Going 1216 hopefully

[Svsam]

I picked up this ‘bit Smokey when it’s running’ mk1 1200 motor yesterday. Was cheap enough, happy to find busa pistons in it when I opened it up. 
there is some considerable heat damage where the cam lobes  have got so hot they have worn down the rocker arms. 
I have a complete head here left over from a dot head conversion on a different bike. 
 

Upon closer inspection of the bores earlier I noticed these marks (only) on no:3, like cavitation almost. Its not deep, but can feel it when I run my nail over it. 

What could have caused this? The pistons don’t look any more work than a second hand set. 
Can I get it re-bored I fraction to keep the busa pistons?

 

The plan is to build a strong engine for my turbo that’s currently on standard b12 motor. 
 

Edited May 9, 2021 by Svsam

[wombat258]

Corrosion because of condensation sitting in bores over a long period. Give it a hone and see if it cleans up.

[Gixer1460]

The only thing that'll cause the rocker pads to wear excessively is oil starvation - if its bad up top then i'd be checking out all the other bearings particularly the head cam bearings!

[Svsam]

Decided to give up on that engine and buy another 1157 and build my own 1216, I got the busa pistons for it now. 
I read about prepping the pistons to prevent getting hot spots on them, can any one advise, or got a pic of how much I should be taking off? Obviously don’t want to cock them up otherwise I’ve paid for five fifths of feck all. 
 

Also, anyone get any experience with maxpeeding rods? Worth it? 

[Gixer1460]

You just need to remove sharp edges - if it looks or feels sharp then round it off. A thin sharp section will heat up to the point where it will cause pre-ignition or detonation which is a piston killer so nice smooth edges and job done.

More people are reporting use of the MaxSpeeding Rods but don't believe their claim of using ARP bolts - they ain't so budget for a set of Real ARP rod bolts. They ain't Carillo's but they ain't Carillo prices either!