From: doug@alliant.com (Doug Bloomberg)
Subject: Re: prevalence of engine failures
Organization: Alliant Computer Systems
Date: Wed, 29 Jul 1992 16:48:23 GMT

In article <19810@leadsv.UUCP> netnews@leadsv.UUCP (Leads Network News) writes:
>From: claude@leadse9.UUCP (Claude Goldsmith)
>Path: leadse9!claude
>
>>I have just learned that my Clubs Piper Archer II  PA28-181 just had a
>>unplanned landing in a field in Montana. ....
>
>>The plane is at this moment being trucked to a local airport and AVEMCO
>>has indicated that they will buy a new engine! 
>
>If AVEMCO really does buy him a new engine it is a strong positive
>testimonial for AVEMCO.  When my Mooney suffered a catastrophic engine
>failure many years ago due to a connecting-rod failure, the insurance
>company would not pay for the engine.  They argued that such a failure
>is "normal wear and tear".  I had the policy reviwed by an attorney
>and he agreed with the insurance company.  The Mooney was landed on an
>airport without any additional damage.
>

I had origanally posted  the Piper Archer II engine failure.

At first I had been told AVEMCO would buy an engine.
THIS WAS wishful thinking on the part of the local insurance adjuster 
and our club treasurer.  Claude is correct, the dead engine is "normal
wear and tear" item.

We flew up to retrieve radios and logs Sat. The 75 hr pilot put it down
into waist high weeds and clover. No dents, scratches, or other airframe
damage.  I did note that No.3 connecting roday have seperated. Two holes
in the case opposite No 3 cylinder. The engine was movable (not frozen).

The good point (maybe) is that I have dibs on the old engine. I can use
parts for my RV-6.

A point was also made about the failure of Lycoming Cams. That could be
a very valid point. We bought the plane in March, with 620 hrs total
time. I looked at the logs and some years had only 15 hours time on the
tach. If I had been present when the decision was made to buy the plane
last March, I would have made exactly the same protest, there might be
cam problems down the road. But the majority of our group is United and
Continetal Captains.Which really means that they don't know piston engines.

For you wondering about what the heck I'm talking about. Lycoming engines
have their cam shaft located above the crankshaft. Here it is out of the
oil which accumulates in the oil sump when the engine is not running. 
Also, being above the oil  the the cam tends to dry out (oil drips off
and will evaporate off the cam) So... when you start up after a long
period of non operation you have a very good chance of excess wear on
a cam lobe. Past experiances by Lycoming users show that running their
engines every two weeks of so prevents this problem of dry starts.

There is more to this such as the methods that Lycoming uses to harden
their camshafts and lifters. The posibility of sticking valves etc.
Continental engines do not usually have this cam problem.Their cam is
buried below the crankshaft, submerged in oil when the engine is not
running. Also, Cont. cams have a different hardening process which also
prevents cam lobes from being wiped out. 

When we get the engine apart I will post our findings.

Doug Bloomberg  (doug@alliant.com)
Littleton, CO

RV-6 Builder