Ski

The process is on the net, you can google (sorry for the spelling) Klobershmidt Aluminum Engine repair, it may take a few hits to find it but it's there, with number of passes, rpm, etc. m42racer is correct on the last phase, which is done with felts, paste, and oil to finish the bores. Should look like this:

TT

All the latest VW/Audi/Porsche Alusil blocks are now machined using a 3 stage stone honing only process, no more etching paste w/felts. Has anyone seen this offered outside the factory?

Ronin951

Sorry guys, I guess I should RTFM before asking questions

So the numbers are..

Step 1 "Roughing" 0.07 mm (.0027")
Step 2 "Dressing" 0.03 mm (.0011")
Step 3 "Polishing" 0.01 mm (.00039")
Step 4 "Lapping" 0

Based on this, what I would need to make my number is step 3 & 4. However, if I understand correctly you won't get anything out of step 3 without step 1 & 2. I assume you can do the lapping step without 1, 2, and 3, therefore for me that leaves step 4 (for grins) and a tight .0025" tolerance. Otherwise I'd be 0.07 + 0.03 + 0.01mm over.

I did my best to get some closeups of my bores. They are all pretty much identical. The scratch marks are from the bore gauge.

Ronin951

The guy at the place I got it done at showed me a can of black pasty "stuff". He also showed me what I assume is a felt pad that had been previously used (paste and aluminum all over it). What do these pads look like exactly? PM me and I'll give you the name of the shop. It's within driving distance of you. YMMV.

Ski

TT, I haven't come across it yet but I haven't done one in a few years. AFAIK Duffin in San Antonio who does our work, is still on the "old" process. But with the recent engine failure, we'll be sending 1 of our spare blocks up there in the next couple of weeks.