Roller Case Conversion from Standard A3B6D

[good2eat]

If you saw my post looking for a new case, boy are they hard to come by.  My plane has been down since November and looks like it could be another year at this rate.  So, I’m looking at options.

Another forum member has a certified Roller case available.  Looking at the Service Instruction document,

https://www.lycoming.com/sites/default/files/attachments/SI1514D%2520Roller%2520Tappet%2520Part%2520Info%2520Update%252002-05-18.pdf

It appears the only parts required are the case, camshaft and roller lifters (was already replacing these so cost-wise just the delta between is the extra expense), tubes, seals and washers.

Has anyone completed this conversion or have additional knowledge as to whether or not there are additional parts from the current A3B6D that won’t just bolt on?

I do realize there are other options - reman. new, move away from the dual mag, etc.  At this point in my evaluation I have eliminated those options due to both cost and availability.

Thanks in advance for info and advice!

-Rob-

[PT20J]

@jetdriven probably knows.

[good2eat]

He and I are talking!

[A64Pilot]

Tomorrow is Monday, give the Lycoming help desk a call, I bet they have a list of every part required as your not the first.

My 2c if you have the option of going roller I certainly would.

Edited July 9, 2023 by A64Pilot

[good2eat]

Ok, so the conversion is as easy as……finding parts.  Lycoming says the service instruction is the all of it.  Parts needed are:

Roller case, roller camshaft, roller tappers, new (shorter) push rods, tubes and gaskets.  All other parts can be swapped out from my current engine.  Was told Lycoming is not expecting kits to be available until January.  My builder tells me we can find the parts, just not in a complete kit.

Change over delta seems to be around $7k more.  It’s kind of  a “the devil you know vs the one you don’t” situation.  No idea how long finding a useable non-roller case will be vs the extra cost.  Feels like a bite the bullet deal….once I know time frame on camshaft and other parts, will have to decide to just wait and hope or move forward.