With all the new spark plugs being advertised

[Michael C Henry]

I have a 427 side oiler with dual 4s and I want to buy new spark plugs. I'm taking out a set of AutoLite 46 spark plugs. With all the new stuff available what would you buy?

[CompClassics]

Depends on what ignition system you are using. I have a stock dual point distributor with a stock yellow top coil and I use the Autolite 45s.

[blykins]

The 46's would be a hotter plug. I usually run the 45's as well with most of my factory head combinations. Autolite does make an "AR" plug in 18mm, but if this is a street engine, you're probably better off with the regular plug.

Post some pictures of a few of your spark plugs and we can tell you if you need a little colder heat range or if the 46's will be fine as a replacement.

[Michael C Henry]

I removed Auto lite 46 plugs, had to have been in for 15 years = around 1.000 miles. I have sand blasted several times. I have Mallory Unilite electronic pickup distributor W/mech tack drive , Mallory Pro Master coil, Mallory HyFire VI box, Dove tunnel wedge 2x4 intake aluminum Dove Canadain Super cobra Jet replica heads. Intake is ceramic coated inside and out. Starting it needs some extra throttle to lite it and keep it running to get it outside and warmed up, even with manual choke. It really depends on it being warmed up to get it running clean and idling.. Present plugs are all black. I've driven it home from Reno, up the peninsula , Ocean Shores, and Tacoma to Astoria and back
I'm considering buying new plugs for new smooth porcelain. better materials to alleviate some of the black build up, and so on.

[blykins]

If the plugs stay black, it's probably not the plug's fault unless it's just way too cold. But by your description of how it starts and how it doesn't like to warm up, in addition to the carbon build-up, I'd look at the carbs a little closer.

[Michael C Henry]

The plugs are black, mostly from what happened Easter weekend. I forgot my own rules and ran the car cold way harder than probably ever had. It launched , the front end came up , torque steer, hit rev limiter and the car coasted down another block left turn, another block ,another left short block and another left and coasted to stop. Limping all the way just trying to keep it running. I had to be towed home. I had other projects and let the car set in the garage until now. My first thought was that the cold engine dumped a lot of gas on cold plugs and rev limiter just fouled everything. Then I thought what if the sudden surge did something to carburetor fuel bowls? then, What if I had broken the distributor drive gear pin again. It was making oil pressure but was hardly running. What if I had only bent the pin and it was now firing way late? The time before When I sheared the drive pin everything coasted to a stop and died. That is when I installed this coiled spiral roll pin because it was tougher than the original split spring pin. Problem I didn't think and just reinstalled the gear. one hole but as I found out later, there are 15 teeth on that drive gear and 180° isn't the same where the distributer was. I found that the distributor was now where I could twist the distributor to get the correct timing. Mechanical tack drive on the distributor housing, won't let the distributor twist much
So suspecting the drive gear pin, I removed the distributor , wiped as much oil away as possible and blew through the suspected drive gear pin. I could see lite, the pin wasn't bent. but it was miss timed or miss installed So I'll fix that I center punched the ring above the drive gear and the now still wrong drive gear so I could tell where the drive gear was supposed to go. Removed the pin no problem. I repositioned the drive gear and went to reinstall the pin, but it now wouldn't go. The coiled spiral roll pin I used started out with 15 years ago was too long but had beveled ends. the beveled ends helped align everything. then I later cut the excess pin with a cut off disc. The now square ended pin wouldn't align anything and now mushroomed pin probably dented shaft around the hole. I tried to stick the 1/8" punch in from the other side to align everything. punch was now stuck in the shaft. I used my hand on the punches handle and a pair vise grip pliers and twisted the tip of that pin punch off leaving the broken piece in the distributor shaft and the gear holes empty but the drive gear still stuck on the shaft. I gave up and delivered it all to a machinist. Yeh! the plugs are carbon fouled.

[Michael C Henry]

The saga goes on. two weeks and the machinist didn't get any result except bending his pin punch. I told him that I believed that the broken tip was only in the shaft. He could hold the drive gear and drive the shaft out of the gear. That worked for him but, my mistake , the drive gear and shaft pin hole will only align one way. My Mallory distributer was drilled with a slightly of center hole and angled downward . Will not align any other way. He tried and I rescued the distributor from him with the roll pin partially installed with the exposed end of the roll pin all mushroomed and fractured. The pin was inner end was against the other inside wall of the drive gear ( hole not there. I had to cut the mushroomed exposed portion of the pin off with a cut off wheel on my Dremmel. Then I used various carbide burs to enlarge the pin center and hollow the pin out beyond the depth of the drive gear side wall. I also used a set of optical magnifiers. I was able to finally weaken the pin to a point where I could again drive the shaft through the gear. With the gear removed now the last of the old pin can be removed. I turned the gear around on the shaft . All the holes now align and a new pin was installed. Reinstalling the distributor, I didn't have any pops or backfires. The timing light was working. The electric fuel pump was running but no fuel pressure in pressure regulator indicator gauge. I added a five gallon jug of gasoline I had. Now the pump is making a different sound. OH CRAP. I WAS OUT OF GAS. I had jumped to the wrong conclusion. I installed a new set of NGK spark plugs. Now running great again.

[MaSnaka]

Hmmmm. Sounds like you figured it out. Now go drive it. 1000 miles in 15 years is not enough.

John

[Gaz64]

Originally Posted by MaSnaka

Hmmmm. Sounds like you figured it out. Now go drive it. 1000 miles in 15 years is not enough.

John

Agree.

The engine could be worn out chemically before mechanically from acid in the oil.

I hope the oil has been changed by time not distance.

Gary