Community Forums

RTegarini · 08-23-2017, 05:11 PM

I've done a 'search' regarding spark plugs for the 8.1L engine in this forum looking to answer a couple of questions I have, which of course left me without a definitive answer.

My first question is what is the proper spark plug gap for the 41-101 41101: I find two different answers posted, .045 and .060. Which is now considered the ideal gap?

Second question is there any such thing as the 'best' brand spark plug for the 8.1L? Due to the one-time affiliation with Chevrolet, I would assume the ACDelco would be the logical choice, but is this still true for 2017?

Last question pertains to the replacement time-frame. By the manual, I believe it states that the first spark plug replacement is due at 100,000 miles. I'm just under 40k miles and feel the the engine runs well. I do notice that at idle, on either side of the exhaust pipe, I hear what could be called a 'miss', which could be the way it's always been but didn't notice for quite some time. At idle, the tach shows no erratic behavior. When driving, the engine seems strong with no noticeable issues. I'm currently planning a two thousand mile road trip and just not sure if I should, or need to, replace the spark plugs and wires.

Any suggestions would be appreciated.

Thank you. -RT

CJ7365 · 08-23-2017, 05:38 PM

Read this and you can decide

http://www.irv2.com/forums/f22/chang...gs-229011.html

I have mine at .045, but I have the Ultra RV ECM upgrade.

lrsses · 08-23-2017, 07:37 PM

I do not have the ECM Upgrade but have the plugs 41-101 capped at .045 8.1 at 65 plus

AKIQPilot · 08-24-2017, 09:04 AM

I installed AC Delco Iridium 41-101 plugs gapped at .045. Ultra Rv Magnum wires. Installed at 40,000. Huge improvement over what was a perfectly good running motor to begin with.

Go with fresh plugs and wires. You will not be disappointed.

.045 is the correct gap. Proven performance gain on the dyno with lridium plugs gapped to .045.

vettenuts · 08-24-2017, 05:41 PM

Quote:

Originally Posted by AKIQPilot

I installed AC Delco Iridium 41-101 plugs gapped at .045. Ultra Rv Magnum wires. Installed at 40,000. Huge improvement over what was a perfectly good running motor to begin with.

Go with fresh plugs and wires. You will not be disappointed.

.045 is the correct gap. Proven performance gain on the dyno with lridium plugs gapped to .045.

Same here. Been problem free and it runs great. Now have 66K miles, installed at around 50K miles.