Maxam

My Feedback: (62)

Hey Tom, You are within 250 rpm of the maximum of this engine. The prop will unload to beyond that in the air. 4850 rpm on a 24-10 is actually good performance. My older 7-70 turns a 22x10 three blade at 4300 rpm and gives solid performance on my 91 inch corsair. It also unloads to near 5000 in the air....Do not throttle up in a dive!

tsnaylor1964

Thanks Maxam, good advise. What Corsair do you have your Evo 70 in? I want to build the Top Flite corsair or maybe the ARF for my 77 so I am interested in what Corsair you are using and what it weighs. I have to be aware of how heavy I build for the 77 since I don't get quite the performance I would like at the elevation I fly from.
Thanks,
Tom

Maxam

My Feedback: (62)

Well Tom, It is the Black Horse Corsair from Hobby people. It has a span of 91 inches and yet it is 20.5 LBs ready to fly. It has been discontinued. This is very light for this size. The hangar 9 one is 9 pounds heavier and a bit smaller. Flies very well though! Since the vibration of these engines is so low you can build lighter. -Tom

tsnaylor1964

Thanks Maxam. I am still trying to decide which one to get. I am considering the top flite kit or arf, H-9, or the ESM corsair. So many choices, so little time. I really am.enjoying flying the H-9 Cub with the 77 up front. Even though it is not scale, it looks and sounds good. I am surprised though that it is not over powered. I use almost 200 feet for take off on my rough pasture at this high elevation so it is flying very realistically. I get 6050 rpm static before take off but it flies around nicely at half throttle.
I want to take this opportunity to thank you again for sharing your expertise with the EVO radial engines. I learned so much from your posts that my learning curve running these engines was greatly accelerated. My next investment will be the 99 to put on my Howard DGA-15. I think if had a smooth paved runway at a lower elevation the 77 would have been enough. But now I have a good excuse to buy the 99!
Good EVOing,
Tom

tsnaylor1964

Well, Maxam, I committed the cardinal sin with my 77. I put the starter to it before clearing out the bottom cylinders and got a hydraulic lock and I think I bent a rod. At first I thought I got away with it because pulling it through a few times by hand it seemed okay. But when I did get it started it ran poorly, barely able to get 3800 rpms. Then it started rattling like a stuck valve but worsened to loud knocking. I knew I had screwed up big time. What makes me so mad at myself is I am always so careful to drain the two lower cylinders after flying and pulling several blades by hand before using the starter on the next run, but this one time I must have forgotten. And to make matters worse, I Really do know better! I used to fly passager rides in a Travelair 4000 open cockpit biplane with a 300 hp Lycoming 9 cylinder radial and pulling several blades by hand was always the most important part of every preflght. So, I really have no excuse. So it is time for a tear down. I haven't called Horizon yet so I do not know if they will sell internal parts for it or make me send it back for repair. I'll bet that wouldn't be cheap! I guess at almost 70 years old I am not too old to still learn a good lesson.
I do feel better now though, after confessing to the great EVO guru Maxam for my bone head mistake.
Oh well, thanks for listening to my sad tale.
Tom

cymaz

I wrote out a small check list for my7-77. Very useful. May be when the engine is repaired a check list for yours would be an idea.
We all do things sometimes, you have my sympathies.
I had a problem of my 7-77 running lean and not idling slow....turns out ALL the inlet manifold nuts had worked loose!

Maxam

My Feedback: (62)

Oh Tom, Very sorry to hear that. Don't be too hard on yourself. Horizon does stock all the parts. Be sure to give them a call. Their customer service is renowned. Poor engine! Since you are only 70 you are good for AT LEAST 15 more years flying these things. It is true you must pay attention. One day I nearly fell into the prop of a running big radial.........That was a wakeup call. Now I back up on my knees then stand up. Cymaz has a good idea.... just like full size plane checklists. Wow a Travel Air 4000????? Doesn't that have a P&W R1340? I think I read a great article about one that was restored to flying condition. Oops...wrong airplane. But I looked it up. Beautiful plane. Bet it was a joy to fly. -Tom

tsnaylor1964

Thanks for the advise Guys, I feel much better after confessing the the radial brotherhood Yes, I do need to make a checklist and use it! I was never was so careless when I was flying for a living, I was very strict on procedure and with thousands of hours in classic and antique airplanes and gliders I never had and accident or incident. I just got too complacent with the rc airplanes.
The 1927 Travelair was restored several times with different engines in it's lifetime. The Lycoming R-680 was much bigger than the original engine which I believe was a Wright Whirlwind with not near the horse power. It was like flying a locomotive with blinders on, especially with two passengers in the front cockpit waving their arms and acting silly when you are trying to land on a small airstrip that disappears behind that big radial.
Anyway, I am way off topic. Sorry about that. Time to open up the 77 and see how bad it is and put the asp 160 twin back on the cub.
I sure enjoy this forum, hope it stays alive.
Tom

Dad_Roman

wow...so sorry Tom.

