RE: Everything Radial Engines
Roger, Some Saito 3 cylinder engines do not get even distribution of fuel to all three cylinders. At full throttle you might be having either one cylinder going wery rich or very lean. Read back a few posts where I was giving George some ideas with his ST540. You might try the partial carb rotation method and/or adjust the throws so that full throttle is 3/4 open on the carb and tune the engine for that adjustment. -Tom
Posted on: 5/16/2013 3:56 AM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11512953

RE: Hangar 9 60cc Corsair
16 to 20 oz is fine. The other nice benefits of these radials is; far lower vibration, less oil mess due to running on 8% oil, and they can swing a nice big near scale size prop. They sound really cool too. I use a Xoar 3 blade warbird style 22x10. -Tom
Posted on: 5/15/2013 4:38 PM by Author "Maxam" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11512591

RE: has anyone flown the new 50cc size black horse corsair
OK roger, Try a servo tester.Now to the struts. 1. Remove the anti rotation screw and take the strut apart and go to a local hardware. Many sell springs in yellow packages. Get the strongest springs that will slide in. You will need to cut them shorter for a descent amount of travel. Now the anti rotation hex nut screw..... Chuck the thread portion up in a drill press and with a good file grind a step in the screw that matches the width of the slot. That will remove all play in the strut. Use good grease. There you go. -Tom
Posted on: 9/12/2012 5:05 PM by Author "Maxam" in the forum "ARF or RTF"
http://www.rcuniverse.com/forum/fb.asp?m=11226633

RE: has anyone flown the new 50cc size black horse corsair
Try another radio for proper function. -Tom
Posted on: 9/12/2012 6:25 AM by Author "Maxam" in the forum "ARF or RTF"
http://www.rcuniverse.com/forum/fb.asp?m=11225997

RE: UMS Evolution Radial Care and Operation
That would then be three cam pairs at 1/6 speed. There are 5 I believe for the 9-99. -Tom Pete???
Posted on: 9/6/2012 5:18 PM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11220069

RE: UMS Evolution Radial Care and Operation
Steve you must adjust to the highest lobe. If you do not, a valve may not seat all the way and thus get burned. -Tom
Posted on: 9/6/2012 2:31 PM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11219922

RE: UMS Evolution Radial Care and Operation
Oh yeah you are fine with that clearance. Make absolutely sure that you have good airflow. Radius the front of the firewall on the fuselage to allow more air around the cowl. One problem with the Top Flight is the cowl flaps are barely open restricting flow. -Tom
Posted on: 9/5/2012 2:58 PM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11218661

RE: UMS Evolution Radial Care and Operation
Rick, That is pretty close and please account for when the valves open. There has been concern for side play with the rockers. The force from the rods will keep them in a specific location during operation. When testing for valve gap clearance the rockers will move to the same location. Yes the pushrods have side play but they do work well. I have flown the hell out of these engines and they are still solid. -Tom
Posted on: 9/5/2012 5:59 AM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11218121

RE: MOKI RADIAL Care and Maintenence
Nice to hear from you Noah. Did you get a new research assignment? I have not heard from Jim in a long time so I do not know if he is still flying the beast. I did not attend any meets but I will this weekend down near Louisville. I spent a bit of time in Germany this summer which limited the meets I could attend. My experience with Moki's being run before and after installing the turbulator demonstrated much greater smoothness and improved throttle transition. The cylinder temps evened out greatly to within 10 degrees F of each other. Detlef is a wise man with high standards. His invention is worthwhile. -Tom
Posted on: 9/4/2012 4:30 AM by Author "Maxam" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11216688

