Candele giuste per Yamaha 996 carburatori 4 tempi
fautosa (autore)
- 1/4
Salve, pongo un quesito agli amici della rete: sul sito di commercio on line "il marinaio", che reputo assai interessante per la vastità del catalogo e per i buoni prezzi, ho comperato le uniche candele disponibili per il mio motore e cioè le DPR6EA-9 mentra il libretto e l'adesivo sul motore consigliano la stessa sigla ma col numero "5" . Il modello 6 ad sempio è consigliato anche per il motore 930.
Cosa succede se uso comunque queste candele? come cambieranno le prestazioni? sarà sensibile la differenze?
Grazie e saluti
Cosa succede se uso comunque queste candele? come cambieranno le prestazioni? sarà sensibile la differenze?
Grazie e saluti
Fausto
fautosa (autore)
- 2/4
Mi rispondo da solo, cioè il sito ngk fornisce qualche spunto tecnico. https://www.ngksparkplugs.com/tech_support/spark_plugs/p2.asp?mode=nml
Sono comunque gradite le Vs esperienze.
Dal 5 al 6 la candela diventa "più fredda".
"NGK Spark Plugs Heat Rating
The spark plug heat range has no relationship to the electrical energy transferred through the spark plug. The heat range of a spark plug is the range in which the plug works well thermally. The heat rating of each NGK spark plug is indicated by a number; lower numbers indicate a hotter type, higher numbers indicate a colder type.
Heat rating and heat flow path of NGK Spark Plugs
Some basic structural factors affecting the heat range of a spark plug are:
Surface area and/or length of the insulator nose
Thermal conductivity of the insulator, center electrode, etc.
Structure of the center electrode such as a copper core, etc.
Relative position of the insulator tip to the end of the shell (projection)
The major structural difference affecting the heat rating is the length of the insulator nose. A hot type spark plug has a longer insulator nose. The insulator nose of a hotter spark plug has a longer distance between the firing tip of the insulator, and the point where insulator meets the metal shell. Therefore, the path for the dissipation of heat from the insulator nose to the cylinder head is longer and the firing end stays hotter. The insulator nose of a hotter spark plug also has a greater surface area that is exposed to more of the ignited gases and is easily heated to higher temperatures. A colder spark plug functions in an opposite manner.
The heat range must be carefully selected for proper spark plug thermal performance. If the heat range is not optimal, then serious trouble can be the result. The optimal firing end temperature is approximately between 500°C (932°F) and 800°C (1472°F). The two most common causes of spark plug problems are carbon fouling (< 450°C) and overheating (> 800°C).
Causes of Carbon fouling:
Continuous low speed driving and/or short trips
Spark plug heat range too cold
Air-fuel mixture too rich
Reduced compression and oil usage due to worn piston rings / cylinder walls
Over-retarded ignition timing
Ignition system deterioration
Pre-delivery fouling
Carbon fouling occurs when the spark plug firing end does not reach the self-cleaning temperature of approximately 450°C (842°F). Carbon deposits will begin to burn off from the insulator nose when the self-cleaning temperature is reached. When the heat range is too cold for the engine speed, the firing end temperature will stay below 450°C and carbon deposits will accumulate on the insulator nose. This is called carbon fouling. When enough carbon accumulates, the spark will travel the path of least resistance over the insulator nose to the metal shell instead of jumping across the gap. This usually results in a misfire and further fouling.
If the selected spark plug heat range is too cold, the spark plug may begin to foul when the engine speed is low or when operating in cold conditions with rich air-fuel mixtures. In some cases, the insulator nose can usually be cleaned by operating the engine at higher speeds in order to reach the self-cleaning temperature. If the spark plug has completely fouled, and the engine will not operate correctly, the spark plug may need to be cleaned / replaced and the fouling cause identified.
Causes of Overheating:
Spark plug heat range too hot
Insufficient tightening torque and/or no gasket
Over-advanced ignition timing
Fuel octane rating too low (knock is present)
Excessively lean air-fuel mixture
Excessive combustion chamber deposits
Continuous driving under excessively heavy load
Insufficient engine cooling or lubrication
The most serious result of selecting a heat range that is too hot is overheating. Overheating will cause the electrodes to wear quickly and can lead to pre-ignition. Pre-ignition occurs when the air-fuel mixture is ignited by a hot object/area in the combustion chamber before the timed spark event occurs. When the spark plug firing end (tip) temperature exceeds 800°C, pre-ignition originating from the overheated insulator ceramic can occur. Pre-ignition will dramatically raise the cylinder temperature and pressure and can cause serious and expensive engine damage. When inspecting a spark plug that has experienced overheating or pre-ignition, blistering on the ceramic insulator and/or melted electrodes can sometimes be found.
