This is a pic of my plug at 65mph,,,It is also a new motor....Is it to lean or is it cause its a new motor?? The white showing in the picture goes blacker ,,,richer at slower speeds.. Any help appreciated Cheers!
[img][img]http://i152.photobucket.com/albums/s193/suffolk_photos/100_0388.jpg[/img][/img]

You need to get a shot of the electrode more in focus.

Usually if there is carbon on the outside but the centre electrode is white then the heat range is off, too hot I think. The reason is excess carbon on the outside indicates rich-ish mixture but the plug is burning this carbon off the centre electrode as it is too hot.

I always recommend to run the coldest plug your ignition will fire during a cold start. Most original Mini ignitions are pretty crap due to the points (they can't fire modern coils) so if you convert to an electronic dizzy this could be a better option and allow a colder plug.

Daniel

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Videos - Turbocharged A-Series on Dyno & at Wakefield
Mafs waz not my strong subgeckt at skkol

Thanks for you input Daniel,,The plugs that are in there are BP6ES...Are these hot plugs?Whats the number for a cooler or cold plug?? Cheers!!

http://www.dansmc.com/Spark_Plugs/Spark ... talog.html

^^^^ I recommend adding this site to your Favorites for future refernces.

Hope it helps.

Cheers, Mark.

Thanks for the link i'll check it out after i post this pic..Cheers
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Thanks for the link i'll check it out after i post this pic..Cheers
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When you say that that is what the plug looks like at 65mph, do you mean that you've cut ignition after a few minutes at a steady 65mph. . .or have you diven at 65mph for a while and then driven to a stop and checked the plugs?

It looks to me like at 65mph you're running a bit lean but at lower speeds/idle it might be fractionally rich - what needles/springs are you running. . together with what compression/cam/engine size (from memory, your motor was a 20 thou over MkI S 1275?)?

Looking at the better pic, I tend to agree with Peter in that it's most likely that the engine is running rich at a certain point and leaner at another.

BP6 or eqivalent should be fine in terms of heat range. Often people think they need to run a hotter plug during run in as the engine won't be thrashed.......

Check the low speed/idle mixture/colour and then do the highway run and compare.

For confidence I would be finding a tuner with an oxy sensor to shove up the tailpipe and confirm the mixture. The readings from an oxy sensor are less affected by ignition variances than the plug colour. This is especially the case if the engine has had mods done during the rebuild.

Daniel

_________________
Videos - Turbocharged A-Series on Dyno & at Wakefield
Mafs waz not my strong subgeckt at skkol

Thanks again Daniel,,I agree its booked in for the dyno on 4/3/08,,Trouble is ive got to select some needles before hand,,as it takes days to get them here..Have to try something richer i think....Cheers!!

Hello Peter and soaf,,yes do 65mph and stop straight away to rip the plug out and thats the result[pic]...Its 1330cc,Acording to G.R one of the best heads he's done,Re13,,maniflow manifold,,maniflow lcb's and twin 1.5 SU's...My mates dyno has the exhaust monitor,,,but he doesn't know much about su's...Don't want to drive it to much the way it is...The needles in there are ABD...Springs not quite sure maybe reds,,shorter and softer than blues anyway,,,some one said maybe the springs could make it run leaner,,so i might put the blues in and see how it go's...Can you recommend any good SU places in Perth..with a dyno or gas monitor...Cheers suffolk..

Stiffening up the springs will certainly make it run a bit richer (on the same needles).
I would have said that ABD's wouldn't be far off the mark - maybe just need a bit taken off them at the top end?
Not sure on SU-friendly dyno places in Perth - I've always tuned 'by hand' myself wih plug cuts and needle filing.
May be worth dropping the guys at SU Midel an email - every needle reccomendation I've ever asked them for has been absolutely spot on (provided the engine spec you give them is correct).

O.k Thanks Peter,,I'll try the blue springs and see how it goes....bit of trail and error..should get there in the end hopefully..Thanks mate!! suffolk..

Those plugs look fine, white electrode is OK with new plugs and unleaded. If it blisters it's too hot a plug or running way lean.
You don't get the colours with premium unleaded like we used to with Super.

BTW DOZ, with 98 fuel I've seen BP5ES plugs give more torque on GR's dyno than BP6ES, he reckons you need a hotter plug than stock when using unleaded. BP's website agrees.
This is for road use, for track use what you say is correct.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.