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Two Piece to One Piece Cam Shaft

Steve Pierce

Graham, TX
Just put a straight O-320 together for Lance. We opted for a new cam and lifters along with new ECI cylinders. According to Lycoming service data you have to replace the accessory case when going to a single piece cam/gear because the slinger ring is different. I found that Divco who does all my crankcases can modify the accessory case from a two piece cam/gear to accept a one piece cam/gear. Cost was $160. Here are some pictures.

Original accessory case for two piece cam.

Original two piece cam/gear.

One piece cam/gear not fitting the slinger ring that is riveted to the accessory case.

The newly machined accessory case for a single piece cam/gear.
Steve I'm sending one down to ECI off an O-235 to be machined. $85.50 for the work and $3.50 for the slinger.

Guess I got screwed. Is this on an O-320? I did replaced one on an O-540 but it was riveted in, no machining.
I think I had ECI do one for me a while ago and it was quite reasonable, also had them reface the oil pump area and do the SB on the oil pump shaft. I think they have a list of services and current price on their web site.
Is the snap ring that holds the tach driveshaft in, MS16625-1081?? do i have the right part number or is there a lycoming number? And where can i get just 1 and not 10 or 100?
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Bolduc Aviation at Anoka County Airport in Minnesota made the mod for my engine, an 0-320. Cost was $200 about 5 years ago.