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-   -   UMS Gas Radial Engine Enthusiasts Rabbit Hole (https://www.rcuniverse.com/forum/gas-engines-142/11698637-ums-gas-radial-engine-enthusiasts-rabbit-hole.html)

Hyjinx 04-18-2022 03:52 PM

UMS Gas Radial Engine Enthusiasts Rabbit Hole
 
Here goes Tom. Thanks for helping me start the new thread.
Aaron (Hyjinx)
My new UMS 125 from CH ignitions in Florida USA.
https://cimg6.ibsrv.net/gimg/www.rcu...3dadfcee2d.jpg
Brand new UMS 125 in a new to me Waco 60 Arf. Un started as of yet 4/18/22.
Thanks to anyone who is interested in sharing info on the current design UMS Gas Radials....


​​​​​

Maxam 04-18-2022 05:23 PM

Well done Aaron!
 
I hope this thread comes alive.
The UMS 5-100; I now have 15 8 oz tanks of 40;1 redline ethanol free gas/ oil with 2 oz of Sea foam/ gallon. Nearly perfect carburation through the entire range from 600 rpm to 4500 turning a Xoar 25x12 prop. True horsepower is 4.65. Think of a DA50 with belt reduction. A Moki 215 is 9.5 Hp at 4000 rpm...This engine is very easy to start. The mid throttle is slightly lean but a lightly rich setting at idle takes care of that. No blubber rich areas through the throttle range. All cylinders run evenly!!! My UMS 5-55 and 5-100 do run rather hot at 230 F. The APS power fuel fuel pump is required (5-100).

okcrcpilot 04-18-2022 05:52 PM

I am running a UMS 5-100 on a 1/5th scale Ziroli AT-6 Texan although I haven't done the maiden yet. Long story about that but the maiden probably won't happen till the end of the year. As Tom has stated, the 5-100 is an easy to start, smooth running engine. I am turning a semi-scale Biela 25x14, turning 4400rpm's.






okcrcpilot 04-18-2022 05:55 PM

Seems RCU requires a member to have 10 posts before pictures/URL's can be uploaded, so let's see how this goes. This should be post #10 for me.



okcrcpilot 04-18-2022 05:57 PM

Picture of the Ziroli AT-6 with a UMS 100-5 up front.
https://cimg3.ibsrv.net/gimg/www.rcu...6a3ee432cb.jpg
Ziroli 1/5 scale AT-6 Texan.

Hyjinx 04-18-2022 07:45 PM


Originally Posted by Maxam (Post 12724446)
I hope this thread comes alive.
The UMS 5-100; I now have 15 8 oz tanks of 40;1 redline ethanol free gas/ oil with 2 oz of Sea foam/ gallon. Nearly perfect carburation through the entire range from 600 rpm to 4500 turning a Xoar 25x12 prop. True horsepower is 4.65. Think of a DA50 with belt reduction. A Moki 215 is 9.5 Hp at 4000 rpm...This engine is very easy to start. The mid throttle is slightly lean but a lightly rich setting at idle takes care of that. No blubber rich areas through the throttle range. All cylinders run evenly!!! My UMS 5-55 and 5-100 do run rather hot at 230 F. The APS power fuel fuel pump is required (5-100).

Super cool Tom. Really looking forward to this flying season. I too have a Moki, yet un-started new 250 -7. Dr G recommended Amsoil Dominator for it. I have it so I think I will start out with it in the new UMS. Adrian recommended a APS for the 125. I bought in. I am using Spectrum equipment now from Frsky. Checking into sensor options.

Hyjinx 04-18-2022 07:47 PM


Originally Posted by okcrcpilot (Post 12724455)
Picture of the Ziroli AT-6 with a UMS 100-5 up front.
https://cimg3.ibsrv.net/gimg/www.rcu...6a3ee432cb.jpg
Ziroli 1/5 scale AT-6 Texan.

That makes my knees shake! Absolutely beautiful Sir!

Hyjinx 04-18-2022 07:48 PM


Originally Posted by okcrcpilot (Post 12724454)
Seems RCU requires a member to have 10 posts before pictures/URL's can be uploaded, so let's see how this goes. This should be post #10 for me.

