Best Spark Plug
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Melting Slicks
Joined: Jul 2010
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From: SUFFIELD CT USA 2023 C8 CORVETTE UN-MODIFIED FINALIST
2023 C8 of the Year Finalist - Unmodified
Thread Starter
Melting Slicks
Joined: Jul 2010
Posts: 2,762
Likes: 820
From: SUFFIELD CT USA 2023 C8 CORVETTE UN-MODIFIED FINALIST
2023 C8 of the Year Finalist - Unmodified
Le Mans Master
Joined: Apr 2011
Posts: 6,284
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From: Hermosa
Agree with Jebby, NGK. I use heat range 5. Absolutely reliable and clean. I just pulled them to clean and they were pristine clean and the gap was still right where I set it at .045”. I use the “V” grove type electrode.
BKR5E to be exact.
https://www.instructables.com/id/Sav...ide-Gapping-S/
look into side gapping plugs, makes ignition of fuel easier/ better.
BKR5E to be exact.
https://www.instructables.com/id/Sav...ide-Gapping-S/
look into side gapping plugs, makes ignition of fuel easier/ better.
Last edited by REELAV8R; May 26, 2020 at 01:04 PM.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
Agree with Jebby, NGK. I use heat range 5. Absolutely reliable and clean. I just pulled them to clean and they were pristine clean and the gap was still right where I set it at .045”. I use the “V” grove type electrode.
look into side gapping plugs, makes ignition of fuel easier/ better.
look into side gapping plugs, makes ignition of fuel easier/ better.
NGK street plugs are fine.....they come in X,R or U depending on the style...I.E. UR4, XR5, FR6.....these plugs are better if you have a high powered sound system
Jebby
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Verdad Gallardo
Safety Car
Joined: May 2001
Posts: 4,757
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From: Fairfax Virginia
I just use the AC Delco Rapid Fire spark plugs on my high compression 427 in my 1968 C3. They are cheap and they work great with my MSD ignition system.
I used to use the NGK Iridium plugs but did not have great luck getting them to fire in the high compression environment. Maybe it was the .060 gaps I ran with them but they misfired a lot of the time.
The AC Delco plugs were used before the NGK's and ran fine with the big gaps. The plugs would always be nice and golden brown.
Being in the process of getting my Corvette converted to the Holley Sniper Stealth I want to start with a known part. I have the fuel system working now but am getting ready to switch over to the Sniper Ignition system control. I want to enjoy all the benefits this Sniper offers. They say that once the timing is under the Sniper's control that it will use it to get the idle right under all conditions. I want to have the Sniper control everything it can so I get the most out of it. Maybe even get out of the single digits for fuel mileage....
I used to use the NGK Iridium plugs but did not have great luck getting them to fire in the high compression environment. Maybe it was the .060 gaps I ran with them but they misfired a lot of the time.
The AC Delco plugs were used before the NGK's and ran fine with the big gaps. The plugs would always be nice and golden brown.
Being in the process of getting my Corvette converted to the Holley Sniper Stealth I want to start with a known part. I have the fuel system working now but am getting ready to switch over to the Sniper Ignition system control. I want to enjoy all the benefits this Sniper offers. They say that once the timing is under the Sniper's control that it will use it to get the idle right under all conditions. I want to have the Sniper control everything it can so I get the most out of it. Maybe even get out of the single digits for fuel mileage....
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
if a guy is racing then yes cold heat range would be appropriate. Street/ strip maybe heat range 7 depending on CR and altitude. But I have been running 5 for years and it has provided the best performance with no detonation. CR 10.6:1 @ 4000+ ft elevation.
Last edited by REELAV8R; May 26, 2020 at 01:20 PM.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
.
That's a mighty big gap. I would not be surprised to get a misfire at high RPM and compression with that gap.
Never considered iridium for this type of application. Logic would dictate that a fine wire iridium would fire easier though vs a conventional plug.
I used to use the NGK Iridium plugs but did not have great luck getting them to fire in the high compression environment. Maybe it was the .060 gaps I ran with them but they misfired a lot of the time.
Never considered iridium for this type of application. Logic would dictate that a fine wire iridium would fire easier though vs a conventional plug.