Hi all

further to my earlier thread I have now established that I have an intermittent fault with a couple of my spark plugs

Can someone let me know which are the correct/best spark plugs to use in my 4.2 (1974)

Many thanks

Richard

 

I have always used NGK BP5EY on all the XK engines for as long as I can remember.

 

Thanks Grant. Spark plugs are on order

 

Grant, I just recently put BP5ES......is there a huge difference?

 

I've had both, ES & EY. Same heat range,reach etc. Only difference is the V.
Did not notice any difference between them, the ES were a week old when I replaced them with EY's.

Grant will have an answer for sure.

Had a slight problem so changed plugs first, turned out to be a new dissy required and went electronic.


BP5ES








BP5EY

 

Hi Daf11e,

The last letter signifies firing end design.

In English, that means the tip of the spark plug which screws into the combustion chamber.

Y is a grooved end with a projecting centre electrode.

S is a standard centre electrode.

Spark of Y type is better than S type in our XK engines.

S will still work, Y is better suited and less trouble when starting.

Like you need more trouble starting a 30 -40 year old engine.

Also, Y provides a better spark and better performance than S in every day motoring.

Sorry to steal Grant's thunder.

Cheers,

Nigel