A broken apex seal usually takes out the housing, but if you have two faces making compression then maybe not. Any auto machine shop can grind your irons flat. Check for warping first. Discard warped irons.
Nitriding was not used in early engines. It would take 20 years of flying to tell the difference between Nitrided and not Nitrided. You can lap them yourself after grinding. Apply valve grinding compound to one iron and rub another iron on it. Keep the oil on it. Plan on a week end of hand work. There should be no shinny spots when you finish. I did this on all race engines I built. Even new irons. Makes a great surface for quick beak-in and and good for two years of racing at 9,600 RPM with better compression as engine time builds up. the high pressure car wash is required to get every particle of compound out. Since the engine will be a bit shorter, I put a chamfer on the front of the rear main bearing so it cannot touch the radius on the crank. Assemble as normal. Use solid corner seals. Set side seal end gap at just zero. One corner seal pushes one side seal around the engine.
It will be wearing in the side seals quickly during a 2 hour fast idle break-in. If the corner seal and both adjacent side seals pop up after being compressed that is all of the clearance required. This design has dozens of places to loose compression. A warn engine with no compression will start if the engine is spun up fast enough. As in a push start for a car. Or two batteries in series for the starter on the dyno.
Our first race car was an RX-2 with a junk engine. It was a gift to us because of no start. I poured in 1/4 cup of engine oil and 1/2 a cup of hot coffee and get an instant start. A big cloud of smoke as well. Not a good idea for an airplane, but a demo of how robust the design actually is. If your rotors are good. Put them in a press and push on the gear to be sure it is set as deep in the rotor as far as it will go. I grind the index tab off of the new rotor bearings. I install the bearings with a pusher with a flange to stop the bearing perfectly. I heat the rotor and freeze the bearing. Wipe on the Red Locktite and press it home quickly. That index tab makes a bump on the inside of the bearing. Hit that with sanding drum on a Dremmel. (just a bit)
I use 100 PSI oil pressure but aircraft need only 75-80 PSI up to 6,000 RPM. For steel Apex seal use axle grease to hold them in place during assembly. I like to keep the end piece of the apex seal on the end facing up where I can see it. The little buggers will fly across the shop and hide for months.
Use some cheap 30 weight fleet oil for 2 hour to 4 hour break-in. Then dump that oil and look inside the filter for bearing material. Probably a bit of sealant material but nothing else. Refill with RedLine 40 weight racing synthetic. Add 1 ounce of RedLine synthetic 2cycle oil for each gallon of fuel. Twice that for break-in.
Never use a Fram filter on anything even a lawn mower. K&K is best. "Check Real World Solutions" for parts and then Racing Beat. Maybe a dealer who has been sitting on parts for 30 years. Ask for the friends and family discount. Ask for all of the parts you need. Might strike gold.
Any questions anytime.
Lynn E. Hanover
In a message dated 8/23/2019 1:39:24 PM Eastern Standard Time, flyrotary@lancaironline.net writes: