Walter Williams wrote:

hi Paul,  glad to see you back safe and sound.  my oldest son has built

two trochoid grinders in house. we are getting ready to recondition used
housings to better than new, we hope.  the problem is

the foundry does not get the liner centered good enough. Mazda does not

usually grind the liner before the chrome is applied. they put in a lot of
chrome and then grind which leaves the chrome

thickness varying a bunch.  we believe this has a lot to do with the

foliation problem. we have one liner that Mazda ground to .020 under before
and got away with it.  but when we tried it we went

through the liner in one spot in the center just below the exhaust port.

we are wondering if this could be some warpage in service.  do you know what
alloy the liner is? what process Mazda uses to

chrome it? do you think the oil retaining cracked surface is still

neccesary given the better lubricants available today?  the first ten
housings a plater in denver did for us was not satisfactory.

does anyone know of a quality plater in the rocky mountain region?

anyone want to help us test these housings? any advice will surely be
appreciated thanks a bunch. walt.williams 307-635-4104

wgw75@bresnan.net

The liner is a steel alloy but I don't know if it is hard or what alloy is

used.

It is a porous chrome plating with a coating of teflon. The porous part
is very important to get good oil retention and distribution.

Paul Lamar

Walter,
Too true on the casting being off centre - that goes for all of it.

I support Paul's recommendations on porus chrome, I believe Francois
(Mistral) had a non-porus coating fail because the surface could hold no
oil.

I have noticed that there are Laser Companies who supply a service to etch
hard surfaces - it's a series of minute dots and dashes which you can design
yourself.

You will have a winner if you can pull this off, I know it's been tried
before without success - all the best.

I assume your using Hard Chrome.
George ( down under)

 
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