Orion09

My Feedback: (1)

Hey Reverend. I had the same issue with my EVO 777 I got in Nov 2011. Intake valves not closing. Like you I adjusted the valves and the engine fired right up.After running for a summer have no issues with the engine,runs great.BTW using a Microsens onboard glow.Pete

Joel_L

Hi,

So, it's been a while since I've worked on my Staggerwing/Evo735 project. I thought I'd take the engine out for a run today. It starts and runs fine while the plugs are connected, but I still can't get more than 30 or so seconds of run time one the glow power is disconnected. Any things to look for? I've tried fiddling with idle and high speed needle settings to no avail ( HS needle seems very unresponsive up until the point of being too lean ). Has anyone been successful without using an on-board glow driver?

Thanks

Joel

Maxam

My Feedback: (62)

Joel, My experience with this engine is that full throttle the choke area is too large. Try readjusting the engines operation where full throttle is 2/3rds open. The idle might be too rich. Problem is when the idle is leaned out for ideal running the midrange is too lean so lean out the idle to ideal and richen until the midrange is running well. -Tom

warbird51

My Feedback: (12)

Does anybody know if Horizon is going to have the Evolution radial engines on display at the AMA EXPO in Ontario, Ca in Jan.? I think I got my friend all talked into buying a E777.
he wants to see one first hand.

Joel_L

Hi Tom,

That might actually make a bit of sense. I thought I had it adjusted well at one time. Today I notice that the RPM actually dropped off just before getting to full throttle. Maybe I'll make a few sleeves to reduce the intake area as an experiment and see how that works out. Might also see if I have a better carb to put on it.

Thanks

Joel

cymaz

I was running a 24x10 Xoar for a while on a 777 but found it was too much load at full throttle. Changed to a 22x10 got an extra 1000 revs and it seems much less stressed. I have not needed to change the carb, though I took it off added some gasket sealer to all the joints to stop any chance of air getting in. Also used the biggest fuel line I could and used bigger bore brass tubing through the tank to stop any fuel restriction.

Reverend

My Feedback: (3)

good to know, thanks. Looking forward to summer Currently theres cold white stuff in my back yard

I too have a microsens. Almost a must, being patriotic The owner is a very nice and helpful guy.

Rev

slskn

My Feedback: (4)

well I just weighed the Stearman and with out the tank or the engine and the servo for the throttle it is 22lbs. so with the Evo 777 is another 5.2 lbs. and the tank and throttle servo should be around 28 lbs. or so, so with the flying wires and all I hope the Evo 777 will be enough power??, -Steve

Cymas I was going to use the 24x10 Xoar but you are saying the 22x10 is a better choice? thanks- Steve

slskn

My Feedback: (4)

RichardGee Here`s my Corsair in case you have not seen it
http://www.youtube.com/watch?v=q-E9t...eature=related
http://www.youtube.com/watch?v=tAx0G...eature=related
http://www.youtube.com/watch?v=BOOUp...eature=related

Maxam

My Feedback: (62)

Steve, Go with a 22x12 will be perfect. The higher pitch will also fly the plane well at reduced more realistic throttle settings. My older 7-70 turned a 22x10 too fast and would really over rev in the air. SLSKN That corsair is excellent and a bit overpowered!

cymaz

I thought a 24x10 would be ideal but turns at wot 4500... A 22x10 is 5400/5500 and produces more thrust, it doesn't over rev in the air and is still big enough to be quite an
effective air brake on shutting the throttle.
Maybe I have a one off 777 that likes this prop??????

Pull Up Now!

My Feedback: (3)

Supposed to go 6k rpm. But they never tell you exactly which prop of the 3 or 4 they list was the basis for the stated rpm. Probably the 22x12. So you'd think a 24x10 would get within 300 rpm of that due to the reduced pitch. Just to be thorough, I wonder if all your cylinders are firing? Use a non-contact temp probe and check each head while it's running. One not firing will give a much cooler reading. The other possibility is one cylinder has a leaky valve, or too tightly adjusted rocker arm. Just some thoughts...maybe you've already done all that.

cymaz

Don't worry, they all fire. I lost a push rod in flight once so landed because it sounded "odd". Came in on 6 beautifully but I didn't know until I checked the engine over.

Reverend

My Feedback: (3)

cymaz and pull up now

what makes of prop are we talking about? One would not believe the difference between makes. I have a wooden Metts Prop doing 6400 on a FS400, an APC with the same dimensions (20x10) is running with 7200 rpm. Really makes a difference.

