Mailing List flyrotary@lancaironline.net Message #67971
From: Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: 13B Teardown
Date: Sat, 27 Dec 2025 22:32:12 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
I may be able to reuse the ones in the engine. Not sure I'm comfortable making the inner ones that are exposed to combustion.

I started to look up prices of side seals. $200 for 12 or $24 for one. Are they now made of gold?
I'll try to not break the stuck ones, or maybe see if the used ones I have from decades ago will fit.
Then another $150 for the springs. I'm stunned.

Well, you're welcome to come pick up the RV-3B. Just let me know before the end of the year so I can cancel the weekend Light-Sport Repairman- Inspection Course I signed up for. I have repairman cert for the RV-4 I built so I really only need it for the RV-3B.

Finn

On 12/27/2025 7:57 PM, Andrew Martin andrew@martinag.com.au wrote:
Hi Finn
You can make your own orings. Actually this is now my preference as it is extremely cheap & reliable process.

that plane must be a real hoot to fly. Do you want to send it to Australia?

Andrew Martin
+61 0427477144
andrew@martinag.com.au




On Sun, 28 Dec 2025, 6:29 am Finn Lassen finn.lassen@verizon.net, <flyrotary@lancaironline.net> wrote:
I was unable to get compression on more than one chamber.

So I removed the engine from  the RV-3B today.

I decided to heat the front bolt with a propane torch for several
minutes when my HF 3' breaker bar began to deflect noticeably. Then it
broke loose.

Fortunately I still have the rear nut remover that I fabricated (by
hand, no less) and welded up back in the late 90ies. Still needed a 2x4
to keep engine from moving. Also had to heat the nut with a propane
torch. Wood block splintered, so used a 5" socket extension between
counterweight tip and bottom right rear plate corner. Recommend using
edge area of rear plate that is not used in your application, just in
case it breaks off.  Evidence of threadlocker on both front bolt and big
nut. Required a rivet gun with mushroom head on the rear shaft to get
the counterweight off.

Interesting that he rebuild uTube videos I've been watching do not
mention threadlocker  on front bolt and rear nut.

Anticipate several days of cleaning before I'll know what to order.

I wonder if the $80 "reusable" o-ring kit on eBay is junk or if safe to use.

Finn

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