Using spark plugs at 1 'heat' rating higher

[WildCard]

Will using spark plugs of one heat-rating higher than require have any adverse effects?

 

Example: My bike requires a heat rating of 9, as in CR9EK if I'm using NGK plugs.

I know normally, for older bikes, a 8 (i.e. CR8EK for NGK) rating or 'hotter' plugs is recomended to avoid perpetual fouling of the plugs due to aged piston rings and other contaminants leaking in.

 

But for a fairly new bike with no such problems, is it still safe to use such 'hot' plugs? Any side-effects? For EFI system bikes, is a remap needed?

 

Note: I'm not talking about hot racing plugs or such. Its normal or iridium plugs.

[slowrider]

Will using spark plugs of one heat-rating higher than require have any adverse effects?

 

Example: My bike requires a heat rating of 9, as in CR9EK if I'm using NGK plugs.

I know normally, for older bikes, a 8 (i.e. CR8EK for NGK) rating or 'hotter' plugs is recomended to avoid perpetual fouling of the plugs due to aged piston rings and other contaminants leaking in.

 

But for a fairly new bike with no such problems, is it still safe to use such 'hot' plugs? Any side-effects? For EFI system bikes, is a remap needed?

 

Note: I'm not talking about hot racing plugs or such. Its normal or iridium plugs.

 

Should be no problem but if you run 'hotter' plug of 1 rating up, then you should ride in not so congested roads most of the time and perferably in expressway riding!

 

Then less carbon fouling and a bit better performance if you tune fuel/air mixture to match the hotter plug but not really neccessary if you don't do so.

[WildCard]

Should be no problem but if you run 'hotter' plug of 1 rating up, then you should ride in not so congested roads most of the time and perferably in expressway riding!

 

Then less carbon fouling and a bit better performance if you tune fuel/air mixture to match the hotter plug but not really neccessary if you don't do so.

 

Ok.

 

When you say "should ride in not so congested roads most of the time and perferably in expressway riding", what's the implication in tat?

Does it mean I should avoid excessive heat buildup from slow / standstill traffic?

Is there a side-effect to be avoided from there?

 

Most of my daily work commute are in expressways (KJE -> BKE -> SLE -> TPE).

But I do get some heavy traffic in between at normal trunk roads.

 

At any given slow traffic, even with squeezing, the bike will reach 97+ degC easily.

[299]

my agent told me tat recommended plugs by ur bike make/model are the best. What they told me tat when i change to iridium's ones which had caused one of the pistons to blow in one of the cylinders, dunno whether true or not.

[WildCard]

Manufacturer recommends CR9E for mine as shown in attachement.

I know what spark plug part number for mine.

 

Its a matter of the heat rating and whether a 'hotter' plug will have any adverse effects on the engine.

 

As shown in attachment, there is a risk of running too lean when changing to a 'hotter' plug.

But is it a confirmed occurance?

[mepkoh]

hi..

 

hot plugs are meant for normal ridng..ie engine is not stressed.. lower rpm like in city riding m, short dsitance...where the temperature in the engine is much lower to those high rpm rides...

 

cold plugs as the name implies the plugs will be colder..ie the plug is designed to transfer away the heat better keeping it cool..thus there are meant for high speed and long distance ride,,,,as this plug is able to handle the high temperature in the engine.. off course cold plugs have hard starting when engine is cold.(esp in cold weather...maybe not in singapore)

 

as to what plugs to use...it depends on how your rides are eg..high speed for extended period or the opposite...

 

best is to ask your mechanic..a good one shoul be able to advise you and tune your engine accordingly..

[mepkoh]

the following is aguide to hot/cold pluds usage..

Racing engines, for the most part, are above 7000rpm 100% of the time - these are the ones that require the colder plugs. Quite often a set of "hotter" plugs must be used to get the engine started and warmed-up, because the race plugs will not fire consistently below 4000rpm.

 

Spark plug choice, for any given engine, can then be stated as "Hot" enough to fire consistently at the lowest RPM and load normally needed (without fouling), and not overheat (and burn-up) at the highest RPM/load for the given application. This translates to : The "Hotter" the engine (turbo, modifications, load, usage, etc.) the "Colder" the spark plug needed

[Demon]

Will using spark plugs of one heat-rating higher than require have any adverse effects?

 

But for a fairly new bike with no such problems, is it still safe to use such 'hot' plugs? Any side-effects? For EFI system bikes, is a remap needed?

 

Note: I'm not talking about hot racing plugs or such. Its normal or iridium plugs.

 

No problem. Your ECU will relearn during closed-loop operation.

 

[WildCard]

No problem. Your ECU will relearn during closed-loop operation.

 

 

Ok, I'll state up front first I'm still learning about the finer points of ECU operations.

