stunthanger.com
Engine basics => Engine set up tips => Topic started by: Randy Ryan on August 28, 2020, 07:28:00 PM
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Hi Guys, been a LOOOONG time since I've been here. My serious stunt days are over due to nerve damage but I still play. I've acquired a ST .60 in nice but disassembled condition. Looking it over and considering using it on a Top FLight Score I have the following questions for those in the know:
1. Fuel Castor percentage, assuming 22% about min.
2. Prop recommendations 2 and 3 blade.
3. Venturi size
Any help would be appreciated.
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Try Search .
But .312 intake , down to .285 for a sub 60 ounce 56 or 58 in plane . the .312 is the Patternmaster size . big thick wing 70- + ounce ship. Unless your Jesus Christ & build it a 60 ounce .
so likely .290 / 295 /.300 ish bore .
The 12 x 6 three blade masters fine , but not light .
A 12 x 6 Zinger or Master - Wood . Best thinned / shaved . to 13 x 5 7 14 X 5 trimmed to 12 3/4 . Cording to Urtnowski .
If youve got a big uugly timber prop , put a few flights on so you can decide wether to loose or gain some pitch , before reworking it .
Whadayagot fora muffler ?
can you do a picture . Theres maybe four distinct series of v 60. or more . The Double Star muffler bolts on the ' No ear ' case- with a custom strap .
5 thou. ring gap , a smidge less . Maybe .
https://rmjmachineworx.com/ or pommy ones on Ebay . Randy ( Aero Products ) has new S Tigre N O S ones at $ 20 .
If the gaps past 8 thou. youll benefit replacing it .
Gudgeon / wrist Pins are a Pia . Polish on 1200 Wt. on glass . a wire through it . Dont ping it off into oblivion holding it with pliers/ forceps .
Theres ST 46 ' maintanace ' drivle , on SEARCH here ( a few pages back on this ' Open forum ' ). But DONT modify it !!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Just Clean imaculately . Heat with heatgun to fit new bearings . A Seal on the front of the Front Brg. C3 spec for clearance .
Maybe one extra gasket on head .
Look at ' Engine Set Up ' page . And read fixed pposts at THE TOP .
H^^
http://www.clamf.aerosports.net.au/newsletters/ACLN/Issue39.pdf
At Your Peril . Early series head , is ' full ' hemi. Narrow squishband . Like 1 m.m. .
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Thanks, good stuff.
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Randy,
If you really want that tiger to run right you should consider sending all the parts to Randy Smith and have him build the engine. He has extensive experience with the ST60's and parts to get it set up for a reliable stunt run. Send him a PM for details. You will be a happy flier.
Best, DennisT
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Randy,
If you really want that tiger to run right you should consider sending all the parts to Randy Smith and have him build the engine. He has extensive experience with the ST60's and parts to get it set up for a reliable stunt run. Send him a PM for details. You will be a happy flier.
Best, DennisT
Dennis,
Randy Ryan can take a case of empty beer cans, melt them down and make an engine. He is just looking for the numbers to hit. Some numbers from Randy Smith may help as you have suggested.
John
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Venturi size depends on altitude, largely. When I lived in Idaho at about 3800 feet, I used a .320 venturi and a 13x5 (sometimes cut down 14x5) single blade prop or a cut down 13x5 3 blade (12.5). When I moved to Puget sound area, altitude, well, sea level, I reduced to a .285 venturi and generally 12x5 two blade or 11.5x 5 three blade. Fuel was usually all caster 22-24% 10% nitro at sea level. 15% at altitude.
Edit: forgot to say that this is for a drilled spray bar, not stock. If you are using stock, then venturi size would drop to .150-.170 for sea level. Bit more for altitude.
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I used a 13x5 (sometimes cut down 14x5) single blade prop.
[slightly editeded]
How did that single blade prop work for you? I have never seen one on a stunt engine. <=
Keith
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>>How did that single blade prop work for you? I have never seen one on a stunt engine<<
Yea, yea. Typo. 2 blade, of course.
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" How did that single blade prop work for you? I have never seen one on a stunt engine. "
Picture of one in flying models or model aviation , on the front of the adamisin Tri Canard - FP 40 . !
ST 60 , usually have cutaway at front of piston skirt to clear the front bearing . ( Like wit my DS 60 LITE does . >:()
or front and back . Seems all but the last ' three window ' port suffer from this . Earlier being more pronounced .
Put piston at TDC and glare up the port .
Being so , doesnt pay to put a entirely restrictive muffler on em , or the blow back can choke the horses .
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Hi Guys, been a LOOOONG time since I've been here. My serious stunt days are over due to nerve damage but I still play. I've acquired a ST .60 in nice but disassembled condition. Looking it over and considering using it on a Top FLight Score I have the following questions for those in the know:
1. Fuel Castor percentage, assuming 22% about min.
2. Prop recommendations 2 and 3 blade.
3. Venturi size
Any help would be appreciated.
Randy use a sealed front bearing when you put it back together, The ST 60 runs very well on a 13 x 6 prop, The venturi size should be .184, if a restrictor then use a 290. Be careful to make sure you have a Needle assembly that does not leak, many of the ones out there do. We used 23% oil half castor, 5 , 10, or 12.5 nitro depending on how hot it was. Use the head as ST made it with the squish intact, do not hemi it out. we used 64 to 65 ft lines eyelet to eyelet, on planes SV11 size. If anything goes amiss I have parts.
Regards
Randy
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Thanks Randy, exactly the info I needed!!