CM 871 Burnt Valve

[Rawze]

Nice.

[2dlb]

Well the saga continues. Spent the last 2 days cutting in the liners, all good there, Today started to roll in the new Mains everything went good till i got to #5.
Any thoughts, The bearing actually looks decent for 700K, Thoughts on polishing this?
      

[Rawze]

scotch-brite pads (hands only, not a drill, etc) are your friend.

[2dlb]

(04-11-2020 )Rawze Wrote:  scotch-brite pads (hands only, not a drill, etc) are your friend.

Hi Rawse
Would a load of coolant cause this, Its almost like a pit or if it was a hydralic cyl i would think the chrome was letting go.
Thanks

[smorgan87]

Are u saying thats pitted right there? It looks like something dried on the surface .

[2dlb]

(04-11-2020 )smorgan87 Wrote:  Are u saying thats pitted right there? It looks like something dried on the surface .

no its definitely a pit, like a piece flaked off, its hard to get a good picture but if you zoom in on the bottom one you can see the 2 shiney pieces they are the same diameter as the journal

[Rawze]

biggest Q would be ... is it in the thrust side of the crank? Or the bottom where there is little to no thrust?.

Next would be if it can be polished with a dremel + wire wheel to remove / dull its edges?.

Last would be to determine how long it likely has been like that?.

What did the bearing look like that came out of it?.


If it happens to qualify by .... Not being on the thrust side of the crank, Looks like it has been there a very long time, bearing that came out was acceptable, and a simple wire wheel can clean it up a bit,.. personally, I would just polish it a bit and go again. Check it in 100k miles to be safe and to ensure it was not causing excessive wear to the bearing ... but that is just me.

[2dlb]

Happy Easter Everyone
Thanks for the suggestion Rawze. Morgan87 i was mistaken. When i looked at it last night i could have sworn and it felt like there was a nick. This morning following Rawzes suggestion i started with scotch brite enden up going 400 grit then 600 grit then scotch brite and finished of with fine crocus cloth. I'm feeling a lot better today. What ever it was still left a mark. Rawse im not sure about the thrust , If cyl 4 is at TDC then this mark on the 5th main is at 10 oclock and the rod journal for 5 is down at 4ish. I attached a picture of the mains that i have done so far.
Thanks Again.
         

[Signature620]

The cleaned up journal looks good to go.

The removed bearings are also quite tidy