 

Does the re-learn part of the ECU involves the utilization of a O2 sensor?

[Demon]

Does the re-learn part of the ECU involves the utilization of a O2 sensor?

 

yes yes

 

[WildCard]

yes yes

 

 

Well,

we have a problem there.

 

As per requirement of installing a Power Commander, the O2 sensor has to be disabled (by closing off the loop using an eliminator plug).

Right now its depending mostly on the PC3 mapping.

So I assume now a remap is pretty necessary.

[bigboystoys]

something to add on

 

A hot plug can cause pre-ignition detonation (knocking) and this can be very detrimental to the engine. Prolong knocking can cause cracks in the engine block. The detonation happen when the fuel mixture comes in contact with the plug.

 

This doesn't mean we should get cold plugs for our engines. There is an issue with heat transfer from the plug to the valves. A cold plug typically can lose its heat fast via transfer to other bodies. In this case, the surrounding gets heated up. The valves are the next closest thing to the spark plug that can get heated up. Overheated valves are never a good thing and there is also the danger of the hot valves causing detonation again.

 

Choosing the heat rating of the plugs very much depend on the compression ratio, operating rpm, ambient air temperature, fuel octane number and most importantly, the efficiency of the cooling system.

 

Try to stick to manufacture's recommendation.

 

[gabriel06]

something to add on

 

A hot plug can cause pre-ignition detonation (knocking) and this can be very detrimental to the engine. Prolong knocking can cause cracks in the engine block. The detonation happen when the fuel mixture comes in contact with the plug.

 

This doesn't mean we should get cold plugs for our engines. There is an issue with heat transfer from the plug to the valves. A cold plug typically can lose its heat fast via transfer to other bodies. In this case, the surrounding gets heated up. The valves are the next closest thing to the spark plug that can get heated up. Overheated valves are never a good thing and there is also the danger of the hot valves causing detonation again.

 

Choosing the heat rating of the plugs very much depend on the compression ratio, operating rpm, ambient air temperature, fuel octane number and most importantly, the efficiency of the cooling system.

 

Try to stick to manufacture's recommendation.

 

 

 

haha i only understand ur last sentance

[ççãæˆæç¾]

something to add on

 

A hot plug can cause pre-ignition detonation (knocking) and this can be very detrimental to the engine. Prolong knocking can cause cracks in the engine block. The detonation happen when the fuel mixture comes in contact with the plug.

 

This doesn't mean we should get cold plugs for our engines. There is an issue with heat transfer from the plug to the valves. A cold plug typically can lose its heat fast via transfer to other bodies. In this case, the surrounding gets heated up. The valves are the next closest thing to the spark plug that can get heated up. Overheated valves are never a good thing and there is also the danger of the hot valves causing detonation again.

 

Choosing the heat rating of the plugs very much depend on the compression ratio, operating rpm, ambient air temperature, fuel octane number and most importantly, the efficiency of the cooling system.

 

Try to stick to manufacture's recommendation.

 

 

any ways to differentiate cold and hots plugs?

[bigboystoys]

any ways to differentiate cold and hots plugs?

 

 

read the part number of the spark plugs.

then refer to the chart provided by the plug maker.

 

different makers use different number to mark their heat rating so you have to check

[bigboystoys]

haha i only understand ur last sentance

 

 

that's good so you know you won't be changing to something not recommended by the manufacturer...

[gabriel06]

that's good so you know you won't be changing to something not recommended by the manufacturer...

 

yeah thats right

[dinie]

Ok.

 

When you say "should ride in not so congested roads most of the time and perferably in expressway riding", what's the implication in tat?

Does it mean I should avoid excessive heat buildup from slow / standstill traffic?

Is there a side-effect to be avoided from there?

 

Most of my daily work commute are in expressways (KJE -> BKE -> SLE -> TPE).

But I do get some heavy traffic in between at normal trunk roads.

 

At any given slow traffic, even with squeezing, the bike will reach 97+ degC easily.

 

 

 

kinda guessed u were riding a gsr as well.. cos when im in a jam, it heats up to 97 deg celsius pretty fast. then the fan comes on and burns my legs.. cos its jus so darn hot!

[scoobydoo]

this is good stuff... answers to many of our questions

 

taken from http://www.ngkspark.com.au/tech_index.htm?http://www.ngkspark.com.au/pages/tech_content.htm

 

SPARK PLUGS

 

Installing spark plugs

 

Torque is one of the most critical aspects of spark plug installation. Torque directly affects the spark plugs' ability to transfer heat out of the combustion chamber. A spark plug that is under-torqued will not be fully seated on the cylinder head, hence heat transfer will be slowed. This will tend to elevate combustion chamber temperatures to unsafe levels, and pre-ignition and detonation will usually follow. Serious engine damage is not far behind.

