From: N20087 <n20087@yahoo.com>
Subject: [LML] Piston oil cooling jets
To: lml@lancaironline.net
Date: Sunday, October 7, 2012, 12:34 PM
> Folks

This is addressed to the hard core engine experts on the
forum.  I would love your feedback on this I am considering having my io360 crankcase modified so that
I can install piston cooling jets which are standard in
200hp engines.  The reason being, I have had to take
aircraft out of service twice, once at 80 hrs and now at 160
due to lousy break-in and high CHTs. I have done all the
obvious stuff such as plenum, timing, plugs, flowed the fuel
servo to the rich side, baffles etc.. I am running 9:1 eci
cerminil cylinders and they will hit 430 on climb out. 
They went to 450 twice in the initial break-in. They will
run 370 in 75% cruise and 340 lop

All this aside, the pistons at 80 hrs (both times) were
coated in dark varnish under the crown and the top of the
crowns were heavily carbonized from oil blowback

I am just getting tired of it and don't want to pul the
engine apart again anytime soon after this downturn

So,,,I am wondering if anybody has any experience or data
concerning the cooling benefits of the piston oil
nozzles.  Ie is it 5 degrees or 20+

Also, I am debating whether to split the crankcase myself or
take the closed case (jugs and every accessory removed) with
con rods still attached to the local shop and have them
split the case, do the machining and reassemble.  The
shop is very very reputable but of course the cost will be
higher if I get them to do the breakdown and reassembly As another cooling remediation measure I was thinking of
opening up the cowl inlets to 4 inches but a little
reluctant due to the increased drag and limited
benefit.  I added an electric cowl flap by the way and
achieved only a 2 degree CHT improvement in climb at 130
knots Go figure!

Again, any feedback on my plan here would appreciated Thanks in advance Tom --
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