Best spark plugs for 15% reduced sized puley mod

[philly c]

Hey i have just changed my standard pulley for the version 2.0 Alta pulley with amazing results.

I remember reading that the standard spark plugs should be changed for a colder plugs is this correct and what would be the best plug to use?

Has anyone who has fitted a pulley descoverd that the belt squeels a little when the engine is cold?I have replaced the old belt with a new one is it simply because it is new?

Many Thansk for any help

Phil

[CoolCarStuff]

Hi

As for plugs, do a search on here - there is much already written about suitable replacements, and what is std on the Works.

As for belt, most tuners suggest you replace the belt witha shorter one so that the pulley tensioner stays in the same place.

If the belt is making a noise, I would get it checked for alignment. Also, make sure it is the pulley belt and not the alternator belt. Check this by running with the heated screen/lights etc on when cold and revving - if it gets worse, then its likley its the alternator belt...

DJ

[philly c]

I got a new belt with the pulley when i ordered it and i am sure that this is the problem surely it cant be the right size?Or it must have streched?

It stops squeeling when it has warmed up but this is probably due to heat expanding it??

Does anyone no the correct size belt which i should have been given?


Cheers Phil

[k-huevo]

The best plug is one that is gapped properly and changed often, a copper plug changed with every oil change is just as good (and cheaper) than an iridium center electrode plug changed at 20,000 mile intervals. A colder range plug is not necessary when using a 15% reduction pulley, but no harm is done either. I use NGK BKR7EIX iridium plugs with my 19% pulley. Here is a good discussion on spark plugs; at least Petrich post# 13 has some good input MINI COOPER :: North American Motoring - Denso or NGK plugs? , as far as the brand discussion I’ve seen three sets of Densos with less than 20,000 miles on them and they all had some deterioration of the center electrode and the NGKs maintain their integrity for far longer. The stock plug has four prongs to increase service life; spark will choose the closest electrode so as one prong wears away the spark will move to the next healthy one. The problem with the multi prong design the increased likelihood of pre-detonation, extra prongs set aglow in the combustion chamber creating possible hot spots.

[DaFlake]

I, and a few others, agree with the above post where many others will not. The stock plugs are actually fine for the 15% pulley. If you go lower than that, then a colder plug should be used. I just swapped my stock plugs for some NGK iridiums to see what all the fuss is about. TBH I see no difference in the way the car runs....

That also added I would avoid Denso as not even their site shows MINI as a supported vehicle.

The head design of the MINI is best suited for the stock plugs and if you actually compared the NGK plugs to the stock, they sit lower in the chamber. The only reason I am trying them is that the JCW plugs are HGK, but I should think that stock is fine for the long terms as well.

As for the belt, you can run the stock belt with a 15% reduction pulley. I have been with no problems.

[philly c]

the reason i went for the 15% pulley is that i herd the other pulleys such as the 17 and 19% spin too fast causing air bubbles from the speed the water pump is spun at within the cooling system causing slow damage to the engine as the cooling become less efficiant.

I changed the belt wheni got the pulley as though it would be a good idea. I am not sure on the size of the belt but i came with the pulley. It was ok to start with but then slowly started to squeel when starting the car when it is cold. As sopon as the car is warm there are no problems.

What would be the best solution?Change the belt again?

Many Thanks to everyone for there help

Think i will stay with the stock plugs!

[DaFlake]

Could be several things.

1. Belt wear.
2. Tension is worn and needs to be replaced.
3. Misaligned pulley.

Either way, I would work to get it sorted.

[philly c]

wiht the pulley being a version 2.0 alta should it not align its self?
the gas damper on the tensioner didnt look to clever wheni took to tensioner off didnt seem to be doing much??
might try a new belt first??

[DaFlake]

I've installed three of the version 2 and it should "self align" provided that it was fully seated during installation. Of the three, I had to tap (rubber mallet) two of them all the way to the bottom to get them seated right.

If your tensioner seemed to be weak, that might also be letting the belt slip.

[philly c]

arrrr hmm this maybe where the problem lies and i only pushed the pulley on to the tensioner i didnt hit it on do it was tight as could be to the shaft. Prahaps this is the problem??

I will try this first i think and see what happens??

Seems strange that the belt would be faulty???

Many Thanks
Phil

[DaFlake]

It should be hard to actually get the allen key onto the first screw as it is partially covered by the SC lip.

[philly c]

Thats the problem than wih out a doubt as i pulled the hub back clightly to allow the allen key to access the bolt and be tightened.

Cheers Da flake your a hero!!!

Phil

[DaFlake]

You're welcome mate.

[robble]

If you change the plugs do yourself a favor and check the torque on them every few thousand miles. Lots of people have had the plugs blow out of the heads due to aftermarket plugs loosening over time. Ruins the threads the plug was in. Not cheap to fix.

[DaFlake]

I have seen lots of threads on this (one reason I don't recommend Denso). There have been instances of NGK doing the same but there is something I noticed on install. The washer that they use gets tight and then loosens a bit before fully seating. I wonder if the people didn't hand tighten them all the way BEFORE torquing? Anyway, I will continually check mine to make sure that all is well.

Another possibility is that people got carried away with the anti-seize compound that they put on. I little goes a long way and too much is counter productive. There was plenty on my threads when I installed my new plugs.

Lastly if the plug does blow you can get it repaired pretty cheaply by using a heli coil or something of this nature.