7 replies to this topic

[Lordcroker]

I own an unmodified 1989 Mini Thirty with it's original engine and running with the original ballast points ignition. Being a 1989 model it was one of the first to have an unleaded head as standard and it is run on 95ron unleaded currently. My car is currently fitted with NGK BP6 plugs, which I believe are wrong. My problem is working out what plugs are right!

The original Austin Rover handbook lists the plugs as Unipart GSP4382. The NGK equivalent to this is a BP5ES. Minispares reckon that a BP6ES is correct and Bull Motif Spares reckon that a BPR4ES resistor type is correct for an unleaded 998 made between 1989 and 1992.

Thoughts please, or doesn't it really matter which of these I fit? I would have thought that an NGK '4' series would be a bit hot.

Thanks, James

[Fast Ivan]

Bp6es and make sure you gap them

[Guess-Works.com]

5 or 6, certainly not a 4...

The number relates to the 'temperature' or the shrouding around the nose of the plug, the lower the number the less the shrouding and hence the hotter the plug runs... too hot and you'll suffer pre-ignition and plug burn out, too cold, and you'll get a poor burn and clogging.

[ACDodd]

I have found the 5's to run a bit hot in high comp 998 if driven hard. If it is only ever pootled about put 5's in. I use 5's in older lower compression 998's. If you drive on the motorway or have a stage 1 kit fitted put 6's in.

As above deffo not 4's.

Ac

[Earley86]

I have found the 5's to run a bit hot in high comp 998 if driven hard. If it is only ever pootled about put 5's in. I use 5's in older lower compression 998's. If you drive on the motorway or have a stage 1 kit fitted put 6's in.

As above deffo not 4's.

Ac

This is interesting as most of your videos you say to use a 5 on a 998cc.

I have a standard 998cc from 1991, I drive it semi hard so should i now be fitting 6 plugs?

[gazza82]

Knowing how poorly BM handled their A30/A35 parts business (since sold off) I'm not surprised their advice is poor.

[Earwax]

As above  ---  the number refers to heat range but R in the NGK title(BPR6ES) refers to a resistor type  -  supposedly helps if you have sensitive electronics you don't want interfered with.  I have never bothered ,  because my mini(s) are carb type - and the one mini that has a radio that battles road noise, wind noise ( windows down ventilation) and gearbox whines doesn't really care.

[cal844]

I use BP6ES in a 998 A+ with stage 1 kit. With mixed driving....

I use a 65D distributor, 0.8 ohm coil and check the plug leads are in spec.

I got the car tuned locally, by someone with AC Dodd's training. The only change I have had to make is to refill the dashpot oil to how AC Dodd does it these days. I put it half way up the outise of the piston tube, using the oil the car was set up with.

In the 3 years since it's been built all it's had is basic servicing and still never misses a beat!!

This car can keep up with a 1275cc mini with ported and polished head and stage 1 kit (unknown cam!)

So, if you are struggling get AC Dodd to come out or pay someone with his training to look at your car.... It will TRANSFORM the car

Regards

Cal

Edited by cal844, Today, 09:20 AM.