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Old 21st Jan 2014, 00:23
  #85 (permalink)  
Jabawocky
 
Join Date: Jul 2007
Location: in the classroom of life
Age: 51
Posts: 6,879
Deadstick

Just to clarify then.
1. Caltex 98 is fine, but it will increase CHT over Avgas (100MON or about 110RON) The shandi mix of 98/avgas is fine and I agree with the blocking 91UL/avgas.

2. The piston ring sticking with avgas is a known issue, should have been helped with the latter piston design with wider grooves not the std groove of a ULP auto engine. I have no idea how successful this was or is.

3. Seems CHT is a major contributor and I wonder just how well the cooling works around the whole area of the cylinder.

My opinions.....OK...these are WAG's but from a semi reasonable position to comment. Oil changes every 25 hours and not 50. Keep the indicated CHT (not necessarily the entire head) below 300 as there may well be parts that are much higher. Head torque checked every 25.

Climb speeds need to be nothing like the range of Vx or Vy and my suggestion is take Vy and x 1.32. Good reason for this, but not related to the topic but it will give you the climb sped I feel is likely to yield better results.

Email address is on its way. Probably not much more I can add here.

Recap gents,
the 230 suffered a cylinder head overheat on number 4 only no valve seat movement or valve failure, the subsequent bulk strip at the factory, revealed the bottom end was destroyed by the original inadequate thru bolt design.
How does a run away CHT relate to the bottom end being destroyed? Unless the rer was a destroyed piston and the debris went through the places wrecking everything else. Or magically the heat was channelled through one pot? Does not add up does it?
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