Millennium cylinders?

[BigT]

I am helping a friend with a new to him 2008 TwinCam with 35,000 miles that has a few issues. He doesn't know the history of the prior motor work. The bike is burning oil and has a 25% leak down on the rear and 10% on the front. Pulled the rear cylinder and it has "Millennium" cast on the outside of the cylinder but nothing on the front cylinder.  The bore looks to be 3.935. Any idea if these might be plated cylinders? What cu. in would that make it with the stock crank?
The engine also has a pretty bad shake at idle. The crankshaft runout was .0035. The motor mounts are tight. What would cause excessive shake other than a poorly balanced crank?

[calif phil]

 

[thirdjld]

By googling it sounds like this might be what you have. https://www.revolution-performance.com/107bigbore.php

[Don D]

You picked the worse of the two, so what was leaking?

[Coyote]

[Ohio HD]

Do they look like these jewels?     


[attach=0]

[kd]

How about compression balance. 

[BigT]

You picked the worse of the two, so what was leaking?

We could hear the air coming through the open cam chest so it looks to be an issue with ring seal. I had to leave after the we did the leak down test and my friend started to tear it apart and measured the cylinder diameter. I am heading back over there today to check it out.

[prodrag1320]

nikasil cylinders,we wont use them here.never have ,never will

[Buglet]

  Not to get of the subject but I just seen a new M 8 40% leak down. I know that not right but what going on when you buy a new bike. Is this what Harley allowing now. 

[Don D]

My opinion of air cooled nikasil coated aluminum cylinders, not relevant. Broken is broken.
Uneven compression is the shake.
Now the fix, use OEM cylinders bored and honed properly and a 107" KB line2line coated pistons, fixed.
I have cylinders and the pistons in stock.

[PoorUB]

It would be interesting to know if the one cylinder is standard cast iron bore and the other appears to be nikasil. Perhaps the front cylinder took a dump, someone swapped it out, leaving he rear alone and sold the bike.

BigT, have you tore down the front cylinder ?

[aswracing]

nikasil cylinders,we wont use them here.never have ,never will

Smart man.

I wish I had been so smart. I had to learn the lesson the hard way.

[Raleigh111]

Nickel Silicon Carbide Plating on aluminum cylinders has a great place to live in the  liquid cooled world. Not so great of a reputation in big twin air cooled. They dont seem to like to stay O .. Keep us posted on the other cylinder.

[Eglider05]

Just throw them in the trash and don't look back.

Rick

[JW113]

Not an advocate of Nikasil either, but... BMW used it on their '81 and later airheads, with great success. Why you suppose that is? 250,000 miles on a top end is not uncommon. Much less stroke, piston velocity, and rod angle? Just trying to understand why it does not work in the Harley world when it has a proven record in the beemer-verse. Or is it maybe not Nikasil per say, but related to the supplier and how they make them?

-JW

[Hossamania]

Could it be the angle of thrust difference between a V twin and an opposed cylinder layout?

[TorQuePimp]

Not an advocate of Nikasil either, but... BMW used it on their '81 and later airheads, with great success. Why you suppose that is? 250,000 miles on a top end is not uncommon. Much less stroke, piston velocity, and rod angle? Just trying to understand why it does not work in the Harley world when it has a proven record in the beemer-verse. Or is it maybe not Nikasil per say, but related to the supplier and how they make them?

-JW

Short answer.....BMW isn't using wiseco pistons

[JW113]

That is certainly true! So what is Wiseco bringing that spoils the party? Too much piston/cyl clearance?

-JW

[BigT]

The front cylinder looked good. The rear cylinder was pretty scored up. Decided to use a set of seasoned 96" cylinders bored out to 103" with 10:1 CP-Carrillo pistons. I have no idea what make the old pistons were but the oil ring on the Carrillo pistons looks to be twice as wide.

[Buglet]

   Moto Guzzi use Nikasil cylinders and they are a V twin air cooled.

[PoorUB]

I am guessing that anyone that uses Nikasil successfully has one hell of a lot more engineering into them than anyone that builds them for Harleys.

After all the negative talk I have seen about Nikasil cylinders for Harley I wouldn't touch 'em if they were free.

[Deye76]

Or maybe the producers of Nikasil v-twin cylinders already know Harley riders will put up with a lot more mediocrity than most.

[TorQuePimp]

That is certainly true! So what is Wiseco bringing that spoils the party? Too much piston/cyl clearance?

-JW

Ok.....they had a "Potty mouth" ton of failures

From what I gather.....they blamed the rings

Seems they don't quite have the issues fixed

Was a guy in Tennessee that was selling 113" kits with mahle pistons

From what I know they held up fine

[JW113]

I am guessing that anyone that uses Nikasil successfully has one hell of a lot more engineering into them than anyone that builds them for Harleys.

Are you saying that BMW had done more and better engineering than some small USA aftermarket outfit? Say it ain't so!


As I suggested earlier, the technology is tried and true. That does not mean that it's easy or cheap to make it work. And I agree, have not/would not touch them either from any company currently supplying them for Harley-Davidson motorcycles. Wonder if BMW could be talked into making them?


-JW