True/False and Essay Test Options

[Poor-sche Lover]

Here's a test for y'all.

Please state whether each statement is true or false. If the statement is false, please explain:

1. 94 mm cylinders can be bored out to 96 mm with no trouble.

2. 96 mm pistons/cylinders will fit on 2.0 Porsche heads with NO machining necessary on either heads or cylinders.

3. If exhaust studs are stripped, you can simply tap them out, and put slightly bigger ones in.

4. If the cylinders have worn to oval, so have the pistons.

In your own words, please answer the following questions.

5. What is crankshaft end play? On a related note, by holding onto the fan hub, I can wiggle the shaft in and out a little bit. Is this a bad thing?

6. What are the tolerances for ovality of cylinders?

I'm sure there will be a follow-up, but that's all I have for now. If you read my last post, "which heads?", (sorry, I don't know how to link) here's the deal. I have acquired a 3-stud 2.0 engine, with 96 mm pistons, but the insides are trash. I would like to put the 96 mm pistons in my 94 cylinders, bored out, with my 2.0 heads on my 1.7 case (with 2.0 crank). I know this really turns it into kind of a bastard, but I simply don't have the cash right now to send my heads to Len. Trust me, I would love to. Maybe I will next year. Anyway, I appreciate your comments.

[Cap'n Krusty]

1. By the right machinist, probably.
2. No. There ARE NO "European" 96mm pistons. They're ALL aftermarket, and mostly
Japanese.
3. No. You REALLY should drill, tal, and helicoil the holes, although there are OE 9mm
stepped studs.
4. Probably, but many forged pistons aren't exactly round to begin with, to allow for
expansion.
5. "End play" better called axial play, is the spacing between the thrust bearing face
and the surface with which it makes contact. In this case, the back of the flywheel,
via shims. In many cases, it's determined by the crankshaft itself against a bearing
in the center of the crankshaft.
6. Ovality is a question I can't directly address without some research. Any GOOD,
experienced machine shop should be able to tell you. "Experience" meaning air
cooled engine experience.

The Cap'n