From: hurvitz@oscar.UUCP (Dennis Hurvitz)
Newsgroups: rec.aviation.owning
Subject: Re: Another cylinder cracked!
Keywords: Mattituck O-360 Overhaul
Date: 7 Jan 93 18:50:24 GMT

In article <1993Jan6.205555.5427@eco.twg.com>, reece@eco.twg.com (Reece R. Pollack) writes:
> 
> It seems we've cracked another cylinder in N6151H. Since this is the
> second one to go in this plane, I'd like to solicit the opinions and
> experiences of other Rec.Aviators.
> 
> cylinder is cracked from plug to plug, and is missing a chunk too. This
> is at 1100 hours SMOH.
> 
probably the rule, rather than the exception.

i just topped the rear two cylinders in my cutlass. this bird has 850
hours on a firewall forward. it is also in a flying club. i have a few
comments.

first off, firewall came thru and immediately fed-ex 2 cylinders to my
mechanic. they were warrantied, and the cost wasn't so bad. the valves
(exhaust) in both cylinders were stuck open. there is a little followed
service bulleten from lycoming calling for cleaning the valve stems and
polishing the guides every 400 hours on the o-360. it likely also covers
the io-360.

the fact that your airplane is "not used for training" while operated on
your leaseback, is basically smoke. you really have no idea what they're
doing to your bird. granted their intentions are almost always
honorable, but the reality is, and forgive me fellow netters, my
experience of operating a large flying club for 4 years has jaded my
attitude..  i digress, the reality is most of the pilots flying your
airplane really don't know much of what the hell they're doing. ask
5 of them how to start your fuel injected engine when hot, and you'll
get 5 different answers. i rest my case..

BUT, the cracked cylinder issue is interesting. the rear cylinders
typical suffer the worst abuse. they get the least amount of forced air
cooling. i'll wager those rear cylinder saw a bit of shock cooling over
their 800-1000 hours...

PERHAPS, the most significant issue however is one we're all faced with.
HOW DO WE KNOW HOW MANY TOTAL HOURS THOSE OVERHAULED, CHROMED, OR
CERMACHROMED CYLINDERS HAVE REALLY SEEN ? truth is, we don't. seems that
they just keep plating,grinding,and overhauling until they are worked
out of limits, or they are cracked beyond repair...   and there it is.

this points to buying strictly factory new cylinders if you want the
peice of mind. 


dennis hurvitz
cutlass n5271u
duchess n6009k
mei






> Since this happened so recently, we haven't had a chance to involve
> Mattituck in this one yet. If people are interested, I'll post details
> as they become available. We haven't been all that happy with our
> mechanic recently, and are considering switching to another.
> 
> We're beginning to wonder how long it's going to be before we lose
> another cylinder. This airplane is our primary IFR trainer, and I'd
> really hate to lose a cylinder in IMC. So far, both incidents have
> occurred in daylight, within gliding distance of an airport, and in
> VMC, but we're worried that this kind of luck won't last.
> 
> Just to forestall some of the questions I know are coming, here's a
> little background on the plane, again from memory:
> 
> * This aircraft flies an average of 30 hours per month; a bit more
>   in the summer and a bit less in the winter.
> 
> * The oil is AeroShell 10W-50, changed at 50 hour intervals. An oil
>   analysis is performed at intervals, but I haven't seen the results.
> 
> * No student training is done in this airplane -- all pilots are licensed.
> 
> * The compression test at the last annual was nominal, and 100 hour
>   inspections are performed.
> 
> * The engine seemed normal for at least the 3 tach hours prior to
>   this incident. This I know first hand, since I flew those hours.
> 
> Anyone have any ideas? Comments? Questions? Suggestions?
> 
> --
> Reece R. Pollack
> PP-ASEL-IA -- Octopus Flying Club (based GAI)
> email: reece@eco.twg.com


Newsgroups: rec.aviation.owning