Uploading pictures and video has been harder than landing the Texan for me lol.

GIJon 04-19-2022 03:59 AM

Hi Tom,
Did you have to use an adapter to mount the Saito carb on your 5-55.

okcrcpilot 04-19-2022 04:05 AM

Here is a picture of the business end on my 1/3 scale BUSA PT-17. UMS 260-7, that has performed flawlessly for 30+ flights now.
https://cimg9.ibsrv.net/gimg/www.rcu...e8fb033f73.jpg

Hyjinx 04-19-2022 04:18 AM


Originally Posted by okcrcpilot (Post 12724487)
Here is a picture of the business end on my 1/3 scale BUSA PT-17. UMS 260-7, that has performed flawlessly for 30+ flights now.
https://cimg9.ibsrv.net/gimg/www.rcu...e8fb033f73.jpg

Do you watch temperature on cowled and open air set ups? Seeing both, I wonder if the Texan rums hotter? Assuming the same oil mix and octane rating and non ethanol gas blends....

okcrcpilot 04-19-2022 04:40 AM

I no longer monitor head temps on the 260 since I have a lot of flights on her. Since I fly Spektrum I am using their temperature sensor to keep an eye on the 100 in the AT-6. Not having flown the plane yet, I don't know what the readings will be although on the test stand average was 170°

EDIT: Depending on the head temps of the 100-5, I may have to construct some sort of engine baffle. This would be a new undertaking for me so any and all suggestions/recommendations will be appreciated. Also, I used Amsoil Dominator in my radials at a 50:1 ratio and so far have not encountered any problems. I lube everything on the first flight of the day with gear lube.

Maxam 04-19-2022 04:43 AM

GI Jon, yes I did. I hope the O-rings last with gasoline. Neat little engine. (5-55)
One other thing I like about the 5-100, still uses the little glow size spark plugs. I talked to Adrian about the thick R-Excel spark wires that are cumbersome especially on the smaller engines. He said the thinner wires do not work well with a hot spark.
To anyone interested. I have completed my Schlundt 46% Bowers Fly Baby using a Moki 257.
Nice Texan and Stearman and Waco!

-Tom
PS Great title for the thread!

GIJon 04-19-2022 05:05 AM


Originally Posted by Maxam (Post 12724503)
GI Jon, yes I did. I hope the O-rings last with gasoline. Neat little engine. (5-55)
One other thing I like about the 5-100, still uses the little glow size spark plugs. I talked to Adrian about the thick R-Excel spark wires that are cumbersome especially on the smaller engines. He said the thinner wires do not work well with a hot spark.
To anyone interested. I have completed my Schlundt 46% Bowers Fly Baby using a Moki 257.
Nice Texan and Stearman and Waco!

-Tom
PS Great title for the thread!

Yeah Tom. I'll probably want to install the Saito carb as well.

okcrcpilot 04-19-2022 05:37 AM


Originally Posted by Maxam (Post 12724503)
GI Jon, yes I did. I hope the O-rings last with gasoline. Neat little engine. (5-55)
One other thing I like about the 5-100, still uses the little glow size spark plugs. I talked to Adrian about the thick R-Excel spark wires that are cumbersome especially on the smaller engines. He said the thinner wires do not work well with a hot spark.
To anyone interested. I have completed my Schlundt 46% Bowers Fly Baby using a Moki 257.
Nice Texan and Stearman and Waco!

-Tom
PS Great title for the thread!

Tom, By chance are there any pictures of the Fly Baby?? Just have to see the 257 on the front end of that Baby!!

Gary

Jesse Open 04-19-2022 06:32 AM


Originally Posted by Hyjinx (Post 12724464)
That makes my knees shake! Absolutely beautiful Sir!


