I still say there is a differential thermal expansion problem that Everett did
not address. Racing Beat has not addressed it either but they are very careful
about warm up and not overheating the engine. The aluminum rotor housings
that "creep" are from engines that have been overheated. A common problem
in the old days. If you run the engine hard before the steel bolts are
as warm as they are going to get the problem is worse.

Paul Lamar

Paul, I want to mention that the piston engines that you mentioned do have one piece blocks. The rotary does have
several splits through the "block". This creep idea is the one thing that makes me think the oil pan plate mount has some merit. I also want to mention the current engine mount designs that you have been doing, P-51, or Schertz Beam do eliminate a lot of the worry of plate sliding.
Since the engine bolts don't support the PSRU and prop! This is the only worry I have about the Mistral rear plate with Lyc style dynafocal mount. The Le Mans engine used two carbon fiber plates to improve the engine twist and logitudinal stiffness.
Bill Jepson

There are two different problems here.

Problem 1: Angular motion between the parts.
The more I think about the aluminum tension bolts idea the better I like it.
In effect you have 18 dowel pins keeping everything in alignment. The stock engine
only has two. For awhile there somebody in NZ or Aus were adding hollow steel dowel
pins at each bolt location. REAL expensive. I don't want to over emphasize this 
"problem" as it does not appear to be a real problem at the HP levels we are running. 
It starts to show up around the 400 HP level. 

Problem 2: Al housing creep or crush. Here is a shot of an engine from AUS using large 
diameter steel tension  bolts. If anything this aggravates the differential expansion
problem because these bolts are much stiffer in tension. Another possibility we
discussed a long time ago was to use bellville springs under the heads of the bolts.
Again aluminum tension bolts, if they work, would expand and contract at the same
rate as the housings.

Paul Lamar
 
The Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2004 All world wide rights reserved.