What plugs in a competition engine - Hi Comp

[Evogone]

Its been discussed before about what plugs you should use but what is the outcome:-

1. Can NGKs be used in engines using high comp pistons ?
2. What heat rating plug should be used (std one are 6 i believe) ?
3. What are the options ?

Any info welcome...

[Coops]

think you have to be careful with multi electrode NGK's in high comp engines as they can foul pistons, pretty sure i read that somewhere

think 6 rating should be fine for all n/a applications

[sideways danny]

how high are the piston tops? I'd run BCPR7ES if you can without making piston contact. If not, go for BCR8ES

[Evogone]

how high are the piston tops? I'd run BCPR7ES if you can without making piston contact. If not, go for BCR8ES

Any reason with have a heat rating of 8 rather than 7s ?

[sideways danny]

7s would probably be idea but you can't get them with a recessed electode. 8s have a recessed electrode and will clear if you run the pistons with the highest crown available (I've run one engine with these before and 7s just kissed) The only down side of 8s is possibility of coking up slightly if you drive it too gently too often.

[sideways danny]

A BCR7ES would be ideal, but it doesn't exist ;)