The going has been a bit slow, but Im near ready to remove the heads, this week, and then Inspect the bottom end. I sure its done a bearing, rotating the engine by hand is not smooth at tdc on piston 1, its notchy. The good news is the valves look ok, both exhaust and inlet valves all look the same as the pics. The not so good news is the scuffing on the bores thrust sides, in all 6 pots, not great but my feeling is it'll hone out, won't really know until the heads are off.
So the bores look ok, I reckon after 10.000k the ware is normal. What is not normal is the damage on piston one and the head above p1. The quelch pads have taken a beating, and the top of p1 is covered pock marks, no doubt from detonation. The p1 bore has hardly any marks on the walls at all, go figure. I haven't dropped the sump, but I'm expect the rod bearing under P1 is shot. This is no one's fault but my own for running a shit tune briefly not long after the engine was broken in.
Hi Beaver, The damage looks to me like it was caused by a foreign object. Maybe a spring washer that got squashed between the piston and head to cause the big dents and then broke into pieces and got bounced around between head and pistion. It doesn't look like detonation at all.
You may be right ivan, i put the damage down to detonation having blown a piece of the side of the piston initially and then spread that around. I have aftermarket rails and they use small ss washers to hold the injectors in place, and I did find 3 of them in the valley.
Yea, I've never seen detonation do that sort of damage. What did the plug look like? It must have got worked over too. You may as well pop the sump and take a look at the BE anyway; but if the engine was holding good oil pressure and the oil was clean, then the problem was inside that cylinder. I'd be inspecting the valve faces & seats., cos if something got in there and wasn't found in the chamber, then it must have got tossed out. Maybe time for a little chamber work on the heads to clean up the mess.
Thanks, ivan, Ive just taken the sump of and removed piston 1, and good news, the rob bearing and crank journal look new, the journal itself looks like a mirror, and the rod bearing shows minimal ware TFFT. The piston is not reuseable because of the side damage, but the skirt coating remains with little ware, the piston rings are undamaged. The sump had not a sign of shiny bits and is clean as a whistle also. When I removed the plugs they all looked fine, electrodes in place, no sign of damage, I still have those plugs I'll have another look at them, but I'm sure there ok. I ran a straight edge across the driver side head and its still straight, but square across chamber one where the damage is, its proud by around 0.762mm. The plane now is to remove both cams from the head, rebuild the lifters, lap the valves, and generally clean out any crap that might be in there. I'll post up more of my gigantic pictures later today.
That's good news. If it were me; I'd take the heads into a machine shop and have them both surfaced. Maybe get them to tidy up the chambers too. They could syncro seat the valves also for a guaranteed seal. If the top ring land hasn't been damaged, I'd be inclined to clean up the piston and reuse it, cos it will be difficult to source just one piston, pricey if you can. I won't use those composite gaskets, especially on a boosted engine. They usually blow out around 1 bar, although, copper coat and good head stud might get you past that. I always use Cometic MLS head gaskets hit with copper coat. Cometic say not to spray their gaskets with copper coat but all the engine builder I know, all claim its a must. Its a good idea to also use a high zinc content oil when breaking in again.
Mmm... That piston has had something scuff the side of it. If you're going to take the heads into a machine shop (I would), I'd seek their opinion on the piston as it still might be saveable. I think that's a word. Jounal & bearing look good.
