goopy rotor housings compression test !!

[TitaniumTT]

But they're not. Goopy has been doing this for a while.... do you think a different machine shop could do it for the same price?

And I just spent 2 hours today w/Johnathon picking up my housings and getting a good look at the shop and all of the services that he offers. He's doing a lot of innovative things for very high HP rotaries.

[yzf-r1]

I'm not questioning that Goopy does good work. I suppose I'm questioning the merit (or lack thereof) of the OEM chrome surface, if the buffed out housings, which are not re-surfaced, seem to work just fine

I hadn't heard of JHB (Canadian outfit, I noticed they offer a similar service) http://jhbperformance.com/services.php but I thought this was interesting

http://jhbperformance.com/technical.php (Chap 1)

Cost is always the bottom line. This is true for Mazda in the 1960’s as well (just as in any manufacturing facility). Recall, back then Mazda was a small manufacturer taking a big chance on a new engine design. They could not afford to spend huge sums of money on new technologies to develop this engine. They needed to focus the monies spent on the real problem areas, not on re-inventing the wheel. Hence, where possible they would rely on economical, proven technologies such as chrome plating and gas nitriding.

Ironically, these types of decisions are not always the best and may have become an Achilles heel for Mazda in the end. It is the opinion of the engineers at JHB Performance that the cause of problems such as wear, chatter marks and poor compression are due to the use of chrome plating. Mazda spend lots of time and effort trying to alleviate these problems with alternative seal designs and material compositions rather than attacking the root cause of the problem that we feel is the chrome plating itself. Nonetheless, Mazda stuck with their huge capital investment into hard chrome plating and invested over 30 years of development time into trying to make this type of wear coating work in the rotary engine wth little success. This is not to say that Mazda did not achieve an engine with moderate reliability, but to point out that their success would have been compounded many times had they not stuck with chrome plating.

Hard Chrome plating in the 1960’s was a cheap and easy surface treatment with very low friction that was easily adapted to the rotary engine. However, this type of coating has many problems and disadvantages when used in a rotary engine application. The effects of these inherent problems are notoriously associated with the rotary engine today.

Hard Chrome is a dry coating; this meaning that hard chrome will not naturally retain any oil or lubricants. In a piston engine or a hydraulic cylinder type of application this is not an issue because there is ample lubrication applied to the chrome during operation (oil splashing on the cylinder walls of a piston engine during operation OR hydraulic oil that fills a hydraulic cylinder during operation). However, rotary engines are sealed from the oil pan and there is not oil or lubrication for the trochoid surface. Hard Chrome will not naturally retain or absorb oil. Through special honing and etching variations of chrome plating such as channel chrome or porous chrome can be achieved whereby micro-channels or pores are created to try and retain lubrication.