Best spark plugs for M20?

[dobbie82]

sorry to interrupt your springer show, but seeing as we are so knowledgable about plugs, is there any reason they would go white in only a few miles other than running too hot? Plugs fault (ie wrong ones) or cheap asda fuel burning too hot?

[Andy335Touring]

At the moment in my M30 with 9.0:1 i'm using Bosch Super W8LCR from Sytners, so when i fit the Alpina B10 bottom end in at 10.6:1 i could do with changing over to some W7*** to suit the higher compression/combustion temps ?

[Turbo-Brown]

But Argos, you still haven't answered the question on whether you have data on ALL the variables able to effect power.

You've changed ONE variable on the engine, and assumed that the result change came about as a direct effect of that change.

Perhaps if there had been lots of tests, back to back, changing back and forth with each type of plug, the results would have more credibility?

Also, it does appear that you're saying the engine made less power with the wrong plug, and more with the right plug, but regaining power lost to the wrong component isn't really a gain in the real sense is it?

That'd be like me using a pair of socks as air filters, doing a power run, changing to normal filters and then heralding the power gain as a result of my wonderful new filters.

[Turbo-Brown]

Are you two experts SERIOUSLY suggesting that the combustion temperature (controlled by plug heat ranging)

And are YOU suggesting that it's only the plug heat range, and no other factor that effects chamber temps?!

[Turbo-Brown]

Oh my GOD!

I can't believe I only just thought to ask this!

Argos, please tell me exaclty what the atmospheric pressure in the cell was when all these tests were being run?

[billgatese30]

anyone got some more popcorn...i've just ran out and the corner shop doesn't open on tuesdays

[H35-IAN]

lol this is pure class! all this over 6 spark plugs! fukkin hell id say its harder to row about it than it is to actually go buy them and fit them lol
keep it up lads im just getting a beer lol

[oguz327]

I dread to think what would happen if i asked which is the best oil to use

[Turbo-Brown]

you gonna answer the question then?

It's pretty obvious this one, and pretty well documented too, and with the 1.4%ish increase in power (cause of which under debate) it's a reasonable line of enquiry.

Please note, I'm not saying you're wrong, just questioning whether you're right.

Love the way you avoid some pretty pertinent questions which would case doubt on your arguement, and instead resort to insults.

Like what you did with my username there too, very clever....taking the word "turbo" and making it "turdo". How witty! No one else has ever gone there, but you did....you, you went there! You took that leap of faith, into the unknown and changed a letter, in my username, and now it says "turdo" instead of "turbo". Well done, pure genius.

Try not to take this all too seriously mate, these forums are all about having a light hearted debate. Looking at the overall cause of this one, you've stated that product X leads to result Y, and a couple of us have questioned it, whereupon you've started throwing insults around rather than backing your arguement up with facts and figures. It's all we ask mate

[Demlotcrew]

whereupon you've started throwing insults around rather than backing your arguement up with facts and figures. It's all we ask mate

He doesnt have any!

Andrew

[E30Mark]

Keep it up guys, there is more action here than in SW19....

Just hope it don't rain, i can't stand Cliff Richard

Standing back and looking at this as an outsider, the quality / type of plug must have a effect on the engine efficiency (whether that relates to power is something else) i seem to remember that BMW introduced the multi-point plug on the M42 lump? to overcome some sort of problem? any thoughts?

[Turbo-Brown]

I reckon, and it's pretty feasible, that an increase in pressure of just 0.21psi would bring about the 1.4% power increase, which is only 14.5millibars which a glance at a barometer says is a tiny pressure change which could be brought about by a quick weather change, and we all know what the weather's like for changing in 10mins in this country.

All I'm arguing is that all of that 3bhp may not be down to the plug change.

[ed325i]

This has probably been discussed before but here goes again.
What sparks do you guys use/recomend for best performance or does it really matter?

So what plugs are you going for??
Has anybody ask what engine you have
I all ways use bosch in mine.


ED

[oguz327]

This has probably been discussed before but here goes again.
What sparks do you guys use/recomend for best performance or does it really matter?

So what plugs are you going for??
Has anybody ask what engine you have
I all ways use bosch in mine.


ED

Ive got a tech1 so early m20 engine.
I am tempted by the Denso's and Bosch W7DCR.
I may try one set this service then try the other next time and see how they go.
Havnt made my mind up which to try first yet, may just go for the tryed and tested NGKs.

What is the life span of a spark plug anyway?
I guess it differs between manufacturers but you should change regardless of condition on each service?

[ed325i]

Well in the haynes manual it says to change them every 24 000 miles or 2 years I all ways change mine every 12 000 miles.

ED

[ed325i]

Just found this.

