The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Crossrodes on April 12, 2009, 05:24:46 PM

Title: '79 Cylinder Liner Etc
Post by: Crossrodes on April 12, 2009, 05:24:46 PM

I have the pot off my '79.  I just finished cleaning it and the head externally.  I cleaned up the cylinder wall also and it is very smooth.  I was thinking it may need some roughing up before I re-install it.  The first question...is the cylinder liner on a '79 nikasil/ceramic or good old steel/iron?  The second question...would it be sufficient to rough up the cylinder with some fine crocus cloth (assuming the cylinder is steel/iron) or should I buy the drill attachment stones that are used by mechanics?  Third question...is there a recommended chemical to remove carbon from the head etc?

Title: Re: '79 Cylinder Liner Etc
Post by: Justin B. on April 12, 2009, 07:00:04 PM

The '79 and '80 models used cast iron liners.  If you are going to put in new rings then the cylinder needs to be honed with the correct crosshatch pattern so the new rings will seat in.  If you are going back with the same rings/piston in the same bore then leave 'em alone.  Simple Green or Greased Lightning and a brass brush will get the carbon out...