flyrotary@lancaironline.net Mailing List Archive

Kelly,

Don't know. It crossed my mind, but not really thinking of flattening, before I pulled the iron I was thinking the seals themselves may be broken and that it may be due to detonation. I have not had anything that would make me think detonation was an issue. Remember, my boost is low at 3lb (using a preset spring in the wastegate : no adjustment ability).

I think I read about the springs on the RX7 club site but do not recall. I did read about it in the last week, but the post may have been a few years old. My rebuild kit from RA or Bruce T was purchased a number of years ago...perhaps circa 2005 (?)

Chris

From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of Kelly Troyer [keltro@att.net]
Sent: Thursday, January 13, 2011 9:36 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Apex seal update cont

Chris,

Have not heard of bad RA springs but has anyone in the racing crowd (Turbo)
ever mentioned detonation as a suspect in flattened apex seal springs and/or

broken corner seals and flattened springs ??..............

Kelly Troyer
"DYKE DELTA JD2" (Eventually)

"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil Manifold

"TURBONETICS"_TO4E50 Turbo

From: Chris Barber <cbarber@texasattorney.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Thu, January 13, 2011 8:49:13 PM
Subject: [FlyRotary] Apex seal update cont

I pulled the rear iron tonight to check the apex seals. Luckily, the apex seals themselves look good. Also, the combustion chamber looks as I think it should. However, I did find some issues.

The one I was expecting was that the apex springs were flat. Also, one of the apex corner seal plugs was broken as was a small piece off of one of the side seals. No damage was apparent inside the chamber so I think they broke as I was taking them out. Donno , but there is not apparent damage inside at all.

Also, the springs for the corner seals were flat.

The really strange thing to me is that the rubber apex corner seal plugs, the little rubber inserts that seems to hold the assemble together were gone....none of the six were anywhere to be found. This engine has not been overheated to any abusive degree, but the inserts were gone.

I am still waiting for the Mazda apex seal springs to arrive from Mazdatrix . I will now need to order the rubber inserts as well and the corner springs and wait for them to arrive.

Thoughts?

I on an RX7 forum that some of the early RA springs are now known to be weak links.

I am attaching some photos. Note, the springs are laying on their sides.

All the best,

Chris Barber

Houston