UMS Evolution Radial Care and Operation
#26
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RE: UMS Evolution Radial Care and Operation
Nils,yes actually. When I got my first 7-70 I did run it on 16% oil and 15 % nitro and frankly it ran great! Just produced an oily mess! The higher nitro compensated for the high oil so low reliable idle was possible. Lars,the problem with on board glow is the great weight of the large batteries required. many people are happy however. The first picture of your most recent post was great! -Tom
#27
RE: UMS Evolution Radial Care and Operation
Sounds great!
I found a place where i can purchase pure methanol, but it is directly from the raffinery in a 200 litre barrel as lowest quantity... a little much. I would have had fuel for the rest of my life !
But if i bought a 770 it would be absolutely best to run it without nitro and 6% oil to avoid the oil mess.
I found a place where i can purchase pure methanol, but it is directly from the raffinery in a 200 litre barrel as lowest quantity... a little much. I would have had fuel for the rest of my life !
But if i bought a 770 it would be absolutely best to run it without nitro and 6% oil to avoid the oil mess.
#28
Senior Member
RE: UMS Evolution Radial Care and Operation
<span id="result_box" lang="en"><span class="hps">Tom</span>
<span class="hps">You</span> <span class="hps">say it</span> <span class="hps">huh</span> <span class="hps">little</span> <span class="hps">broblem</span> <span class="hps">with</span> <span class="hps">them</span> <span class="hps">first</span> <span class="hps">carburetors</span> <span class="hps">to</span> <span class="hps">7-35</span><span>.</span>
<span class="hps">should I</span> <span class="hps">replace</span> <span class="hps">or upgrade the</span> <span class="hps">carburetor</span> <span class="hps">with other parts</span><span>.</span>
<span class="hps">Lars</span></span>
<span class="hps">You</span> <span class="hps">say it</span> <span class="hps">huh</span> <span class="hps">little</span> <span class="hps">broblem</span> <span class="hps">with</span> <span class="hps">them</span> <span class="hps">first</span> <span class="hps">carburetors</span> <span class="hps">to</span> <span class="hps">7-35</span><span>.</span>
<span class="hps">should I</span> <span class="hps">replace</span> <span class="hps">or upgrade the</span> <span class="hps">carburetor</span> <span class="hps">with other parts</span><span>.</span>
<span class="hps">Lars</span></span>
#29
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RE: UMS Evolution Radial Care and Operation
Lars, Sorry it took so long to reply. I was in Philadelphia hearing the Philharmonic Orchestra playing along with the worlds largest pipe organ! Exciting concert. The carb is decent. I have heard there might be changes. Until then enjoy the engine!
#30
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RE: UMS Evolution Radial Care and Operation
Todays discussion refers to the danger of hydraulic lock on these radials. Due to the design of radials oil can seep down and pool into the bottom cylinders. Because liquids are basically non-compressible, if the engine is not checked first, the use of an electric starter or a strong arm can damage a connecting rod to the flooded cylinder. When getting ready to start the engine for the first time for the day, slowly turn the prop by hand. If you encounter a point where the compression is felt to be much higher, STOP!!!!!!! Drain that cylinder by removing the glow plug thus allowing the oil (or fuel) to leave. Over priming can also cause this condition. Next topic will cover valve adjustment -Tom
#31
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RE: UMS Evolution Radial Care and Operation
Hi guys - I am starting the build of a Top Flite Giant Scale Corsair and am determined if possible to power it with a Radial! I'm currently looking at the 7-77 or even 9-99 UMS engines but diameter is an issue especaially with the 9-99.
With an estimated weight of around 30lb I am concerned that the 7-77 which may fit does not quite have the power.
I'm looking to acheive ascale flight envelope with a three or evenfour,if I can,blade prop.
I will be following this thread with interest and would appreciate your thoughts.
Dave
With an estimated weight of around 30lb I am concerned that the 7-77 which may fit does not quite have the power.
I'm looking to acheive ascale flight envelope with a three or evenfour,if I can,blade prop.
I will be following this thread with interest and would appreciate your thoughts.
