I finally got to cleaning the carbon off my rotors and did find some damage on the front rotor. I have two areas I'm concerned about

First is where the apex seal chewed into the compression side of the rotor face




Second is on the apex seal groove right where the seal broke. Its very hard to get the camera to pick it up.

 

how the hell did you get the rotors that clean? i tried everything to get all the carbon off. nothing worked for me.

i'd say that is going to be very questionable about sticking back in.. might give the apex seal too much room to wiggle, but idk im no expert. i personally prolly would try trackin down a new one

 

check clearances with a micrometer, its the only way to know

 

Hmmmmm.... Ive got no clue about the nick on the compression side of the rotor.

However, it seems to me that if you really want to keep these rotors that you could mill them out to 3mm and solve the problem with the apex seal groove.

 

you will have to smooth that scrape out , check the rotor weights you could try to use it as the rear so its not the primary compression face,
either way it could cause hot spots that can lead to detonation
for the amount you could get a spare rotor for it would almost be worth it to just find a replacement thats within the other rotors weight specs
especially since the apex seal groove is messed up

13bre and 13brew's have the same rotors as a S5 TII, you could also use one from them

 

LOL used a wire wheel. It probably looks all shiney cause i wiped it with WD40 to keep it from tarnishing while all the parts are on the shelf.

I've got feelers out for a good housing, also gonna cover my bases and see if I can't find a replacement that would balance with my C weight rear rotor.

I bought a 1" micrometer to spec my seals, but I"m new to using it. Seems like the only way to get a reading would be to hold it over the groove and eyeball it. Is that going to be accurate enough?

 

I need to read about 3mm milling and seals. IIRC 3mm seals aren't ideal for turbo applications cause they are more prone to breaking. That wouldn't be my first choice because I live in no-man's land when it comes to rotary shops and I don't know that I'd trust any old machinist to do it.

Hell I was gonna pay the machine shop I've used in the past to spec step wear on my irons. But the guy was flabbergasted when I explained what I wanted and that it was for a rotary engine. Soon as he heard rotary he said "we don't have tools to test that." Of course I asked him "You don't have a dial indicator???" but decided I should probably just buy my own tool and test it myself.


Thanks for the heads up on compatible rotors. I'm curious about the scrape. That little bit could be enough to throw the weights and balances off?

If I end up using the rotor I'll definitely smooth out the scrape. I'll have to read about hotspots and detonation.



I didn't even think to do it while I was working on the engine, but I bet if I put the rotor in the housing the mark on the rotor and the one on the housing match.

 

Would the wire wheel damage the rotors at all?

 

PR recommends using a wire wheel to clean off the carbon... I think if it hurt the rotor they wouldn't use it. It's not like the stock rotor is made out of "soft" metal (like brass or aluminum). They do have a factory cad plating and some type of "soft" metal coating on the ouside of the side seal grooves that will end up being removed by the wire wheel though.

 

Yeah, Pineapple online vid has him using a wire wheel on a grinder and brass brushes.

I used a wire wheel drill bit and it came right off with very little pressure. I only used as much pressure as needed for fear of doing any damage. Just like the video, I used a side seal from my old n/a engine to clean the side seal grooves and an apex seal to clean the apex seal grooves

http://www.rebuildingrotaryengines.com/videos/cleaning_rotors

 

They are the same weight and compression, but the dish is slightly different. And the 13B-RE and 13B-REW have hardened apex seal grooves.

People mix S5 and S6's together with no problems though.

 

i meant usually you want to keep the heavier rotor at the front of the engine, i had just saw it on a pineapple video about the rotor weights

i tried to email you that last night jeff but it was to big to send through hotmail, i'll compress it and resend it tonight after work

 

actually if you look at the part numbers the S5 t2, and cosmo engines have the same part number rotors. the FD has a different part number, although its still 9.0 compression and the same weight

 

Cool, I look forward to reading it

 

I took the rotor to a machine shop and let them measure across the seal groove. At it's widest where the damage is measured 2.03mm.

While eating lunch I read how to check tolerances between apex seal and the groove. I used my old seals to do this...I put the apex seals in the groove with both corner seals but I did not use any springs. I pushed the apex seals as far to one side of the groove as it would go and tested with feeler gauges. Then pushed the seal to the opposite side of the gauge and used feeler gauges again.

On the suspect side I could barely get the tip of .006 gauge in. .006 was tighter on same side of groove but opposite end of rotor. Thinnest gauge I could get to slid between the seal and groove was .003 but it wasn't really slidding freely. BUT it was more free on the suspect side.

I compared on one of the non-suspect grooves and it was consistent. .003 would fit and barely slide. One variable is that I have not cleaned the old apex seals, but I'm not sure if that even matters once the engine has a few 1000 miles on it?

The short of it is that the damaged area has about .003 more clearance than the none damaged area. Is that enough of a concern that the seal will be able to wiggle .003 on one end but not the other?