Piston problems

1. wicked-vtr Saxperience Forum Bum Joined: Jan 2009 Surrey Posts: 2608 200sx s14a mark 1 vts

   #1 9th March 2011, 10:31

   Hi guys, thought id put this in here rather than the problems section to get a better/more knowledgable response.
   
   Basically my timing belt has slipped so I whipped the head off this morning. from a quick inspection id say all 16 valves have made contact judging by the notches in the pistons. Will this damage to the pistons make them dangerous to use? I can get pictures of the damage if necessary.
   I dont particuarly want to risk a piston giving up at full chat, if its any danger its a good excuse for some wossners anyway
2. Gabbastard Saxperience Post Whore Joined: Dec 2002 United Kingdom Posts: 8390

   #2 9th March 2011, 12:11

   Happened on my old engine dude. It ran fine for another 40k, then I sold it and the guy who bought it has run it for about another 30k with no problems.
   
   Its not ideal, but it wont lead to a failure IMO.
3. wicked-vtr Saxperience Forum Bum Joined: Jan 2009 Surrey Posts: 2608 200sx s14a mark 1 vts

   #3 9th March 2011, 13:35

   I thought as much bud, much more material would be removed if I where to have them pocketed, just wanted to make sure before I put it all back together.
   
   Cheers for the reply
4. yr51ocw Frequent Poster Joined: Oct 2005 Posts: 751

   #4 9th March 2011, 17:09

   like gab says, the marks wont lead to immediate failure. It is likely they will be the initiation point for fatigue but these engines are pretty strong.
5. atspeedracing Frequent Poster Joined: Aug 2008 ESSEX Posts: 727 106 GTi Turbo

   #5 9th March 2011, 18:50

   pics needed really
   - colin.

   1 user thanked this post: blackie_2k5
6. blackie_2k5 Saxperience Hardcore! Joined: Oct 2008 Birtley Posts: 22253 VTR Turbo, 106 xsi track slag, Transit recovery, B

   #6 9th March 2011, 18:58

   agree with colin. Can and most probs will be fine, but without seeing you cant really say, piston pockets would probs be deeper, but you forget they are milled out, not chiselled out by a piston crashing into the valve under load
7. atspeedracing Frequent Poster Joined: Aug 2008 ESSEX Posts: 727 106 GTi Turbo

   #7 9th March 2011, 19:08

   depends where the damage is. someone in the know will need to see.
   
   its not a competition engine. so can most likely just be dressed with a file etc to remove any sharp edges. long as its cleaned afterwards. but as i say, depends where it is, and how bad. for instance if its caught it right on the edge of the piston crown, its gonna gauge the bore to death. or if the damage is deep enough, crown thickness will be minimal and susceptible to failure.
   
   valve to piston contact varies, so without pics you cannot conclusively advise.
   
   - colin.
8. wicked-vtr Saxperience Forum Bum Joined: Jan 2009 Surrey Posts: 2608 200sx s14a mark 1 vts

   #8 10th March 2011, 12:50

   Yeah that's what had me worried blackie, the nicks are smaller than the valve cutouts, but they where done in a way more likely to stress the metal. They are inside the valve cutouts, so nowhere near the crown. After a more thorough look and a bit of a think think i rekon they will be ok tbh, but il get a few pics up anyway.