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2,170 Posts
Discussion Starter · #1 ·
It's been cleaned up, it took two hours at a machine shop to clean up the head.

Stock engine from my 1992 NX2000, with 208,000 kilometres, S4 cams, intake, exhaust, unshielded/uncoated Stillen header, JWT ECU.

Hot day at Shannonville Motorsports Park, ran hard all day; very hard, over an 8-hour track day.

Baked the alternator like it had been thrown into an oven. Lots of smoke from the tailpipe. Upon revving, a spray of black water and black smoke would come out the tailpipe, and it at idle it became even rougher.

Oil floating in the rad and rad overflow. Began drinking almost as much oil as gas.

Still made good power!

Look at the pics, and I will shoot down the answers as they come :)

Hint, it's not what you think. See if you can guess the problem from the pics.

James





































 

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Professor Dingbat
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5,543 Posts
What's with that pic #9? Almost looks like the transfer ports on a 2 stroke. Looks the wrist pin somehow came loose and punched its way through the side of the bore? I really don't see any way that could even happen, and if it did, the motor would certainly not run with any sort of power, if at all. So rule that one out.....

edit:

Of course not, it's inside the bore, not a chunk missing. What was i thinking :confused:
 

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Discussion Starter · #4 ·
FastNX said:
Of course not, it's inside the bore, not a chunk missing. What was i thinking :confused:
LOL!

You answered your own question, that's not the problem.

James
 

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2,170 Posts
Discussion Starter · #6 ·
SERprise In WV said:
Valve guides/seals....maybe? Hard to tell from the pics, but thought I'd throw it out there.
Bingo.

All of the exhaust valves are toasted!

I thought it would be head gasket and maybe a cracked ring, but everything else is pretty good.

The head was encrusted with a lot of burned-up oil. My temps were very high. I won't do that again.

James
 

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2,170 Posts
Discussion Starter · #8 ·
I should send you a burned exhaust valve as a reward :)

I've posted that on two other boards, and NO ONE else got it. Good stuff.

James
 

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1,199 Posts
Were you running too lean? Is that why your exhaust valves were burnt?

I remember reading once that the symptoms of running too lean is that you get extra high combustion temps and you start you use parts of the motor (valves) as your fuel. :)
 

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Discussion Starter · #10 ·
I ran too long, too hot. Way too hot. It was stupid.

I'm much smarter now.

James
 

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G-unit
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1,132 Posts
I swear it looks like you have NO spark plug threads left in the first pic!!!!!!!!

Travis E.
 

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spnx said:
I should send you a burned exhaust valve as a reward :)

I've posted that on two other boards, and NO ONE else got it. Good stuff.

James
If i post the answer on the other two boards will I still win a prize? ;)
 

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Discussion Starter · #14 ·
sr20.fox said:
If i post the answer on the other two boards will I still win a prize? ;)
Sure, stop by my house and you can get a burned-out exhaust valve. Plenty to go around! ;)

James
 
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