Millennium can repair extreme deep gouges, oval, virtually any damage.

They weld it, then bore it, then coat it. Then bore the nikasil.

 

Hmmm, have you had them do this? I’m wondering if they may have discontinued this portion of their service. They rep I spoke to yesterday said they don’t do repairs. Please let us know. It would be fantastic if they still did repairs.

 

Look into Mahle pistons. I think they were the only ones compatible with the stock FRM cylinders.

 

https://millennium-technologies.com/cylinderrepair/

The first page off their home page is their cylinder repair service. They say 80% of cylinders they apply nikasil also need some amount of repair. So seems unlikely they'd discontinue.

You'll note almost all of their web page text is about motorcycle cylinders. That is their bread and butter. They sponsor motorcycle racers. They also do a lot of repairs for classic bikes.

But they do car engines too. I spoke to them last year to confirm that. Send them your pistons and they'll even bespoke bore them to match each one.

 

Nice! Looks like one stop shopping for F 20s and 22s.

One of the guys that I talked to you there said they did an f20 for a road racer, who took it to Road America and never heard back so that’s a good sign.

 

This seriously would change the game for a lot of us on track car stuff. Other parts availability is becoming somewhat of an issue, but most stuff can be worked around, have aftermarket stuff or can just be purchases used (aka stuff that does not commonly fail). But the $5k used motors is a serious detriment to us. Even if you still had $3-$4k into a rebuild, at least you have a fresh motor instead of a 100,000 mile unknown used sample.

 

A couple of things:

-OEM pistons cannot be run on Nikasil, because Honda pistons are Iron plated. Iron and Nikasil are not compatible, so you need aftermarket pistons. Also, you cannot run Mahle Golds with Nikasil for the same reason.

-The rings need to be barrel shaped and not of the taper or napier type. Rings cannot be chrome plated.

-Standard Nikasil plating thickness is 0.0015 -0.0020. Millenium Tech can do up to 0.040 but not recommended as it may flake off.

-OEM rods cannot be ran on aftermarket pistons because where most aftermarket pistons use a 23.00mm pin, the stock rod accepts a 22.98mm pin only. Additionally, since the stock rod has no bushing, the pin needs to be DLC coated. Most aftermarket pins are designed for bushed small ends.

-The best course of action is to open up the bores to say... 87.50mm (forget the repair manual on this), send your chosen forged piston to Millenium and have them recoat the alum cyl wall after reboring with whatever P/W clearance you want. Don't forget to open up the cyl head to accept that 87.50 piston. Make sure to pick a rod of your choice and you will be golden.

 

Wow, amazing info! Thx!

 

When I called Millennium about a year ago, they said our stock pistons compatible. Then I learned in this thread our pistons iron coated, which would mean not compatible (well documented iron piston coatings and nikasil not compatible). So I assumed Millennium just didn't know about our stock pistons.

Then in another thread slowcrash mentioned he just called them, and they again mentioned our stock pistons compatible. They do know they are iron coated (and now I recall that Millennium mentioned they had already done a few F series S2k engines, so they should have tbat knowledge).

Slowceash found out Millennium is not actually Nikasil. Its thermally sprayed on, not applied in a bath like Nikasil. Apparently its closer to SUMEbore than to Nikasil.

This has several advantages. One, its way more impervious to scoring. Only two downsides my Nikasil research uncovered is oil consumption, and potential for bore scoring of any dirt gets into cylinder.

But SUMEbore seems indestructible. It also has 82% less oil consumption. Compared to what I don't know. But even if that is only compared to Nikasil, its still awesome news.

As fatjoe mentioned in other thread, game changer.

Can use stock pistons (or Mahle Gold), stock rings (I think, more research needed). Stick pistons means can use stock rods. Low oil consumption means only other downside does not apply.

 

Reading this makes me so happy and excited at the same time. I have 2 complete blocks sitting in my garage. I was never a big fan of sleeving the block for 2 reasons.

1. Most sleeved engines I have seen need to be refreshed/ rebuilt more often.
2. The stock engine has been proven to make plenty of power. Riceball is a great example. He has made over 600hp for many years now.