Type 4 Engine build basics, Best approach on rebuild options Options

[TomL]

I am hoping to build a good, solid, higher performance Type 4 which will be used as a daily driver, touring car and perhaps an occasional AX. I have some questions.
1. Are all type 4 engine cases identical? If so, why are "GA" cases preferable?
2. What practical difference is there between a 78.4 stroke crank and an 80mm crank--since the 80mm seems to be more prevalent and a little less expensive?
3. Which is the most preferable bore--94mm, 96mm or 103/4mm?
4. Is there any practical difference between standard 2.0 sized crank journals and chevy sized?
5. Can 1.8 heads be "massaged" enough for decent performance?
6. Pure speculation--What kind of HP might I expect out of an engine with: 80mm stroke, 96mm bore, a moderate cam, re-worked 1.8 heads (8.5 or 9:1CR) and carbs?

Thanks for any answers you can give
TomL

[Dave_Darling]

QUOTE (TomL @ Mar 30 2006, 03:15 PM)

2. What practical difference is there between a 78.4 stroke crank and an 80mm crank--since the 80mm seems to be more prevalent and a little less expensive?

That's one point I haven't seen addressed...

From what I can tell by reading around on the forums, the 78.4mm crank, if set up with the right rods, will not hit the camshaft anywhere on its travel. The 80mm crank will, unless you start to take "extreme measures"... Those including downsizing the crank journals and therefore the rods, and going with a reduced base-circle cam. The latter introduces a few issues of its own...

If you want the fun of doing it all yourself, and the risk of blowing it sky-high, get the parts and build it! If you want to take all the guesswork out, then wait for Jake's store to re-open.

--DD