 

An over-torqed spark plug can suffer from severe stress to the Metal Shell which in turn can distort the spark plug's inner gas seals or even cause a hairline fracture to the spark plug's insulator...in either case, heat transfer can again be slowed and the above mentioned conditions can occur.

 

The spark plug holes must always be cleaned prior to installation, otherwise you may be torquing against dirt or debris and the spark plug may actually end up under-torqued, even though your torque wrench says otherwise. Of course, you should only install spark plugs in a cool engine, because metal expands when its hot and installation may prove difficult.

 

Gapping

 

Since the gap size has a direct affect on the spark plug's tip temperature and on the voltage necessary to ionise (light) the air/fuel mixture, careful attention is required. While it is a popular misconception that plugs are pre-gapped from the factory, the fact remains that the gap must be adjusted for the vehicle that the spark plug is intended for. Those with modified engines must remember that a modified engine with higher compression or forced induction will typically require a smaller gap settings (to ensure ignitability in these denser air/fuel mixtures). As a rule, the more power you are making, the smaller the gap you will need.

 

A spark plug's voltage requirement is directly proportionate to the gap size. The larger the gap, the more voltage is needed to bridge the gap. Most experienced tuners know that opening gaps up to present a larger spark to the air/fuel mixture maximises burn efficiency. It is for this reason that most racers add high power ignition systems. The added power allows them to open the gap yet still provide a strong spark.

 

With this mind, many think the larger the gap the better. In fact, some aftermarket ignition systems boast that their systems can tolerate gaps that are extreme. Be wary of such claims. In most cases, the largest gap you can run may still be smaller than you think.

 

Heat Range

 

With modified engines (those engines that have increased their compression) more heat is a by-product of the added power that normally comes with increased compression. In short, select one heat range colder for every 75-100 hp you add, or when you significantly raise compression. Also remember to retard the timing a little and to increase fuel enrichment and octane. These tips are critical when adding forced induction (turbos, superchargers or nitrous kits), and failure to address ALL of these areas will virtually guarantee engine damage.

 

An engine that has poor oil control can sometimes mask the symptom temporarily by running a slightly hotter spark plug. While this is a "Band-Aid" approach, it is one of the only examples of when and why one would select a hotter spark plug.

Using "racing" spark plugs

 

Be cautious! In reality, most "racing" spark plugs are just colder heat ranges of the street versions of the spark plug. They don't provide any more voltage to the spark plug tip! Their internal construction is no different (in NGK's case, as all of our spark plugs must conform to the same level of quality controls) than most standard spark plugs.

 

NGK as a company tries to stay clear of saying that a racing spark plug (or ANY spark plug) will give you large gains in horsepower. While certain spark plugs are better suited to certain applications (and we're happy to counsel you in the right direction) we try to tell people that are looking to "screw in" some cheap horsepower that, in most cases, spark plugs are not the answer.

 

To be blunt, when experienced tuners build race motors, they select their spark plugs for different reasons: to remove heat more efficiently, provide sufficient spark to completely light all the air/fuel mixture, to survive the added stresses placed upon a high performance engine's spark plugs, and to achieve optimum piston-to-plug clearance.

 

Some of these "specialised racing plugs" are made with precious metal alloy centre/ground electrodes or fine wire tips or retracted-nose insulators. Again, these features do not necessarily mean that the spark plug will allow the engine to make more power, but these features are what allow the spark plug to survive in these tortuous conditions. Most racers know screwing in a new set of spark plugs will not magically "unlock" hidden horsepower.

 

Using high power ignition systems

 

Many of the more popular aftermarket ignition systems are of the capacitive discharge type. They store voltage, or accumulate it, until a point at which a trigger signal allows release of this more powerful spark. Companies like Mallory, MSD, Crane and Accel, to name a few, offer such systems.

 

They affect spark plugs in that they allow the gaps to be opened up to take advantage of the increased capacity. The theory is that the larger and the more intense the spark you are able to present to the air/fuel mixture, the more likely you will be to burn more fuel, and hence the more power you will make.

 

We encourage the use of such systems, but only on modified or older non-computer controlled vehicles.

In reality, computer controlled vehicles do such a good job of lighting off the air/fuel mixture (as evidenced by the ultra-low emissions), added ignition capacity would do little to burn more fuel since the stock configuration is doing such a good job. Older non-computer controlled vehicles or those that have been modified with higher compression or boosted (nitrous, turbo, supercharged) engines can certainly take advantage of a more powerful ignition system.

[scoobydoo]

remove your sparkies and take a look... then compare with this

http://www.dansmc.com/spark_plugs/Spark_Plugs_catalog.html

 

pretty comprehensive range showing how to prevent sparkies from failing