I will outline what we are talking about.
There are four coolant sealing O-rings per rotor housing.
Two outer and two inner.
There are also four oil sealing O-rings per rotor. Two on each side of
the rotor proper. These are located on the flanks of the rotor.
Two per side.
http://www.creavey.com/
Coolant O-rings:
1. Inner coolant oring -
circumference = 28.625
diameter = 9.111
slot depth = 0.062
slot width = 0.141
section size = 0.103
2. outer coolant oring -
diameter = 11.340
slot depth = 0.062
slot width = 0.110
section size = 0.093
This is critical! The proper outer section size is 0.093
Snip
Paul,
Are the diameters of the coolent O-rings ID or OD?
Kelly Troyer
I am not sure. Lets go over the Geometry 101 calculations together.
>From inside the inner slot to inside the inner slot side to side is 7.5 inches.
That means that the ID diameter of the semi circles at top and bottom
of the inner slot is 7.5 inches. About 19 cm. Looks like it was designed
in inches as inches units are closer.
This means the inner lengths of the curved sections of the slot are
3.1416 (pi) times that or 23.562 inches.
>From inside the top of the slot to inside of the bottom
of the slot the dimension is 9.9 inches. 9.9 - 7.5 is 2.4 inches. So we
have two straight sections 2.4 inches long on either side.
The total ID circumference of our inner O-ring is therefore:
2.4 + 2.4 + 23.562 = 28.362.
Dividing that by 3.1416 (pi) to get the ID diameter
gives us an ID for the O-ring of 9.027.
Close to the 9.111 number above calculated by Ken Powell.
I would say it is the ID. In any event there is less
than 1% difference.
Do I need to work it out for the outer slot?
The outer slot is 9.8 inside to inside from side to side
and 12 inside top to inside bottom from top to bottom.
If you have an end housing lying around check my measurements and
calculations and let me know what you measure and calculate.
BTW there is no problem cutting an O-ring and gluing it back
together with red RTV if it is too big in diameter. Put the joint
near the cool intake side of the engine. If it is a bit too small
it can be carefully stretched (less than %5 too small) by
slipping it over the plywood form.
Paul Lamar
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