Just for kicks I ran all my .50 sized Diesels today, I may have a SuperTigre .45 conversion somewhere too.
MVVS .49 with Graupner 12x7 DDD ABC mix===9,775 rpm
Fox .50 Graupner 12x7 DDD ABC mix===9,150
Irvine .53 Graupner 12x7 DDD Abc mix===10,121
Webra .50/Bisson Pitts=Gr.12x7 DDD ABC=====9.950

SuperTigre .45 ABC Gr.-12x7 DDD ABC mix===9,800
SuperTigre .51 Graupner 12x7 DDD ABC mix===9,650
OS LA .46 Graupner 12x7 DDD Plane Fuel==9,450
OS LA .65 Bolly 13.5x8 DDD Plane Fuel===9,300
PAW .60 same Bolly 13.5x8 DDD Plane fuel===7,300

Francis, the fuel can adapter you made for me came in mighty handy today, Thanks

I found the SuperTigre .45 ABC with DDD head. I bought it about 3 years ago, today it provided an interesting story. When I first tried to start it it would not draw fuel. I opened the HS needle to about 4 turns, still no go. I opened the throttle about half way, it would fire a couple of times but still no go. I bottomed out the compression screw, it fired some more but would not start. Finally I opened the throttle to full and it started but could only manage about 4,500 rpm. As soon as I would try to reduce the compression or lean it even a little it would quit. I began to think I had bought a worn out engine but it didn't feel like it when flipping. Upon inspection the reason was obvious, it had been assembled with the sleeve rotated 45 degrees toward the front. The notch in the cylinder phlange was lined up with the exhaust side front head bolt. After proper assembly it started instantly.
Using the same 12x7 Graupner, DDD ABC mix and Hobby-Lobby spinner as the others it turned 9,800 rpm. It surprised me by being stronger than the ST .51, although the .51 has a lot of time on it, about 16 years worth.

This is great information and I like that you reported it all the same format. It would be great to have this on one smaller prop size and one larger (say 11x6 and 13x6). Do you have any idea about the run time per oz on these engines?

Great stuff thanks for taking the time to do the test.

I could easily rig up a 4 or 8 OZ tank and do a timed run at various throttle settings, attempting to duplicate a flight. My Rascal 40 has an 10 oz tank and in a 10 minute flight it doesn't even burn half of it.

I ran my PAW .60 today and put 16 OZ more fuel through the Fox .50.

PAW .60, Bolly 13.5x8 Davis Plane Fuel, rpm===7,500 plus a few.

Fox .50, Graupner 12x7 Davis ABC Mix, rpm===9,500, it improves every time I run it.

Here are two more .50 sized engines, I received the heads for my Webra .50 and Fox .46 ABC yesterday as posted in another post. The Webra turns the Graupner 12x7 at 9,950, it turned it at 9,570 with its stock muffler and 9,950 when I put the Bisson Pitts muffler you see on it.
The Fox .46 turns the 12x7 at 8.590.
Webra .50/stock muffler====9,570
Webra .50/Bisson Pitts=====9,950.

Hobbs numbers of course excellent the surprise is that "clean look: with the new head on the Webra the look beats anything (my opinon diesel or glow) very contempary martin

To day i started my new tiger 51 and gave me 10k+ with a 12x6 apc but i think the stock mufler is chokeing the engine cause it has a lot of partions inside i whant to find a plain mufler to compare.

Ldalmas the STs are noted for needing break in time put some more fuel thru it before worrying about the muffler the revs will come up martin
that big stock muffler is fine as a ringed engine it will be 500rpm less than ABC 50 just a charateristic of ringed engines for sport and pattern they are prefered, on rpms with time it will come up
the 51 as after thought may be ABC but still needs more running martn
the timing on the STs is such they develop their power at a lower rpm than OS so prop to the engine looking at Hobbsies post it turned a 12x7 at 9650

It is a ringed it allready had a few tanks of glow on it I whant it witha 13x4 for 3d on a ¨ucan do 3d

Put a gallon through it, then it will be close to being broke in.
Maybe 1 1/2 gallons.

Slow to break in slower to wear out.

I didn't like the 13 x 4 on my U-Can-Do.

The U-Can-Do is a real floater and the 13 x 4 realy torks the plane around.

I liked the 12 x 6. Fast spool up, good power but you can still fly it slow
with out the tork factor.

Munin, the LA .46 has the Spinner on it.

Hobbsy, am I correct in noting that you have placed an MVVS .49 Carb on the Webra?

If so, was performance improved over the stock Carb?

That is indeed a 7mm MVVS carb, I stuck it on there mostly because it was already set up on another Diesel engine. I like the MVVS carbs as they are very linear and easy to set up. I can run that one at full throttle with no issues at all.

That webra is a fine looking engine.

Nice MVVS quiet silencer on the Fox as well

Cheers, and thanks for posting your figures Hobbsy!

Moved up for Jim.

Dave,


The Webra .50GT seems to be equipped with an MVVS carburettor...
I know it is a drop-in fit into the Webra's 13 mm socket.

Was the TN II not doing a good job, or what?


EDIT: Fiery saw it first...

Here ya go Mike109

Hobbsy good to see this reappear since you first did this about a year and a half ago. As I remember my Irvine 53 and Fox 50 got very similar numbers This is relavent with the write up the 46LA conversion in fly RC a month or two ago since we have have some new " lookers Due to
work schedule and family things have not had a lot of time lately. Did mess with the 07TT briefly, we may have a lame horse on this one
For not a lot of bucks looks like the STS and OS LAs are real winners as conversions, My ST34 Davis conversion will be the upgrade for the beaver
with the Enya 25 plane has not yet flown when I get a chance will do an A/B comparison in the air is what counts martin
Now 745 AM work calls martin

********


Super Tigres can be like Fox engines of the distant past. A few tanks of fuel is just the beginning of the break-in process. Seriously, don't judge the engine until you have two or three gallons through it.


Ed Cregger

Dar, I stole the .50s carb for another Webra.

David, you thief! Give it back to the MVVS, now!

Hah, I have a whole collection of SuperTigre, Fox, Webra and other brands of carbs that people thought were bad, amazingly non were. I swear the ride in the Mail Truck fixes them.

Dar and Hobbsy my PAW 40 wears an MVVS carb and it did not come off my MVVS engines great throttling and response martin
far better than the antique stock PAW