woppi
Pro
Posts: 1362
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posted September 28, 2007 07:24 AM
???????????
quote:
quote:
Those pistons are quite different then mine.At 13/1,my 87mm pistons have a flatter top.
Tomorrow i go back to the dyno and see what happens.
and ???? do you know more ???
what the dyno says ??? 248 rwhp ????
woppi
  
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tcchin
Zone Head
Posts: 867
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posted September 28, 2007 12:20 PM
It is very unlikely that the piston crown could present a more convenient ground path to the center electrode unless the piston somehow manages to get between the center electrode and the ground electrode. This would be true regardless of the ignition timing, as it boils down to geometry. In Karl's case, the piston tried to get between the spark plug electrodes, but ended up closing the gap between them, establishing a very convenient ground path.
The thing that still baffles me is the existence of what appears to be spark erosion at the base of the center electrode on these very low-hour plugs. Could that just be plastic deformation related to the piston contact? I smell a conspiracy, and I'm blaming the Barbies.
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tcchin
Zone Head
Posts: 867
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posted September 28, 2007 12:24 PM
I think Karl is using a Factory Pro dyno which uses a different scale, so we shouldn't expect readings in excess of 247 rwhp from this motor.
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TRNorBRN6001
Needs a job
Posts: 2021
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posted September 28, 2007 01:01 PM
More like mid to high 180's, I think...................................but high190's would sure put a smile on his face!
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tcchin
Zone Head
Posts: 867
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posted September 28, 2007 02:42 PM
 Edited By: tcchin on 28 Sep 2007 15:44
Is that high 180's using STD or SAE? Oh that's right, FP doesn't play those games. I think Karl would become incontinent of bowel if he pulled high 190's on a FP dyno, and I'd pay a dollar to see it happen.
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Y2KZX12R
Needs a job
CompetitionCNC.com
Posts: 3762
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posted September 29, 2007 03:28 AM
Vince, i dont think this ignition system is a "waste spark" system.
Typically a waste spark system uses one coil for every two cylinders and each end of the secondary winding gos to a plug wire lead.
The zx12r having 4 coils would not need to do this. also with 4 coils vs two the coil saturation time (dwell) can be doubled as needed by the ecu producing much higher outputs and allowing higher rpm operation.
Increased coil saturation it the main reason cars and bikes have gone to one coil per cylinder.
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Y2KZX12R
CompetitionCNC.com
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Y2KZX12R
Needs a job
CompetitionCNC.com
Posts: 3762
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posted September 29, 2007 03:38 AM
Karl, I'm convinced you had a heat issue also. I was looking more at the heat issue with that plug than expecting physical contact. but notice how the first few threads are discolored? they must be sticking into the chamber.... not good.
An extremely lean engine can also melt the ground electrode and disform it like you see there. Ususally you see it only in turbo and nos lean conditions to be that bad.
I'll bet you are too lean on the fuel map. check that a/f ratio closely on the next few pulls.
If the plugs look too hot like that again and the dyno a/f monitor is reading a "safe" a/f ratio then his w/b o2 may be dirty and need cleaning or replacing.
W/b o2s are very delicate and dont last for ever or very long if run at either end of the spectrum for very long. also some fuels and additives (proplyeneoxide) can damage them.
You will see a bad o2 sensor get slow and lazy on the dyno before it starts to just plain fail.
Anyway, check those new plugs after you do several pulls and some tuning etc. just to verify what the dyno is telling you for peace of mind.
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Y2KZX12R
CompetitionCNC.com
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