Mailing List flyrotary@lancaironline.net Message #32852
From: Finn Lassen <finn.lassen@verizon.net>
Subject: Re: [FlyRotary] Re: Joe Hull's OSH Trip - Part 2
Date: Wed, 26 Jul 2006 11:09:10 -0400
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sure looks good! Too good to change.

I don't think that the flange has much significance.

Time will tell, but you may find that the thermal stresses are where the bends are welded to the collector.

Now, you do have fairly long bends which may absorb the expansion. Then again, the length of the bends may make it worse.

A lot of factors here: difference of EGT of the three rotors, airflow over the outside of the bends and collector, vibration, etc.

In any case, please keep looking for cracks in the collector where the bends are welded to it.
If so, you'll have to at lease cut two of the bends at a straight point (near port?) and slide pieces of tubing over the cuts. Better would be to add actual expansion joints.

How thick is the material of  the collector?

If this were a pusher, definitely safety wire the collector!

Finn

Mark R Steitle wrote:

Finn,

 

Maybe that’s why some of the aftermarket flanges are one piece.  That’s how I made mine for that very reason.  So far, so good.

 

Mark S.

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Finn Lassen
Sent: Wednesday, July 26, 2006 9:37 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Joe Hull's OSH Trip - Part 2

 

Ground running won't necessarily get you into that thermo cycle range. Seems you consistently have to get above 5,000 RPM before anything happens.

No expansion joints: it will crack.
Unless you use ridiculously thick material. Which is probably why the stock Mazda manifold is so heavy.

Finn






-- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster