Mailing List flyrotary@lancaironline.net Message #20687
From: david mccandless <daval@iprimus.com.au>
Subject: Re: [FlyRotary] WARNING V Grooves
Date: Sun, 24 Apr 2005 06:35:37 +0800
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Hi to all, has anyone ever considered ball-milling out the apex seal grooves and pressing in a round tough steel insert and then milling the seal slot in the steel insert. This would then be' horse shoe' cross section, so to speak. The corner button seals could also fit into the ends. Maybe a new rotor would be cheaper, but this may have better reliability and longer life. FWIW, Dave Mc
On 24/04/2005, at 5:24 AM, Ed Anderson wrote:

I don't how I missed it before, but I was reading over the helpful instruction set that Tracy sends out with the Overhaul Kit.  There is only ONE thing that they suggest checking on your rotary engine.
 
Quote:  " Check the apex seal groove carefully.  The stock seals tend to wear a "V" shape at the opening (mouth) of the groove (rotor).  If the grooves have been "V'ed" more than 0.010" clearance, (a groove opening width of more than 0.125") your rotor MUST be replaced or machined to accept 3mm apex seals.  The overall seal to rotor clearance should be 0.002 to 0.006".                 I added the red and bold to the "must" in the statement (Ed)
 
So I think its quite clear that Bruce T (whom I assume provided the input on the instructions) feels that "V" apex grooves could lead to BAD things.  Now my V was outside Mazda spec but within the limits of above - however, if all the factors stack up against you at the same time, perhaps bad things could happen before you reach the above limit.
 
FWIW
 
Ed
 
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
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