March 2, 2012

Mc21 "R" cylinder port layout

It's about time to take some rough measurements and a layout of my nsr250 cylinders, so as to see what needs to be done and make a plan.

I have a pair of mc21 and one mc18 cylinders, so let's see what they will reveal...

First layout is out of an "R" cylinder,  as there is an "H" marking on the lower LH side.

I estimate the deck height to be about 0.6-0.8mm, haven't measured it yet. 
Exhaust timing of "R" cylinder looks to be a bit on the conservative side as are the tranfer ports. 
Total cylinder height is 86.2mm while most references speak for a height of 86.3mm, so it seems like it has been lapped 0.1mm. 

There are serious mismatches, especially on the width of main transfer ports, I haven't measured them precisely yet but they are in the region of 1.5-2mm. 

Let's go on... 

No comments:

Post a Comment