820 rings

[ted johnson]

Does anybody know? The 820 single ring pistons that K Precision was selling, is the ring chrome, or is it a standard steel/iron ring like a normal 820. According to Dave Bonbright, you should NOT run a chrome ring against a chrome bore. I'm hoping these pistons and rings were meant to retrofit an earlier 820 so you can upgrade the engine. )f course, you can run a chrome ring OR a standard ring on Nikasil, but not on chrome bores. Any thoughts? Thanks. Ted

[ted johnson]

I can't believe NOT ONE kart guy wrote in answer to this valid question. I finally got an answer from Jeff K. at K Precision himself. I'd have thought that one guy could have taken five minutes to help these 820 owners who have bought these pistons. Thanks! Ted

[Mark Loraine]

I believe they are all on facebook Ted, the VKA FB buy and sell a thon....its really detracting from these dedicated forums, but hey, you all wanna put your private contact information out there in cointelpro land, go ahead.
You wont see me on it!

I always thought that you couldn't use chrome faced rings in a chromed-nikasil lined bore, thats still correct right?

Regards,
Mark L. / SWNY

[ted johnson]

Hey, Mark. I'm on zero social media, unless you think of this and "Vintage Karts" as social. I refuse even to put my credit cards on line. If a company won't accept a phone order, I don't buy the item.
I never knew they chromed over Nikasil. I believe chrome rings are O.K. on steel, cast iron and plain Nikasil, but I may be wrong there as well. I'm not sure what the Wiseco bike/snowmobile rings consist of. I DO know that the Arias pistons Louie Figone was selling used Wiseco rings on Nikasil. My Nikasil 610 had almost no static compression, but ran very well at bottom and top end with the Wiseco ring. There was absolutely no evidence of the ring running in the bore at all. When I gave Pruit Ginsberg the engine, it was like new inside. This whole ring business needs someone with more knowledge than I have to write a definitive article telling EXACTLY which ring to run in which cylinder material. It doesn't affect me, as I run only iron bore 610's now, and can run any ring I want. I have buddies who have 820's with chrome bores, and with Nikasil. Ted

[Mark Loraine]

by me saying "chrome Nikasil", I may have mis-spoken, someone needs to set me straight for certain.
I guess over decades of assumption I always equated Chrome WITH Nikasil and that could be a misnomer.

By today's standards, these Karting forums could not be considered a social media.
Example: no one is going to give me a strike for letting out disinfo on nikasil here, the kindly Gentry will get it straight without deleting/censoring/flagging/demonetizing/blocking/or get it checked by online fact checkers with an agenda.

Mark Out

[ted johnson]

I'm a Republican. NOBODY except God, is going to give me any kind of "strike". Nobody, except for our good Rob and Bob, is going to "block" me and anyone who wants to can "dislike" Me. I don't give a sh## what anybody except my handful of friends thinks of me. When I write "advice", it is as good and correct as my 63 years of karting can provide. And that doesn't mean that it is always gospel! I can be as wrong as anyone else. I just try.
On the Nikasil thing. Nikasil is really a completely different animal from chrome. It is less brittle, less apt to peel, and even tougher than chrome. The only thing I dislike is that it doesn't add physical strength to the cylinder like a steel or iron bore do. I remember my buddy used to run a stroked 820 that had a .100 overbore. That beast ran several seasons and never did break. I still wonder at that! Aside from the Palmini equipped AH58 PP's, we never even heard of using tie rods in the early sixties. Ted

[ted johnson]

Oh, yes, by the way, US Chrome can Nikasil coat a cylinder up to .025 thick, then hone to final bore size. This can save a cherished old cylinder when you can't get a piston with a large enough oversize to accommodate a thin hard chrome coating. An expensive ported cylinder can be saved for more years of running. I don't know if they can mask off the port edges. Port timing could be screwed up with a .025 coating lowering the tops of the ports! Ted

[Rob Voska]

Ted lots of snowmobile & 125 / 250 bike guys would have more experience with that than many karters. I have read some good articles years ago on it. I agree std. ring in plated bore is what I have run in my 125 shifter. If you don't stick them little to no wear.

I will say there are only a couple of good places to send stuff for plating. Not for the plating but for the diamond hone to get a cylinder round. Our kart cylinders are pretty wild compared to many bike & snowmobile cylinders. Honing round with little to no support is hard to do.

[ted johnson]

Rob, I had been in contact with Scott Reath at the main Fond Du Lac, WI Nikasil plant years ago. If I were going to Nikasil a cylinder I would send it to US Chrome there. They still seem to be a solid shop. I'm afraid, as engines get worn, the Nikasil ability to build up the surface might well be the only option to save worn aluminum cylinders. I didn't ask about Nikasil-ing blind bores. It might be a good thing to know, especially for Homelites and 700 five port Benders. There are still a decent number of West Bend 700 three port blocks around. If a Mac or 610 Bend guy wanted the last word in RPM, he could overbore the iron bore in his engine and have it Nikasiled over the iron. Probably worth a few hundred RPM if he could get the right rings. Ted

[Rob Voska]

Blind cylinders create a whole new problem when honing.

I have talked to him in the past about a sleeve for an engine at work. He didn't want to do it because it was hard to hold and ran at 100" of boost.