Hello

A friend who owns a Series II RX-8 claimed that the rotor housings of the Series II were different from Series I in that the inner sides were treated with a special surface coating such as Teflon to make them more durable and withstand higher temperatures. By saying so he implied that the Series I didn't have such special coating and therefore they were more vulnerable to inner deterioration or deformation.

Me as a happy owner of Series I RX-8 was distracted by that and looked to Internet pages to see if that was true. So far I couldn't come across any page or any information where it was true.

On atkinsrotary there are 2 different rotor housing products for Series I (04-08) and Series II (09-11) each has identical photos and descriptions but different prices the first $712 and the second $728. But it's not certain if the difference is due to the surface coating or something else.

Does anybody know if there is a difference on Series II housings such as a surface coating? Thanks.

 

Yes there are differences, the SII engine has 3 oil injectors in the housing and the oil pan is different so the bolts will not line up on a S1. You can use them but it will require blocking the third injector port and drilling an tapping a hole for the S1 oil pan.


As for the coating on the S2 housings, that is BS AFAIK. The S2 rotors do have a treatment on them though.

 

Yes there are several differences as you said, the 3rd oil injector per housing being the most well known and some other geometrical and size changes such as oil pan or oil filter cap.

Yet all of these changes are minor changes yet the inner sides having a surface coating is not particularly when you consider that many problems arise from that area.

That area being surface coated would mean that in identical maintenance conditions the engine would last longer than an engine whose housings were not treated with such a coating.

The Series II rotors have a treatment on them? but then why is there no separate product entry for Series II rotor on Atkinsrotary? See Mazda, Rx2, Rx3, Rx4, Cosmo, Repu, R100, Rx7,... there's only one entry titled as 04-11 Rx8 Front Rotor (N3Z1-11-B10C)

 

Because Atkins rotary is not Mazda. And what do you mean by oil filter cap? The oil filter has nothing to do with the housings.

And here is a thread about the Series II rotor coating.

https://www.rx8club.com/series-ii-te...oating-232785/

 

By the oil filter cap I meant the length of the oil filter was longer in Series II, a change which doesn't sound so important.

I took a look at the link and noted the expression ROTOR that is, only the rotor is applied a surface coating. Though it looks nice, it shouldn't be so important to have a coated surface on the rotors, at least not so important as the housings because they are in direct contact with the rotors' apex seals making them the most heavily worn parts, IMHO.

 

its also not attached to the rotor housing. the S1 is attached, via an adaptor to the rear side housing, and the S2, is on the front cover.

the rotor housings have a coating. the coating on the rotor housings is the same from the start of FD production in 1991 to 2012. its a porous chrome plating (MCP) of a pressed in steel liner (SIP) with a carbon graphite layer sprayed on and then baked.

the coating on the rotor was added during the S2 production.

 

Curious, without searching for hours, has anyone here done cryo on their rotors and housings?