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Author Topic: Wrong Super Tiger?  (Read 1879 times)

Offline Ward Van Duzer

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Wrong Super Tiger?
« on: June 07, 2007, 09:35:17 AM »
Some time ago I bought a ST .35 flat topped piston engine NIB at the Perry Ga. swap meet. Though I had a (reasonably) hot combat type engine fo 30 bucks. Later installed it in a Gotcha 500 airplane with a Streak styled fuse, etc. (See pic) Thought I'd have a semi hot sport plane for windy days! But, alas, apparently I have the wrong ST .35! This is a ball bearing version with the 35 stamped in a circle inside a large "V". (See pic). Ok, It's a little quick, and smooth, but not up to what I had hoped for.

Maybe some of you combat types (Mr. Phil?) can help me get it running a little quicker...It runs on a tin (profile/combat) tank, 9-6, 9-7 APC prop, and 10% nitro with a mix of mostly Castor with some synthetic added (about 25% oil overall).

Or did I just get the wrong engine!   n~

Ward-O










 
I hate spelling errors, you mess up 2 letters and you are urined!

Don't hesitate to ask dumb questions.
They are easier to handle than dumb mistakes!  Ward-O AMA 6022

Offline Mike Greb

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Re: Wrong Super Tiger?
« Reply #1 on: June 07, 2007, 04:26:14 PM »
Looks like you have a G21-35. This is the combat motor .To go a little faster  more nitro, less oil, perhaps a apc 8-8.   Back in the day we used anywhere from 25 to 50 percent nitro. To go much faster a pressure venturi and bladder tank. Word of warning though.  The crankshaft is only 12 mm and the faster you go the shorter the lifespan of the crank. Lots of luck finding a replacement crank. Back in the early 80's some top combat fliers kept a Flight log and replaced the crank on a regular basis.

Remember this is about a twenty five year old motor or older.  Some modern 35-37 ball bearing sport type motors can probably outrun it with a little bit of work.

The old super tiger that you have is actually now a pretty good sport motor run on a setup like you have now.

Offline Ralph Wenzel (d)

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Re: Wrong Super Tiger?
« Reply #2 on: June 07, 2007, 06:37:10 PM »
If you'd like to sell the ST, please email me. I'm hoping to fly Speed Limit Combt with a bunch of old G21.35s on the Guillotine. It was a nice combo 45 years ago..

As Mike said, on 40% Nitro they went pretty well. I plan to limit that to 20% Nitrro, just to aid longevity.

Sounds like you had expected to get the old ST C-.35, which was a plain-bearing engine of the same vintage. A good engine, but it had the startling habit of starting without the battery being connected.
(Too many irons; not enough fire)

Ralph Wenzel
AMA 495785 League City, TX

Offline Ward Van Duzer

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Re: Wrong Super Tiger?
« Reply #3 on: June 07, 2007, 07:22:30 PM »
Yup! one of the things I was told by a local speed merchant down here was that the plain bearing version was the "hot" one. I just don't know, or really care. I just want a "semi hot" sport engine for this airplane...

What do I need to do?

W.
I hate spelling errors, you mess up 2 letters and you are urined!

Don't hesitate to ask dumb questions.
They are easier to handle than dumb mistakes!  Ward-O AMA 6022

Online Paul Smith

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Re: Wrong Super Tiger?
« Reply #4 on: June 08, 2007, 04:41:56 AM »
That unit should clock about 85 MPH, assuming the engine is still healthly.  No need to dump nitro to it, unless you need to get 2 MPH faster than the next guy.

Remember, it's a used engine, and it might be used up, that's what old combat dudes did to G21's.
Paul Smith

Offline Ward Van Duzer

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Re: Wrong Super Tiger?
« Reply #5 on: June 08, 2007, 01:04:00 PM »
Actually, it's near new! I bought it new in the box! A little (1/2 hr.) run in, and about ten flights!

That's it. What's it worth?

Can I swap it for a new/near new T.T. .36?


W.
I hate spelling errors, you mess up 2 letters and you are urined!

Don't hesitate to ask dumb questions.
They are easier to handle than dumb mistakes!  Ward-O AMA 6022

Online Paul Smith

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Re: Wrong Super Tiger?
« Reply #6 on: June 10, 2007, 05:44:53 PM »
I dunno,,,

I used to buy new G21/35's $18.

What does a new TT 36 cost? And what is is used for?

-------

PS: The late, great Bob Baron won AMA Stunt at the Nats with a G21/35.
Paul Smith

Offline Ward Van Duzer

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Re: Wrong Super Tiger?
« Reply #7 on: June 11, 2007, 02:31:36 PM »
That could be because there were no Aero Tigers way back then....


W.
I hate spelling errors, you mess up 2 letters and you are urined!

Don't hesitate to ask dumb questions.
They are easier to handle than dumb mistakes!  Ward-O AMA 6022

Offline phil c

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Re: Wrong Super Tiger?
« Reply #8 on: June 17, 2007, 06:09:38 PM »
I'd try a 9/6 prop and drill out the venturi a bit.  That looks like a homemade venturi.  The stock G21 suction venturi had an id of about 3/16 in.  You can easily go another 1/32.  If you really want to go fast, run crankcase pressure to the tank, put in the pressure venturi, which is about .375 id, and use an 8/7 or 8/8 prop.  The crank won't last terribly long though.  The id of the crank needs to be either edm machined smooth or ground and polished inside.  Also the machined edges on the crank port need to be ground smooth and polished to help prevent fatigue cracks from starting.
phil Cartier


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