Maxam

My Feedback: (62)

There is a video on youtube where a gentleman runs his 7-35 and replays the video in slow motion. The sound is very interesting!
evolution 7-35 slow motion is the title.

UMS-EVOLUTION

Dear Maxam

Can you forward your emails to [email protected]

Thanks

UMS-EVOLUTION

Tom

Regret for the inconvenience caused , We at UMS Technologies , not received any of your emails. Please forward them once again , i will investigate and take appropriate action.Please let me know what spare your require , Your required part will be couriered immediately at free of cost.

Thanks for understanding.

Ramaraj

Fulcrum2111

Hello I plan using a biela 18x8 semiscale (picture) do you think the evolution 7-35 stock with methanol will handle it? will it get to the 6000 rpm?

Linkan2

A propeller 18x8 then you should probably have more rpm.
I have flown with a 18x8 Graupner with 7000 rpm.
6000 will probably be a little weak.
now I have an APS 17x10 giving 6400 rpm.
It is after I have switched to a carburetor from Saito 120r3
Lars

Fulcrum2111

how many rpm are good for keeping this engine happy? between 6000 and 7000? I feel the engine has not a lot of thrust and my experience is that biela props load more engines than other propellers.

Maxam

My Feedback: (62)

Ramaraj, I already have the part and it is installed as discussed on the thread. I will contact you privately too. -Tom

Maxam

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Fulcrum, the 17x10 as Lars said is very good for many applications. Your prop is in the range so try it!

badangle

My Feedback: (1)

I have installed. New carburetor. And love the change....my confidence in the engine has given me hope my stearman will fly in the spring.thanks to Maxam and the rest of the forum...have 2.5 gallons of fuel run through engine...starts right up...idling great....still sometime lower cylinder loads up....but still running rich a bit...for break in....7-77

Maxam

My Feedback: (62)

Hey if you have 2,5 gal of fuel through the engine you can lean the idle and the top end. I suggest adjusting the top end with the full throttle setting at 3/4 open on the carb and idle such that the engine stays running for quite a while. If too lean the engine will run quite awhile and then quit. I hope to see photo's of your Stearman. -Tom

badangle

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Thanks again Tom...my tachometer seems to fluctuate and getting a. Good reading is tough...any help tuning this beauty will be appreciated. ..

Maxam

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Could be the suns angle. Try using your ears rather than a tach.

badangle

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Tom. .I have constructed a test stand that I can rotate 90 degree. ..180 and 270....would it make a difference if engine was upside down as far as. "Lower" cylinders are concerned???

Maxam

My Feedback: (62)

I do not think so. What is your oil content in the fuel?

badangle

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15% nitro, 18% oil cut 50/50 with methanol. .so 9% oil

Maxam

My Feedback: (62)

Just about ideal!

badangle

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Got the recipe From you..

CannonFodder

My Feedback: (23)

Hi All,

I am building a Yellow AT-6 and putting the 7-77 in it. I have concerns about cooling, the cowl has a big opening but the exit is very narrow about 1/2" around the cowl. I have these pics I will have to get a picture of he cowl on with ou the engine so you can see the engine compartment exhaust. Comments???

cymaz

Block off the gaps in between the cylinders, leave about 1/16 around the pistons. Your exit for the warm air should be 3x the entry for the cooling air.

tih

My Feedback: (1)

When blocking the gaps between the cylinders, be sure not to block off the exhaust pipes. Insufficient cooling of those will lead to burnt exhaust valves.

CannonFodder

My Feedback: (23)

cymas & tih,

Thanks for the information, you sound like you have done this. As I am new to radials can anyone give an example with pictures of exactly what this might look like.

Mark

cymaz

Gooooogle says....
http://www.modelairplanenews.com/blo...etailing-tips/

CannonFodder

My Feedback: (23)

Don't you just love the internet. There is all kinds of info on making baffles. Sometime when your brain is hurting from thinking on a subject, ideas as simple as a general search of the internet never rise to the top. :-)

Thanks, cymaz

CannonFodder

My Feedback: (23)

Hi All,

I have about an hour break in run time on my 7-77, so far so good. I have seen all your post on the improvement you get when you change out the carb to the OS carb. This Christmas with all the savings going on at tower I purchased the replacement OS carb> This got me thinking about how well does this engine draw fuel and would there be the need for a fuel pump. I really do not want to pressurize the tank with exhaust and my tank will level with the carb. Thoughts???

cymaz

TBH , I may be lucky but I have always used the stock carb with exhaust pressure and the McDaniels glow system...utterly reliable !