Ivan's RV-7

Removed the pistons and the connecting rodsTimer icon4h

January 24, 2023

Today I removed all the pistons and the connecting rods.

The first order of business was to make a tool to push the piston pins out. I pretty much stole the idea from the tool one can buy from Aircraft Spruce.

Took me a couple of iterations to get it right. First, I did not measure the pin diameter correctly and the hole in the brace was not big enough. It cracked during use, so I had to replace it with a wider one (I used an aluminum sheet because that's what I had from the "trim bundles").

Then I did a couple of iterations to design the "thrust button". In the end, I turned one that fits over the Superior's piston pin plug and has a small indent for the bolt. The idea is to avoid the bolt going sideways and scratching the sides of the hole (even though connecting rods will get new bushings and pistons are going to trash).

A piston pin removal tool.

It worked perfectly.

Piston removed.

I removed all the cylinders.

All the cylinders removed.

Finally, I removed the connecting rods from the crankshaft.

The connecting rods.

I noticed two things:

  • They were not in order. The Superior Overhaul Manual says to put them in the order of their serial numbers (the lowest number goes to the first cylinder, the next number -- to the #2 cylinder, etc).
  • At least two rods had their serial numbers up! I remember from Lycoming's engine assembly presentation that you are supposed to put them toward the sump. It does not matter, they work either way, but they said it is a sign of "professionalism".

The next step would be to remove the accessory case, and the gears, then try to split the case somehow.