ST2300 conrod, wrist pin end

[Ron Lockhart]

Hi Ed,

I have a 2300 that has been run hard, trying to pull a 13 lb CAP.
Over 100 runs on 17x10 to 16x8, on 15 & 30% nitro 17% synthetic, 
3% castor oil S&W - trying to pull a 13 lb CAP.  100 plus flights, 
and power is still good.  I tore it down to replace rear bearing, 
and didn't measure rod, but it seemed fine.

Another one has been in my Excess, 100 flights or so.  17x10N and
mostly 15%, some 20% S&W.  No problems so far.

Both were Italian built.

Later, Ron Lockhart - See you at Pocono.

>  From: Ed Miller 
>  To: discussion at nsrca.org 
>  Sent: Monday, June 23, 2003 9:41 PM
>  Subject: ST2300 conrod, wrist pin end
> 
> 
>  Any of you folks out there that have been running ST2300's ever 
> experience a short lived wrist pin end of the con rod ?? I have 
> approximately 100 flights on a ST2300 in a Hanson Dalotel spinning 
> an APC 18x8 with S&W fuels 20% to 30% nitro ( 20% oil in all fuels 
> ) and the bushing in the wrist pin end of the con rod is worn out. 
> I'd say there is at least .030" clearance, maybe more. Engine was 
> down about 700rpm on the ground and never really settled on a rpm 
> and acted lean in the air, in verticals it went flat, would no 
> longer haul plane vertically indefinately. This all happened in 
> maybe 5 or 6 flights, went from a powerhouse to a dog. There is 
> only one small hole in the top of the conrod to lube the wrist pin 
> ( approx .040" in dia. ), the wrist pin is fine and measures no 
> wear at all where the conrod rides on it. I'm going to order a new 
> conrod, if the new one only has one hole in it I may enlarge it a 
> bit as well as add a second hole from the bottom of the wrist pin 
> boss on the rod. Luckily I have a 2nd ST2300, just installed it 
> and I'm back to 8800 rpm on 25% nitro with the 18x8 so I'm ready 
> for the Pocono pattern contest. Both my ST2300's are Italian made, 
> the only notable difference is one has a longer crankshaft ( prop 
> end ).
>  Thanks...Ed M.

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