Actual re-plating results at Millennium

[Glenfield]

All,

Wanted to share results of 95mm cylinders I had re-plated at Millennium. A lot has been written on this subject (including some sad stories), and so hopefully these results are a useful reference for others doing the same.

I specified that they hone for an Ra of ~6. Millennium did this. When explicitly requested, they can and will do it with seemingly consistent results. Based on discussions with them, their default appears to remain ~15 though so specify what you’re after.

I did not specify RK, RPK and RVK but you can see the results that came back. Compared to Ra, these specs are comparably un-discussed. Not sure if this is Millennium’s default and/or whether it’s acceptable. Hopefully some of the learned folks here can shed light on the topic for others.

The other apparent blind spot is what ring to use at these Ra’s. Default appears to be Goetz but am assuming that’s not exhaustive. Hopefully that gets cleared up in time.

Cheers,
Tom

[john walker's workshop]

Goetze w/Total Seal oil rings.

[wjdunham]

Who did your measurements? I have a spare Millenium plated cylinder that I would like to have the Ra measured if not too expensive to have done.

Bill

[Glenfield]

Engine builder took care of it in the end. Found a profilometer nearby.

I was in a bind and there was a gentleman on here called Cgarr that was kindly offering to help. He is local-ish and I don’t want to volunteer his time but he may be worth checking in with if you can’t track one down.

[Trackrash]

Originally Posted by john walker's workshop

Goetze w/Total Seal oil rings.

Good to know.

[Mike Andrew]

Most any precision machine shop, especially those specializing in grinding, will have a profilometer in their facility. Now, as for charges or willingness to perform surface finish inspections for private individuals may require a few calls. Might even get lucky and the owner is a Porsche guy.
Another thing I lost access to when I retired but sure wouldn't go back.

[Glenfield]

LN Engineering is one such reputable shop that provides the service for a fee. If I was doing it second time around, I’d probably have LN intermediate the re-plating from the get-go.

John’s comment above on rings is much appreciated. That’s as good as gospel but I’d love to appreciate the reasoning and for good sport, other options. LN as an example uses Mahle performance rings in their Mahle+Nickie P+C sets. Maybe the Nickies have a different Ra RK/RVK/RPK etc matched to the rings (or vice versa)?

Cheers,
Tom

[shoooo32]

I've inspected three sets of cylinders plated at Millennium in the past month. All were 4-6 Ra.

[fred cook]

When I rebuilt the engine in my SC, I used the 100mm slip fit LN Engineering cylinders, Mahle pistons and Mahle rings. The rings seated almost immediately and the compression measured 160-161 across the board. The cylinders were pricey but worth the $$$ in my opinion.

[Glenfield]

Your 3.3 sounds great Fred. Have seen your posts about it. Story for another thread perhaps, but would love you to post a little more detail on how you modified your CIS and throttle linkage to more dynamically moderate A/F.

[Mike Andrew]

This must mean that reassembly is imminent...

[Glenfield]

Don’t jinx me Mike! It’s been a rolling “2 weeks” all summer ... does feel very close now though