More surprises!

Curiouser and curiouser! I spent a fair amount of time during disassembly taking measurements and writing things down, and then promptly forgot to worry about any of those numbers. When I was sold this engine, it was sold to me as a 2180. There was some mystery behind its history, but I didn't think too much of it. However, as I was ordering parts today, I realized that the numbers didn't match up.... specifically, the cylinder and crank numbers. 

A Volkswagen 2180 engine begins life with around 2/3 that displacement, and then a bit of machine work is down. The crankshaft, which comes stock with a stroke of 69mm, is replaced with a crank with a stroke of 82mm. In addition, the cylinders and pistons, originally in the 85-90mm bore range, are replaced with 92mm sets, which gives the final displacement of 2180cc.

My Volkswagen "2180" engine no doubt had similar beginnings, but the end result is a bit different - the pistons are not 92mm, but 94mm. The crank stroke, likewise, instead of 82mm, is 78mm. The engine I'm working on has, in fact, a displacement of approximately 2165.

What does that mean? I'm not sure. Obviously the parts for it are different. As far as power and reliability, those depend a lot more on quality of workmanship than they do on any other factor. Bottom line, I *may* have a little more torque, or I *may* not, and at the end of the day it's still up to me to build a solid engine. 

This does cause some complications, though. The main one I've run into so far is that nobody sells cylinders for a 78mm stroke... only 69mm and 82mm. That being said, some folks sell the 82's as "78-84mm," and don't give any other dimensions. There are three possibilities, as I see them (in order of most preferable to least preferable from my point of view):

1. The cylinders are short enough for 78mm stroke, and you add shims to use them for longer strokes

2. The cylinders are long enough for 84mm stroke, and you cut them down on a metal lathe if you need shorter cylinders

3. The cylinders are somewhere in the middle, and we don't really expect you to worry about compression ratio that much.

I'll know better once they show up and I can measure them. One way or another I'll get this engine built.... but if I have to custom cut each cylinder, it'll probably cause me to wait a little longer before the next rebuild.

On a more normal note, I finally got my crankshaft ready to send out for NDT (Non-Destructive Testing). Here's the key in the slot:

Partway removed:

All the way out:

I hope to spend some time this weekend cleaning the parts I intend to reuse... we'll see if I can pull myself away from this guy long enough to get any work done.