UMS 7-70 engine.
No manual seems to be available on-line.

Check this additional info on the engine and contacts for further questions:

http://www.umsindia.com/product_deta...d_201072052134

http://www.seidel-triebwerke.de/englisch/englisch.html

http://search.rcuniverse.com/search....200+&i2=seidel

"Lnewqban - Any object falling freely (no air drag) increases its velocity in 9.81 m/s (32.2 ft/s or 22 mph) for each second."


However, there is a terminal (maximum) accelerating velocity for any object dependent upon its shape (drag) and mass.

Yes, the statement is only true for the hypotetical case when no air is around the object (it could happen very high in the atmosphere, where air is very thin).
Thus, the friction forces are eliminated in order to measure the acceleration coming from gravity forces.

Read this link about free fall (includes video):

http://en.wikipedia.org/wiki/Free_fall

In real life close to Earth, as the falling speed increases, so does the drag force (at a square rate respect to the speed), reaching the object its terminal speed.

The point of the signature is to provide an idea of the dynamic of the forces that our planes challenge..........

Any object falling freely will according to Murphy's Law be your most precious model and will impact the most costly item on the ground.

Or find that smallest spot of concrete!

Don,

Everything alright?

Since your visit to Holland you are loaded with the most wild ideas and plans

I've got the digital manual from the UMS Seidel 7-70, it's a 7.5Mb pdf file. If you are interested and your mailbox can handle the large file, send your Email by Pm.

Teus

P.s. The 7-70 is a perfect engine for the Proctor 1/4 scale E.III.

Fuel info from the manual:

Here the full manual, much easier than mailing a big Pdf file.

And as Pdf file.

That scale event really lit my fire! So many things seem possible now that I had never thought of as possible before!

Thanks! I'm printing it out as I'm typing this!

That's good to hear but I've been thinking (and Frank has also suggested the same) that the 7-70 might be "too heavy" for some of the lighter 1/4 fighters (like the Pup). But it would sure fit perfectly in the cowl! So do you already have your ST770? Did you have any problems ordering it or did you have to wait for delivery?

I see that the manual suggests doing the break in with straight methanol with just a bit of oil and NO nitro. Interesting. I suppose there much be a source for plain methanol here in Japan.

Ya know Don a nice Saito 200 radial would fly many 1/4 scale WWI planes very nicely.

Lots of engines would fly a 1/4 scale WWI model just fine. But my opinion, only the Seidel looks scale enough to consider not covering it with a dummy engine. The Saito 3-cylinder 170 is a nicely made engine and beautiful in its own way, but I wouldn't want it poking out the front of my scale model. The Seidel still isn't quite right (looking a bit more like a Pratt and Whitney) but it's the only one of the radials that would look right in WWI cowl.

http://www.horizonhobby.com/Products...odID=SAIE170R3

You can wait and get the OS 7 cyl radial. It's not cheap either but were I you I'd wait. The OS should be available this fall.

You're talking about the Sirus7? It's a beautiful piece of machinery, but doesn't look like a WWI engine. And it costs something like 3x as much as the Seidel.

Not yet Don, still very high on the wish list. I almost bought one back in January but decided then first to buy a lathe so I could make a lot of my own parts like turnbuckles.

A good friend of my bought the 7-70 and fitted it to a Caudron G3. Unfortunately he couldn't make it to the Dutch Dawn Patrol.

Teus

I have seen you know the ums 7.70. I have just bought a new one but I have some problems. At the first beginning I installed the electronic ignition suggested by Seidel ( Herbert Holze) but practicallyit remains always inserted discharging rapidly the lipo battery. i have disconnected it and started with the standard 2v pb battery. The current is regulated to 3 A per glow.
But I have problems anyway. If I disconnect the power at any RPM rate the engine stops!!. I wrote to Seidel assistance in swisse and they suggested me to open the jet nozzle more( 3 or 4 turns) but I have the same problem. Can anybody help me? Have I perhaps done something wrong?

I have followed all the builder instructions!!
Thanks to all
Fabrizio<br type="_moz" />

Are you using OS 4 stroke plugs? Wrong plugs can make it not run right. Might need to be broken in for a while too; a lot of friction compared to a single cylinder engine.

The plugs are the ones supplied with the engine. They are OS F .They seem to be ok at the sight!!! It's the first thing I have thought of.The strange is that when you run the engine cold, it runs correctly for a while (until it warms up) and in these conditions you can switch the power supply off and everything is ok. When the engine warms up it becomes difficult to accelerate and overall it stops if you switch off the plugs. It's my first radial and this is the reason why I ask to the people that have got it. A question: I'm using the green run mixture, methanol 90%, stynthetic oil 10: That's what the supplier suggest for the first running hour. Is it ok? somebody suggested me to add nithrometane but in the instruction book it is absolutely forbidden until the seventh hour!
Please.....help me!!
I do not know what else doing.

Maybe it's a problem of break in, because I've never been able to let it run for a while ( 10 minutes ) continuously . I'll try to do it later , should I be obliged to leave the plugs switched on!!!
Thanks