R44TS for stock ‘72
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,030
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From: US-PNW
The only way to know if the 44s are too cold for your particular engine is to run them for a few hundred miles and then "read" them. The hot/cold terminology merely refers to the plug's ability to efficiently burn off the combustion residue from itself. A plug too cold (for your particular engine) would allow carbon build up closer to the strap tip and the electrode end of the porcelain, eventually fouling itself. A plug too hot, again for your particular engine, would allow too much combustion heat to move off the strap and into the threaded portion of the plug, causing the strap to erode away. There's not going to be a huge difference between a 44 and a 45, so I doubt you'd see any ill effects with either.
There's a great YouTube video on reading plugs by a race engine builder but his name escapes me... I'll see if I can look it up and post a follow up.
There's a great YouTube video on reading plugs by a race engine builder but his name escapes me... I'll see if I can look it up and post a follow up.
Last edited by barkingrats; Nov 1, 2021 at 10:03 AM.
Safety Car
Joined: Jan 2004
Posts: 4,549
Likes: 343
From: Glastonbury CT
Go with Iridun spark plugs these last for ever and as far as your choice R44T are the correct AC plug for your Corvette but try and find them. You will have to cross reference them on line.
Thread Starter
Instructor
Joined: Oct 2021
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Safety Car
Joined: May 2001
Posts: 4,747
Likes: 1,642
From: Fairfax Virginia
I have used the Iridium Spark Plugs on my 427 and they get Fouled Out. They had a lot of deposits on them and they were not firing. They forced the spark to jump someplace else to ground out! I have not had good experience with them. When I switched to new plugs the arcing went away and the engine ran better.
The AC spark Plugs called "Rapid Fire" lasted a long time for me. The iridium worked okay in my C4's L98 and went for a few years.
The A.C. Delco "Rapid Fire" spark plugs worked the best with my MSD ignition system in my C3. They have a hefty ground strap that doesn't get burned away.
The AC spark Plugs called "Rapid Fire" lasted a long time for me. The iridium worked okay in my C4's L98 and went for a few years.
The A.C. Delco "Rapid Fire" spark plugs worked the best with my MSD ignition system in my C3. They have a hefty ground strap that doesn't get burned away.
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,030
Likes: 4,174
From: US-PNW
Here's the YT video: Steve Morris Engines:
and the thread that it was posted to: https://www.corvetteforum.com/forums...park-plug.html
Last edited by barkingrats; Nov 1, 2021 at 10:31 PM.
