Spark Plugs

Belts, Plugs, Filters, Fuels, Oils, additives etc..... Told you this might morph into servicing and service items.

Moderator: Board Moderators

Post Reply
User avatar
GJ1
Senior Poster
Posts: 273
Joined: Sun Sep 10, 2006 22:27
Model: Ex Excel SE Owner
Colour: Pearlescent White
Year: 1990
Location: Alcalali, Spain

Spark Plugs

Post by GJ1 »

I am currently on NGK BPR6ES plugs and considering putting new ones in as per the manual. However, when I looked at the servicing being done by SJS, it appears they use BPR7ES plugs.

What is the difference in the two versions?

Am I correct in thinking that the Gap on the ***6ES is 0.9mm and on the ***7ES it would be 0.8mm?

What is the general opinion of the forum on which to use?

Just a little confused at present :oops:
I used to be indecisive..........
but I'm not sure anymore.

198

User avatar
amarshall
Moderator
Posts: 8282
Joined: Tue Nov 01, 2005 18:09
Model: SE
Colour: Monaco White
Year: 1990
Location: Darlington
Contact:

Re: Spark Plugs

Post by amarshall »

6/7 etc are the heat rating numbers on NGK

Everything you ever needed to know about NGK plug codes : http://www.spark-plugs.co.uk/pages/tech ... l_code.htm
https://www.lotusexcel.co.uk/
SORN - just say NO!

User avatar
mds666
Senior Poster
Posts: 482
Joined: Thu Dec 01, 2005 15:43
Year: 0
Location: Midlands CV47

Re: Spark Plugs

Post by mds666 »

as standard all "base" cars (82-92) are fitted with BPR6ES and all "SE" (86-92) cars are fitted with BPR7ES. as stated before the sevens are "hotter" than the sixes, 6's will generall start better

Simpatico
Senior Poster
Posts: 1259
Joined: Mon Aug 18, 2008 21:44
Model: Esprit

Re: Spark Plugs

Post by Simpatico »

My LC engine definitely runs/starts better since replacing the 7s with proper 6s last month
I am an EX owner; I have ceased to be

User avatar
GJ1
Senior Poster
Posts: 273
Joined: Sun Sep 10, 2006 22:27
Model: Ex Excel SE Owner
Colour: Pearlescent White
Year: 1990
Location: Alcalali, Spain

Re: Spark Plugs

Post by GJ1 »

Thanks for the info chaps :D

So from what I can gather then is that although I have a HC SE which probably left the factory with ***7s but is now fitted with ***6s, I am better of by sticking to the 6s as they are better for starting?

P.S. The car has always ran well on the 6s and even better after a clean up once in a while. So I suppose I should stick with them. Or...........

do i give the 7s a go :roll: decisions, decisions.

Oh well, at least I should count myself lucky that thats all I have concerns about at the moment with the Old Girl :lol:
I used to be indecisive..........
but I'm not sure anymore.

198

User avatar
Redexcel
Senior Poster
Posts: 352
Joined: Tue Nov 01, 2005 17:20
Year: 0
Location: Maidstone

Re: Spark Plugs

Post by Redexcel »

The numbers 6 and 7 give an indication of the operational heat range of the plug. The 6 has inferior cooling to the 7 and can therefore only operate in a (relatively) cool environment such as found in the combustion chamber of the LC 160 BHP model. Lotus obviously felt the 7 was more suitable for the higher combustion temperatures of the 180 BHP HC engine.
I doubt if it really matters unless you drive your car hard all the time, but obviously Lotus had to take that possibility into account when engineering the HC engine.
There should be no difference in starting from cold with between the two assuming they are in similar condition and correctly gapped.
Paul
'88 MY Excel SE #2551, 1996 TVR Griffith 500, 2006 Ford Fusion 1.6 diesel

Post Reply