Chrome cylinder in radials

[GTH]

One of my buddies flies a radial powered vintage airplane.
He says that all the radials he is aware of have one chrome cylinder
corresponding to the master rod, and the rest straight cylinders.

Anyone around has seen this, and has any info as to why it would be so ?

Thanks in advance,
Regards,
Gilles Thesee
http://contrails.free.fr

[Charles Vincent]

GTH wrote:
> One of my buddies flies a radial powered vintage airplane.
> He says that all the radials he is aware of have one chrome cylinder
> corresponding to the master rod, and the rest straight cylinders.
>
> Anyone around has seen this, and has any info as to why it would be so ?
>
> Thanks in advance,
> Regards,
> Gilles Thesee
> http://contrails.free.fr

The cylinder associated with the master rod has additional sidewall
loads due to the forces transmitted by the slave rods, so wear would be
more of an issue on that cylinder. Quickly scanning the overhaul and
parts manuals for Wright and P&W radial engines, there are no special
procedures called out for the master cylinder, and no special part
numbers, but my copies are vintage, i.e. they do not incorporate all of
the bulletins, which I have largely on microfiche in storage.

Charles

[Highflyer]

"GTH" > wrote in message
...
> One of my buddies flies a radial powered vintage airplane.
> He says that all the radials he is aware of have one chrome cylinder
> corresponding to the master rod, and the rest straight cylinders.
>
> Anyone around has seen this, and has any info as to why it would be so ?
>
> Thanks in advance,
> Regards,
> Gilles Thesee
> http://contrails.free.fr

I have been flying and maintaining radial engines for over fifty years. I
don't know of any that were built with a chrome cylinder for the master rod
cylinder and plain steel for the others.

Generally a chrome cylinder is a cylinder that has been worn beyond limits
and then chromed back up. I don't know of any NEW cylinders that are made
chromed. I may be wrong. If so, name me a maker who makes NEW chrome
cylinders.

There would be no reason for that in any case. On all the radial engines in
my shop at the moment, ( about six I think ) all of the cylinders are
steel.

I recently overhauled the engine on the Red Lady. I figured she had about
2500 hours since the last overhaul, which was about thirty years ago. All
nine cylinders miked up within NEW limits! I changed one cylinder because I
had some good spares and the valve guide was wallowed a bit and it was
easier to change the cylinder than press in a new valve guide insert. I
will probably put a new valve guide in it and return it to my spare cylinder
collection! :-)

Highflyer
Highflight Aviation Services
Pinckneyville Airport ( PJY )

PS: The rec.aviation annual flyin at Pinckneyville is coming up soon. May
18, 19, and 20. Plan to attend now. There is a faq on the web at
http://www.ousterhout.net/pjy-faq.html

Anyone coming please let Mary know at since she is already
buying the groceries and starting the prepwork for the meals.