Doing Plug Cuts - ZR-1 Net Registry Forums

XfireZ51 · 03-31-2012

So while waiting for the top end to come back from the paint shop, "idle hands are the blah blah blah...". Decided to replace spark plugs and while I was at it do some plug cuts. Plug cuts are where you remove the threaded collar of the plug to reveal the lower part of the ceramic insulation. This is what you do to tell what is really going on in the AFR department. As rpm and load increase, the burn characteristics of the AFR moves down towards the bottom of the insulation casing.

Here's what I found:

Also, looking at the #2 cylinder, I found the primary valve perfectly clean
while the secondary and most of the other valves had the expected carbon build up on the back face of the valve.

Injectors??

03-31-2012	#1
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,708	Doing Plug Cuts So while waiting for the top end to come back from the paint shop, "idle hands are the blah blah blah...". Decided to replace spark plugs and while I was at it do some plug cuts. Plug cuts are where you remove the threaded collar of the plug to reveal the lower part of the ceramic insulation. This is what you do to tell what is really going on in the AFR department. As rpm and load increase, the burn characteristics of the AFR moves down towards the bottom of the insulation casing. Here's what I found: Also, looking at the #2 cylinder, I found the primary valve perfectly clean while the secondary and most of the other valves had the expected carbon build up on the back face of the valve. Injectors?? __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX