spark plugs question

[sickboy2345]

hi all

was gonna change my spark plugs but i have spoken to my mate and he said that i need 2 pairs of different plugs 2 for rotors and two plugs for something else but they MUST be different...

i got these ones:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=001&sspagename=STRK%3AMEWN%3AIT&viewitem=&item=110250198297&rd=1

and they all the same ...can i still replace them? is it true that they must be different?

cheers

[Lum]

Not sure about those specific plugs mate but your mate isn\'t entirely correct.
What he\'s refering to is each rotor has a leading & trailing plug, so there is 2 plugs for each rotor/housing.
Some people, mainly those running fairly high power (including me) use differant plugs in the leading & trailing positions, the differance between the two being the heat range.
If your only running mild mods on twins then it\'s fine to run the same plugs all round, most comonly NGK 9\'s i believe.

[peterwolds]

ngk 9\'s all round fine

[Mazdarotaryparts]

As people have stated above, unless you have a car with a big power increase you never need look any further than NGK 9\'s, also plugs with the heat range shown on the link are far to cold for normal engines and may well led to flooding,

Also please do not buy the Denso plugs as these have killed Rotarys over here because of the end of the plug falling off into the engine, destroying a tip and wiping out the engine.

An ex Mazda technician told me that Denso actually know they have a problem "sometimes" just with the Rotary because the Rotary combustion sets up something like an harmonic frequency that shatters the end of the plug where as the NGK can copes with out a problem,  

If you want to buy some NGK that our customers tell us are very competitively price you can follow this link if you wish,
http://www.mazdarotaryparts.com/bfd-ig001-ngk-bur-9eq-spark-plugsb-781-p.asp

Hope this helps

[sickboy2345]

now when i replaced the plugs you telling me this...

these r my old ones just replaced my old spark plugs 25 mins ago they were ngk, took my car for a spin and it works fine, even misfire dissapeared. would you still recomend to replace them? i proper hammer my car even if i drive it only few miles a day..isn\'t it enough? i will be modifying it in the future so maybe i should keep them?

thing is i have already spent 90 quid to buy them and they been installed...

[sickboy2345]

i got these ones:

http://www.gbsalpine.com/english/collection_part/electro/densoracing.html

heat range translation into NGK numbers will be equal to a # 11.5 heat range

they are iridium racing spark plugs i paid 90 quid for them and the thing is  i got standard engine and you\'re saying they are too cold for my car. i installed them on saturday and they in my car already (car is in the garage at the mo) i have been driving with them on for 2 days so far so they r still brand new.

dont want to just sell it but if someone wants them i will replace it to a NEW set of these: NGK Spark Plugs BUR 9EQ + 30 quid. i think it\'s a fair deal.

please let me know

[trotter]

As Peter and Clive say above - for mildly modded engines 9\'s all round are perfectly acceptable. I changed mine over last saturday and could feel the difference on the first drive. Power delivery just seemed smoother somehow, and she seemed to want to rev more freely - although in saying that the ones I took out were in a pretty sh!tty state.

I\'m staying with the NGKs, IIRC these were fitted as OEM by Mazda? And Pip @ WGT fitted them ion my rebuild. So thats good enough for me!!

T

*EDIT* Just checked that e-bay link for the Denso spark plugs... +73bhp increase??? Yeah, maybe on a car running with NO spark plugs....