Dave
#32
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RE: UMS Evolution Radial Care and Operation
Dave, My corsair shown on this thread weighs 20 pounds 4 oz with a 91 inch span and it is powered with the older 7-70. The newer 7-77 should give 10% more power. Mine swings a Xoar 22x10 3 blade well. The plane flies fine at 1/2 throttle. Actually I usually take off at less than 3/4 throttle. Be mindfull always with weight while building. No glue glops, less epoxy more CA. Recall these engines have low vibration so the airframe does not have to withstand massive vibration from a single. -Tom
#33
Senior Member
RE: UMS Evolution Radial Care and Operation
<span lang="en" id="result_box"><span class="hps">How</span> <span class="hps">nice</span> <span class="hps">it looks</span> <span class="hps">in the</span> <span class="hps">UMS</span> <span class="hps">Seidel</span> <span class="hps">7-35</span><span>.</span>
<span class="hps">It has</span> <span class="hps">been run</span> <span class="hps">in</span> <span class="hps">6</span> <span class="hps">hours</span><span>.</span>
<span class="hps">Nice and clean</span> <span class="hps">and no</span> <span class="hps">rust</span> <span class="hps">at all.
Lars</span></span>
<span class="hps">It has</span> <span class="hps">been run</span> <span class="hps">in</span> <span class="hps">6</span> <span class="hps">hours</span><span>.</span>
<span class="hps">Nice and clean</span> <span class="hps">and no</span> <span class="hps">rust</span> <span class="hps">at all.
Lars</span></span>
#34
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RE: UMS Evolution Radial Care and Operation
Tom - thanks for your reply. I am very conscious of managing weight whilst building, particularly aft of the Cof G and even more so at the rear of the fuse. Being conscious of it and achieving it are two different things though and I appreciate your comment.
I note these engines have an oversquare cylinder so that helps torque and from your experience its seems that the 7-77 may just be a good choice after all! I'm not sure that 10% more displacement will deliver 10% more power but its got to help. Unless I've missed something of course!!
This won't be quick build but I'll keep the thread informed . . . . either way.
Dave
I note these engines have an oversquare cylinder so that helps torque and from your experience its seems that the 7-77 may just be a good choice after all! I'm not sure that 10% more displacement will deliver 10% more power but its got to help. Unless I've missed something of course!!
This won't be quick build but I'll keep the thread informed . . . . either way.
Dave
#35
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RE: UMS Evolution Radial Care and Operation
Dave, Please feel free to post progression of the build particularly the engine installation. I highly recommend bench running of the engine so you can become very familiar with its operation. They do run very cool so any overheating would be due to an extreme lean condition. The Xoar warbird 22x10 3 blade prop is excellent! -Tom
Lars, Thankyou for posting those internal pictures! I like to see engines being well cared for. -Tom
Lars, Thankyou for posting those internal pictures! I like to see engines being well cared for. -Tom
#36
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RE: UMS Evolution Radial Care and Operation
Todays discussion concerns proper valve adjustment. First in my 30 years of 4 cycle engine flying I have found with complete consistency that valve adjustment is NOT critical. I have numerous times purposefully misadjusted valves and could barley perceive differences. What IS important is adjustment must allow both intake and exhaust valves to close completely or running goes to hell and valves and their seats get damaged on the double. Do not get me wrong I have high expectations of running quality and smooth transition through the throttle range.
Radials excepting the Saitos have a cam ring with multiple lobes to operate the valves. The more lobes the slower the cam ring runs relative to the shaft speed. Take a quiz! A cam ring has 5 lobe pairs.....what is its speed relative to the crank shaft?
OK on to the process; Removing all the glow plugs makes timing much easier so rotation is easy and the pistons can be seen at top dead center. Now start with the top cylinder even though this does not make a difference(you can start with any cylinder). Turn the prop to the point where both rockers are just moving and then one full turn to top dead center. You can see the piston through the glow plug hole. Turn the prop to the pistons highest point. Both rockers should have play. Adjust for correct clearance. You are NOT finished with this adjustment!! Now rotate the prop two full turns clockwise to the exact same position. The rockers might have the same clearance or have greater or lesser clearance. If lesser, readjust to correct. If greater leave alone. Now rotate the prop clockwise two full turns to again the same position. Check the clearance yet again, If lesser readjust if greater leave alone. The point is to never have a valve with too little clearance. A bit more does not hurt. Repeat this process for the remaining cylinders. You see each adjustment position is on a different cam lobe pair. This sounds like horrible tedium but once you get through a couple of cylinders it will go much faster than you thought. I can do the 9-90 in about one half hour. Maybe one glass of wine will help (only one!).
Radials excepting the Saitos have a cam ring with multiple lobes to operate the valves. The more lobes the slower the cam ring runs relative to the shaft speed. Take a quiz! A cam ring has 5 lobe pairs.....what is its speed relative to the crank shaft?
