Ignition timing and piston rings...
07-22-2008, 02:35 AM
#21
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Re: Ignition timing and piston rings...
Originally Posted by Joseph Davis
Sewell, Blundell, Xeno, I, and others do.
My main mojo that I can lay on you, that I don't hear *anywhere* is that sometimes the plug looks like there's trash on it but it's just from a misfire or wear. The definitive answer is looking at the face of the piston witha bright flashlight; if the carbon coat looks like you've poked holes through it with a pin, so that you can see pinpricks of shiny aluminum, you are experiencing detonation and timing needs to be backed off in that cylinder.
My main mojo that I can lay on you, that I don't hear *anywhere* is that sometimes the plug looks like there's trash on it but it's just from a misfire or wear. The definitive answer is looking at the face of the piston witha bright flashlight; if the carbon coat looks like you've poked holes through it with a pin, so that you can see pinpricks of shiny aluminum, you are experiencing detonation and timing needs to be backed off in that cylinder.
Good to know. That makes sense.
I assume a good penlight would work well for peering into the combustion chamber? A borescope would be awesome, but being a full time student won't allow for such expensive toys.
I really do need to play around with reading spark plugs and det cans. I built a det can setup, but have only used it once.
Any good way to determine optimal ignition timing off of the dyno? I assume that reading the spark plugs alone will not yield optimum results. Is this correct?
I generally seem to get a pretty solid tune on the street. Keep in mind that I pretty much only tune NA cars.
07-22-2008, 02:39 AM
#22
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Re: Ignition timing and piston rings...
that dragstuff link and the others at the bottom is them.
I got it thru www.yellowbullet.com a very big drag racing web site.
Lets just say Billy Glidden and J. Hump are memebers, ALOT of varied knowledge there.
I got it thru www.yellowbullet.com a very big drag racing web site.
Lets just say Billy Glidden and J. Hump are memebers, ALOT of varied knowledge there.
07-22-2008, 12:43 PM
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Re: Ignition timing and piston rings...
Originally Posted by snm95ls
I assume a good penlight would work well for peering into the combustion chamber? A borescope would be awesome, but being a full time student won't allow for such expensive toys.
Originally Posted by snm95ls
Any good way to determine optimal ignition timing off of the dyno? I assume that reading the spark plugs alone will not yield optimum results. Is this correct?
07-22-2008, 02:39 PM
#24
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Re: Ignition timing and piston rings...
Originally Posted by Joseph Davis
borescopes are needed for some cars where either the plug entry is at a wack *** angle or you can't stick your head in there (scooby) but for a normal B or D I wouldn't use a borescope even if I had one. Straight drop in on the piston crowns, use a good power LED pen or flashlight and FTW!
If you define optimum as your engine doesn't come apart and you get 90%+ of possible power, then reading plugs works.
If you define optimum as your engine doesn't come apart and you get 90%+ of possible power, then reading plugs works.
JD, thanks for the replies so far. I would buy your *** a beer, but I doubt I'll be out to the east coast any time soon.
Is watching the fuel consumption a good way gauging what the engine is wanting for ignition timing. Say you get the A/F stabilized to a safe range, add ignition timing and the A/F gets leaner. Add timing until this trend stops. If you add timing, and the A/F gets richer, then pull timing.
Is that correct?
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