Advice sought on k321 - Page 3
Page 3 of 3 FirstFirst 123
Results 21 to 22 of 22
  1. #21
    Senior Member CobyDog$10's Avatar
    Join Date
    Sep 2017
    Beloit, Wisconsin
    Thanked 680 Times in 345 Posts
    That piston is junk. I would rather give a better evaluation after seeing the bore and more views of the piston but...

    You have some pretty good scoring. The top of the piston looks like there was carbon buildup it was slamming into. Carbon buildup can make the engine run poorly and from the looks of the piston, oil was getting past the rings.

    How much carbon was in the combustion chamber? I'm wondering what the valves look like in this engine. Perhaps this engine could live again. You will know once you measure the bore with your new tools.

    Head warpage on these engines is repairable as long as they haven't been machined too many times. It can normally be repaired with a flat surface, sand paper, and some time if you don't have access to a mill.

  2. The Following 2 Users Say Thank You to CobyDog$10 For This Useful Post:

    dundee222 (Yesterday),iko (Yesterday)

  3. Remove Advertisements

  4. #22
    Senior Member iko's Avatar
    Join Date
    Sep 2019
    Port McNicoll Ontario Canada
    Thanked 295 Times in 166 Posts
    I guess how I got to this point got lost in the previous thread perhaps. The scored piston is out of the old block, which had been bored to 030 and I found it with the head gasket broken. Perhaps pieces of the broken gasket are the reason for the scored piston. It was smoking badly and running really rough. There wasn't that much carbon buildup. When I posted at the time, the combined wisdom here concluded that most likely the rings weren't installed properly by the previous owner. So I bought new rings and was going to just give the old block a hone and new rings. However, since the old block is at 030 already, and at the time measured at 3.533 roughly, and having come across a STD block on ebay, I just decided to get that block and do a full rebuild, so here I am. Got the STD block which measures quite good, and will get new piston and rod, etc.

    I'll still check the old block for scoring, just because I'm really curious.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts