.6mm is .0024 inches ..
or just a bit over 2 thousandths of an inch. ..
which isn't much.

I'd smooth up that surface a little..
I think you'll be all right.
Use Water Wetter in the coolant mixture eventually when it's all working
right.

it looks kinda bad in the picture.
I have lots of waterboxer engine cases.

seems that a weld-up and resurface on the bare case would be possible but
kinda extreme.

scott

----- Original Message -----
From: "Tom Lambas" <twlambas@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, September 11, 2011 2:45 PM
Subject: Water pump impeller wore into case

> How serious is, and can it be corrected? The wear is .6mm at the worst
> point. The engine came out for
> overheating issues and a little exhaust in the coolant.  I'm doing a
> complete rebuild because of the high mileage.
>
> *http://tinyurl.com/44q9da9*
>
> Thanks, Tom