when i took the plugs out of the NSR last night i noticed thart the previous owner had put a 8ECM in the front and a 9ECM in the top.
could there be any other reason other than he was to tight to buy the 9s to do this
and why does it say BR9ECM - BR10ECM on the inside of my fairing _________________ MC21SP - Roth-tax
CBR400 - track
MC21R - sold
MC21SP - sold
An 8 is going against convention, as it's a "hotter" plug. A cooler plug, and HRC recommends a 10 or 10.5, will remove heat from the combustion chamber quicker and more efficiently, which aids against pre-ignition and detonation.
I think both Wrench and Matt@TYGA have widely experimented with spark plugs in different motors/configurations, so will hopefully chip in soon. _________________ Andy.
NSR-WORLD.COM
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I have all 3 heat ranges and like to stick with the 9's for normal use and plug chops.
The 8's work well for street use if your engine is not running on the edge, they tend to help prevent fouling for those who run a tad rich and not change their jetting often.
I would use 10's for the track, but dont frequent the track here much. _________________ Paul Herr
'88 FZR4/GSXR/YZF Frankenbike
MY BIKE PICS
hello everyone....why would you run a different heat range plug on a water cooled engine? the cooling on these lil beauties has nothing to do with the air....educate me i can see being an issue on a aircooled bike if it was a 90 deg V but in this case i dont understand why it would even matter _________________ DAYTONA SPECIAL,74 RD350 LONG ROD, 2 RD200 ELECTRIC'S,88 NSR 250RG, MICRO SPRINT CAR W/CR 250 ENG
motulman wrote:hello everyone....why would you run a different heat range plug on a water cooled engine? the cooling on these lil beauties has nothing to do with the air....educate me i can see being an issue on a aircooled bike if it was a 90 deg V but in this case i dont understand why it would even matter
i was going to try and explain but cant be bothered read below and all will be revealed
Also click the link and go to the '#2 HEAT RANGE' section there are some pretty pictures aswell.
Lots of other interesting information too well worth a look.
Heat range
The term spark plug heat range refers to the speed with which the plug can transfer heat from the combustion chamber to the engine head. Whether the plug is to be installed in a boat, lawnmower or racecar, it has been found the optimum combustion chamber temperature for gasoline engines is between 500ｰC・50ｰC. When it is within that range it is cool enough to avoid pre-ignition and plug tip overheating (which can cause engine damage), while still hot enough to burn off combustion deposits which cause fouling.
The spark plug can help maintain the optimum combustion chamber temperature. The primary method used to do this is by altering the internal length of the core nose, in addition, the alloy compositions in the electrodes can be changed. This means you may not be able to visually tell a difference between heat ranges. When a spark plug is referred to as a 田old plug・ it is one that transfers heat rapidly from the firing tip into the engine head, which keeps the firing tip cooler. A 塗ot plug・has a much slower rate of heat transfer, which keeps the firing tip hotter.
An unaltered engine will run within the optimum operating range straight from the manufacturer, but if you make modifications such as a turbo, supercharger, increase compression, timing changes, use of alternate racing fuels, or sustained use of nitrous oxide, these can alter the plug tip temperature and may necessitate a colder plug. A rule of thumb is, one heat range colder per modification or one heat range colder for every 75・00hp you increase. In identical spark plug types, the difference from one full heat range to the next is the ability to remove 70ｰC to 100ｰC from the combustion chamber.
The heat range numbers used by spark plug manufacturers are not universal, by that we mean, a 10 heat range in Champion is not the same as a 10 heat range in NGK nor the same in Autolite. Some manufacturers numbering systems are opposite the other, for domestic manufacturers (Champion, Autolite, Splitfire), the higher the number, the hotter the plug. For Japanese manufacturers (NGK, Denso), the higher the number, the colder the plug.
Do not make spark plug changes at the same time as another engine modification such as injection, carburetion or timing changes as in the event of poor results, it can lead to misleading and inaccurate conclusions (an exception would be when the alternate plugs came as part of a single precalibrated upgrade kit). When making spark plug heat range changes, it is better to err on the side of too cold a plug. The worst thing that can happen from too cold a plug is a fouled spark plug, too hot a spark plug can cause severe engine damage
nsrmonkey wrote:when i took the plugs out of the NSR last night i noticed thart the previous owner had put a 8ECM in the front and a 9ECM in the top.
could there be any other reason other than he was to tight to buy the 9s to do this
and why does it say BR9ECM - BR10ECM on the inside of my fairing
Howdo Monkey ,Just out of interest how much did you pay for your plugs ? .
ok?...thats fine but it doesnt say why or that you should run a different plug in each cyl like the original topic asks _________________ DAYTONA SPECIAL,74 RD350 LONG ROD, 2 RD200 ELECTRIC'S,88 NSR 250RG, MICRO SPRINT CAR W/CR 250 ENG
I'm no expert, and hence this could be bollox, but I thought that the front and rear cylinders have different heat rated spark plugs simply because in addition to liquid cooling, the front cylinder receives significantly more additional air cooling than the rear. Obviously much more cool air will hit the front cylinder, whereas the rear is tucked away and hence will run hotter, therefore a plug which draws more heat will be in the rear.
While I'm talking about the rear cylinder - There is a little duct which runs from the lower left side scoop on my fairing, and disappears of under the tank. Is this to get some fresh cool air to the rear cylinder - I assume it isn't ram-air, what is it
Colin NSR wrote:I'm no expert, and hence this could be bollox, but I thought that the front and rear cylinders have different heat rated spark plugs simply because in addition to liquid cooling, the front cylinder receives significantly more additional air cooling than the rear. Obviously much more cool air will hit the front cylinder, whereas the rear is tucked away and hence will run hotter, therefore a plug which draws more heat will be in the rear.
Yes that is correct the front cylinder will run Cooler than the rear (But not just because it is more open the rear cylinder is buried in the centre of the bike ),But the extra heat at the rear cylinder is normally taken care of by running a larger Main Jet as the atomised fuel actually cools the cylinder (well the piston crown more to the point) this is why SAFE jetting is rich as this will keep the cylinder cooler and reduce the risk of a seizure.
While I'm talking about the rear cylinder - There is a little duct which runs from the lower left side scoop on my fairing, and disappears of under the tank. Is this to get some fresh cool air to the rear cylinder - I assume it isn't ram-air, what is it
This is obviously just to get the air moving freely past the buried cylinder ,And will draw away some heat in the process.
Cant say ive noticed one on my MC21 but ive not stripped the bke yet and its about 2 months since ive seen it as its tucked away in the unit all wrappped up _________________ MC21R Repsol replica
SC36 'Fire storm'
RG250 MK3 GAMMA 'WALTER WOLF'
DR350SEV winter hack
I know thats the function of the big vents, but this little vent in the left side lower fairing has a duct on it which goes under the tank somewhere. It's supplying some cool air to somewhere under the tank, it's not to do with getting more air through the radiator.
motulman wrote:ok?...thats fine but it doesnt say why or that you should run a different plug in each cyl like the original topic asks
quote:
--------------------------------------------------------------------------------
Originally posted by motulman:
hello everyone....why would you run a different heat range plug on a water cooled engine?
I answered your quiry not the subject matter as it seems from your post you do not understand what the specific heat rating of a spark plug does.
it would make more sense to run a cooler plug (BR10ECM) in the rear and the hotter one (BR9ECM) at the front but if the engine is standard i cant see a reason not to use the manufactures recomended plug (BR9ECM in the front and rear .
I suspect the listing of the BR10ECM which Monkey says are listed on the inside of his fairing is for extreme weather conditions experienced in Japan.
As in the soutern islands (okinawa ,Kyushu area's) it is in line with the Tropics and is pretty hot all year round and is extremely hot during the summer so therefore a cooler plug would be safer.
As Japan is a very large place and the weather conditions go from one extreme to another this is why Honda have listed a couple of plugs.
On all the Hondas i have owned there is always a couple of variations on plug ratings stated in the owners manuals.
Also the reason Monkeys bike had an even hotter plug in the front is more than likely down to the fact that it is allways cold and rainy in England and is no where near as hot as it gets in Japan where the bikes are designed to be used.
It may also have had some other work carried out on the engine as each engine tuner has there own way of extracting more power from an engine this may be this particular engine tuners way of compesating for over jetting the engine. _________________ MC21R Repsol replica
SC36 'Fire storm'
RG250 MK3 GAMMA 'WALTER WOLF'
DR350SEV winter hack
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