I ran the ST60 w/ABC Upgrade today for the first time. Must have burned over half a gallon of fuel. I wanted to find out a few things...
One - If it's forgiving.
Two - If it can run well on my standard Powermaster 5%Nitro 22%Oil fuel(11%Synth11%Castor)
Three- If there's more usable power or less than a standard ST60.
Four- If it's consistent from flight to flight.
Report from today:
Plane- Intrepid XL - (700Sq, 60 Oz) 64ft eye to eye lines.
Engine - ST 60 Light case w/ABC P/L, w/muffler lugs, but NOT the K-motor. NO perry ports. Stock head and a .285 venturi in it. Added a Bru-line air filter. GloDevil 300 plug. Running a metal tank on uni-flo.
First Flight - Started with a chip/bin muffler (Noisy!) and a ZingerPro wood 13x5. Launched in 4cycle at about 7600RPM. once in the air it settled into a deep 4 cycle and was a little soft on power and lap times were 5.5 Probably could have tweaked the needle and/or put in a bigger venturi but moved on to...
Second Flight - Switched to Bolly 12.5x5.5 CF prop. Launched cackling back and forth into a 2 cycle/4cycle around 8200RPM in a cackle. Backed off to a mean sounding 4 cycle in the air. Much better line tension, Lap times around 5.3 laps. Beeped into a 2 very briefly in the uplegs of some maneuvers. Had a fair 4cycle slowing effect in the downlegs. Great run.
Third Flight - Switched to Tube muffler (Old Style Enya) Much quieter, maybe robbed a tiny bit of power, but worth it. Same Bolly prop, tweaked needle to same RPM. Had a great 4 cycle slowing effect in the downlegs. Awesome run.
Fourth Flight - Let buddy Wayne Smith fly it while I watched. Saw my wing popping up. Took out a 1/4 Ounce tip weight. He loved it. Sitting next to Owen Richards who commented that he thought it sounded a lot like a AERO PA piped motor with the Enya muffler.
Fifth Flight - Wayne asked if I had any 3 blade props with me, he thought they enhance the turn (I agree). Put on a Bolly 12 x 5.25 CF 3 Blade. Tuned up to 8200 RPM in a fast cackle. Stayed a little fast in the air, 5.0 Laps in mostly a 2 cycle, but not over lean and still leaving a healthy smoke trail.
Sixth Flight- Backed off 200RPM to 8K RPM. Took off in a cackle, backed off to a deeper cackle, but not a solid 4 cycle. In level flight it would switch from 2 to 4 from upwind to downwind. A very good run. 5.2 Laps. Good tension. Probable a good windy weather setup. Wayne was right, the corner did clean up nicely.
Seventh Flight - Same - Just more practice and to see if motor would remain consistent with same setup. It did. Owen comments "It runs like a watch".
Eighth Flight - Same - More of the same. As the day wore on and the ambient temp came up, I had to turn in the needle to maintain the same launch RPM.
Ninth Flight - Same - Kept subtracting fuel, as I've been getting over-runs. Down to 4 ounces now. Just about right. Yikes she's stingey on fuel. Wind is coming up and choppy, she just plows through.
Conclusions & Observations
One - I like it!
Two - It seems able to run well with different props and mufflers, very forgiving. It resisted wind up in the wind very well with all props tried.
Three- There would appear to be a lot more power to be had by opening up the venturi and reducing exhaust restriction. I'd say it's right on par with a stock ST60 for power, but more refined. Much more efficient burn, maybe due to the engine being hot in all the right places when running? No sign of flame outs even when rich at low RPM.
Four - It starts easy and I was spinner starting it back against the compression with a snap of my fingers easily.
Five- It runs well on and can be very economical on Powermaster 5%Nitro 22%Oil fuel - 4 Oz to do pattern.
Interest - I paid for the motor and ABC P/L, as well as an extra P/L set. I have no affiliation with Brian Garnder nor have any ecconomic ties.
Product Cost - $90.00 for Piston and Liner
Availability - Contact Brian Gardner - [email protected]