RE: MOKI RADIAL Care and Maintenence
All, I have owned a 150 and an older 215 and learned much running them on the bench. Recently I replaced an engine in my OMP Yak 55M with a brand new 215 from Gotz Vogelsang. I am using the APS fuel pump and the Kunkle Turbulator just like on the two previous engines. It is a real pleasure to actually fly a Moki for once. What a true thrill. I am using Amsoil Interceptor at 40 to 1. Airflow has been optimized and all cylinders are at the 190 F range after taxiing in and shut down. It seems that the quality of the Moki's has improved. The finish is finer and the exhaust is far cleaner with nearly nonexistent black goo. I recall the 150 and the older 215 producing a great deal of the dreaded black crud and was all over the place. No I was not running overly rich then or anything else different, same oil too, even later at 50 to 1. I am using a Fiala 32x18 prop. Later I will progress to 50 to 1 oil. At 40 to 1 the five spark plugs show good combustion. I am happy with my 215. -Tom Noah Butler, Are you still flying that wonderful warbird of yours?
Posted on: 9/3/2012 5:30 PM by Author "Maxam" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11216208

RE: UMS Evolution Radial Care and Operation
I use size N concentric connectors from Radio Shack and 12 to 14 guage wire. The female connector hides well. -Tom
Posted on: 8/31/2012 7:15 AM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11212538

RE: UMS Evolution Radial Care and Operation
My brain failed me completely. I ment the intake valve!!!!! (I am a moron and I'm OK) From the lumberjack song from Monty Python. -Always proofread! Tom
Posted on: 8/29/2012 4:30 AM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11210028

RE: UMS Evolution Radial Care and Operation
When an exhaust valve opens the piston is traveling down pulling air and fuel in. This is occurring 3.5 times / revolution in a seven cylinder. The volume in a radial crankcase is nearly constant because when some pistons are going to bottom dead center, others on the crankpin side are going towards top dead center. This is why a walbro carb cannot rely on fluctuating crankcase pressure to operate its pump in a radial. -Tom
Posted on: 8/28/2012 3:57 AM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11208712

RE: UMS Evolution Radial Care and Operation
Thank you Roger, There is always room for learning and improvement. I have learned much from a German gentleman named Detlef Kunkel. He is the ultimate expert. I have recently read a book called Pratt and Whitney's Major Miracle. It is a 400 page book all on the 28 cylinder R4360. There are so many concepts I have learned from that book! Also Kevin Camron is a brilliant writer on engine theory. As I have said before, these new "affordable" radials have completly rejuvinated my interest in the hobby. -Tom
Posted on: 8/23/2012 3:55 AM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11203061

RE: UMS Evolution Radial Care and Operation
Jerry, I prefer niCds. They are more durable and their actual voltage is 1.37V. The glow plugs are 3 amps apiece so 3x7 =21 amps. The connection to the plane I use is a N size plug and socket from radio shack. I have drawn as much as 30 amps for short periods through this connection. The female socket hides well. The battery must have very thick wire to prevent voltage drop. 14 guage is fine. My starting battery is 8 700ma nicads all in parallel. This pack can suppy 50 amps with nearly no voltage drop. You want yellow glow at the plugs, not red. Now 21 amps for an hour or the battery can be 10 amp/hr for a half hour or 5 amp/hr for 15 min assuming they are on all the time which they will not. -Tom
Posted on: 8/22/2012 11:27 AM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11202301

RE: UMS Evolution Radial Care and Operation
Jerry, These are good engines. I personally do not use any glow driver and my 9-90 has 108 flight on it. No problem using one though. What in the manual is contradictory? -Tom I am also very satisfied with how the 7-70 (older version) flies my 91 inch corsair.
Posted on: 8/22/2012 3:47 AM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11201848

RE: UMS Evolution Radial Care and Operation
Pete, Pete, pete, Do not change those type F plugs!!!!!!!!!!!!!!! They are good for 15 years! Just clean out the one not firing and it will work good as new!!!
Posted on: 8/21/2012 5:47 PM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11201448

RE: UMS Evolution Radial Care and Operation
Roger, Do not be afraid to adjust the low speed needle while the engine is running. Tune to the point of smooth low idle running without the glow heat. Then open the screw about a quarter turn richer for reliability. You know when it is correct when the engine runs at idle and when you accelerate it speeds up without hesitation or slowing down first. You must experiment until you begin "to get"the engine. -Tom A bit of nitro helps greatly with reliability!
Posted on: 8/14/2012 3:19 PM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11193520