Heli-NuBee

So sorry to hear about your engine Tom. My 7-77 was down for a full year and just flew again today for the first time since last October. I was flying my BH Corsair last year at our annual war bird event and the engine lost power. I had to put the plane down in a rough plowed field and it did a lot of damage to the plane as well as knocking out several push rods from the engine. I just got around to repairing the engine and plane in the last few weeks for our annual war bird show. Thankfully, the engine and plane flew well this year and came home in one piece. The engne ran great and all is well. This year I flew all radial powered war birds at the event. The Evo 7-77 powered BH Corsair, an ASP 400 5-cylinder powered military Stearman and a Saito 200 R-3 powered Sea Fury. I got in lots of flights and had a great time. Best wishes and good safe flying.

Heli-NuBee (AKA Roger the radial rabbit)

Heli-NuBee

Sorry, I should have included some pictures of the planes.



Best wishes and good safe flying.

Heli-NuBee (AKA Roger the radial rabbit)

tsnaylor1964

Thanks for the kind words. That is a nice fleet of radial powered aircraft, all three are on my to do builds as well. Especially the Corsair. Did you figure out why the 77 lost power on you? How do you like the ASP radial compared to the EVO's?
My next radial will be the 99 for my Howard DGA-15. The 77 was not quite powerful enough at my elevation.
Tom

Heli-NuBee

Hey Tom, I love my radials too! I had a bad receiver battery that caused the UMS Evo 7-77 engine to go into fail safe on my BH Corsair flight last year. The ASP 400 has done well so far but is not the same quality as the Evo and Saito engines.

Best wishes and good safe flying.

Heli-NuBee (AKA Roger the radial rabbit)

slskn

My Feedback: (4)

Hello Tom
you will like the 9-99 for your Howard DGA, I have the 9-99 on my Ziroli corsair, at 36 lbs. it flies great, and I have the 7-77 on my 32 lb. Stearman and just love these engines, got a lot of flights on both airplanes this season, and now almost ready to put them away for the winter, just acquired another bigger Stearman 96 in and am thinking of another 9-99 for it .Hope you get your 7-77 back up and running.The Stearman http://youtu.be/udRhKyPidM4 and the Corsair 1. http://youtu.be/BOOUpFG2ZZ0. 2. http://youtu.be/tAx0G1IyQ5c sorry about the poor vid from my son.

Maxam

My Feedback: (62)

Roger, Very glad you got your corsair repaired and it is flying again!! Mine is safe and sound too. Just last week I flew my Robin Hood 99 with the nine cylinder. It now has about 150 flights with this engine. It really is a great engine like the 7 cylinder. Read my posts on corrosion prevention of the 99. That large crankcase can hold a lot of water vapor that will condense. -Tom

Heli-NuBee

Hey Maxam (Tom), I really appreciate all of the help and support of the radial engines that you have provided. I have found your advice very helpful. Thanks again for your assistance. I am very pleased to have my UMS Evo 7-77 on the BH Corsair back in operation.

Best wishes and good safe flying.

Heli-NuBee (AKA Roger the radial rabbit)

Heli-NuBee

OK I know that this is the wrong forum for this but I just had to share a picture of my ASP 400 radial engine powered PT-17 Stearman flying at our annual War Bird event on Saturday.



Enjoy, best wishes and good safe flying.

Heli-NuBee (AKA Roger the radial rabbit)

tsnaylor1964

Rodger and SLSKN,
Thanks for sharing your information and the videos and photos. I think the Stearman with ASP 400 is appropriate to share on this forum. I'm not sure where else you would put it.
Took the 77 off the Cub and put the ASP 160 twin back on so I can repair the 77. I hope when I open it up I will find all it needs is a connecting rod.
Maxam, any advise on opening up the 77 that I should know? I think I remember back somewhere on this forum I remember you or someone had done a teardown on one.
Tom

cymaz

This might help....page 2

tsnaylor1964

Thanks Cymaz, I knew there was something back in this forum showing the back open on the 77. I still haven't started working on it yet, with refitting the J-3, putting a larger engine on H-9 pawnee, ranch chores, ect, ect. (It is probably going to end up a winter project) I am still thinking somone posted a repair for ther 77 on this forum but I haven't taken the time yet to go through all the posts. If someone knows about it I hope they will advise me.
Haven't pulled the trigger on a 99 yet but getting close. I think I will buy it from Chief Aircraft because I will save about 150 bucks on sales tax. (sorry Pete) I have been very pleased with Horizon's service for many years and I am a loyal customer but that is too much of a price difference.
Tom

cymaz

If you pull your 7-77 apart, take LOADS of photos as reference

Maxam

My Feedback: (62)

Good advice from Cymaz. There might be posts on repairing an older 7-70 or Seidel in the Everything Radial Engines thread. -Tom

Heli-NuBee

Here are a few pictures of my UMS Evo 7-77 radial engine powered BH Corsair in action at our annual War Bird event this last Saturday. It is not as pretty anymore after the major damage done last year but at least it is back in the air.



Best wishes and good safe flying.

Heli-NuBee (AKA Roger the redial rabbit)

Maxam

My Feedback: (62)

Kinda tragic they don't make it anymore. Sure looks good in the air! I hear the H9 corsair is quite good! -Tom

slskn

My Feedback: (4)

hey Roger looks good, glad to see it is back in the air, look at it this way for now it is what they looked like after a few sorties, a few bullets here and there (repair later).