OK on to the process; Removing all the glow plugs makes timing much easier so rotation is easy and the pistons can be seen at top dead center. Now start with the top cylinder even though this does not make a difference(you can start with any cylinder). Turn the prop to the point where both rockers are just moving and then one full turn to top dead center. You can see the piston through the glow plug hole. Turn the prop to the pistons highest point. Both rockers should have play. Adjust for correct clearance. You are NOT finished with this adjustment!! Now rotate the prop two full turns clockwise to the exact same position. The rockers might have the same clearance or have greater or lesser clearance. If lesser, readjust to correct. If greater leave alone. Now rotate the prop clockwise two full turns to again the same position. Check the clearance yet again, If lesser readjust if greater leave alone. The point is to never have a valve with too little clearance. A bit more does not hurt. Repeat this process for the remaining cylinders. You see each adjustment position is on a different cam lobe pair. This sounds like horrible tedium but once you get through a couple of cylinders it will go much faster than you thought. I can do the 9-90 in about one half hour. Maybe one glass of wine will help (only one!).
#39
Senior Member
RE: UMS Evolution Radial Care and Operation
<span id="result_box" lang="en"><span class="hps">I have tried</span> <span class="hps">to adjust the</span> <span class="hps">valves</span> <span class="hps">as</span> <span class="hps">you</span> <span class="hps">said</span><span>.</span>
<span class="hps">There</span> <span class="hps">vase a</span> <span class="hps">new experience</span> <span class="hps">that worked well</span> <span class="hps">thanks</span> <span class="hps">Tom</span> <span class="hps">for the tip</span><span>.</span>
<span class="hps">I</span> <span class="hps">had a beer</span> <span class="hps">instead of</span> <span class="hps">wine
Lars<br type="_moz"/></span></span>
<span class="hps">There</span> <span class="hps">vase a</span> <span class="hps">new experience</span> <span class="hps">that worked well</span> <span class="hps">thanks</span> <span class="hps">Tom</span> <span class="hps">for the tip</span><span>.</span>
<span class="hps">I</span> <span class="hps">had a beer</span> <span class="hps">instead of</span> <span class="hps">wine
Lars<br type="_moz"/></span></span>
#41
Senior Member
RE: UMS Evolution Radial Care and Operation
If anybody happens to be in the Chicago area this weekend I will have the entire line of EVO radials at the IHobby Show in Rosemont. All decked out with the new collector rings, choke levers, glow harnesses and throttle bellcranks. I'll be available both Saturday and Sunday to talk engines with anyone who wants to come by.
Pete
Pete
#42
Senior Member
RE: UMS Evolution Radial Care and Operation
<span lang="en" id="result_box"><span class="hps">Hello</span> <span class="hps">radilal</span> <span class="hps">lovers</span>
<span class="hps">I have</span> <span class="hps">been in contact</span> <span class="hps">UMS</span> <span class="hps">about</span> <span class="hps">carburetors,</span> <span class="hps">to</span> <span class="hps">7-35</span><span>!</span>
<span class="hps">if</span> <span class="hps">there is an update</span><span>,</span> <span class="hps">they</span> <span class="hps">rekomender</span> <span class="hps">to change</span> <span class="hps">carburetors</span><span>.</span>
<span class="hps">Does anyone</span> <span class="hps">know what is</span> <span class="hps">to be</span> <span class="hps">modified</span><span>?</span>
<span class="hps">It costs</span> <span class="hps">$ 40</span> <span class="hps">not so bad
Lars
</span></span>
<span class="hps">I have</span> <span class="hps">been in contact</span> <span class="hps">UMS</span> <span class="hps">about</span> <span class="hps">carburetors,</span> <span class="hps">to</span> <span class="hps">7-35</span><span>!</span>
<span class="hps">if</span> <span class="hps">there is an update</span><span>,</span> <span class="hps">they</span> <span class="hps">rekomender</span> <span class="hps">to change</span> <span class="hps">carburetors</span><span>.</span>
<span class="hps">Does anyone</span> <span class="hps">know what is</span> <span class="hps">to be</span> <span class="hps">modified</span><span>?</span>
<span class="hps">It costs</span> <span class="hps">$ 40</span> <span class="hps">not so bad
Lars
</span></span>
#44
Thread Starter
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RE: UMS Evolution Radial Care and Operation
I have been doing some winter maintenance on my 7-70 in my corsair which means I removed the cowl. On an earlier post I discussed the importance of preventing corrosion. My last flight was about 3 weeks ago and two weeks later I happened to turn the prop and the engine felt just a bit "crunchy" meaning there might have been a bit of corrosion set in. I removed a bottom cam follower and the draining oil had that corrosiony smell. What I did was I added much more air tool oil and blu-block and turned the engine with an electric starter. I drained the new oil and added another shot of oil. It was clear and smelled good. I decided to inspect the interior and fortunately it was not corroded but I feel better! I heard some one liked the corsair and wanted to put a new 7-77 in it so here are some photos of my installation. Looking closely I made a ply and cherry stand-off for the engine that was painted with dope. The engine box is not in the correct location for the engine. The two lower mounting holes are fine for blind nuts behind the firewall but the top mounting hole could not be used but the inner one could if you run a bolt from the inside to the front and then use a nut to secure the engine. I hope the photos are useful. -Tom
PS the stand off length is one inch and a sixteenth. The manual for this model was way off.
