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-   -   Will a 13B Motor free spin???? (https://www.rx7club.com/general-rotary-tech-support-11/will-13b-motor-free-spin-849132/)

snapcaseacilec 06-30-09 06:13 PM

Will a 13B Motor free spin????
 
Will a 13B engine spin freely when all the corner seals are removed and spark plugs removed as well and when the vehicle is out of gear or in neutral??? (side seals only though)



I'd like to get ten different views on this.



And if it does spin like I'm imagining (Like the BIG WHEEL on the Price is Right) does any body in the central valley have non working/broken 12a or 13b to donate for an experiment???

( Just looking for a core if the my thoughts are right)

farberio 06-30-09 06:16 PM

Yes, you can spin a rotary engine when its put together. But probably not as easy as you are describing.

If the corner seals are removed though, you definitely need to do a rebuild as they are important for compression.

At this point you should probably look for three even puffs out of the spark plug holes of each rotor as you turn it around. If you have those then you can move to a real compression test.

snapcaseacilec 06-30-09 10:11 PM

roughly about how hard would it be to turn the motor in those circumstances that I was speaking about???


I'm not worried about compression, or seals in the motor. I'm just trying to find how much resistance is on the motor with just the rotors and the E-Shaft.

Integrals 06-30-09 11:19 PM

its not going to spin like a wheel, it will take a bit of effort still just due to the rotational mass.

jgrewe 07-01-09 08:01 AM

How about this, what do you have in mind for this free spinning engine? Maybe if we had some more info we could give a more precise answer.

There is still a lot of friction to overcome as well as the weight of everything. Just the rotors and e shaft are, what, 25lbs? Plus, there would still be some compression going on. Even with out apex seals the slot for the air to bleed past is pretty small.

TwistedRotors 07-01-09 09:06 AM


Originally Posted by jgrewe (Post 9327455)
Plus, there would still be some compression going on. Even with out apex seals the slot for the air to bleed past is pretty small.

That depends on how fast the engine is turning over. While developing my compression tester I used an engine that had one apex seal completely wedged into the rotor. It didn't make any contact with the housing face. During testing there was no measurable compression from the two faces affected by that apex seal while turning it over with a starter.

-John

snapcaseacilec 07-01-09 03:38 PM


Originally Posted by jgrewe (Post 9327455)
How about this, what do you have in mind for this free spinning engine? Maybe if we had some more info we could give a more precise answer.

There is still a lot of friction to overcome as well as the weight of everything. Just the rotors and e shaft are, what, 25lbs? Plus, there would still be some compression going on. Even with out apex seals the slot for the air to bleed past is pretty small.



I can't give to many details because of what I'm trying to accomplish. Little science experiment I'm thinking about, came to me in a dream.


What about like a little plastic model to test my theory out on, anyone know where I can find one??


BTW How much does each rotor weigh and how about the e shaft alone????

BlinD26 07-01-09 03:54 PM


Originally Posted by snapcaseacilec (Post 9328391)
I can't give to many details because of what I'm trying to accomplish. Little science experiment I'm thinking about, came to me in a dream.


What about like a little plastic model to test my theory out on, anyone know where I can find one??


BTW How much does each rotor weigh and how about the e shaft alone????

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/engine-bay-weights-388361/

snapcaseacilec 07-01-09 06:00 PM


Originally Posted by BlinD26 (Post 9328429)

That's good, thank you for that , I appreciate it.


How about a scaled down version of the wankel in like plexiglass form or so. For like a demonstration for folks that can;t understand how one works, and if there is one out there, how can I get my hands on one???

ratboy 07-01-09 09:05 PM

There is an early 80's plastic model kit of a rotary engine that I see on ebay everyonce in a while. My cousin built one a long time ago but said he spent tons of time sanding all the pieces so it would actually spin. Spark plugs lit up and everything though!

edit** Theres one on ebay right now --> 12.50$
http://cgi.ebay.com/Vintage-Wankel-R...3A1%7C294%3A50

snapcaseacilec 07-02-09 12:12 AM

I've seen those earlier this week, I was looking for something on same size scale but simliar material or lightweight material.


What about designs to make one, I might just try that??? I'll google but if anybody knows of any links for creating one post em please

much thanks everyone, I'll still be looking for a donor motor for the actual experiment.

l4nc3r 07-02-09 12:22 AM

Nice, the motor of the future. I like that :P

But about it spinning freely. I can say, turning the shaft while outa gear, all seals, all plugs, it's a tad hard. I'm not sure it will spin as freely as you are hoping, maybe 1/4 at most without help without seals, sparkplug, etc.


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