Marc.
What are the numbers that indicate a later
version?
Bill
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net]
Sent: Tuesday, February 10, 2015
9:56 AM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: 20B
Engines
There are 3 series
of 20B engines IIRC. The center housing and the crank on some of the earlier
versions was reported to be a weak link……..later versions had mods to some
internal parts. I have a later version of the 20B. You can tell from the rotor
housing engine numbers (where the 20B is in black surround).
Marc
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net]
Sent: Friday, February 06, 2015
4:17 PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: 20B
Engines
Thanks Mark........That is the info I was looking for............I
happen to have a 13B Cosmo that has the later housings
and I had only read about the reinforced housings.........
On Fri, Feb 6, 2015 at 6:49 AM, Mark Steitle <flyrotary@lancaironline.net>
wrote:
I wouldn't hesitate to
use an early 20b. The early 20b housings are plenty robust enough for a/c
use. The beefier irons could be an issue if you're building a turbo race
engine due to the higher loads imposed during up shifting and down
shifting. We don't experience any of those loads.
I'm pretty certain that
my 20b is an early model and I have not experienced any issues with irons
cracking around the dowels. The weakest area is along the inner walls of
the o-ring grooves nearest the water jackets. If your o-rings aren't to factory
specs, you run the risk of cracking an o-ring wall which ruins the
housing. Been there, done that. If you treat the engine with the
same care you would a certified a/c engine, then you won't have any trouble
with longevity.
Mark
On Fri, Feb 6, 2015 at 12:00 AM, Kelly Troyer <flyrotary@lancaironline.net>
wrote:
Mark Steitle or other 20B Drivers,
I am looking at a 20B that looks to be an early one
before they added additional
metal in the dowel/oil passage area of the iron housings because of
some that I have
read developed cracks in this area in service in the autos I presume.......
Can you tell me if this a potential problem for the
20B in our aircraft use ?.......Also
can you tell me if your 20B has the later reinforced housings
?.........