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STOP! Phil. Don't turn the engine over again.
I encountered a very similar situation when I hastily rebuilt a 13B that had lost a rotary in order to get my aircraft off the derelict airfield I had landed at when the incident happened.
After rebuilding the engine, I noticed that it took some effort to turn the engine over by turning the flywheel - more than I had ever noticed when playing with the engine. I couldn't even get a good compression check because the starter would not turn the engine over fast enough. Despite several individuals suggesting that all was not as it should be, I persisted and re-installed the engine in my aircraft. I told myself I had really done a good rebuild job and the engine was simply "tight!"
Another indication that all was not well was after firing it up, initially if I decreased idle speed below 2000 rpm the engine would die. But, after an hour of running, idle speed came down, engine would turn over easily and all was well - so I thought!!!
Flying from NC to MS to attend a flyin I noticed my coolant pressure slowly increasing by approx 1/2 psi for each 3/4 hour of flight reaching almost 18 psi by the time I landed. Then some time after landing and after discussing my increasing pressure problem with others (I was by this time beginning to suspect what was wrong) I pulled on the pressure release lever of my radiator cap and a stream of yellow/green water sprayed about 2" up into the air due to the pressure in the coolant system.
There is much more to the story, but suffice to say I had to tear the engine down again in southwestern Louisiana where I had flown to visit relatives after the flyin in MS. In tearing the engine down, I discovered that - Yes indeed, the inner coolant "O" ring had been compromised and as suspected that was why the coolant system was getting pressurized. On the center and front iron side housings across the rotor housing from each other were two spots the size of a silver dollar where high temperatures had turned the iron blue in color. Also one tiny part could not be accounted for.
It appears that one of the small triangular pieces of apex seal had unknown to me popped out of its slot and laid on the side of the front rotor. Now, if it had laid anywhere but where it did, I would not have been able to turn the engine over after tightening the tension bolts it would have caused such binding. However, I had the bad luck to had this tiny piece of metal land in one of the small holes machined to remove metal for balancing the rotor. There in this recess it provided just enough clearance, I could manually turn the engine over against a lot of friction. Naturally after 1 hour of run time the friction had finally caused this piece to disintegrate - but not before creating tremendous heat and compromising my O rings.
So do yourself a big favor as one who had been there. Tear the engine down again to find out what the problem is. It may not be the same one I had, but the engine should be easy to turn over - even with three rotors, so something is not right.
Good luck
Ed
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
http://www.andersonee.com
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.dmack.net/mazda/index.html.
----- Original Message ----- From: "Phil White" <philwhite9@aol.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Monday, April 28, 2008 1:45 PM
Subject: [FlyRotary] How loose or tight should an engine be?
I finished rebuilding my 20B some weeks ago, using Bruce's video as a guide, and since then I've read someone's post stating that he was able to turn over his engine with a bare hand on the eccentric shaft.
I put in Tracy's new apex seals. As I assembled the engine, it was easy to turn with one rotor in and one side plate, much stiffer with 2 plates and 2 rotors. Once I had all 3 rotors in and 4 side plates bolted together and torqued, I could only turn the engine over using a 15" wrench on the acces end nut, and applying maybe 75 ft lbs of force. I used the recommended lubes on bearings and housings.
Is this normal? Or did I mess up some part of the assembly process that leads to so much drag with only rotors and shaft being turned (no accessories installed yet)?
Any suggestions would be welcome (but I hope I don't have to disassemble the whole thing again!)
Phil 20B to install in an RV-10 in IL
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