deformation of the new spark plug electrodes on my caddy coupe devill 64

Hello everyone,
yesterday I changed spark plugs with new (preventatively) ordered from (brand see photo) further I changed all belts and coil, cables from spark plugs I described not to confuse it.
After the engine started, the engine sounded as if it were driving on fewer cylinders.
I immediately switched off the engine and, after removing the spark plugs, I was horrified as they deformed.
Thread on new spark plugs is as long as old ?!
this deformation only occurred on the cylinders on the left side of the cylinder 2,4,6,8
on the other hand everything ok, I put back the old spark plugs and the engine goes ok,
after removal, no candle is distorted and the engine is running ok?
What's the moth happening?

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I belive there is a big risk that one or more of the pistons are damaged, there are some examples on this and other sites showing deformed plugs and later on when the heads are removed you find that pieces of the piston top are gone. When the pieces come loose they bounch around and close the plug gap before the leave through exhaust, somtimes they can go back in the intake and find its way into a other combustion chamber, so one cracked piston can create damage to more than one plug.

This is reminding me --of when i started to work on my brand new 63 409 425 Hp Chevy to get to know how to keep it running-- perfect
My drag race carrier was off and running in 63
I forgot to tighten down the screw that holds the points in and the car stopped dead on me a few blocks from the house
Walked back to the house to get the tools to fix it -a newby future Hobby race mechanics snafoooooo
Everybody does start someplace on there --hobby mechanic quest

Thanks for the memory



That's what I said, I do not want to bother or abuse you just for information.
I apologize to everyone.
Have a nice day.

Jan, it would be highly unlikely you've got 4 damaged pistons.

Set the plugs at 32 thou gap, fit the plugs back and start it. Somehow, I reckon the plugs went in that way with no gap.

Pop up a photo of the tip of the plug, because if the plugs have been hit by a piston, there would be a witness mark on them. 

Tony, did you have an Impala, Biscayne or Bel Air?

I love those 409's 1961-1965!

Not likely -that four piston tops are damaged and closing the plug gap on one side of the engine


When you install the new plugs in the engine -- pull out the coil wire and crank the engine with just with the starter - pull the plugs to see what they look like
If they look right start the engine and run it - then inspect again
If you installed the plugs without gaping them -- gap them- install and run the engine
Inspect plugs again


The "S" in the suffix of the plug number denotes extended electrode or tip. These look like the proper heat range for the Cadillac but R43 (without the S) may be better. Is anyone else out there using R43S plugs? I don't want to offer bad information if other folks are successfully using these plugs.  


Impala Super Sport Palamar red ( burgany red ) black interior - bucket seats and center console



I had --Whilaway --( famous race horses name ) painted on the front ( top side) of the fender of the car
About one foot long -by 4inches wide
It was done in white with a black background by a famous pin stripper on Long Island
There were a few other 348's and 409's back then with names that were well know for there very high performance street racing
The - Outcast -The White Lady and The Farmer --come to mind

I raced the presidents of the Pagen motor cycle club on Long Islands
It had a radical 60's phycodelic paint job
The fastest street racer would go looking for each other
His wife raced the car and it said on the back - "if you beat me you could eat me ! "
She got me by a car
I was true legal stock with a legal crane came and a blue printed engine - 538 rear with various slicks on the street --always
The vet had one of the very first nitrous system i ever experienced
My first ever experience with nitrous then
We were dead even and when he hit the nitrous it sounded like he started another engine up
The very best times a challenge would be set up the sides of the entire quarter mile were lined on both sides with with cars just like in the movies ( how crazy is that if one looses control )
Both cars on street tires would be fishtailing a good part of the quarter mile next to each other
The best way i know of to be spending a wonderful summer night in my youth

I haven't had those thought cross my mind for some time
Just remindes me of how much fun and excitement that was


The above should read — WHIRLAWAY - my edit  attempt  did not fix that 


I ran AC Delcos (R43S) for our cars, and my 64 ran and idled like crap! The Autolites are the ones to get, 85’s to be exact. 

After installing the Autolites, my 64 ran much better.



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