While platinum spark plugs are not recommended with multi-spark ignitions, they should still fire.  With that said, insure that the engine is producing spark from the distributor cap end of the coil wire when cranking the engine over with the key on.  If no spark, then it’s troubleshooting time to find out where the ignition is breaking down.  Make sure you are running a full 12 volts to the MSD coil and not through a resistor.

Lorena, Texas (South of Waco)

I know this sound dumb but you tighten the plugs. They have no gaskets and need to be tight for grounding. Found that once on a Merc my brother did a tune up.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

I've seen that NO Platinum recommendation before - but have no idea why they would print such a thing. Perhaps it has to do with their "red box" CD  ignition scheme - that works on very high voltage / low amperage (like 400v on the coil primary) and multiple sparks - not the high amps of the souped up inductive schemes. Maybe the high voltage doesn't get along with the platinum plating so well.

 
 Steve Metzger       Tucson, Arizona

I seem to recall MSD recommends not using platinum ?

Put Autolites APP 45 in my car today, gapped at 35, won't fire a lick. At least with my old plugs it would start. Any causes?

I just put a set of NGK V Fire plugs in mine. It's too early to tell if they are in the right heat range. I plan on putting a few miles on them and I'll let you know how they look.

Durham Missouri

Currently using Champion RF14Y but their very dirty which tells me the car has never been running right, one day I hope to have it running the way I know it can. Just found out the other day that the guy who sold it to me put a different type cam in and supposedly that could be effecting the idling, he set this car up for himself and when it sold he didn't offer any changes me made to the motor other than it was rebuilt, rebored to 292 specs and that was it.

Autolite #45 works for most Y applications.  If the compression ratio is on the low side or the engine is pulling some oil past the rings, then Autolite #46’s.  I run the Autolite #46’s in my ’55 Customline with its 272 and original small valve heads.

Lorena, Texas (South of Waco)

Well I think he had a purpose for keeping it stock as possible as most of them came with champions, but thanks I will try the autolites.

Which plugs are currently installed?
The stock plug would be an equivalent to an Autolite 46.  There is no reason that Champion only should be used.  Maybe the seller just likes champion.



Lawrenceville, GA