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Hi guys,
I'm in the process of rebuilding my 8's engine.
I need some help if there's possible to grinder my iron plates. all the plates have some wear in the opposite side of the intake port/exhaust port. I measure the wear to be about 0.11mm (I used a dial indicator to measure it). So my question here is... Is it possible to grinder it and then re-nitrate or is it too much wear?
The next problem is my rotor housing... I got the marks on the surface there too. I saw that some companies can offer a "re-surfacing" for less than half the price of a new rotor housing. Do you guys think it's possible to "re-surface" it?
Here are the the "scary" pictures. (NOTE rotors are not correctly marked)
Last edited by Mike_rx8_swe; 01-02-2021 at 01:54 AM.
Reason: Wrong marking on picture
That wear area on the plate is normal. Its the rotor bouncing back and forth from the play of the side seal springs. Particularly in the area you reference. In fact its in the Mazda engine rebuild manual. There is an acceptable amount of "depth" to that wear area. I can look it up tomorrow; but I seem to recall about .0017 inch. I am rebuilding one now and have done one once before. I take the stationary gears off and take valve lapping compound and put two plate surfaces together and lap away, frequent wipe and visual check. This not only helps to see when you have prepped the surface for new side seals and corner seals; but also to see that the plate is even and not warped. But that area you point out is typical and unless real deep considered acceptable by Mazda specification.
As for the housing, without more photos its hard to tell; but if no scoring and no chipping/flaking it look's like a good candidate for housing re-surfacing. The area to watch is to be sure the surface before at and after the spark plug holes are flat with a square/flat guide to make sure its not worn in that area.
I think you are okay at .11mm especially if you hone the plates. On a different note are you sure the rotors are marked front and rear correctly? They are not the same on a 13B MSP. Edit. Ah yes above at top you note that rotors are not marked correctly. I didn't think they were.
Rotors
You're right I managed to mark them wrong but realized my mistake straight way when I looked at the picture... I will put a note there to not confuse people! Thank you!
Rotor housing
Unfortunately the "Devil's nails" were too depth. I had it checked by a Wankel specialist. I dont recall the "depth" of the marks.
I had also some cracks at the spark plugs but they were within specifications.
Well I was wondering why Mike_rx8_swe hadn't responded and now I see it was an old post with a recent response. Oh well. Wonder how the rebuild worked out.
05-18-2020, 02:23 PM