Rev

Pull Up Now!

My Feedback: (3)

Yeah, it makes a huge difference. When I wrote "Of course, then never say which prop they used....", I mean both the pitch AND the brand and style. I once ordered and tried some of the large Hobby King props. What a performance disaster that was. Companies often put a lot of money into development, but they fail to address the details when they market their products. Ever notice Spektrum's website lacks any technical details at all on their products. The tabs are there, but they are empty. I once was ordering online robart's new electric retracts and noticed they just copied the same description into every model. I got a free pair of struts from them because of that. For engine rpms, if the company is going to advertise HP and RPM, the customer is going to expect to duplicate that performance so why keep the conditions under which that performance was attained a secret???? We're not talking about park flyers here...some of these products are serious. Another example is Troy Build Models section on Kingtech turbines. They have two lower priced models, one $1825 and another $1725 without detailing what the difference is. In fact, the manuals attached are identical. There's one murky reference to "kero start" but no clear explanation that would account for the $100 price difference. In most cases, the companies are quite unconcerned about incomplete information. I should mention one standout exception is Tower. Their tech notes links are second to none.

TANGLE

Hi All
I thought you guys might be interested in a couple of mods I've done to my 777.The pushrods and rocker shafts are only for cosmetic reasons although it seems a little less rattley.probably just my imagination! The glow connector is practical ,makes it very easy to check for a duff plug.Cheers Tim

Maxam

My Feedback: (62)

Tim, For thought. Yes the original pushrods are ugly but lightweight. Please compare the mass of yours to the originals. If they are heavier they will have a greater moment of inertia and thus put a greater load on the cams, followers and valve springs especially at higher RPMs. -Tom

For all of the propellor concerned guys. My prop numbers posted on this thread are Xoar props. Recall I voiced concern for someone running a 22x10 two blade on a 7-77. That was for a Xoar. Too fast! I do have a real "thick" chinese 22x10 that loaded the engine 750 RPM slower! Many American Moki users where using too small props and were throwing pushrods and ruining their engines.

TANGLE

Hi Tom
Yes they do weigh a gram or two more than the originals,I did some research before making them and it seems that valve train weight becomes a factor in high performance, high reving engines.The weight is similar to those in my Laser 70's which run at about 10,000 ,amost double the radial .The reason I didn't like the originals apart from as you say the're ugly,is the amount of play.While this probably doesn't affect the performance it just dont seem right! The engine is going really well now after having about 4 gallons through it.
It drags my 20lb Jungmeister around with no trouble,loops as big as I like,wont quite prop hang but almost.Funny thing is whenever I take it to the club field they dont really want me to fly it, they would rather I just left it idling so they can all stand around listening to it!!
All the best Tim

Maxam

My Feedback: (62)

Tim, That is great to hear they are working out well. Yes the other ones do have a lot of side to side play. These engines do run well don't they. With your new rods, is your engine mechanically quieter? -Tom

TANGLE

Tom
It seems quieter,hard to say, might be wishful thinking.With the old rods at a low idle you could see them rattling sideways so I guess that movement must make some noise! Tim

slskn

My Feedback: (4)

Hello Tim,
just wondering any chance on producing and selling those push rods?
would like to try them myself, I had a couple of rods on my 999 that fell out, not sure exactly why, but I tend to think maybe they were too loose?, Love those engines though!! I am hoping to get the 777 for my Stearman, but at 28 lbs. not sure if it will be enough power with all the flying wires and all? I think maybe a longer take off roll, but that would be OK...............Steve.

77chickenhawk

Some stearmans had nine cylinders in them also. Just put the nine cylinder in your Stearman

TANGLE

Hi Steve
Hadn't thought of producing these.My equipment is very basic. the set I made for myself took a long time, too long to be viable as a business venture.I have a friend with a modern cnc lathe,but it would only be economic in decent quantities.I'll see him next week and find out his minimum order.
Cheers Tim

Reverend

My Feedback: (3)

ok guys, started breaking in my 7-77. I just love the sound. Not quite as growly as the FS400 at low rpm but it sounds more like a radial in the higher revs.

Hope I am doing it right

[youtube]http://www.youtube.com/watch?v=GZm511EJkFw[/youtube]

slskn

My Feedback: (4)

where did you say you got that sprinkler ring? I need to get one made up for my 777, any chance of making another one for a price? also where did you get the aluminum blocks for attaching the individual exhaust pipes? thanks for the info