Type 4 mechanical compression ratio, Why is the factory compression so low? Options

[Beebo Kanelle]

OK, here's a fun one for the novice to ponder and you experts to answer:

Why is the factory mechanical CR so low?

and for reference, what is the highest mechanical CR that can be physically achieved? assume no octane limitations -

I'm just looking for the design limit for the highest CR that can be / has been in a Type 4 engine using available technology.

Thanks

[brant]

The materials used in a stock 914 engine do not like high compression.
Water cooling provides more controlled cooling than does steel cylinders on an air cooled motor

It's expensive to rebuild with modern components/nickies/etc
additionally the metallurgy of the block/heads can play into high theoretical numbers

[ConeDodger]

The materials used in a stock 914 engine do not like high compression.
Water cooling provides more controlled cooling than does steel cylinders on an air cooled motor

It's expensive to rebuild with modern components/nickies/etc
additionally the metallurgy of the block/heads can play into high theoretical numbers

(IMG:style_emoticons/default/agree.gif) engine sealing becomes an issue. Cylinder head temperatures become an issue. Oil cooling which is important to consider separately from CHT becomes an issue.
Your numbers, 100 HP/liter are doable, but I know only a couple builders who can make that live very long. At the raw number, 200-210HP, you might as well put a 3.2-6 in it as you've spent the money...