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Costa P Costa P is offline
Slippery slope skier
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Join Date: Sep 2010
Location: South Africa
Posts: 179
Finishing and fine grinding

Some feedback to whoever wishes to attempt this;
The following PFERD abrassive rolls worked well for me:


The CO-COOL (cermanic oxide grain) worked like a charm.
The aluminium oxide type rolls were a waste of time/money!

80grit works best and leaves the right texture on the port surface to help with the flow (turbulent boundary layer blah blah blah).

The PFERD store didnt have stock of the 1235 in 80Grit. So using the 120 grit was next best. The result is a bit on the "too smooth side".....but in the grand scheme of things I believe it is just fine.

Try and buy the longest arbor you can reach deep into the port without running the risk of the rotating collet of the die grinder making contact with the valve seats etc.

I wasn’t able to find a long arbor, so I had to be extra cautious not to hurt something with the rotating collet. Covering the collet with a strip of plastic (ice-cream tub) provided a small margin of protection in case it made slight contact with something.
Old 11-21-2016, 11:56 AM
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