spark plug spec?

Post by **wibble_puppy** » Sun Jun 01, 2008 6:44 pm

ello,

another beginner question ( - I'm sorry about this but I have tried the "search" facility, honest! I hope it isn't one of those questions which come up every two months

)

what is the correct spec for standard spark plugs for a standard 1098 engine?

my local motor factor has given me some Bosch Super" plugs which say "WR 8 CC - 0 242 229 533" and have a little diagram showing the tip gap to be 0.8mm.

my handbooks etc say the plugs should have a gap of a little over 6mm

can anyone help with advice on this one? are the plugs I've bought okay, or do I need to go back and change them?

wibble

Post by **Welung666** » Sun Jun 01, 2008 7:11 pm

I use Champion N9YC with a gap of 0.025" (0.64mm).

According to my books your Bosch plugs are the wrong ones! The Bosch equivalent should be W5DC's The WR8CC plugs are equivalent to Champion RN5C plugs which are way to hot.

Post by **wibble_puppy** » Sun Jun 01, 2008 7:18 pm

lee, you are a SUPERSTAR

Post by **Welung666** » Sun Jun 01, 2008 7:19 pm

Post by **bmcecosse** » Sun Jun 01, 2008 8:14 pm

Yes - stick with N9Y o r maybe N7Y in a modified engine. 1 mm = 40 thou - so your '6 mm' would be almost 1/4 inch - it will never work. Stick to 25 thou unless using a high power electronic system when the gap can be increased to 40 thou, ie 1 mm !!

Post by **wibble_puppy** » Sun Jun 01, 2008 8:46 pm

lol I meant 0.6 mm

Post by **Stig** » Mon Jun 02, 2008 9:22 am

I've always used NGK BP6ES - I thought these were equivalent to Champion N9Y.

Post by **Welung666** » Mon Jun 02, 2008 11:08 am

Stig28 wrote:I've always used NGK BP6ES - I thought these were equivalent to Champion N9Y.

Correct along with the Bosch W5D or W6D.

Post by **wibble_puppy** » Mon Jun 02, 2008 12:18 pm

well, have come back from motor factor with Bosch WR7DCs

they reckoned the W5DCs would be rather too cool - kind of racing engine sort of thing. they said the WR7DCs were the equivalent of Lee's Champion N9YCs.

The gap is still 8mm - apparently that's how most of the plugs come these days? anyway I guess I can reduce the gap myself, can i?

wibble xx

Post by **alex_holden** » Mon Jun 02, 2008 12:38 pm

You mean 0.8mm. Setting the spark plug gap is a bit of a knack. Get a feeler gauge set to 25 thou and put it between the electrodes. If the gap is too large, lightly tap the outer electrode against a hard surface, then try the feeler gauge again. You're aiming for it to be just possible to slide the gauge between them, not too loose or too tight. If (when) you close it up too much, don't jam a screwdriver between the electrodes and lever them apart or you are likely to damage the plug. Instead use a pair of pliers to grip the sides of the outer electrode and bend it up slightly. If you have some old plugs sitting around, practise resetting the gap on those first.

Post by **wibble_puppy** » Mon Jun 02, 2008 2:36 pm

Brilliant. You are a star, Alex (and betraying your background again

)

And yes, I did mean 0.8mm - been a long couple of weeks

wibble xxxxxxx