PS the stand off length is one inch and a sixteenth. The manual for this model was way off.
#46
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RE: UMS Evolution Radial Care and Operation
Thank you Kostas! Better get yourself one of these!
What to do with future projects!!!
for my 7-35.........Sig's Waco SRE would be great if they would ever get them in. Lars Stearman is rather convincing.
I hear Horizon will offer a gas 160cc 7 cylinder radial.............Beast anyone??? No 3D but an acquaintance has a Moki 150 in his and it is an excellent flier with strong up-lines and will do all full size maneuvers.
What to do with future projects!!!
for my 7-35.........Sig's Waco SRE would be great if they would ever get them in. Lars Stearman is rather convincing.
I hear Horizon will offer a gas 160cc 7 cylinder radial.............Beast anyone??? No 3D but an acquaintance has a Moki 150 in his and it is an excellent flier with strong up-lines and will do all full size maneuvers.
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RE: UMS Evolution Radial Care and Operation
ORIGINAL: Pete Bergstrom
If anybody happens to be in the Chicago area this weekend I will have the entire line of EVO radials at the IHobby Show in Rosemont. All decked out with the new collector rings, choke levers, glow harnesses and throttle bellcranks. I'll be available both Saturday and Sunday to talk engines with anyone who wants to come by.
Pete
If anybody happens to be in the Chicago area this weekend I will have the entire line of EVO radials at the IHobby Show in Rosemont. All decked out with the new collector rings, choke levers, glow harnesses and throttle bellcranks. I'll be available both Saturday and Sunday to talk engines with anyone who wants to come by.
Pete
Although I am still waiting for a suitable airframe for the engine to go into, I was wondering if Horizon Hobbies will be supporting the 7-70 as well. Not so much for warranty, but with spare parts and accessories. Specifically, I would like a collector ring. The other items, I have not seen yet, but I'm betting I just have to have them too LOL.
I look forward to hearing from you sir.
CHeerz,
Dave
#48
Senior Member
RE: UMS Evolution Radial Care and Operation
[/quote]
Pete, I purchased my Seidel/UMS 7-70 radial when Hobby King first started selling them. (I believe I was the first purchaser actually)
Although I am still waiting for a suitable airframe for the engine to go into, I was wondering if Horizon Hobbies will be supporting the 7-70 as well. Not so much for warranty, but with spare parts and accessories. Specifically, I would like a collector ring. The other items, I have not seen yet, but I'm betting I just have to have them too LOL.
I look forward to hearing from you sir.
CHeerz,
Dave
[/quote]
Dave,
Yeswe will have parts and spares available for the 7-70 engines already in the field. The collector ring for the 7-77 will fit the 7-70.
Pete
Pete, I purchased my Seidel/UMS 7-70 radial when Hobby King first started selling them. (I believe I was the first purchaser actually)
Although I am still waiting for a suitable airframe for the engine to go into, I was wondering if Horizon Hobbies will be supporting the 7-70 as well. Not so much for warranty, but with spare parts and accessories. Specifically, I would like a collector ring. The other items, I have not seen yet, but I'm betting I just have to have them too LOL.
I look forward to hearing from you sir.
CHeerz,
Dave
[/quote]
Dave,
Yeswe will have parts and spares available for the 7-70 engines already in the field. The collector ring for the 7-77 will fit the 7-70.
Pete