Re-torquing Spark Plugs - ZR-1 Net Registry Forums

XfireZ51 · 05-24-2010

Before heading to BG I installed a fresh set of NGKs. They were torqued down 1/4 turn from seating with anti-seize. After about a 1000mile round trip, I removed the plugs just to do a check. Pretty easy to remove as if they backed off a bit. My left side seems to run a bit leaner than the right side. Wish there was a way to adjust fueling in calibration from side to side. It could be my own
imagination, but the motor seems to run smoother and quieter after re-installing plugs and re-torqued. I also noted a couple of plugs that appeared to be running leaner and these needed to be re-gapped. Gap was smaller than the spec .035".
Interested in hearing if anyone else has made similar observations. Also, do you do anything to keep plugs from loosening up or do you just recheck and retorque?

jonszr1 · 05-24-2010

dom, i use the ngks that are for the 93-95 cars and gap accordingly, they dont seem to loosen like the gasketed plugs . i just torque them to 20 ft lbs and call it good

XfireZ51 · 05-24-2010

Brad

I use the BKR 6E because of the heat range. They have gaskets for the 90-92 heads. However, when I first got car, it had the tapered seat NGKs in it although the plug seat is for gaskets.

tomtom72 · 05-24-2010

I thought it was my incompetence

I still use the 41-602's and I found that by not using anti-seize they didn't back out after some use. In place of the anti-seize I mimicked what must have been done at MM, motor oil on the threads. Not much, just enough to see that the threads are damp with it was what I found when I did my first plug change. I made the assumption that since I pulled out FR2LS's, that showed 14 yrs of age on the out sides, that MM had used the motor oil in place of anti-seize.

Two plug changes with anti-seize yielded loose plugs. Three changes using a light coat of motor oil, and the plugs were tight.

Tom

jonszr1 · 05-25-2010

you could be on to something with the motor oil . dominic , is the plug you use 1 step colder ????

XfireZ51 · 05-25-2010

Brad,

Yes the BKR6E is a step colder than stock. With my motor, I have found it to be the right heat range plug.

05-24-2010	#1
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,669	Re-torquing Spark Plugs Before heading to BG I installed a fresh set of NGKs. They were torqued down 1/4 turn from seating with anti-seize. After about a 1000mile round trip, I removed the plugs just to do a check. Pretty easy to remove as if they backed off a bit. My left side seems to run a bit leaner than the right side. Wish there was a way to adjust fueling in calibration from side to side. It could be my own imagination, but the motor seems to run smoother and quieter after re-installing plugs and re-torqued. I also noted a couple of plugs that appeared to be running leaner and these needed to be re-gapped. Gap was smaller than the spec .035". Interested in hearing if anyone else has made similar observations. Also, do you do anything to keep plugs from loosening up or do you just recheck and retorque?

05-24-2010	#2
jonszr1 Join Date: Sep 2006 Location: lone pine and mammoth lakes Posts: 1,407	Re: Re-torquing Spark Plugs dom, i use the ngks that are for the 93-95 cars and gap accordingly, they dont seem to loosen like the gasketed plugs . i just torque them to 20 ft lbs and call it good

05-24-2010	#3
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,669	Re: Re-torquing Spark Plugs Brad I use the BKR 6E because of the heat range. They have gaskets for the 90-92 heads. However, when I first got car, it had the tapered seat NGKs in it although the plug seat is for gaskets.

05-24-2010	#4
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: Re-torquing Spark Plugs I thought it was my incompetence I still use the 41-602's and I found that by not using anti-seize they didn't back out after some use. In place of the anti-seize I mimicked what must have been done at MM, motor oil on the threads. Not much, just enough to see that the threads are damp with it was what I found when I did my first plug change. I made the assumption that since I pulled out FR2LS's, that showed 14 yrs of age on the out sides, that MM had used the motor oil in place of anti-seize. Two plug changes with anti-seize yielded loose plugs. Three changes using a light coat of motor oil, and the plugs were tight. Tom __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

05-25-2010	#5
jonszr1 Join Date: Sep 2006 Location: lone pine and mammoth lakes Posts: 1,407	Re: Re-torquing Spark Plugs you could be on to something with the motor oil . dominic , is the plug you use 1 step colder ????

05-25-2010	#6
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,669	Re: Re-torquing Spark Plugs Brad, Yes the BKR6E is a step colder than stock. With my motor, I have found it to be the right heat range plug.