ausmini :: View topic - What Spark Plugs

V-Power

V-Power spark plugs are a patented design by NGK to improve ignitability and reduce quenching. Ignitability is improved by the V-groove cut in the center electrode parallel to the ground electrode, this directs the spark to to the edge of the center electrode thus exposing it to more of the air/fuel mixture. Quenching is reduced in much the same manner, drawing the spark to the edge of the center and ground electrodes reduces the surface area available to quench the spark. See quenching for more info.

Quenching

Quenching is when the heat generated by the spark is absorbed by the center or ground electrodes instead of igniting the air/fuel mixture. To understand quenching and how it is reduced it is first necessary to review the basic purpose of the spark plug is to ignite the air fuel mixture in the combustion chamber. To do this your vehicle ignition system generates tens of thousands of volts to jump the gap between the center and ground electrodes. However it is good to know that it is not the actual electricity that ignites the air fuel mixture, it is the heat energy generated by that electricity or spark. Therefore when you are creating the spark you want as much of the heat from that spark to be used to ignite the air fuel mixture and not have the heat from that spark be re-absorbed by the center and ground electrodes. Thus NGK makes a variety of designs(cut back ground electrodes, V-groove center electrodes, fine wire center and ground electrodes) all resist quenching by reducing the contact(surface) area between the electrodes and the flame nucleus.

Author:	Drexxle [ Fri May 08, 2009 5:38 pm ]
Post subject:	What Spark Plugs
I was down at Supercrap getting some new leads and i was looking at spark plugs. Didnt buy any yet, was interested in everyones opinion. I noticed in the bosch manual in the shop it says BP6ES I look on my car and it currently has BP5ES plugs on it. I dont know what the difference is, and whats best suitable plugs for 1100.

Author:	850man [ Fri May 08, 2009 5:44 pm ]
Post subject:
NGK BP6ES are a direct replacment for the Champion N9Y factory fitted plug. I use these in all my mini engines except the race motors.

Author:	Drexxle [ Fri May 08, 2009 5:50 pm ]
Post subject:
Whats the difference in 5 and 6.

Author:	sitnlo62 [ Fri May 08, 2009 5:57 pm ]
Post subject:
Drexxle, The heat ranges for Bosch and NGK are as follows. Bosch :- the higher the number the Hotter the plug. NGK :- the lower the number the Hotter the plug. A Hot plug will heat up quicker and stay Hot. A Cold plug will heat up slowly and cool down quickly. NGK Therefore for a standard low performance Mini engine in good condition NGK BP6ES, High performance Mini engine being driven hard and generating lots of heat NGK BP7ES Oil Burning Mini Engine NGK BP5ES, plug will stay hot and burn off oil. BOSCH For a standard low performance Mini engine in good condition WR7DC+, High performance Mini engine being driven hard and generating lots of heat WR6DC+ Oil Burning Mini Engine WR8DC, plug will stay hot and burn off oil. Hope this helps, Dave

Author:	drmini in aust [ Fri May 08, 2009 7:12 pm ]
Post subject:
Graham Russell says when running unleaded fuel in a daily, go 1 heat range hotter. I saw this also on the web, can't remember if it was on the BP site or Bosch one. My 1412 stroker made 2 ft/lb more torque on Graham's engine dyno with BP5ES than with BP6ES.

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Author:	sitnlo62 [ Fri May 08, 2009 7:35 pm ]
Post subject:
drmini in aust wrote: Graham Russell says when running unleaded fuel in a daily, go 1 heat range hotter. I saw this also on the web, can't remember if it was on the BP site or Bosch one. My 1412 stroker made 2 ft/lb more torque on Graham's engine dyno with BP5ES than with BP6ES. Admittedly the goal posts have been moved slightly with the change of fuel and the use of additives for valve seat protection. It must be kept in mind though Kevin that the specified plug from NGK for the Cooper S was in fact a BP7ES and from Bosch it was the W6DC. which are both colder plugs than recomended for a mini such as a 850, Delux or K. So one heat range hotter for your engine would in fact be a BP6ES. A run up on a dyno will not put the same heat into a spark plug as 100km of highway driving at 4000rpm, I feel the BP5ES is too hot for a high performance mini engine which is in good condition. Dave

Author:	sitnlo62 [ Fri May 08, 2009 7:44 pm ]
Post subject:
Yes

Author:	Drexxle [ Sat May 09, 2009 12:00 am ]
Post subject:
nice guys, the 5's i had were out of a previous 998. So i think ill get some 7's and see how they run.

Author:	sgc [ Sat May 09, 2009 12:13 am ]
Post subject:
FWIW, my roadie 1152 was fouling BP6ES's a little, running BP Ultimate but also burning just a little oil as well. Switching to the hotter BP5ES sorted that out, they're perfect now.

Author:	BALLISTIC [ Sat May 09, 2009 6:52 am ]
Post subject:
I use NGK's BP6EY plugs havn't had any problems with "dead" or fowled plugs........the only difference between the EY and ES plugs is the EY's have a small "V" in the bottom electrode............................... www.ngk.com wrote: V-Power V-Power spark plugs are a patented design by NGK to improve ignitability and reduce quenching. Ignitability is improved by the V-groove cut in the center electrode parallel to the ground electrode, this directs the spark to to the edge of the center electrode thus exposing it to more of the air/fuel mixture. Quenching is reduced in much the same manner, drawing the spark to the edge of the center and ground electrodes reduces the surface area available to quench the spark. See quenching for more info. Quenching Quenching is when the heat generated by the spark is absorbed by the center or ground electrodes instead of igniting the air/fuel mixture. To understand quenching and how it is reduced it is first necessary to review the basic purpose of the spark plug is to ignite the air fuel mixture in the combustion chamber. To do this your vehicle ignition system generates tens of thousands of volts to jump the gap between the center and ground electrodes. However it is good to know that it is not the actual electricity that ignites the air fuel mixture, it is the heat energy generated by that electricity or spark. Therefore when you are creating the spark you want as much of the heat from that spark to be used to ignite the air fuel mixture and not have the heat from that spark be re-absorbed by the center and ground electrodes. Thus NGK makes a variety of designs(cut back ground electrodes, V-groove center electrodes, fine wire center and ground electrodes) all resist quenching by reducing the contact(surface) area between the electrodes and the flame nucleus.

Author:	miniDave [ Sat May 09, 2009 7:36 am ]
Post subject:
sgc wrote: FWIW, my roadie 1152 was fouling BP6ES's a little, running BP Ultimate but also burning just a little oil as well. Switching to the hotter BP5ES sorted that out, they're perfect now. I did ask GR a question about what plugs to run in the engine he did for me . . . and of course I have forgotten (1098 + 0.080, 10:1 compression, flat top pistons) . . . but I did think he said NGK BPES7 Does compression also come into the equation? Regards

Author:	drmini in aust [ Sat May 09, 2009 8:49 am ]
Post subject:
Nope he would not have said BP7ES. Too cold for general use in a smallbore. More than likely he said 5ES, maybe 6ES.

Author:	1071 [ Sat May 09, 2009 1:00 pm ]
Post subject:
IME plug grades really aren't that critical. To hot a plug will start to melt (you'll see little lumpy bits of the centre electrode on the outer edge) when run hard for long distances. Too cold and it will misfire in traffic jams and the plug will look gungy. Somewhere around right and you won't notice anything...... I reckon Kev was holding his tongue the other way "My 1412 stroker made 2 ft/lb more torque on Graham's engine dyno ........" and the extra draft caused increased atmospheric pressure at the carb mouth javascript:emoticon(':shock:'). Even with NGKs its not unusual to buy brand new duds. After going through several sets, the current 5ESs work when pottering around town or driving to Hay. They haven't missed a beat since I bought them 10 years or so ago. Cheers, Ian

Author:	sitnlo62 [ Sat May 09, 2009 2:00 pm ]
Post subject:
Drexxle wrote: nice guys, the 5's i had were out of a previous 998. So i think ill get some 7's and see how they run. I would recomend NGK BP6ES Dave

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