V8S Spark Plugs

[Barkychoc]

I am well and truly confused now.

On Pies website (haynes datasheet) plugs are listed as NGK BP7ES, and they are what I've bought.

I took the old ones out - which are B7ECS which set alarm bells ringing.

B7ECS are listed in Steve Heaths Bible, but there is a footnote to say there are others but that this plug is best at preventing pinking.

Anyway should I use the BP7ES plugs ?

The body of the two plug types is identical but the electrodes stick out the end of the plug further on the BP7ES plugs (The ones on Pies website, Haynes datasheet).

The plug gap is another story - with various plug gaps quoted.
0.032 inch in Steve Heaths Bible (B7ECS)
0.6mm (0.023mm ish) on Pies site (Haynes datasheet).

I did notice later that the sheet on Pies website says 4280cc at the top for engine size.

I've already done one side of the engine with the new plugs, with the gap just left as they came out of the box as I couldn't decide what to set them at (and it does run, nothing went bang).

I don't know whether to continue or put the old ones back in now.

Chris

[GreenV8S]

B7ECS at 0.9mm is an absolutely safe bet. But it's not fussy and I don't suppose any harm will come from fitting the longer plugs in a standard spec engine.

[pies]

BP7ES


B = Thread dia = 14mm
P = projected centre electrode insulator
7 = heat rating lower number is hotter rating
E = thread reach = 19 mm
S = standard super copper core centre electrode

B7ECS

B = Thread dia = 14mm
7 = heat rating lower number is hotter rating
E = thread reach = 19 mm
CS = Short angled ground electrode

Edited by pies on Saturday 8th September 22:09

[Barkychoc]

GreenV8S said:

B7ECS at 0.9mm is an absolutely safe bet. But it's not fussy and I don't suppose any harm will come from fitting the longer plugs in a standard spec engine.

Pete, I'm going to use the BP7ES plugs as I've bought them now, but not sure what to gap them at.
Would you go 0.9mm, or would it be better to go with a different setting (less?) as they project further into the head. I'd say they are 0.6 to 0.7mm at the moment (I tried a 0.6mm feeler guage which was barely dragging).

Thanks

Chris

[GreenV8S]

Gap it at 0.9mm unless you have a much higher than normal compression ratio, forced induction etc.

[Barkychoc]

Thanks Pete - better go get my overalls !

Chris