Mailing List flyrotary@lancaironline.net Message #31055
From: Wendell Voto <jwvoto@itlnet.net>
Subject: Re: [FlyRotary] Re: Oil pressure port size
Date: Mon, 3 Apr 2006 10:24:39 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Message
 
Subject: [FlyRotary] Re: Oil pressure port size

The oil pressure sending unit on my '87 13B appears to be 10x something.  The adapter diameter is right but threads are too course on the purchased adapter.  Barry mentions a 1/8 BSPT which I have never heard of (haven't heard of a lot of things).  I went to JC Whitney site and they show a 1/8x28 BSP adapter. Barry,is this what you're referring to? 
 
OK, I just did some searching on the RX-7 club forum, and it sounds like the oil pressure thread is indeed 1/8"-28 BSPT.  Someone offered a link to the adapter they used to convert to 1/8 NPT.
 
 
One of the threads mentioned that Honda also used this size for their oil pressure fittings, so it's not inconceivable that you may find one of these adapters hanging on a peg at a local auto parts shop. 
 
I just couldn't understand how I was able to just grab a fitting from the JC Whitney kit if the thread was actually a BSPT, since I figured that wasn't included.  Now that I look at the description of the contents that Tommy sent me, I can see that there was a typo.  What was listed as "1/8" 288SP" should have actually read "1/8" 28BSP".  
 
 Includes, M10x1.0, M12x1.0, M14x1.5, M16x1.5 and 1/8" 288SP external-thread adpaters, all with 1/8" x 27NPTF internal thread.
P/N 13UC9267A....each $4.99 
 
Mystery solved.  Now I just have to change my notes.
 
It might be better to get an original Mazda oil pressure sending unit (original one seeps oil) to fill the hole and use a gauge that will be compatible with it and get oil for the re-drive from some other source. Does anyone know if the Mazda sending unit is compatible with after market gauges?  
 
I believe the stock oil pressure sending unit is an odd duck, and probably not compatible with normal aftermarket gauges.  The other problem is that the stock units (at least on the FD) are probably the least reliable part on the whole engine.  Back when Mazdaformance was in business, they actually listed the oil pressure sender in the "tune up parts" section :-) 
 
Good luck,
Rusty (trying to redeem myself)
 
Okay, you're forgiven, just send me the money I wasted on the wrong part.
 
Seriously, thanks Barry and Rusty for your help.  Will probably need it again soon.
 
Wendell
Image
Blank Bkgrd.gif
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster