Stock vs. Race Spark Plugs: What You Need to Know

[@JohnDoesItAll]

I learned a lot in this video. Thank you!

[@tombrown879]

Great video. I learned me something today:)

[@allhailinternalcombustion]

Another informative video. I love the sound of your distributor machine, very relaxing.

[@BruceCoggins]

Thank you very much

[@josephverdone7099]

AUTOLITE AR3924 racing plug is a 4-ohm resistor spark plug

[@BruceCoggins]

Thanks for pointing that out. For years I was under the impression that all race plugs had no resistor but after looking at numerous plugs it seems some do have a resistor and some don't but they still somehow have very low resistance. Something I should have tested when we had a racetrack was a high resistance set of plugs versus a very low resistance plug to see if there was an ET difference. Our local drag strip was sold in 2018 so tests like that are much more difficult....

[@kirkshuttleworth7138]

To properly check/gap a spark plug you should use a wire type Guage not the flat style you showed.

[@mickangio16]

I like your videos👍I DO have a question. I worked on a car with an HEI last week that was starting and running very poorly and determined it to be the ignition at fault. Removing the distributor cap and coil cover I found that it had an MSD coil installed but the module appeared to be a factory(?)part- (RKD1906B-2107 and another number- R5003361-C) a 4 pin module. I really wanted to use a matching coil and module for reliability's sake and would have preferred to use AC Delco parts but they were quite expensive and I didn't want the owner to get mad. I also checked the price of an MSD module to match the coil but that was about $160 if I remember right. In the end I bought a cheap Chinese module for $15 from Amazon, installed it, and now the car starts & runs very well. Now, I have read before that off brand HEI modules are nowhere as good as genuine parts and the dwell does not vary with rpm as a genuine part will. Seeing as to how the car is running fine now my main concern is whether the module will be a problem in the near future especially coupled with the MSD coil. The car is not a race car. It's a nice 1968 Buick Skylark convertible with Buick 350 power. I didn't want to upset the owner with high price repair but I also don't want it to break down anytime soon or at all for that matter. Do you think the MSD coil and cheap module combination is going to be a problem?

[@BruceCoggins]

Thank you for that. The last 2 MSD modules (83647) I bought both failed within just a couple of months so I have not used one again for many years. As far as running an MSD in-cap coil with a stock module, that should work just fine. A quick note about HEI in-cap coils...I should have mentioned this in the video...anyway, for Chevy engines (or distributors that turn clockwise) use should use the coil with red and yellow wires....distributors that turn counterclockwise (Pontiac, Buick, Olds) you need the coil with the red and white wires. I'm pretty sure the Buick 350 you worked on turns clockwise so the yellow and red wire coil is correct. No matter which module you use, it will have "expanding dwell". Modules are the electronic equivalent of points but are much more efficient. The coil needs time to build up the charge hence "dwell time". So, to answer your question...yes, the stock module with the MSD coil will work.

[@mickangio16]

🤞the Buick is a clockwise spinner. I THINK it had red & yellow wires. It's runnin' real sweet now. My main concern was whether the "hot" coil would put more demand on the questionable module. The car doesn't get driven often but I don't wanna see my friend breaking down because I made a bad call. Thanks for the encouragement. As for the Champion Spark Plugs, I have always used them in the Chrysler engines because that was the ones that I knew for them. I only started using NGK plugs in them in the last few years because the Champions became hard to get in the ranges that I wanted. I've known about the bad reputation that they gained for years but I never had a problem with them and kept using them with confidence. I don't expect for a set of spark plugs to last 50,000 miles in the type of cars that we are interested in and I would never put expensive plugs in an old vehicle, hotrod, or racecar. A modern vehicle that is your everyday transportation "appliance" that you have no ambition to have to work on is a different story. I WILL spend more money on plugs for that vehicle in hope that I don't have to be concerned with them for a loong time. Besides, there's not a whole lot I can do about the state of tune on that vehicle to influence plug life either way good or bad. Guys that put expensive plugs in their 306c.i./325h.p. '67 Mustang or 454 '65 Chevelle and get mad 3 years later when you insist on putting new plugs in it- Lordy, Lord! I could go on with stories but I know that you know what I'm talkin' about.

[@BruceCoggins]

@@mickangio16 I also install Champion plugs in the older Chrysler engines I work on. I figure the factory sent them out that way so I'll keep them factory. I'm not really sure where the bad rap came from on them or what it was all about but they seem to run fine. I've never run them in anything I own though but I am a Chevy guy, LOL.

[@mickangio16]

I had always used AC Delco in GM, Autolite/Motorcraft in Fords, Champs in Chryslers... it's another day, though.

[@mickangio16]

@@BruceCoggins another project that I'm involved in is a 1956 F100 with a 400 Chevy. The owner chose to use headers even though the truck will never be driven hard. He is 84 yrs old and owns other beautiful classic vehicles. With the headers that he chose shorty Accel spark plugs are necessary. They are expensive and only available in colder heat ranges.

[@thomasdemarco617]

best module for a big block chevy street car please locked out distributor

[@BruceCoggins]

If you lock out the advance and retain the module, your timing will retard as RPM increases due to latency between the magnetic pickup and the module. Whenever I lock out a distributor the first thing I do is remove the module. You will need an ignition system capable of firing off the magnetic pickup like an MSD 6al for instance.

[@thomasdemarco617]

use to snap ground off