YES! What a beauty.:)



Maxam 04-19-2022 07:23 AM

Fly Baby
 
About to install windshield.
https://cimg1.ibsrv.net/gimg/www.rcu...d9a1a8e5f8.jpg
https://cimg2.ibsrv.net/gimg/www.rcu...09f5ef017d.jpg

Hyjinx 04-19-2022 08:22 AM


Originally Posted by okcrcpilot (Post 12724502)
I no longer monitor head temps on the 260 since I have a lot of flights on her. Since I fly Spektrum I am using their temperature sensor to keep an eye on the 100 in the AT-6. Not having flown the plane yet, I don't know what the readings will be although on the test stand average was 170°

EDIT: Depending on the head temps of the 100-5, I may have to construct some sort of engine baffle. This would be a new undertaking for me so any and all suggestions/recommendations will be appreciated. Also, I used Amsoil Dominator in my radials at a 50:1 ratio and so far have not encountered any problems. I lube everything on the first flight of the day with gear lube.

Thanks. Good help. I am going to construct the baffle of a 12x12 aluminum flashing blank from the home dope show. Aka Home Depot lol. I'll photo doc and post.

Maxam 04-19-2022 08:26 AM

Place your 5-100 on a sheet of paper with a flashlight shining straight down. The shadow will be your template. Place the flashlight as high as possible so the image has the least enlargement. -Tom

okcrcpilot 04-19-2022 10:37 AM

Thanks for the suggestion Tom. I wish I would have asked this question before mounting the engine on the plane!!! Oh well, it'll give me something to do the next time it rains!!! Thanks for posting pictures of your "Baby". I'll best she flys like a dream.

marksp 04-19-2022 05:27 PM

UMS Radials…
 
I’m on my second UMS made radial, this one the 5-150 going on the TopRCModel P-47 96”. Plan on flying a SEP 23X14X4.

https://live.staticflickr.com/65535/...d93e412e13.jpg

https://live.staticflickr.com/65535/...3205ca898f.jpg

My UMS engine is the Tomahawk branded “Blackstar” 5-250 which I picked up bundled with a 1/3 scale Tomahawk Wilga. My experience with this engine along with Adrain’s support shifted me to this brand.

https://live.staticflickr.com/65535/...47146f99ae.jpg

https://live.staticflickr.com/65535/...ee9320818e.jpg

I run them both, as well as my (2) Moki 250’s & (1) Moki 215 on the APS fuel pump. They run strong, sound great and with the exception of the pump, require no changes out of the box. My Moki’s required switching ignitions, disconnecting the fuel pulse pump and don’t support RPM telemetry.

Cheers

marksp 04-19-2022 05:31 PM

UMS manufactured “Black Star” 5-250 video
 
Here’s a video of the 5-250


Cheers

okcrcpilot 04-20-2022 04:51 AM

GREAT looking planes, Mark, and thanks for posting a video of your Wilga. Do you still have your Stearman??

Gary

marksp 04-20-2022 10:07 AM


Originally Posted by okcrcpilot (Post 12724630)
GREAT looking planes, Mark, and thanks for posting a video of your Wilga. Do you still have your Stearman??

Gary

Thanks Gary, and yes still have the big Stearman w/Moki S215. Still have yours? Have you picked up a UMS radial???

Cheers

Hyjinx 04-20-2022 10:28 AM


Originally Posted by marksp (Post 12724604)
I’m on my second UMS made radial, this one the 5-150 going on the TopRCModel P-47 96”. Plan on flying a SEP 23X14X4.

https://live.staticflickr.com/65535/...d93e412e13.jpg

https://live.staticflickr.com/65535/...3205ca898f.jpg

My UMS engine is the Tomahawk branded “Blackstar” 5-250 which I picked up bundled with a 1/3 scale Tomahawk Wilga. My experience with this engine along with Adrain’s support shifted me to this brand.

https://live.staticflickr.com/65535/...47146f99ae.jpg

https://live.staticflickr.com/65535/...ee9320818e.jpg

I run them both, as well as my (2) Moki 250’s & (1) Moki 215 on the APS fuel pump. They run strong, sound great and with the exception of the pump, require no changes out of the box. My Moki’s required switching ignitions, disconnecting the fuel pulse pump and don’t support RPM telemetry.

Cheers

Hey MarkspThe Tomahawk is the next purchase for me. I haven't been able to come up with a 180 Moki which was (is) my hope. I have one more airframe to finish out my Big Four.
Looking at a non Chinese Arf of a Bucker Jugenmeister single seat. The cz is Chinese unfortunately, so it's ruled out at this point. Please continue to post your experience with the UMS Tomahawk. Thanks Aaron-


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