As a general guideline, among identical spark plug types, the difference in tip temperature from one heat range to the next is approximately 70°C to 100°C. "
Sono comunque gradite le Vs esperienze.
Dal 5 al 6 la candela diventa "più fredda".
"NGK Spark Plugs Heat Rating
The spark plug heat range has no relationship to the electrical energy transferred through the spark plug. The heat range of a spark plug is the range in which the plug works well thermally. The heat rating of each NGK spark plug is indicated by a number; lower numbers indicate a hotter type, higher numbers indicate a colder type.
Heat rating and heat flow path of NGK Spark Plugs
Some basic structural factors affecting the heat range of a spark plug are:
Surface area and/or length of the insulator nose
Thermal conductivity of the insulator, center electrode, etc.
Structure of the center electrode such as a copper core, etc.
Relative position of the insulator tip to the end of the shell (projection)
The major structural difference affecting the heat rating is the length of the insulator nose. A hot type spark plug has a longer insulator nose. The insulator nose of a hotter spark plug has a longer distance between the firing tip of the insulator, and the point where insulator meets the metal shell. Therefore, the path for the dissipation of heat from the insulator nose to the cylinder head is longer and the firing end stays hotter. The insulator nose of a hotter spark plug also has a greater surface area that is exposed to more of the ignited gases and is easily heated to higher temperatures. A colder spark plug functions in an opposite manner.
The heat range must be carefully selected for proper spark plug thermal performance. If the heat range is not optimal, then serious trouble can be the result. The optimal firing end temperature is approximately between 500°C (932°F) and 800°C (1472°F). The two most common causes of spark plug problems are carbon fouling (< 450°C) and overheating (> 800°C).
Causes of Carbon fouling:
Continuous low speed driving and/or short trips
Spark plug heat range too cold
Air-fuel mixture too rich
Reduced compression and oil usage due to worn piston rings / cylinder walls
Over-retarded ignition timing
Ignition system deterioration
Pre-delivery fouling
Carbon fouling occurs when the spark plug firing end does not reach the self-cleaning temperature of approximately 450°C (842°F). Carbon deposits will begin to burn off from the insulator nose when the self-cleaning temperature is reached. When the heat range is too cold for the engine speed, the firing end temperature will stay below 450°C and carbon deposits will accumulate on the insulator nose. This is called carbon fouling. When enough carbon accumulates, the spark will travel the path of least resistance over the insulator nose to the metal shell instead of jumping across the gap. This usually results in a misfire and further fouling.
If the selected spark plug heat range is too cold, the spark plug may begin to foul when the engine speed is low or when operating in cold conditions with rich air-fuel mixtures. In some cases, the insulator nose can usually be cleaned by operating the engine at higher speeds in order to reach the self-cleaning temperature. If the spark plug has completely fouled, and the engine will not operate correctly, the spark plug may need to be cleaned / replaced and the fouling cause identified.
Causes of Overheating:
Spark plug heat range too hot
Insufficient tightening torque and/or no gasket
Over-advanced ignition timing
Fuel octane rating too low (knock is present)
Excessively lean air-fuel mixture
Excessive combustion chamber deposits
Continuous driving under excessively heavy load
Insufficient engine cooling or lubrication
The most serious result of selecting a heat range that is too hot is overheating. Overheating will cause the electrodes to wear quickly and can lead to pre-ignition. Pre-ignition occurs when the air-fuel mixture is ignited by a hot object/area in the combustion chamber before the timed spark event occurs. When the spark plug firing end (tip) temperature exceeds 800°C, pre-ignition originating from the overheated insulator ceramic can occur. Pre-ignition will dramatically raise the cylinder temperature and pressure and can cause serious and expensive engine damage. When inspecting a spark plug that has experienced overheating or pre-ignition, blistering on the ceramic insulator and/or melted electrodes can sometimes be found.
