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 Williams wrote:
hi all, we have been told that chrome porosity is visible to the naked eye. however when we examine numerous mazda housings with a 30 power microscope we cannot find any indication of any kind
that they are porous in any way. where did this idea spring from? we need help! HELP! foliation has probably been mazdas biggest problem with the rotor housings. we are reluctant to change
any of the chroming specs until we are possitive we know what we are doing. if no one has an answer for us can you put us in touch with someone who can? thanks a bunch walt. williams
wgw75@bresnan.net 307-635-4104
So you don't believe me then? :)
It is in all the SAE papers that Mazda every wrote on the rotor housing surface treatment.
It is also mentioned in the book Mazda wrote called Rotary Engine 2nd edition page 30.
Author was Kenichi Yamamoto. No ISBN number. Published 1981 by Toyo Kogo.
They also plate it with molybdenum recently so that may be fooling your eye.
In 1975 to 1983 they used "pin point chrome plating". In 1983 to 1985 they used
micro channel porous chrome plating. In 1985 to the present they use micro channel chrome
plating- molybdenum plating. Quote from March 2003 Rotary Engine press information 2003
Mazda Motor Corporation.
Paul Lamar
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