Good questions Tracy … and the answer to both is yes, we could not see anything wrong with the APEX seals; why one spring set was flattened is still a mystery, so is the broken corner seal but luckily it stayed
in place and caused no further damage. I contribute the broken tension bolt to a combination of over-torqued and perhaps too little anti-vibration RTV.
Fortunately my friend Cary’s bone pile had a set of counter weights.
Jeff
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From:
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Tracy <rwstracy@gmail.com>
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Subject:
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Re: [FlyRotary] Re: Quiet
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Date:
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Tue, 26 Jul 2011 12:12:26 -0400
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To:
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Rotary motors in aircraft <flyrotary@lancaironline.net>
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Couple of questions on the overhaul Jeff.
As you may recall from Chris Barber's experience, if the springs were fried, the apex seals were probably fried as well. Did you check for a sag in the middle of the apex
seal on the fried spring side?
You probably handled this but for builders that don't know,
Did you change both counterweights when you changed the rotors from series 4 to series 5?
Tracy
Sent from my iPad
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From: Jeff Whaley
Sent: Tuesday, July 26, 2011 10:58 AM
To: 'Rotary motors in aircraft'
Subject: RE:Quiet
Yes, it has been a bit quiet and I too have been silent for a while.
Just recently went through a rebuild of my 13B due to low compression … prior to that you may remember that a tension bolt broke and was extracted/replaced.
During disassembly of my engine I found one set of APEX springs flattened, another broken tension bolt and one corner seal broken at the narrow point.
Engine was overhauled with new o-rings from RWS; original APEX seals reinstalled – but all APEX spring sets were replaced with OEM Mazda parts.
I bought and installed a set of solid corner seals from ATKINS.
All the tension bolts were upgraded to the S5 series heavier style.
The ’88-S4-9.4:1 compression rotors were replaced with a pair of ’91-S5-9.7:1 rotors.
The oil-out port was moved from the front cover to the front housing, after drilling through to the oil gallery and tapping for a connector – this removes two 90 degree turns.
The PSRU oil-return port was moved from the front cover to the bottom of the rear rotor housing, after drilling through and adding a connector.
To date only 2 hours on the rebuilt engine … it is making a bit more power – indicated by a richer mixture requirement for best power.
Jeff Whaley