RE: UMS Evolution Radial Care and Operation
The 7-77 is only 4 ounces heavier than the saito 325. The saito is 53cc and the other well obviously 77cc. -Tom My 9-90 had a milestone...flight 100 this week and looks to last another 500!
Posted on: 8/9/2012 5:20 PM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11187537

RE: UMS Evolution Radial Care and Operation
Roger, I am lost for words for your difficulty starting the 7-77. My experience is it is the easiest of the three to start. OK open the High speed needle three turns, Then with your finger over the carb flip the prop about 5 times at high throttle. Now go to lower throttle so the choke is 1/5 to 1/4 th open. All assuming you are starting with a dry engine. It should start right away by hand. Now if the low speed needle is in too far the engine will not draw any fuel and then of course it will not start. -Tom
Posted on: 8/7/2012 1:46 PM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11184614

RE: Everything Radial Engines
Congrats Roger. You will get a ton of flights out of that engine. Saito radials do last a long time. Now get that corsair in the air! -Tom
Posted on: 8/1/2012 2:05 PM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11177517

RE: UMS Evolution Radial Care and Operation
Yep I use riches brew too! I use 16% oil 15% nitro diluted one to one with methanol. Dummy radial Ha!!! -Tom
Posted on: 7/30/2012 8:27 AM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11174470

RE: UMS Evolution Radial Care and Operation
Steve, Having the glow on at full throttle you are advancing the "spark" timing and that will reduce power and overheat the engine. In otherwords the fuel is igniting too early. Can you richen the engine to make it slow down then lean to speed back up? If not it is not getting enough fuel and is running lean. -Tom
Posted on: 7/25/2012 5:49 PM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11169293

RE: UMS Evolution Radial Care and Operation
Tim Advantagehobby.com has them!
Posted on: 7/25/2012 10:29 AM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11168702

RE: UMS Evolution Radial Care and Operation
Tim, 18 pounds, use a 24x10 prop and expect solid spirited performance even at 1/2 throttle it will fly well. -Tom
Posted on: 7/25/2012 8:31 AM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11168552

RE: Evolution 7 cylinder 260cc radial engine - Operation and maintenance
All, I wanted to report immediately do not use Stihl Ultra 2 cycle oil! After cleaning up my radial and making a new keeper for one of the valves( not listed as an available part from Horizon), I went through the valve adjustment procedure. I removed all 7 plugs. Turning the engine sounded like sand was poured into the engine. Seriously the engine sounded like it was ruined!!! There was squeaking from the followers etc. Well being dismayed I went ahead and adjusted the valves and put the plugs back in. I dumped my stihl premix in my weedwacker can and made up a batch of 40/1 Amsoil Interceptor like I used before. Nervously I started the engine on this premix (I did drip some oil over the cams through a follower hole first). It did start up and I ran it for about 10 minutes at different throttle settings. I allowed it to cool down completely and I removed all 7 plugs and Phew!! It turned smoothly and quietly. No wonder this oil is popular with the Moki radial crowd. What a scare........-Tom
Posted on: 7/25/2012 5:51 AM by Author "Maxam" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11168397

RE: has anyone flown the new 50cc size black horse corsair
Not one bit. All batteries are in the center of the fuselage. -Tom
Posted on: 7/23/2012 3:28 PM by Author "Maxam" in the forum "ARF or RTF"
http://www.rcuniverse.com/forum/fb.asp?m=11166317

RE: UMS Evolution Radial Care and Operation
Roger I did a search on youtube and found it right away! Try;evolution 160cc 7 cylinder gas radial. Make sure you use 7 not seven. -Tom
Posted on: 7/23/2012 7:23 AM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11165633

RE: UMS Evolution Radial Care and Operation
Roger, I have no idea how to do this. Sorry. -Tom
Posted on: 7/23/2012 7:02 AM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11165605

RE: UMS Evolution Radial Care and Operation
Thank you for your confidence in me Dadroman. I did PM Mark. Folks permit me to invade the glow radials with my evo gas 160 radial. You can find it on youtube; Evolution 160cc 7 cylinder Gas Radial in RC OMP Yak. -Tom
Posted on: 7/23/2012 5:11 AM by Author "Maxam" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=11165498