I bought my 8 with a blown engine planning to change some seals and be on with it, the rear rotor had almost no compression, but when I tore the engine down the sidewalls on the rear rotor had heat marks and wear marks on them. So I am wondering what's the best way to go about fixing this. Can I take the sidewalls to a machine shop and get them flat again and will I need to replace the rotor, is that machineable? I think it has some wear on it too.

 

The side housings can be resurfaced and are typically done through a process called lapping. The wear marks may or may not be normal. I can't tell without seeing what your housings look like but all housings have some wear marks on them. How deep they are will determine if you can lap the housings. Racing Beat laps housings and Arizona Rotary Rockets has a great way of doing it too.

 

yeah some pictures would help a ton. If its just slight wear on the edges of the housing is pretty normal! now if we're talin deep *** grooves in the center fo the housing of course that is not normal....

try to snap some pics and we can try to help u out

 

http://www.jhbperformance.com/servic...d_intermediate

 

Post pics!

 

^yeah that would help...and all us rotorheads always love to see a motor being built

 

yeah the damage seems to come from the center and go outward, they are some pretty good grooves, I don't know if you can see it too well in the pics. also when you turn the crank there is slight hesitation for the rotor to move, I don't know if that is normal either

 

Isn't there a chrome coating on the side housings? If so he'd need to get it re-coated after getting it machined correct?

 

i'm gonna say there's not, correct me if I'm wrong cause the whole rest of the end pieces and the divider are bare Iron and it would be extremely difficult to only chrome the cycling surface.

 

^ I don't think there is any sufacing done but prob wouldnt' hurt to get those grooved smoothed/machined out......no chroming on the end plates....

 

What do the rotors themselves look like? How bad are the apex seals? Pics!

Too bad you probably don't have any history on the motor to find out what kind of oil was used, how often it was changed, or how the car was driven.

 

the apex seals seem fine, I was planning on replacing all the seals anyway, the rear rotor may be a bit worn

 

The side housings are factory hardened through a multi-layered process to resist wear etc. One term for the process is "soft nitriding." I wouldn't get them lapped, there is no way they will last as long as good condition used side housings of similar mileage, even if they undergo an inferior aftermarket treatment process.



The rotor housings are chrome treated, but the chrome is done in a special way to improve oil retention. There are also other coatings applied now that are not pictured here in this 25 year old document. I just can't see how any kind of resurfaced housing (rotor housing or side housing) would last given how much development and expense has gone into the Mazda manufacturing process.