Eddy head spark plug interference

[supertruck]

I have an issue with the Edelbrock aluminum heads on the 340 I'm building. I got a set of NGK plugs today and threaded them in. Before they can thread in far enough for the washer to seat, the points on the hex head where the socket goes hits the head and it won't turn. Does this on every plug. I've had a lot of experience with plugs but never this. Am I missing something here?

 

[brian6pac]

Wrong plugs, you need cad plated not black and 5/8 head not 13/16.

 

[yellow rose]

Wrong plugs, you need cad plated not black and 5/8 head not 13/16.

^^^^^^^^^This^^^^^^^ on both accounts...the cad plated no black shells and the 5/8 hex.

 

[72Dart6pack]

Edelbrock clearly states that on the product description for there cylinder heads.

 

[supertruck]

Learn something every day. These NGKs were the equivalent to the Autolite 65s I wanted, at least according to the store. Shoulda checked myself. Thanks guys.

 

[supertruck]

Edelbrock clearly states that on the product description for there cylinder heads.
The paperwork in the box says only 14mm threads and mentions a Champion part number. Says nothing about 5/8 vice 13/16.

 

[yellow rose]

I'm sure the Champion plug number was an RC12YC or an RC9YC and the C would tell you it's a 5/8 hex and 3/4 reach.

 

[TrailBeast]

I've had a lot of experience with plugs but never this. Am I missing something here?

Yep, you are missing a little bit more experience with plugs.

 

[Marcohotrod]

the autolite 65 is a 13/16" hex=too big

 

[diymirage]

If your not willing to concede on the plugs, you can always have the pistons machined down so they sit in the hole deep enough to clear the plugs...compression is overrated anyway

 

[72Dart6pack]

Sorry that you glossed over important information that they gave you. I can see your next post (NGK Plugs for sale)

 

[stroked340]

Been running Edelbrocks on 2 different engines always use Autolite 3924's...

 

[Marcohotrod]

man , some people need to read better. the 13/16" hex hit the head, not the plugs hit the pistons

 

[Plymouth 65]

I have an issue with the Edelbrock aluminum heads on the 340 I'm building. I got a set of NGK plugs today and threaded them in. Before they can thread in far enough for the washer to seat, the points on the hex head where the socket goes hits the head and it won't turn. Does this on every plug. I've had a lot of experience with plugs but never this. Am I missing something here?

I used the Edelbrock recommended plugs with no issues. I understand some like certain brand plugs, but proper cross reference is on them. 65'

 

[diymirage]

man , some people need to read better. the 13/16" hex hit the head, not the plugs hit the pistons

right you are
i had to read it three times before i noticed what was going on

 

[famous bob]

man , some people need to read better. the 13/16" hex hit the head, not the plugs hit the pistons

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
I noticed that too !----LOL

 

[mjs69gts]

I'm sure the Champion plug number was an RC12YC or an RC9YC and the C would tell you it's a 5/8 hex and 3/4 reach.

the c means that its a copper core plug

 

[yellow rose]

the c means that its a copper core plug

The second C is for copper. The first C is 5/8 hex 3/4 reach as in rC9yc.

 

[mjs69gts]

The second C is for copper. The first C is 5/8 hex 3/4 reach as in rC9yc.

yes it is sorry about that my mistake

 

[SGBARRACUDA]

I did the same thing on my Indybrocks. Thinking that all Sb's used the 13/16 plug, I bought a set only to run into the same problem. Then I found out I had to buy the smaller plug. Like a Autolite 3924.

 

[71DodgeDemon340]

Ngk BKR5E

 

[71DodgeDemon340]

Ngk BKR5E