The New And Improved Unofficial R65 Forum V2

General Category => Chit-Chat => Topic started by: wilcom on April 16, 2016, 04:37:21 PM

Title: Nikasil cylinder/Heat
Post by: wilcom on April 16, 2016, 04:37:21 PM
I've only owned one BMW with Nikasil cylinders, a 82 R80. I've always thought that the Nikasil  liners on the 82 dissipated more heat than the ones without.

That 82 would blister my ankles without boots on a hot day

Anything to that? Maybe it was just warmer the years I owned that R80..................
Title: Re: Nikasil cylinder/Heat
Post by: wilcom on April 16, 2016, 09:42:19 PM
Quote
Maybe it was just warmer the years I owned that R80..................  

After reading a whole bunch of metallurgy stuff and wading thru GM production costs of cylinders( yyada yada yada) I found the answer in the good ol' Wikki.

" The aluminium cylinders also gave a much better heat conductivity than cast iron liners, "

That's why that R80 would burn my feet off in the summer time. A double edged sword to be sure. Burns your feet but gets the heat out of the motor
Title: Re: Nikasil cylinder/Heat
Post by: nhmaf on April 16, 2016, 10:20:51 PM
Just look at it this way - adding an extra 4-5mm of iron sleeve is going to increase the amount of thermal resistance to the outside alloy of the cylinder compared to the very thin Nikasil coating on the alloy
Title: Re: Nikasil cylinder/Heat
Post by: wilcom on April 16, 2016, 10:34:45 PM
I remember the Nikasil bike was VERY VERY uncomfortable in the summer time. A definite consideration when choosing between two bike. If I were going to put the miles on like a car it would be a no brainer which way to go.

Cars are different as you're not straddling the freaking motor so who cares about the heat, wear is the issue.

But on a bike  I never plan to wear out, do I really need neat last a long lasting  cylinders? I think not, I'll go with the comfort