There's a Continental service bulletin, M84-15, that says that the
compression needs to be referenced to the "Master Orfice Tool," part
number 646953-A. They sell the tool, it's a bar with female spark plug
threads at each end and a calibrated orfice in the middle. The idea is
that you hook up the compressor to it and with the regulator gauge set
to exactly 80 psi, using the tool, the cylinder gauge ought to show 40
to 50 psi. If it doesn't the differential tester is out of calibration
and can't be used.
You'll have to refer to the service bulletin for more details.
Back about 20 years ago, mine cost around $40. Nicely made tool in a
plastic case. Not something you'd find at Home Depot.
David Paule
----- Original Message -----
From: "Dan Yocum" <yocum@fnal.gov>
To: <pietenpol-list@matronics.com>
Sent: Monday, November 16, 2009 5:53 AM
Subject: Re: Certified Engine question
>
> Ben,
>
> I am not an A&P, but during a conversation with a local small
> Continental demi-guru, he mentioned that he found a document that says
> that the compressions on an A-65 arn't considered out-of-spec until
they
> hits 8lbs. Count 'em. 8. That sounds unbelievable to me, so check
> with your local A&P or drop Harry Fenton a line - he *is* Mr. Small
> Continental engine guru, and is generally pretty responsive to such
> questions. Looks like he's got a full section on compressions in his
FAQ:
>
> http://bowersflybaby.com/tech/fenton.htm#compression_limits
>
> Cheers,
> Dan
>
>
>
> Ben Charvet wrote:
<bcharvet@bellsouth.net>
>>
>> I had installed a used Continental A-65 on my recently finished
>> project. In the process of getting ready for my airworthiness
>> inspection with the FAA we did a compression test and found one
cylinder
>> to be low(35/80). The engine ran great but did have a lot of
blow-by.
>> Oil pressure was appx 25 at idle and mid 30's above 1200 rpm. I
pulled
>> the weak cylinder and found that the #1 rod bearing has excessive
wear.
>> I mean like you can do the push pull thing and feel slop. The engine
>> came with log books, was 1500 SMOH, but I was hoping to get through
>> phase 1 flight testing, since the logbook compressions were all good.
>> Basically I understand now the engine needs a total rebuild.
>>
>> So here is my question.. I am no an A&P, but have lots of experience
>> rebuilding engines of both air cooled and water cooled all in
>> automobiles. I'm confident I can do this myself. I already had
started
>> overhauling parts prior to finding this engine and have a rebuilt
case,
>> crank, and cam. I've been told that to call my engine a Continental
>> A-65 and leave the data plate on, that all this work would need to be
>> signed off by an A&P. I have a certified Sensenich wood prop
installed
>> and was hoping for a 25 hr Phase 1. All the paperwork is already
sent
>> in the the FAA and the inspection is scheduled for Dec 4. So if I do
>> this work myself , do I call it a Ben Charvet 65 HP? Bet that would
>> drive the insurance folks nuts.
>>
>> I also have one other option. I have my trusty old Baby Ace that is
in
>> bad need of a restoration, but has a 350 SMOH A-75 with a McCaulley
>> metal prop (would help my W&B). I was really hoping to keep flying
the
>> Baby Ace right up till my first flight in the Piet, but I could just
>> swap that engine on, change the paperwork with the FAA, and rebuild
the
>> A-65 at my convenience while restoring the Baby Ace at some later
date.
>> I was really hoping to sell the Baby Ace, but its not worth more than
>> its engine/prop anyway.
>>
>> This is without a doubt the longest post I've ever made, but this is
a
>> tough choice.
>>
>> My main question is: If a non-certified mechanic rebuilds a
certified
>> engine, can you legally leave the data plate on? Is it still a
>> Continental A-65 legally as far as the FAA/Insurance companies are
>> concerned?
>>
>> Thanks
>>
>> Ben Charvet
>>
>>
>>
>>
>>
>>
>
> --
> Dan Yocum
> Fermilab 630.840.6509
> yocum@fnal.gov, http://fermigrid.fnal.gov
> Fermilab. Just zeros and ones.
>
>
>
>
>
>
>
>