Why replace your spark plugs?
Spark plugs are one of the most important parts of your vehicle's engine. Your spark plugs should be replaced every 2 years or 30,000 miles to maintain maximum fuel economy and peak engine performance. This may vary depending on the make and model of your vehicle. Some models will go as far as 100,000 miles before the plugs need replacement.


ED

[oguz327]

I always thought you changed them at the same time as the oil, shows how much i know
I think mine were last changed about 8k ago in October last year so i guess theres a fair bit of life left in them.
Ive changed the oil since then though

[mattm3]

Hi Chaps,

My first post on this forum. Just to add some info I work in the F1 community, on our static dynos power varys by less than 0.5% in a more controlled enviroment than a RR, the max power gain we have seen from plugs is only about half a hp so I also question wether you would gain 3hp on a road car unless the previous plugs were knackered?

[boybimmerm3]

Its pointless comparing a F1 engine with a M20. All F1 engine components are performing to the maximum possible. I dont think Ferrari or Renault would really believe there is a miricle spark plug out there which is going to boost their hp by 3-4. However a M20 engine with two different plug designs maybe.

[Mark_916]

was enjoying this
sad its all over!

[reggid]

What plugs do alpina use in the C2 2.7 and B3 2.7 with a Kat? Anyone have a part number for these?

Cheers

[stonesie]

i use ZGR5A's in the 320

Anyway i think i am going to throw a couple of words at argos here.......

Repeatability
Calibration
and accuracy

how accurate are these rollers and does he get them calibrated to ensure that with a known torque on the rollers the equipment registers the same torque or to within a known margin of error?

How repeatable are the results? as in given the same known torque applied a minimum of 5 times what range of readings does he get?


And before you try and tell me i dont know what i am on about i was a lab assistant in a UKAS accredited calibration lab for 3 1/2 years and when i say accuracy how does 0.000002mm grab you? thats 2 thousanths of a micron.... the accuracy of our slip gauge comparitor

[bigkev]

Ok everybody's got plenty of holes to rip in argos' story but what are you're solutions to the problems,change plugs in 20 seconds and pray to god the weather does'nt change
if this was an air filter sold from the zone shop i bet everyone would be singing its praise saying how fantastic it was
even if the 'wrong' plugs were fitted and then the 'right' plugs were fitted to gain 3HP then that puts a hole in the story that plugs dont effect performance so someone is talking shit

[reggid]

even if the 'wrong' plugs were fitted and then the 'right' plugs were fitted to gain 3HP then that puts a hole in the story that plugs dont effect performance so someone is talking shit

I think the main argument against Argos is that dynos are not accurate to 1.42857142857143%

also what were the unaveraged numbers?

Ok everybody's got plenty of holes to rip in argos' story but what are you're solutions to the problems,change plugs in 20 seconds and pray to god the weather does'nt change

Run the recommeded plugs if you know what they are.... which brings me back to my original question

"What plugs do alpina use in the C2 2.7 and B3 2.7 with a Kat? Anyone have a part number for these?"

Cheers

[reggid]

Cheers

[Andy335Touring]

All Alpinas use W7DCR's from Herr Robert Bosch as opposed to the W8's used in the equivalent 2.5 - take it or leave it!

Yep, even B6/10 M30 engined E30/4 Alpinas

The only visual differance i can see between Bosch W8LCR(Standard fit BMW M30 plugs) and the W7DCR are the spark gap/electrodes/etc are going to be closer to the head. Electrode, earthing strap and ceramic insulation all seem to be the same sizes but shorter if that makes sense

Would this be to conduct the heat away more quickly ?

Another thing i'm guessing at is Alpina's generally have pistons that stick out of the block more than standard so they are moving the spark closer to the head to compensate ?

[pnd]

I agree that early type plugs especially Ngk's give more power from experience as Ive owned a good many e30's but also from experience the new Bosch super 4's are an excellent if expensive option.

[Fushion_Julz]

Bets plugs, IMHO, are Denso Iiridiums...but they are also the dearest...

On a standard motor you don't want to reduce the heat range/rating of the plug as on the Bosch example, cos it will burn to rich and the plug will end up fouling!

Reducing the height of the plug also slightly lowers the compression ratio due to more space in the combustion chamber and may also affect the "burn" as the plug electrode may no longer be in the optimum space for a perfect ignition of the mixture...

Perhaps the Alpinas have either modified pistons or modified combustion chambers that require a slightly different plug for optimum performance?

[Andy335Touring]

Perhaps the Alpinas have either modified pistons or modified combustion chambers that require a slightly different plug for optimum performance?

Yes, both

My engine(Alpina B10 bottom end) that i'm working on has higher compression ratio pistons that stick out of the block more than standard, this has ment i've had to reshape the squish band of my combustion chambers in my head.

My C/R is going up from 9.0:1 to 10.6:1 so the combustion temps are going to be higher thats why i'm going to use the same plugs as the B10 does.