GrossPolluter

iTrader: (1)

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

GrossPolluter

iTrader: (1)

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

WJM ROTARIES

Are you using new or used apex seals to measure clearance

Howard Coleman

iTrader: (6)

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

GrossPolluter

iTrader: (1)

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?

Howard Coleman

iTrader: (6)

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

GrossPolluter

iTrader: (1)

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.

j9fd3s

iTrader: (3)

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