Lynn, Do you mean Belleville washers? Good idea but they may lose their spring after a few heat cycles.

Bill Jepson


-----Original Message-----
From: Mark Steitle <msteitle@gmail.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Sun, Mar 13, 2011 5:44 pm
Subject: [FlyRotary] Re: Cracking exhaust manifolds/ Crankcase ventilation


Bevel washers... yes!  That would work even better.  Thanks for the suggestion Lynn.  


Mark


On Sun, Mar 13, 2011 at 6:47 PM, <Lehanover@aol.com> wrote:


In a message dated 3/13/2011 6:56:23 P.M. Eastern Daylight Time, fluffysheap@gmail.com writes:
 On my home spun exhaust for my 3-rotor, I tighten the exhaust studs for the center rotor, but only snug down the bolts for #1 and #3 in order to allow the exhaust manifold to grow and shrink as necessary.  With 1600-1700* EGT's, it seems obvious that the manifold will grow more than the engine and if not allowed to move, it will crack.  By torquing them only enough to prevent leakage, they are allowed to grow as needed, preventing cracks.  So far, no broken studs or cracked exhaust manifold on my 3-rotor.  


Mark S.

 
Bingo.
 
How about you torque up the center most stud to auto spec, then use 2 bevel washers flange to flange pulled down just short of flat on all other studs.
 
Then use a short stack of bevel washers above and below a flange on the turbo setup to a strut to support the weight and keep the strain off of the manifold.
 
Lynn E. Hanover