Sent: Sunday, March 09, 2008 10:01 PM
Subject: [FlyRotary] Possible Causes : [FlyRotary] Re: Coolant leak - the
teardown
> Chris,
>
> Take a straight edge and make certain your side housings are not warped.
> The rotor housing and side plate need to have a tight fit. Any debris that
> may have gotten lodged (could be very small piece of metal) between rotor
> housing and side housing could cause a leak into the rotor housing. Same
> bit of metal might be very hard to find upon disassembly.
>
> The fact that your bearing was destroyed may have contributed - check your
> side housings to make certain the rotor wasn't scrapping/pushing on the
> iron housings as it ran due to the failed thrust bearing. Without the
> bearing those rotors could have been moving laterally much more than
> normal and possibly contact the side housings. I don't think that would
> cause the coolant leak, but wouldn't hurt to check closely.
>
> If the O ring had not seated properly (gotten pinched) it can be hard to
> tell upon disassembly but could have compromised your sealing - you might
> be able to spot the pinched area - but perhaps not.
>
> The ONLY ways I am aware of for coolant to get into your rotor housing
> are:
>
> 1. A compromised "O" ring (bad ring, pinched ring or too much heat) -
> generally the most common cause of leakage.
> 2. A bad "O" ring lan in the iron side housing - this can be hard to find,
> because the vertical wall may look fine, but you might have a crack at the
> base of the vertical wall of the outside part of the groove in the side
> housing. Take a dentist pick and pull the tip along the inside of the "O"
> ring grove - particularly on the outside part. If you get any catches -
> check that area very carefully.
> 3. A hole in the side housing or rotor housing through into the coolant
> galleys - but that should be readily apparent
> 4. Very unlikely but made certain your spark plug hole through the rotor
> housing doesn't have a leak to the coolant galleys. Plug up one end
> (inside the rotor house - say with your finger) of the spark plug hole and
> then force compressed air into the other end of the spark plug hole - it
> should cause air to blow past your finger - if not you have a hole into
> the coolant galley.
> 5. With the older aluminum rotor housings - there was a belief that if
> they got too hot, the compressive forces of the tension bolts could cause
> the housing to "shrink" (compress) a bit in width. There was a
> specification about minimum width permitted the rotor housings.
>
> Very early on I overheated my 86 N/A and got a coolant leak. When I check
> the housing, it was at the very minimum limit - now I've always sort of
> doubted this "shrinking" took place, but apparently Mazda did not. So you
> might check the housings width before putting it back together just on the
> outside chance.
>
> All I can think of
>
> Ed
> .
> .
> ----- Original Message -----
> From: "Christopher Barber" <
CBarber@TexasAttorney.net>
> To: "Rotary motors in aircraft" <
flyrotary@lancaironline.net>
> Sent: Sunday, March 09, 2008 10:14 PM
> Subject: [FlyRotary] Re: Coolant leak - the teardown
>
>
>> So guys, what do y'all think. What do you think is causing the coolant
>> in the rotor housings. I really want to figure this out before I put the
>> dang thing back together. Your help is appreciated. TIA.
>>
>> All the best,
>>
>> Chris
>>
>>
>> ----- Original Message -----
>> From: "David Staten" <
Dastaten@earthlink.net>
>> To: "Rotary motors in aircraft" <
flyrotary@lancaironline.net>
>> Sent: Sunday, March 09, 2008 8:29 PM
>> Subject: [FlyRotary] Coolant leak - the teardown
>>
>>
>>> Well.. today we tore the engine apart.. the short and sweet of it is
>>> there is no obvious source of a coolant leak.
>>>
>>> Took the engine apart without too much trouble..
>>>
>>> As we pulled off all the housings we checked the rotor faces, the
>>> grooves, the seals and the intake ports for any sign of a leak or
>>> blowout. None was forthcoming. I had expected to see a blown out coolant
>>> o-ring groove, but all were intact. Felt the intake ports, no sign of a
>>> problem there either. I had only ported the center iron, so the other
>>> two end irons were stock. So as it stands, we have an engine that is
>>> giving us no obvious reason for a coolant leak. The bolts werent loose
>>> at all.. they were so snug from tape and silicone it took a hammer and
>>> vise grips to extract them once they were untightened.. So thats the
>>> semi good news..... nothing obvious.
>>>
>>> Now the bad news..
>>>
>>> When we took the engine apart, I was concerned about how the rebuild
>>> itself went.. and how things held up to our first attempt at building
>>> the engine. I examined things as we took them apart and paid particular
>>> attention to the front end.
>>>
>>> I was even showing Chris how the front bearings can be a problem if you
>>> loosen the front bolt and cause a bearing to get pinched.. well the
>>> front bearing on the outside of the thrust plate looked fine. Took off
>>> the thrust plate and discovered that the other bearing had destroyed
>>> itself. At this point, Chis chimed in that there was metal bits in the
>>> oil when he drained it, and lo and behold the bits resembled the roller
>>> pins in the bearing..
>>>
>>> The spacer had welded itself with the inner ring on the destroyed
>>> bearing, forming a spoked wheel, and the inside of the thrust plate had
>>> wear damage to it as well.
>>>
>>> I am certain i know when this happened. During assembly, everything went
>>> as it should. end play was ok. I had installed the stock pulley on the
>>> front at the time of rebuild. After we added the PSRU I was no longer
>>> able to check end play, as it secured the engine's flywheel travel.
>>>
>>> At some point, we purchased and I added a double pulley, and while i
>>> took care not to let things shift around, I am suspecting that this is
>>> when it happened. The lesson: don't remove the front nut if you cant
>>> check end play or put the engine vertical.
>>>
>>> The remainder of things looked great - no missing pieces, nothing burnt,
>>> no gouges... 10 hours of use on the ground and thats what weve found.
>>>
>>> Dave
>>>
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http://www.flyrotary.com/
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>>
>>
>>
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