Mailing List flyrotary@lancaironline.net Message #5270
From: sqpilot@earthlink <sqpilot@earthlink.net>
Sender: Marvin Kaye <marv@lancaironline.net>
Subject: Re: [FlyRotary] Re: Success
Date: Tue, 13 Jan 2004 19:24:51 -0500
To: <flyrotary@lancaironline.net>
Hi, Mark.....possibly our engines are different.  The existing press-fit hole in my engine was already 17mm, or .690 inches.  The required drill for a 3/8 NPT is 37/64ths, or .570.   The .690 hole is already bigger than the required .570 tap drill size for a 3/8 NPT tap. My engine is a 1989 turbo model.  Hope this is useful to someone?  Paul Conner
----- Original Message -----
Sent: Tuesday, January 13, 2004 7:34 AM
Subject: [FlyRotary] Re: Success

Paul,
I was able to tap mine to 3/8 NPT which left adequate wall thickness. 

Mark S.


At 09:54 AM 1/12/2004 -0500, you wrote:
Hi, Finn....By the time I drilled and tapped the hole for 1/2 NPT, the remaining wall would be so thin, I was afraid it would break during the tapping operation.  The housing is cast iron, and a pipe tap is tapered, so it tries to expand the hole while tapping. Not a good situation when you have thin walls, expecially if those thin walls are cast iron.  Take care. Paul Conner
----- Original Message -----
From: Finn Lassen
To: Rotary motors in aircraft
Sent: Sunday, January 11, 2004 11:11 PM
Subject: [FlyRotary] Re: Success

I curious as to why you didn't simply thread the housing with 1/2" NPT and used the fitting unaltered.

Finn

sqpilot@earthlink wrote:
     The second item I had success with was the 5/8" heater nipple that is a press fit into the engine, underneath the oil filter.  Mine was missing from my engine. I tried to find a new one, with no success. Finally, Mazdatrix sent a used one, but when I put a micrometer to it, it was considerably out of round (probably caused during removal from the casting).
       I found at our local CarQuest auto parts store, a steel 5/8" hose barb to a 1/2" NPT male fitting. I just put it in a lathe, and turned the 1/2" NPT threaded area down to 17 mm, or .160 inches. In the picture, you will see the longer original piece, as well as the new, slightly shorter nipple.
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster