Shaving head on MC engine? BTDT's?

[auditude at neta.com]

Hi Gary,

How exciting!  I've got my own questions, for you and anyone else 
willing to answer.

Is there anything you can tell me about the K24 change?  Does it 
limit max boost?

Do you know the order in which upgrades should be done?  Chip, 
wg spring, bypass valve, single pass intercooler, k24, 2 piece em?

Do you have to fabricate a pipe to install the single pass 
intercooler, or are pipes available?

Are there any reasons that one shouldn't use MC-2 equivalent c/r 
with an MC-1 ignition system?

Thanks,

Ken

On 12 Jan 2001, at 10:35, Gary Erickson wrote:

> In celebration of my '89 200q's impending 200K mile birthday, it's about
> to go under the knife for a full top end rebuild and installation of a
> 20V single-pass intercooler and K24 turbo.
> 
> (Just to avoid confusion, let me state that my car is an early '89 with
> the MC-1 engine that came stock with the lower 7.8:1 CR and K-26 turbo.)
> 
> An Audi-owning friend of mine asked "While you have the head off, why
> don't you shave it a bit to bump the compression ratio up closer to the
> MC-2 engines?"  (8.4:1 CR if I remember right)
> 
> I know from talking to a couple of source and peering at the family
> album, that the CR increase in the MC-2 came from a different piston
> design.  But I'm not planning to tear into the bottom half unless I see
> something wrong while the head is off; so I'm curious as to whether this
> would be an acceptable alternative.  (And likely cheaper, I'm guessing.)
> 
> Does anybody have any comments about this procedure?  (Either BTDT, or
> good reasons not to are both welcome!)
> 
> And yes, I am aware of the slight change in cam timing that would occur
> with the head shaving, but I'm already planning to install an adjustable
> cam gear to play with, so I could easily dial out this issue.
> 
> TIA!
> 
> -Gary