As a general guideline, among identical spark plug types, the difference in tip temperature from one heat range to the next is approximately 70°C to 100°C. "
Fausto
Rocky6
- 3/4
fautosa ha scritto:Salve, pongo un quesito agli amici della rete: sul sito di commercio on line "il marinaio", che reputo assai interessante per la vastità del catalogo e per i buoni prezzi, ho comperato le uniche candele disponibili per il mio motore e cioè le DPR6EA-9 mentra il libretto e l'adesivo sul motore consigliano la stessa sigla ma col numero "5" . Il modello 6 ad sempio è consigliato anche per il motore 930.
Cosa succede se uso comunque queste candele? come cambieranno le prestazioni? sarà sensibile la differenze?
Grazie e saluti
Ciao, leggi quì: https://www.gommonauti.it/ptopic32450_selva_dorado_xs_40_60_sostituzione_candele_montare_un_grado_termico_differente_quali_mettere.html?sp_pid=439494#439494
Io ho messo le "6"......mi pare che si sporchino un pò di più....spesso parte al secondo colpo sia a freddo che a caldo......oppure sono i miei 4 carburatori che hanno bisogno di una doccia
Ciao!
Se fosse per me.....me ne starei sempre in barca a pescare!
Laccetto di sicurezza sempre allacciato !!!
Manó 20 cabin - Mercury 115 EFI ....rivoglio un open!
Laccetto di sicurezza sempre allacciato !!!
Manó 20 cabin - Mercury 115 EFI ....rivoglio un open!
fautosa (autore)
- 4/4
Rileggendo, col traduttore, il sito NgK mi sembra di capire che la candela col numerino più alto ( piu fredda) riesce ad asportare più calore dalla camera di combustione, e questo potrebbe essere tollerato nel caso in cui si utilizzi il motore a regimi mediamente elevati o a carichi elevati ( il motore deve spingere molto e magari non raggiunge giri elevati).
Questo è il mio caso: giro sempre col gommone pieno! 5 persone è il mio carico medio quindi spero che non mi creeranno problemi candele in grado di"raffreddare" di più la camera di combustione.
"Ma, una scintilla freddo è costituito da un tappo isolante naso più corto che aiuta assorbire più calore camera di combustione. This helps the heat to travel a shorter distance, and allow the plug to operate at a lower internal temperature. Questo aiuta il calore per viaggiare una distanza minore, e consentire la spina per funzionare ad una temperatura inferiore interna. It is necessary to keep a colder heat range when performance based engine modifications are done, subjected to heavy loads, or when the engine is run at high rpms. [size=18]E 'necessario mantenere un grado termico più freddo quando modifiche al motore prestazioni basato finito, sottoposti a carichi pesanti, o quando il motore è eseguita a alte velocità.[/size] The cold spark plug removes heat faster, thus by reducing the possibility of pre-ignition/detonation and damage or melting of the firing end of the spark plug. La spina di scintilla freddo elimina il calore più velocemente, così da ridurre la possibilità di pre-ignition/detonation e danni o fusione della fine cottura della candela. (Temperature of the engine can affect the operating temperature of the spark plug, but no the spark plug's heat range) (La temperatura del motore può influenzare la temperatura di funzionamento della candela, ma non la scintilla di calore spina del range)
Questo è il mio caso: giro sempre col gommone pieno! 5 persone è il mio carico medio quindi spero che non mi creeranno problemi candele in grado di"raffreddare" di più la camera di combustione.
"Ma, una scintilla freddo è costituito da un tappo isolante naso più corto che aiuta assorbire più calore camera di combustione. This helps the heat to travel a shorter distance, and allow the plug to operate at a lower internal temperature. Questo aiuta il calore per viaggiare una distanza minore, e consentire la spina per funzionare ad una temperatura inferiore interna. It is necessary to keep a colder heat range when performance based engine modifications are done, subjected to heavy loads, or when the engine is run at high rpms. [size=18]E 'necessario mantenere un grado termico più freddo quando modifiche al motore prestazioni basato finito, sottoposti a carichi pesanti, o quando il motore è eseguita a alte velocità.[/size] The cold spark plug removes heat faster, thus by reducing the possibility of pre-ignition/detonation and damage or melting of the firing end of the spark plug. La spina di scintilla freddo elimina il calore più velocemente, così da ridurre la possibilità di pre-ignition/detonation e danni o fusione della fine cottura della candela. (Temperature of the engine can affect the operating temperature of the spark plug, but no the spark plug's heat range) (La temperatura del motore può influenzare la temperatura di funzionamento della candela, ma non la scintilla di calore spina del range)
Fausto
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