Dennis
which spark plugs
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Plugs are cheap unless you get talked into buying the stupid marketed high tech plugs that will empty your wallet better than anything else they do.
Unless you have cylinder sealing problems reading the plug color will tell you which plug is best for your engine. A light clay or grey color is 'bout what you want to see. Dark or wet is unburned fuel - unless you have poor cylinder sealing. White with silver flecks means your burning the pistons and yes your engine is in trouble. Google search for reading spark plugs will help you more than I can.
Hope this helps ya.
Unless you have cylinder sealing problems reading the plug color will tell you which plug is best for your engine. A light clay or grey color is 'bout what you want to see. Dark or wet is unburned fuel - unless you have poor cylinder sealing. White with silver flecks means your burning the pistons and yes your engine is in trouble. Google search for reading spark plugs will help you more than I can.
Hope this helps ya.
Last edited by cardo0; Apr 3, 2017 at 08:35 PM. Reason: Stupid autocorrect!
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Michael S. Palmer
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,146
Army
It is wrong, I think its a felony in Michigan; third class misdemeanor in Florida.
Seriously, the NGKs just seem to burn a tad bit hotter and idle a little better...in a dual quad C1 in city traffic that helps...
Seriously, the NGKs just seem to burn a tad bit hotter and idle a little better...in a dual quad C1 in city traffic that helps...
Melting Slicks
Joined: Dec 2017
Posts: 2,984
Likes: 494
From: Michigan
2023 Restomod of the Year finalist
Seems like spark plug makers brag about the material they use to make the spark plug. Some metals burn hotter and others claim they can last for 100,000 miles.
Is this all HYPE or WHAT?
Is this all HYPE or WHAT?
Pro
Joined: Sep 2006
Posts: 509
Likes: 141
From: Heaven
For those using the AC Delco’s or the NGK’s mentioned here; where are you setting the gapping at? This would be on a 327/300 HP setup. I don’t need them yet, but I’m looking at buying a set or two for my ‘66. Let me know. Thanks.
Thread Starter
Burning Brakes
Joined: Jul 2016
Posts: 769
Likes: 123
From: Heerde Gelderland
Hey my old thread revived, and I see I didn’t properly respond back then.
well to give a follow up, I went with the AC Delco r45s on my 327 300, the plugs came pre-gapped and ran well.
well to give a follow up, I went with the AC Delco r45s on my 327 300, the plugs came pre-gapped and ran well.
Last edited by Twan Sloot; Oct 6, 2020 at 12:50 AM.
Safety Car
Joined: May 2014
Posts: 3,787
Likes: 659
It's not HYPE and true with modern cars, remember that fuel injection and computer controlled ignitions keep combustion conditions as near to perfect as can be. I have replaced spark plugs with 100000 plus miles, they are wore out in that the electrode is reduced and plug gap is wide but the ignition keeps firing them. Modern technology is very good, just wait until we go all electric and they are fast too.
Our old cars, not true at all but you can extend the tune up interval with some advanced tuning if you desire.
Race Director
Joined: May 2000
Posts: 12,712
Likes: 2,271
Another non-resistor plug for small blocks equivalent to the no-longer-available AC 45 is the Denso W14-U. I believe all late model Corvettes going back to the first C5 were factory equipped with Denso plugs.
Duke
Duke
Pro
Joined: Aug 2017
Posts: 513
Likes: 170
From: Coral Gables Florida
59 Fulie 290: NGK 7355 (XR51X) Iridium 0.040 in. gap.
MSD Street Fire 5520
Call NGK customer service and they will help you cross reference the spark plug. I spent about 15 minutes with the NGK customer service representative finding the correct spark plug, excellent customer service.
MSD Street Fire 5520
Call NGK customer service and they will help you cross reference the spark plug. I spent about 15 minutes with the NGK customer service representative finding the correct spark plug, excellent customer service.
Last edited by Rdelvalle; Oct 6, 2020 at 09:28 AM.
Melting Slicks
Joined: May 2003
Posts: 2,840
Likes: 301
From: Bonita CA
The problem with the NGKs is nobody stocks them. They all have the ACs in stock though. Went to Pep Boys, Auto Zone and O'Reilys. Nobody had the NGK XR-4s in stock but could order them. PITA. Settled for the ACs.
Last edited by 2KREDVert; Oct 6, 2020 at 03:18 PM.
Pro
Joined: Aug 2017
Posts: 513
Likes: 170
From: Coral Gables Florida
I hardly go to a store anymore. I do 99% of my shopping, that is for everything not just auto parts, on line. I even bought a Porsche 1997 911 in Ebay. I still have the Porsche. A few of the NGKs I bought at Amazon the rest from RockAuto. I paid $5 for the NGKs 7355 from RockAuto. From what I remember there were several on line stores that had them. Amazon sometimes deliver their merchandise next day and even on Sundays.
