John McLaughlin wrote:

I'm in the process of determining the parts I need to buy vs. have machined
for my engine rebuild. For what it's worth, the engine is a 1990 13b NA, but
I think the questions apply to all rotary rebuilds.

I have some side seal wear on all the side housings. I need to get a gauge
body and dial indicator to measure the actual wear, but I want to understand
the concepts.

If I am under the wear limits, conceivably I clean the housings and
reassemble. It seems this might accelerate wear on the new side seals and
oil control rings.

If I exceed the wear limits, but are within a tolerance that is not in the
manual, the housing can be lapped. Doesn't this lapping remove the nitride
surface treatment (I may be using the term incorrectly)? Isn't it important
to replace / retreat? Is retreating part of lapping?

Yes but Lapco will re-nitride. PL

LAPCO
5440 HWY. 55 East
Lake Wiley
South Carolina
(803) 831-0761    Bob or Dick Pasture

Bruce Turrentine
BruceT2598@aol.com
(919) 212-0671

You chamfer the rotor bearing if necessary to insure the engine turns freely
with lapped rotor housings. 

Lastly, I've heard Mazda rebuilds limit lapping to one housing (which is
then sent to Japan to be nitrided). Uh... does that mean one needs to buy
new housings if more than one is out of spec? The one housing limit is NOT
mentioned in the FSM, but the variable thickness e-shaft spacer is covered.

Thanks -

John McLaughlin

 
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