So I got a rotor shipped to me without any damage!!! My only issue is that I measured the apex seal to rotor clearance and it seems excessive. I've never rebuilt a rotary engine before, but I checked the specs and it seems some websites are saying .004. I don't know how deep they are talking about, or just the tip of the feeler gauge.

Here is my pic with a .006" on far left, .007" middle, and .008" far right


There are no visual flaws other than the gap measuring a little excessive

 

I have the 3 feeler gauges in it so you can get an idea of how deep each gauge can fit into the groovebut its a little hard to tell from the picture

 

Are you using new or used apex seals to measure clearance

 

the clearance is too much. in the old days you might consider milling the groove for 3 mm seals but they are heavy and it is extremely easy to screw up the milling process.

Goopy provides the proper solution. buy a set of their 2 mm .004 oversize seals, find a proper file and you will be able to custom fit them to a proper clearance.

bonus: they are really good in the knock resistance department.

Howard

 

I am actually using a used one from a low mileage engine, less than 10k. Does it made a big difference? Another reason I posted is because I have a few rotors, and I compared the measurements, and this one has the biggest gap.

Awesome! Well, here is another newbie question. The other rotor I have right now has a maximum clearance of .006". isn't there a Minimum clearance specification?

Another issue was all those debates on apex seals, I was hoping to just use oem mazda, but I guess having tighter clearances would be better huh?

 

i like .0015 to .003, better being closer to .0015. regardless of whose seals you use you should not build your motor w sloppy clearances. Goopy just makes it easier for you and they offer an excellent product that i use in all my engines.

good luck,

Howard

 

Thanks! I'm going to do more searching on engine building , I have a ton of questions. This oversized apex seal is new to me, but I saw old posts from 2010 on this subject. Shows how much I know.

 

Mazdas spec is 0.002-0.004" so yes, 0.002" is the minimum. with a maximum of 0.0059"

with new parts you'd be in the 0.002-0.004" range, and 0.0059" is for used parts.

so your 0.006" rotor is bad, so you can either buy a new part, or do the oversize seal.

i agree with Howard, milling 2mm rotors for 3mm seals is a job that is full of downsides and pitfall.

the slightly oversize seal and filing the slot is a much better idea, as the seal to groove clearance is important, but also the sides of the groove need to be flat as well, as its a sealing surface