Ted62

My Feedback: (2)

Well, it finally happened - I had a fairly severe crash - I wiped out the fiberglass center section of the H-9 Corsair I have been toying with for over a year now due to a 7-77 engine flame-out at a real bad time (on take off). To make matters worse (the reason for posting here), on impact, one of the cylinders was torn off the engine bending and breaking the corresponding con-rod. The cylinder hold-down screws were torn out of their aluminum holes taking the aluminum threads with them. Do I junk the engine (ouch) or somehow get parts. This really hurts, but, at least I wasn't a passenger! Thanks for any and all advice.

BobH

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I'd at least get an estimate of the repair..

j lauria

Tom,
I believe that I shall have to take you up on your offer to test my engine. I tried to start it again after a friend adjusted the valves. No start. Ignition system lights up the plugs. Raw fuel comes out of the exhaust. I tried injecting fuel thru a glow plug opening, no response. All of the rocker appear to be operating.

I am taking a break from flying to go fishing. If you are still able to test run it, I can send it to you in about two weeks. I need a shipping address. I will of course include the return shipping.

John

Ted62

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Thanks, Bob - I wonder if Horizon handles engines that have been obviously crashed? Guess I'll give them a call.

Maxam

My Feedback: (62)

Hey John, I sent you a private message. -Tom

CannonFodder

My Feedback: (23)

Hi Everyone,

Tom,

I am glad you created this thread very helpful. I am looking into purchasing a 7-77 for an AT-6 Texan, its a used engine that has not been completely broken in. I have a couple questions; 1: You mention old vs new carb that deals with the richer setting at idle. I have the serial number to the engine I'm considering, is there a way to determine if this engine has the old or newer carb? 2, when breaking in the engine the original owner used 5% nitro & 9% oil during the process, do you think the nitro had an adverse effect on the engine?

Any help is much appreciated, Mark

BobH

My Feedback: (2)

Ted,
Horizon will do repairs. My bud has sent his Saito 325 in a few times for repairs.

Maxam

My Feedback: (62)

To Mark, I use a higher nitro amount! Go to the early postings about prevention of corrosion! -Tom

Pretendpilot

all,
... i have been running-in my 7-77 on a stand, nad have just noticed that the #1 cylinder has a leak between the head and cylinder. it is bubbling and leaking oil on the rear facing part where the two pieces meet.
... i am missing the summer trying to get this engine in my plane, and dont want this engine to go away for another month(s), causing a complete flying season miss.
.
my questions:
* has nayone else ever seen this? (btw, i wouldnt have noticed except that i happened to look at the spot once (if it was in the plane / under a cowl i wouldnt have seen it).
.
* has anyone ever disassemble a cylinder/head? i tried to 'tighten' the head, but it seemed rock solid (it was not loose). i dont know if they lock-tighted the things together or what.
.
.
i noticed that a copper washer is sold with a head (web search), so there is (should be) a sealing washer in there, indicating that the head and cylinder are probably screwed together?

Maxam

My Feedback: (62)

Yes the head is screwed onto the cylinder, just like many full size radials. This has been a major fault with the Gas 160. I would go ahead and fly the engine and just ask them to send you a new cylinder/head assembly. Pretty easy to exchange cylinders, just do not over tighten the cylinder base screws! -Tom

Linkan2

Hello
you can try to heat up the copper gasket.
that sits between the cylinder and the cylinder head so glowing.
then the copper is softer (if there are other injuries)
Lars

Fulcrum2111

Hello today I have tried to start the engine it is a 7-35 evolution with the rcexl ignition, running on methanol. I have used a custom blend with 6% oil and 6% nitromethane and 88% pure methanol. I set in the day the timing to 30 degrees BTDC. I first tried by hand but couldnt start it. The engine primes well, though. Then I tried a starter. I have set the low needle 2 turns out and the high 2.5 turns out as the manual states. When I turn the engine with the starter I hear it pop and smells like some burned oil, the exhaust and cylinders are warm but the engine wont startand keep turning by itself.
Can you help me with the problem? Is it possible I have set the timing incorrectly or I am missing something else?
Regards.

