Lynn wrote

 Francois is concerned about apex seal life with the PP.

The apex seal does not seem to suffer and abnormal wear from

Pport

operation.

I have one in the old car and it had the same seals in it for

two

years,

and

those seals came from a side port engine. Those were the carbon

seals. I

have

a set of the ceramic seals for the side port engine. They are

harder

than

Chinese arithmetic.

You run 2 springs under them and they still have far less drag

than

either

stock or carbon race seals. They do not bounce even at 10,000 +

RPM.

They do not

wear the rotor housing at all. The stock iron seals wear grooves

in

the

rotor

housings. They are heavy compared to the ceramics.

Both the carbon and ceramic seals will run on giant Port

openings

without a

problem of any kind.

In the event of a top oil failure the carbon seals will loose

tiny

flakes

from the trailing side, and leak a bit. But not enough to stop

the

engine. I did

not screw up that bad on the ceramic seals but I think they will

get

enough

lube from the fuel that no damage at all would occur. As in the

fire

wall oil

tank runs dry, or you forget to premix a fuel load.

The end product needs to have ceramic seals, even if you have to

make a

set

that have the corner piece like the stock seals. I don't know

how

that

would

wear on the cast iron. They are one piece for racing.

Lynn E. Hanover

Do these one piece seals still use the stock round corner seals? How
important are the corner seals?

I am just designing a model wankel engine (I got the plans for the

one

from

VTH.de and want to make one a little bigger). I was thinking of

making

side

seals from a a ring of cast iron. Don't know yet whether to bother

with

oil

seals. It is only going going to run for a few minutes at a time.

Regards,
Mark

Mark,
A great project - mind if I make a suggestion ?

I noticed that the side seals are the same thickness as Bi-metal

hack-saw

blades, these blades don't break like side seals do, as they are much

more

flexible and are very cheap. They will require grinding to size, but for

a

one-off that should be easy enough.

I would continue the seal groove into a solid side seal ( also grooved

for

the apex seal) I don't think you could successfully do a round (one

piece),

however I could be wrong!

George ( down under)

Thanks George. That is worth at try. Both the OS/Graupner and the SW92 model
engines omit side sealing altogether and just rely on a well controlled
rotor to chamber clearance.

The SW92 plans were drawn back in the sixties, and it is a very crude
engine. The trochoid has been simplified to an oval. Since my CNC mill
project is moving along, I figured I'd make a slightly larger model engine
with a proper trochoid.

I would like a use plain bearings, and was hoping to find some off the shelf
camshaft bearings. Does anyone know of a catalog or website which list
plains bearings and sizes, rather than just part numbers?

Regards,
Mark

 
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