John;
I've always wondered about using electroless nickel plating on cylinder
walls. It is easy to apply, it is a low-friction coating, and it heat-treats
to a high hardness, so wear should be minimal. Hard chrome plating has been
used for years in cylinders and I've wondered if electroless nickel could be
a "poor man's hard chrome".
Since electroless nickel plating deposits are pretty uniform thickness,
perhaps grinding wouldn't be necessary like it is with hard chrome.
Has anyone tried this or heard about it's being tried?
Regards, Neil Tucson, AZ
-----Original Message-----
From: John Goodman [mailto:ggl205@yahoo.com]
Sent: Sunday, May 04, 2003 5:40 AM
To: land-speed@autox.team.net
Subject: Addendum to Nikasil coated bores
List:
One or two motorcycle racers inquired about honing
coated cylinder bores. I responded by saying that the
procedure was very much like honing cast iron.
Although the honing process is very similar to cast
iron, these coatings are not very thick. Caution
should be exercised when using various grit sizes to
remove stock and generate a load bearing surface. With
cast iron, the 80-100 grit abrasive is used to remove
stock and set the ultimate valley depth. Nikasil type
coatings will not tolerate such a course grit, nor is
it needed. Whatever surface you wish to put on a
coated bore, stock removal should be restricted to a
safe ratio of coating thickness available. My
experience points to removing no more that .002" of
the coating. This is still enough to create most
plateau and peak surfaces.
Anybody racing the old Vega engine (or one like it)?
Are you using the original high-silica alloy as the
wear surface? Contact me if you are.
John
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