CK5
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There you go
We're home, Amber unloaded while I tore the engine down with a friend. There is clearly something else going on with #8, my datalogs for the final run looked better than any of the previous ones, but the damage says something different.
The valve is torched and tuliped, the seat seems OK but it burned out some material from under it, the spark plug was stuck and took the threads with it when I finally worked it back and forth enough to get it out.
I'm hoping it's repairable, but I'm not sure. I'm hoping to find that out tomorrow. The piston looks fine, I need to turn the engine over to look at the cylinder wall, but I'm assuming it will be fine.
The other 7 plugs looked fine after the run, the rest of the valves on that side look fine, when I made the tune for the last run I took an additional 1° of timing out across the board (16°), reduced the target AFR by another .2, added 20% more fuel, pulled 2° more out of #8 (for 6° extra and a total of 22° pulled on #8) and added 15% more fuel to #8. I thought we were being safe, but the picture says something different.
The valve is torched and tuliped, the seat seems OK but it burned out some material from under it, the spark plug was stuck and took the threads with it when I finally worked it back and forth enough to get it out.
I'm hoping it's repairable, but I'm not sure. I'm hoping to find that out tomorrow. The piston looks fine, I need to turn the engine over to look at the cylinder wall, but I'm assuming it will be fine.
The other 7 plugs looked fine after the run, the rest of the valves on that side look fine, when I made the tune for the last run I took an additional 1° of timing out across the board (16°), reduced the target AFR by another .2, added 20% more fuel, pulled 2° more out of #8 (for 6° extra and a total of 22° pulled on #8) and added 15% more fuel to #8. I thought we were being safe, but the picture says something different.
That is bazaar. Just one cylinder makes no sense. Unless the injector is fubar.
The crazy thing is, this is the second set of injectors and both times the issue has been on #8. I am going to get them tested, but that would be an insane coincidence.
Maybe the wiring is off on that cylinder and the injector isn’t firing right? Have you tried unplugging that injector and seeing if it changes anything? At this point I’d be looking at different nitrous delivery solutions cause clearly something is wrong.
This is what I was thinking of with the second injector poseible failure.
Every time we change plugs, I break out my UV camera to make sure all cylinders are firing. I pulled plugs after the burnout (no nitrous) and they were fine, if it's a problem with the injector, it's only at higher duty cycles, but even with the 300 shot, I was maxing out at 50% duty cycle.
It could be wiring, but only when I'm spraying would be weird.
Would it be worth spraying nitrous with the manifold on the bench and watching the flow? Video would be mandatory. For us. I realize it is not the same as being mounted on the air pump, but it might show something weird with flow.
Something like this?
We did that after the first or second time we blew out #8. I even did slowmo on it. I think those are the 100HP jets, but I don't remember.
On the bench with the cover on it. See how it comes out of each port.
Do you have O2 bungs in each header tube?
Do you have O2 bungs in each header tube?
I can try that tomorrow, but you can see (especially in slow motion) the flow coming out of each of the ports and they seem consistent. I do not have bungs in each tube, but I do have an EGT probe kit that will get installed prior to spraying again. Obviously I should have done that last time, but I thought we figured it out. It also only seems to be a problem over 200hp of nitrous.
Another precaution I forgot to mention. #8 had an 11 plug in it while 1-7 had 10's.
Another precaution I forgot to mention. #8 had an 11 plug in it while 1-7 had 10's.
Thanks for your astute observations
I’m glad I’m not playing with nitrous, I would melt my engine down.
Videos from my 5 runs
[email protected]
[email protected]
I hit a safety and the nitrous shut down right away on this run. [email protected]
This is my new PB ET, [email protected]
This is my new PB trap speed, [email protected], it's also when I burned up #8 plug and exhaust valve.
I talked to Outlaw Race Engines and they think they can fix the head, but their cylinder head guy is out this week at a NHRA event. We're contemplating ordering a new head so we have a spare, but haven't pulled the trigger on that yet. I also ordered an injector test machine so I can test all my injectors. We're still scratching our heads on what the problem could be, but we'll figure it out.
[email protected]
I talked to Outlaw Race Engines and they think they can fix the head, but their cylinder head guy is out this week at a NHRA event. We're contemplating ordering a new head so we have a spare, but haven't pulled the trigger on that yet. I also ordered an injector test machine so I can test all my injectors. We're still scratching our heads on what the problem could be, but we'll figure it out.
Just curious,... 
Do your base timing and fuel maps look different because of the nitrous tune?
Or do they stay the same, and the ecm just does it's math off of that internally when the nitrous is active?
If they stay the same, I'd be interested in seeing a pic of yours just to see how far off base mine may be.
I'm told the one I came up with is pretty odd looking lol.
I believe the words were "I have NO idea where you got that..?" By someone who knows these things lol.
Do your base timing and fuel maps look different because of the nitrous tune?
Or do they stay the same, and the ecm just does it's math off of that internally when the nitrous is active?
If they stay the same, I'd be interested in seeing a pic of yours just to see how far off base mine may be.
I'm told the one I came up with is pretty odd looking lol.
I believe the words were "I have NO idea where you got that..?" By someone who knows these things lol.
