Spark Plugs - Page 2

30psi · #11 20-11-2006, 10:52

Only clarified the above because you dont want people opening the 1.1mm gap further.

PukkaSilvia · #12 20-11-2006, 19:39

lol. Next thread would be

Quote:

misfire problem on boost

JamesS12 · #13 21-11-2006, 17:03

Basically I only asked the question because i was thinking of getting a set of iridium plugs for an s13! Dont know if this changes matters??

Conkers · #14 30-03-2007, 10:57

The bcpr7es plugs.. is that for the 4 plugged ca18et engines?
Mine has the 8 spark plug ca18et and standard the plugs should be 5 on the exhaust side and 6 (heat range) on the inlet side... anybody know how this twin plug set-up works and the purpose...
Maybe I should just run 7's on both sides.... any ideas?

Mike.

30psi · #15 30-03-2007, 11:06

Yeah, run 7's all round.

The 4 plug setup is only geared towards emissions, where by both plugs only fire together up to a low rpm like 3,000rpm, then it switches to just using the inlet spark plug.

Conkers · #16 30-03-2007, 11:07

Thanks mate... so you reckon she'll run ok with 7's all round.... I'll get 8 of those on my way to the workshop later then....

Thanks...

Mike.

edited in:
Was just trying to figure out why they run a softer plug on the ewxhaust side, but it must be as these shut down at 3000rpm and could therefore duff up if there is a tendency for that sort of thing.... probably not helped by the turbo intermittantly smoking on idle from time to time, but not all the time.... Think James Bond.....

But back to plugs... so all 8 run up to 3000rpm for emissions... and then only the inlet side after that... correct????

CNHSS1 · #17 30-03-2007, 11:08

the second set (exh side) were to burnt off any unburnt fuel for use when the vehicles were fitted with catalysers, it was for emissions rather than performance (unlike the Alfa twin spark engines). when i had a car with the 8 plug ET setup, i went colder on both (from 5s and 6s to 6s and 7s) when i turned the boost up.

30psi · #18 30-03-2007, 11:12

I'd say go for 7's on the exhaust. Being near the exhaust valve and prone to more heat than standard, if they're coked up this will glow red leading to pre-igntion.

Conkers · #19 01-04-2007, 08:59

I changed them to 7's all round and she runs fine... ish!.. actually the electrodes were completely missing on some of the plugs, possibly due to fuel surge whilst doing donuts and the engine going lean.... did a compression test and #4 is down a tad... so as we had planned on tuning anyway, I'll pull the head, port it and sort it... but thanks for the advice... 7's all round made it run fine... top tip.

Mike.