Spark plug questions - ZR-1 Net Registry Forums

hiperf406 · 03-31-2014

I went to an all Corvette show on Sat., after show was done I headed to the Pavilions Sat car show. On the way home the car was running great, turned off freeway & went about a block off suddenly the car started making a horrendous noise. I pulled over & checked it out #3 spark plug was gone, it had backed out & was gone. Got car flatdecked home & checked plugs they all were loose. Today I'm going to change plugs but checked Solutions & a couple are mentioned. I was wondering if NGK or AC Delco part numbers were still applicable. Also what is the torque value for plugs. TIA

lorne #1748

Dynomite · 03-31-2014

For my 91' NGK Iridium BKR5EIX Eagle
Gapped .043"

I do not use a torque wrench on spark plugs or some other items. I just tighten (snug but not too tight) with a short handle 3/8 socket wrench and call it a day.

That is one of those items I DO recheck tightness once in a while as the plugs are easy to get to. I also place just a bit of white greese around the Boot ring that fits near the top of the spark plug hole to make the Boots easier to remove and to help seal them.

Use just a bit of antisieze on the plug threads.

Number 8 Spark Plug Removal and Test Drive with Jeff Gordon

Kevin · 03-31-2014

a plug backed out? That's the first i've heard of this happening. I blew a plug out fo the head of my mustang once, but never heard of this on a zr-1

Z51JEFF · 03-31-2014

Quote:

Originally Posted by Kevin

a plug backed out? That's the first i've heard of this happening. I blew a plug out fo the head of my mustang once, but never heard of this on a zr-1

This is the second time Ive heard about this happening.

Racinfan83 · 03-31-2014

Yeah there was another thread on here a few months ago where that happened. Good reminder - I have to change my serpentine belt - think I will check the plugs while I'm at it since I changed them last fall...

efnfast · 03-31-2014

I blew #8 out, but that's the one you can't put a torque wrench on.

efnfast · 03-31-2014

This was an e-mail from Marc H.

For high load operation I recommend a spark plug that is one AC heat range cooler than the OE plug. The best spark plug is the NGK TR7IX. Part number 3690.

It has a tapered seat. All LT5's are machined for both tapered and flat seat plugs. Carefully open the gap to .050"

Best of luck.

Marc

hiperf406 · 03-31-2014

Yeah it really surprised me too, I thought the rubber boot should have retained the plug but it was nowhere to be found!! Thanks for the answers.

lorne #1748

WVZR-1 · 03-31-2014

Quote:

Originally Posted by Kevin

a plug backed out? That's the first i've heard of this happening. I blew a plug out fo the head of my mustang once, but never heard of this on a zr-1

It's been mentioned more than just "a few" times.

OP - What is in it presently for spark-plugs? I'd certainly start there with a check to see what is in the rest of the "holes"!

The anti-seize use I believe is often debated! The which to use anti-seize is also debated!

NGK has a comment regarding it's use:

http://www.ngksparkplugs.com/pdf/tb-...1antisieze.pdf

Dynomite · 03-31-2014

Quote:

Originally Posted by WVZR-1

It's been mentioned more than just "a few" times.

OP - What is in it presently for spark-plugs? I'd certainly start there with a check to see what is in the rest of the "holes"!

The anti-seize use I believe is often debated! The which to use anti-seize is also debated!

NGK has a comment regarding it's use:

http://www.ngksparkplugs.com/pdf/tb-...1antisieze.pdf

NGK says this:
"Summary
All spark plugs that have a blackened or dull appearance on the metal body offer no protection against seizing or bonding to the cylinder head and so it is with these spark plugs that anti-seize would be required."

"Applying anti-seize to the threads of spark plugs that have a metal plating allows the installer to mistakenly over-tighten the spark plug in the cylinder head."

One reason I do NOT use a Torque Wrench on Spark Plugs but rather I just tighten (snug but not too tight) with a short handle 3/8 socket wrench and call it a day.

03-31-2014	#2
Dynomite Join Date: Aug 2009 Location: South Dakota/California Posts: 3,797	Re: Spark plug questions For my 91' NGK Iridium BKR5EIX Eagle Gapped .043" I do not use a torque wrench on spark plugs or some other items. I just tighten (snug but not too tight) with a short handle 3/8 socket wrench and call it a day. That is one of those items I DO recheck tightness once in a while as the plugs are easy to get to. I also place just a bit of white greese around the Boot ring that fits near the top of the spark plug hole to make the Boots easier to remove and to help seal them. Use just a bit of antisieze on the plug threads. Number 8 Spark Plug Removal and Test Drive with Jeff Gordon __________________ Left Clickable links -Solutions- LT5 Modifications/Rebuild Tricks Low Mileage ZR-1 Restoration 1990 Corvette (L98) Modifications LT5 Eliminated Systems LT5 Added Systems LT5/ZR-1 Fluids 1995 LT5 SPECIFIC TOP END REBUILD TRICKS Last edited by Dynomite; 03-31-2014 at 03:13 PM.

03-31-2014	#5
Racinfan83 Join Date: Apr 2013 Location: Eastern Missouri Posts: 773	Re: Spark plug questions Yeah there was another thread on here a few months ago where that happened. Good reminder - I have to change my serpentine belt - think I will check the plugs while I'm at it since I changed them last fall... __________________ [LEFT][SIGPIC][/SIGPIC][/LEFT] [CENTER][COLOR=Indigo][SIZE=4][I][B] Now Sold 1990 ZR-1 #2093, Black on Black..[/B][/I][/SIZE][/COLOR][/CENTER]

03-31-2014	#6
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,492	Re: Spark plug questions I blew #8 out, but that's the one you can't put a torque wrench on.

03-31-2014	#7
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,492	Re: Spark plug questions This was an e-mail from Marc H. For high load operation I recommend a spark plug that is one AC heat range cooler than the OE plug. The best spark plug is the NGK TR7IX. Part number 3690. It has a tapered seat. All LT5's are machined for both tapered and flat seat plugs. Carefully open the gap to .050" Best of luck. Marc

03-31-2014	#1
hiperf406 Join Date: Apr 2007 Location: Spruce Grove Oilberta/In Mex for winter Posts: 1,046	Spark plug questions I went to an all Corvette show on Sat., after show was done I headed to the Pavilions Sat car show. On the way home the car was running great, turned off freeway & went about a block off suddenly the car started making a horrendous noise. I pulled over & checked it out #3 spark plug was gone, it had backed out & was gone. Got car flatdecked home & checked plugs they all were loose. Today I'm going to change plugs but checked Solutions & a couple are mentioned. I was wondering if NGK or AC Delco part numbers were still applicable. Also what is the torque value for plugs. TIA lorne #1748 __________________ lorne # 1748 Stock except for a modified Corsa exhaust. When the flag drops the bull sh1t stops!

03-31-2014	#3
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,632	Re: Spark plug questions a plug backed out? That's the first i've heard of this happening. I blew a plug out fo the head of my mustang once, but never heard of this on a zr-1 __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

03-31-2014	#8
hiperf406 Join Date: Apr 2007 Location: Spruce Grove Oilberta/In Mex for winter Posts: 1,046	Re: Spark plug questions Yeah it really surprised me too, I thought the rubber boot should have retained the plug but it was nowhere to be found!! Thanks for the answers. lorne #1748 __________________ lorne # 1748 Stock except for a modified Corsa exhaust. When the flag drops the bull sh1t stops!