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-   -   rotor seals (https://www.nopistons.com/rotary-engine-building-porting-swaps-55/rotor-seals-57419/)

Bstrickler 02-20-2006 07:02 PM

How many of those circular seals are there supposed to be on a rotor? My dad and I pulled one engine apart, and found 1 on each side, and we just pulled another apart yesterday, and that one had 2 on either side. Which one has the right amount? The first one we pulled apart was a 1980 12A engine, we dont know about the other one. We still have one more engine to pull apart before all of them (except the one in my car) are in pieces. The other thing we noticed is that the rear rotors on the 1st 2 we pulled apart were the one's that were frozen, the front ones turned freely, also the rear rotors were pitted, whereas the front ones were virtually untouched. The last engine we have to pull apart turns freely, but you can hear a lot of scraping and stuff going on inside it.



Okay, I think I've typed enough for now. If you need any more info, just ask me.

Lynn E. Hanover 02-20-2006 09:51 PM


Originally Posted by Brian S.' post='803071' date='Feb 20 2006, 05:02 PM

How many of those circular seals are there supposed to be on a rotor? My dad and I pulled one engine apart, and found 1 on each side, and we just pulled another apart yesterday, and that one had 2 on either side. Which one has the right amount? The first one we pulled apart was a 1980 12A engine, we dont know about the other one. We still have one more engine to pull apart before all of them (except the one in my car) are in pieces. The other thing we noticed is that the rear rotors on the 1st 2 we pulled apart were the one's that were frozen, the front ones turned freely, also the rear rotors were pitted, whereas the front ones were virtually untouched. The last engine we have to pull apart turns freely, but you can hear a lot of scraping and stuff going on inside it.



Okay, I think I've typed enough for now. If you need any more info, just ask me.





There should be two scraper rings on each side of each rotor.



The rear rotor housing is cooled by water that has been through the front housing first and picked up some heat. So, the rear housing runs a bit hotter than the front. S, often there will be heat stress evident in the rear, but not the front.



Pitting is fine. Apex seal groove wear is not. If the seal grooves clean up OK, and the apex seal groove is not "V" shaped, then the rotor is OK to use again. Push in a new bearing. (grind off the tab first) and build it back up.



Lynn E. Hanover

Bstrickler 02-28-2006 12:30 PM


Originally Posted by Lynn E. Hanover' post='803107' date='Feb 20 2006, 08:51 PM

There should be two scraper rings on each side of each rotor.



The rear rotor housing is cooled by water that has been through the front housing first and picked up some heat. So, the rear housing runs a bit hotter than the front. S, often there will be heat stress evident in the rear, but not the front.



Pitting is fine. Apex seal groove wear is not. If the seal grooves clean up OK, and the apex seal groove is not "V" shaped, then the rotor is OK to use again. Push in a new bearing. (grind off the tab first) and build it back up.



Lynn E. Hanover





That's not how many scrapers were on the first engine we pulled apart. There were only 1 per side of each rotor on that engine. The second one we pulled apart had the 2 scrapers on each side, though. My dad wants to pull the 3rd engine apart, even though you can turn it over by hand, with no wrench, and there's no grinding sounds, and the rotors look fine (I turned the engine over, and shone a light into the exhaust ports, and looked at the seals, and they looked perfectly fine, they were still silver, and the rotors were still shiny-ish, they didn't have carbon on them) .

diabolical1 02-28-2006 01:22 PM


Originally Posted by Brian S.' post='804940 (Post 710849)
There should be two scraper rings on each side of each rotor.



as Lynn said, there should be 2 oil control rings on each side of each rotor ... 4 seals x 2 rotors. if you only saw one, then something is not right. where did you get the motor from? maybe someone rebuilt it incorrectly???

Bstrickler 02-28-2006 02:30 PM


Originally Posted by diabolical1' post='804955' date='Feb 28 2006, 12:22 PM

as Lynn said, there should be 2 oil control rings on each side of each rotor ... 4 seals x 2 rotors. if you only saw one, then something is not right. where did you get the motor from? maybe someone rebuilt it incorrectly???







It was the original engine from my car, which the previous owners swapped out, because the owners before them froze the engine, from over-revving it, and they never bothered to re-build it, they just put an '81 in, and it seems to run fine (my dad doesn't like the sound of it because "it shouldn't run that loud". He doesn't know the rotary engines, but still thinks he knows almost everything about them). I'm pretty sure they didn't re-build it at all, because all the gaskets were shot, and the engine was too rusted, and there was too much carbon for them to have re-built it recently. It may have been a mis-manufactured one, also.


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