Anderson Ed wrote:

Well, Gang,
  I went back out to the hanger and re-measured the width of the rear
rotor housing as well as looked at the apex seals again.  I was correct
there is a 20-30 degree bevel on the seal, but its on the edge that
meets the lower part of the the two piece apex seal which has a matching
bevel.  The top part of the apex that touches the rotor housing still
had a nice dome curve to it with no indications of excess or even wear.

Regarding the rear rotor housing.  The limits according to the specs are
3.1485 - 3.1500 ". I measured four points 90 deg apart around the housing
and in back of the steel insert (several times) and got measurements of:

3.1470 - 3.1480" which are below the limits. Also measure the front rotor
housing and it measured 3.1490 - 3.1495 within the limits.

So it looks like I will need a new rear rotor housing and apparently
this shrinkage is the cause of the coolant leak.

By the way, I just received the High Performance Coolant "O" rings from
Hayes.  They are quite different than the stock ones.  Where the stock
ones are rather soft, square in shape? and flimsy the Hayes ones are
round in shape and harder with a silicon red core and a clear
(apparently teflon) sheathing around the red core.

They appear more substantial than the stock from a physical viewpoint
and would it would appear if clamped between the two housings properly
would be more resistance to deforming due to combustion pressure.  The
Ad claims the Teflon shield protects up to 2750 F.  So we will see.

I think that is a mistake. I have heard anywhere between 400 to 700 F 
for Teflon over the years.

So, now need to get my parts order together and review Bruce's video for
the reassembly process and get it together and operating again.

Ed Anderson

Are your housings grooved inside the water jacket Ed?. If not now would
be a good time to do it or have it done.

I suspect that this grooving will also reduce or eliminate the shrinkage
in
case the engine overheats again. It does this be relieving the thermal
stresses on that part of the rotor housing. Not to mention of course
it improves the heat transfer from rotor housing to the coolant.

Also check with ARP bolts to see if they will make a set of necked
down high strength tension bolts for you with a lower spring constant.
This too will reduce the tendency of the housing to shrink when 
over heated.

Paul Lamar
 
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