Interesting read on sleeves

[2001KX5]

This is an article by Transworld Motocross about sleeve technology.

http://www.transworldmotocross.com/mx/features/article/0,13190,598355,00.html

Some text from the article:

    

Mark let us in on some of the advantages of a sleeved cylinder vs. Nikasil-plated cylinders. "What's important about sleeves, is that they hold more compression than a Nikasil cylinder, because of the cross-hatches and the way the sleeve dissipates heat faster. The dirt trackers and flat trackers have been buying sleeves from us for the last 15-25 years?it's their secret. A lot of the Supermoto guys are starting to buy sleeves from us, because they're realizing they're getting 3-4 more horsepower with a sleeve than Nikasil."

"The only reason the factories are running Nikasil is because it's more cost-effective in production. They don't have to have it put in, The cylinder can go in and boom, it's ready. A sleeve has to be dropped in, and matched. The Nikasil was just another way to cut cost with the factories, and it is lighter than the sleeves."

It is an interesting read and it is centered around LA Sleeve.  I just figured I'd post it and probably start some kind of discussion since I have my cylinder at Eric Gorrs for sleeving and porting as we speak due to an extensive crack that was not repairable.

So the question I from this read is are plated cylinder industry hype and the cheapo out or  is it a superior technology.  My last KX250 was sleeved and I never had an issue and had lots of power on tap especially down low to mid range with  a decent top end.

[metallicarebal]

I really don't know to much about the process but I have heard nothing but good things about sleeves. I had one put in my KX 100 last year when I had the motor rebuilt and never had a single problem with it. I wish now that I wouldn't have changed my gearing so I might have been able to notice a possible increase in power. All in all though I'd prefer a sleeve in my motor.

[Timbowe]

Makes sense when ya think about it..

[gowen]

While there is some truth to the article, I do not believe it is to be cost effective. Due to the fact that cylinders are not built with plate on them. You don't just throw it in the fire and boom it is done. A sleeve is like that though, I could just heat my cylinder up... Boom/line up. I'm done.

I dealt with sleeves for a long time and was relieved when I got my first Kawasaki. To be honest. My friends that raced hated sleeves, but used them because they could change the cylinders easily when locked up. That is the only advantage I knew about.

Call me a hard-ass, but I abuse the living shyte out of my cylinders and don't have any issues. Also, sleeves get hot and can cause seizures easier.

[KXcam22]

I'm not sure which I like better but there are some things in the writeup that don't sound right to me. First, a steel liner can't transfer heat as quickly as plated aluminum, It's simply a property of the metal.  The crosshatch thing may be true but the coeffccient of friction is lower for nikasil than steel which should mean more HP and less heat. Just my 2 cents. Cam.

ps. In my locale I have to ship the cylinder 1000 miles to get replated but can get it bored down the street.

[demographic]

So the fact that you can run tighter piston to bore clearances with plated bores, that steel doesn't transmit heat quite as well as aluminium and the fact that Formula one racing cars use plated bores (lets face it the F1 boys don't give a toss about the price difference do they) doesn't make any difference to his arguement?

What was he selling again?

[2001KX5]

I mean there is def. some bias in the article as he is interviewing dude from LA sleeve, but at least transworld does some decent articles from what I have read.

The thing that made me question it was when he spoke of the heat transfer to the sleeve.  It one thing to say that, but you should back it up with facts to prove it imo.  Perhaps the  materials they are using in the sleeve actually have decent heat transfer #'s..... I dunno.

As for the F1 cars, well I mean they are limited in HP so power to weight ratio means every thing. Imagine how much weight 12 cylinder sleeves would add.  Much more weight than they can find to shed off the cars no doubt so take it all for what its worth. And I'm just playing devils advocate here as well so don't shoot me.

I would love to see some power #'s of sleeved motors vs  plated motors. I may try to run my 500 on a dyno the summer, but we'll see.

And you know, talk to 100 different people and you will get a 100 different stories.  While I don't race or hold WOT for long periods of time I still ride it for what its worth.........well, for what I'm worth lol, so I think a sleeve will do just fine.

[gowen]

I'm not sure which I like better but there are some things in the writeup that don't sound right to me. First, a steel liner can't transfer heat as quickly as plated aluminum, It's simply a property of the metal.  The crosshatch thing may be true but the coeffccient of friction is lower for nikasil than steel which should mean more HP and less heat. Just my 2 cents. Cam.

ps. In my locale I have to ship the cylinder 1000 miles to get replated but can get it bored down the street.

I thought so too Cam. I could smell a stink.

[John]

I was gearing myself up for a massive response and I figured... what's the use?

Everyone is entitled to their own opinion. Mine is 100% with coating. Having the same material in the piston and cylinder walls (bar the coating) will at least allow for the same heat expansion. My personal experience is that minor sizes can be fixed when you have a nikasil coated cylinder; this is not true with sleeves.

FYI, I found a lot of information on the net about this but failed to find a definitive (authoritive) source that could claim one or the other to be true.

I think this is a very good subject for a murky, rainy day at the pub, not sure we can solve it here in this forum.

Cheers!!

//John

[duudu]

What you said about sleeves is true, i am also a kart racer and i have never seen a 100 cc kart engine that has nikasil, my engine puts out about 38 hp and does 22k rpm,engine life is one weekend which means half hour of practice and break-in one qualifycation race and 2 heats , will send my kx engine to eric gorr as i see you all respect him and he does a pretty good job. Sorry about divagating from the subject