CannonFodder

My Feedback: (23)

Hi All,

Well I bought a 7-77 and I had a chance to run it today. I was amazed at how easily it started by hand. I am running a blend of Klotz 8% super technniplate and 92% methanol. The person that owned it before me ran 10% redline and 90% methanol, he had a total of an hour running with that mix. I have the Electrodynamics EDR 103 glow driver once the engine was primed it started on the second flip by hand. Here is a picture of the engine and what its going in. The plane is a Yellow Aircraft AT-6 Texan should be a good combination. I have only gotten through about 17 pages of this thread, I think I have the basic down on the maintenance, oiling after finished running for the day after it cools then checking it the next day. I try to run it every time I go to the field to finish the break-in. Must finish the AT-6! Does anyone know if the EDR glow driver uses the same method of igniting the glow plugs as the Sonic Tronics glow driver by pulsing voltage to the glow plugs.

slskn

My Feedback: (4)

the EDR does not pulse it is a constant glo on, I usually put it on a switch to turn on when starting and when warmed up a little I flip the switch off and fly,I never keep it on glo, only goes on again when starting!! works well!! the AT-6 looks great and should be a great combo!!.

BobH

My Feedback: (2)

Maybe its here in the threads but?? does anyone know what size the spark plug is on the Evo 160? It seems likes its 15mm deep well socket but I'm not sure and I want to test the ignition.thank you.

BobH

My Feedback: (2)

Found out the answer... it takes a 14mm deep well socket.

Fulcrum2111

Hello after solving my problems with the 7-35 I adjusted valve and spark plug clearances and running methanol with 5% synthetic oil and cdi ignition I get 8000 rpm out of a menz 18x6 propeller. I get 7000 with a 18x8 mejzlik and 6400 with a 20x6 falcon wood propeller. The pull with the 18x6 is impressive but i think it is too much rpm so do you recommend the 20x6 18x8 or the 18x6? In the manual states practical rpm 6300 and max 6700...

Maxam

My Feedback: (62)

I would keep the RPM's down further.An 18x10 or 20x8. The 18x10 would be closest to ideal. The plane will still fly at lower throttle settings so it will be more realistic. _Tom

j lauria

Chorner,

My 9-99 needs to be rebuilt. It needs new rings and bearings. I received a prompt E-mail response from UMS India and am thinking of sending the engine directly to them. I wasn't very happy with the response from Horizon. Any thoughts?

John

Maxam

My Feedback: (62)

Hey J Lauria, As we discussed, I recommend sending the engine to India. Contact them and see what to do. -Tom

Linkan2

good evening to you
I have been using the exhaust ring from Kelo 2 pieces.
Both have vibrate apart and copper gaskets too.
does anyone have the same experience as me.

It is mounted after the manual.
you should invest in one from UMS ??
engine is a 7-35 who have about 13 hours
Lars

j lauria

Hi Tom,

Your advice has been been invaluable. I am in the process of getting the engine ready to ship to India. UMS India responded promptly to my inquiry so I am happy with their responsiveness. I will keep everybody posted as to my experience.

John

j lauria

I just got a quote from UPS to send my 9-99 to India. $625 each way with $100 worth of insurance. The shipping costs plus the anticipated cost of parts and labor has just eliminated my enthusiasm for this engine. The On board ignition system with two 5000 MAH batteries, Pegasus carb and CH adapter plus the Keleo exhaust ring have run the total cost of the engine to $2000 plus. I may be wrong but further investment does not seem reasonable in view of the problems I have encountered.

I have replaced the 9-99 radial with a DLE 60 twin temporarily so I could fly my Ziroli Stearman. Result, I was able to eliminate 17 oz of ballast in the tail and six pounds overall. The plane flies beautifully with a 22X10 prop turning at 7000 rpm, all for $550 complete. It doesn't have the great looks of the radial nor the pleasant sound but it does have the bullet poof reliability I have come to expect from my gas engines. I think that it has found a permanent home.

.

TimD.

My Feedback: (207)

Very SAD to hear. I have 3 of the 777 myself and two Moki's.

Maybe you can sell it off as a parts engine to recoup some of the losses. Also how much run time did you have on it?

My most used one has 4-5hrs of run time/ 8-10 gallons on it.

chorner

j lauria, was fixing it yourself not an option I guess?

Purchasing a new set of rings from UMS as well as bearings doesn't take long to do. I can see how sending the engine into UMS is cost ineffective; I wouldn't for that cost either, however I would strip mine down and do the work myself.

Why not rip yours apart to get comfortable with it since you're not using it now anyhow? I replaced rings on mine, and actually installed a 2nd set of rings per cylinder and a few other 'mods' to the engine. I have 2 of them as well... one as a parts engine. You really would be doing a disservice and tossing money in a bin to not give it a try at least!

These radials will last a good amount of time, but of course takes more maintenance/patience than a 2 stroke gas engine. That's just a given