Engine rebuild questions.

I have decided to rebuild an io-360 that had a power off prop strike. It has a roller cam and 9:1 pistons built by aeosport. I have for certain decided to replace the crankshaft. I am leaning toward a clone since both Superior and lycoming both have extensive wait times. The engine has 760 hrs. Do I just re-ring or do I bore and go with an oversize and replace the pistons with the 8.5:1. Lycoming says to replace the roller lifters at overhaul but I am leaning on not doing that. It costs $3,000. I had the case inspected and it is good. Any suggestions would be helpful.

If there is no rust in the cylinders, why not keep the pistons/rings/cylinders as 4 matched sets (a set being a cylinder, a piston, and the accompanying rings) and simply reinstall them as is?

Once you split the case it?s hard to find a place to stop, and from your questions it sounds like you have decided to do an IRAN instead of an overhaul. There?s nothing wrong with that approach, but the time, money and parts spent splitting the case is wasted if not applied to an overhaul. For me, with a new crank and bearings I?m going to get the case overhauled as well. As for the cam and followers, that?s a tough one. You?d like to go back together knowing everything inside the case is set to go to TBO. If you don?t spend the $ on those parts now you might be looking at opening it back up before TBO. It?s your money, and a tough call.
Tim Andres

jask said:

Do I just re-ring or do I bore and go with an oversize and replace the pistons with the 8.5:1. Lycoming says to replace the roller lifters at overhaul but I am leaning on not doing that. It costs $3,000. I had the case inspected and it is good. Any suggestions would be helpful.

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You measure and go from there. If there's not much of a wear step you could just clean up the cylinders with a dingleberry hone and put new rings in, reuse the pistons if they're not scuffed.

Lycoming always wants the roller lifters replaced at a prop strike or sudden stoppage. There is no inspection criteria for Lycoming roller lifter inspection.

Engine rebuild

I have been going through the engine log today. The Aerosport parts list was included on the build that listed 9 to 1 superior pistons and a SL3601-SC ring set. This is an actual lycoming engine with no choke in the cylinders and it looks like they installed the incorrect rings. On the tear down, we also noticed a nearly horizontal cut on one of the main bearings. It lists part 18d26098 for the mains. Are those vaccuum packed in plastic with a possible knife cut to open them? Just wondering where the cut came from. The crankshaft seal joint was right at the case joint also but had no evidence of leaking.

ENGINE,

I HAVE HEARD A LOT OF BAD THINGS ABOUT AEROSPORT , WRONG PARTS INSTALLED. YOU LVE IN CA THE ARE LOTS OF GOOD ENGINE SHOPS IN THE US.
YOU NEED TO HAVE CRANK MNAFLUXED, AND CHECKED FOR RUN OUT, ROD'S ALSO , IF ENGINE WAS NOT RUNNING , YOU MAY USE A LOT OD THE PARTS AFTER ENGINE SHOP INSPECTION, LET THEM INSPECT ROLLER LIFTERS, LET THEM CK CYLINDERS.
YOU DON'T GAIN A LOT WITH ROLLER LIFTERS, AND THEY ARE HEAVY , GOOD FOR MAYBE 2 TO 4 HP, NOT GOOD VALUE FOR THE MONEY, A AIRCRAFT ENGINE SHOP WILL BE YOUR BEST BET.

A1AVIATON47 said:

I HAVE HEARD A LOT OF BAD THINGS ABOUT AEROSPORT , WRONG PARTS INSTALLED. YOU LVE IN CA THE ARE LOTS OF GOOD ENGINE SHOPS IN THE US.
YOU NEED TO HAVE CRANK MNAFLUXED, AND CHECKED FOR RUN OUT, ROD'S ALSO , IF ENGINE WAS NOT RUNNING , YOU MAY USE A LOT OD THE PARTS AFTER ENGINE SHOP INSPECTION, LET THEM INSPECT ROLLER LIFTERS, LET THEM CK CYLINDERS.
YOU DON'T GAIN A LOT WITH ROLLER LIFTERS, AND THEY ARE HEAVY , GOOD FOR MAYBE 2 TO 4 HP, NOT GOOD VALUE FOR THE MONEY, A AIRCRAFT ENGINE SHOP WILL BE YOUR BEST BET.

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Why are you always yelling at us?

The crank does not need to be replaced necessarily. It should be inspected. If it is good you don't need to replace it. Even of the prop flange is slightly out of true, it can be straightened.

You need to pick a GOOD ENGINE shop and let them go though it. You will replace and repair as needed.

jask said:

I have been going through the engine log today. The Aerosport parts list was included on the build that listed 9 to 1 superior pistons and a SL3601-SC ring set. This is an actual lycoming engine with no choke in the cylinders and it looks like they installed the incorrect rings. On the tear down, we also noticed a nearly horizontal cut on one of the main bearings. It lists part 18d26098 for the mains. Are those vaccuum packed in plastic with a possible knife cut to open them? Just wondering where the cut came from. The crankshaft seal joint was right at the case joint also but had no evidence of leaking.

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Cylinders from Lycoming have choke in them unless they are plain steel and not nitrided. Plain steel non choke cylinders were only used on low 7:1 compression engines
Good Luck,
Mahlon