Plug chop!

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   How does it run? 

Is it dull at a particular throttle setting?

Is there a lean surge in any portion of the operating range?

For a plug chop to really mean anything, you need to first disable the secondaries and run wot for a spell, then cut the plug.

After sorting out the primaries, only then do you move on to the secondaries

either those plugs don't have enough run  time on them, or , well, if you were that lean to not have a soot ring, there would be drivability symptoms of some type, which we appear to missing that data.

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GottaSki Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: April-21-2005 Location: NE CT Status: Offline Points: 3363	Post Options Post Reply Quote GottaSki Report Post Thanks(0) Quote Reply Topic: Plug chop! Posted: July-20-2017 at 11:40am
	How does it run? Is it dull at a particular throttle setting? Is there a lean surge in any portion of the operating range? For a plug chop to really mean anything, you need to first disable the secondaries and run wot for a spell, then cut the plug. After sorting out the primaries, only then do you move on to the secondaries either those plugs don't have enough run time on them, or , well, if you were that lean to not have a soot ring, there would be drivability symptoms of some type, which we appear to missing that data.
	"There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole

KENO Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 11093	Post Options Post Reply Quote KENO Report Post Thanks(0) Quote Reply Posted: July-20-2017 at 9:57am
	Just my opinion, but I think you're over analyzing all of this You can find at least a half dozen or so different ways of reading plugs and analyzing what they're telling you and they definitely don't all agree with each other

KENO Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 11093	Post Options Post Reply Quote KENO Report Post Thanks(0) Quote Reply Posted: July-20-2017 at 9:44am
	Here's an adjustable secondary plate that I think would work. Key word is Think adjustable plate

TRBenj Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21184	Post Options Post Reply Quote TRBenj Report Post Thanks(0) Quote Reply Posted: July-20-2017 at 9:35am
	"Pretty obviously very lean".... based on what? What's the soot ring measure vs ideal? I'd ignore the staining on the strap, fuel additive like you said.

KENO Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 11093	Post Options Post Reply Quote KENO Report Post Thanks(0) Quote Reply Posted: July-20-2017 at 9:28am
	It seems like you had put in an 8.5 PV last time something was posted. Your stock secondary metering plate has .067 holes for what would be the "main jets" for the secondaries. The plate number is 134-8, you should be going bigger there too. You can get one like a 134-39 that has .073 holes that would definitely add more fuel to the secondaries With the 4160 you either need a new plate like above or a conversion kit to a secondary metering block or a metering plate that you can screw main jets into instead of changing plates. Those look like NGK plugs, what's the number on them? Your engine isn't exactly radical so it doesn't seem like you need to be dumping in massive extra amounts of fuel

KooK Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: February-10-2014 Location: Iowa Status: Offline Points: 143	Post Options Post Reply Quote KooK Report Post Thanks(0) Quote Reply Posted: July-18-2017 at 8:00pm
	Alright, it's pretty obviously very lean. I'm going to run it up two jet sizes from here. Other than being lean, does anybody see anything else I should be worried about (or do I need better pictures or a better read)? 450cfm Holley (6.5 power valve, 65 main jets)

Plug chop!

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