Forgive my lazyness for not scouring the forum but can someone recommend some plugs for an lpg converted BMW 330i (2002 E46).
I'm not confident about gapping the plugs so if you could recommend some that will be ok withouth regapping then I would appreciate it.
Ta
Plugs, again!
this post was deleted by the author using an autoscrub routine.
Last edited by mondeoman on Mon Dec 16, 2013 8:21 pm, edited 1 time in total.
Regards, Paul.
_______________________________________
Former owner of "The Mondeo From Hell"
Now in a Honda.
_______________________________________
Former owner of "The Mondeo From Hell"
Now in a Honda.
Plugs
Cannot be 100% sure of exact part number for your car but I believe NGK BKR6EK is suitable and will fit.
In any case I would recommend only standard spec NGK copper core plugs above any other make or type from personal experience.
Whatever you do avoid anything fancy or exotic such as platinum for LPG applications 'cos they'll wreck your coil packs and HT leads.
The reason for using copper is its high electrical conductivity, which reduces HT stress on the ignition components' insulation, thereby minimising the risk of misfiring and/or corona ringing. I'd leave the gaps as they come supplied.
You may need to go one grade colder if the plugs show signs of overheating. This is not uncommon when using LPG. With NGK this would mean using a 7 instead of a 6 in the part number.
The part number above fits many Vauxhall engines, so you shouldn't have any trouble obtaining them from a decent motor factor. Walk away if they try to flog you anything else. Bosch aren't a patch on NGK for gas.
I'd also recommend a maximum service interval of 20k miles. LPG is a hard life for plugs...
Best wishes
Martyn H
In any case I would recommend only standard spec NGK copper core plugs above any other make or type from personal experience.
Whatever you do avoid anything fancy or exotic such as platinum for LPG applications 'cos they'll wreck your coil packs and HT leads.
The reason for using copper is its high electrical conductivity, which reduces HT stress on the ignition components' insulation, thereby minimising the risk of misfiring and/or corona ringing. I'd leave the gaps as they come supplied.
You may need to go one grade colder if the plugs show signs of overheating. This is not uncommon when using LPG. With NGK this would mean using a 7 instead of a 6 in the part number.
The part number above fits many Vauxhall engines, so you shouldn't have any trouble obtaining them from a decent motor factor. Walk away if they try to flog you anything else. Bosch aren't a patch on NGK for gas.
I'd also recommend a maximum service interval of 20k miles. LPG is a hard life for plugs...
Best wishes
Martyn H
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uncouth
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junkcatcher
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[quote="uncouth"]I've used the NGK part finder and it recommends BKR6EQUP for my car, would I need to regap these?[/quote]
Always a check the gap when fitting plugs ----- all it needs is some wharehouse wallah to have dropped the box of plugs also remember the same plug can be listed for several different engines with different gap settings.
Always a check the gap when fitting plugs ----- all it needs is some wharehouse wallah to have dropped the box of plugs also remember the same plug can be listed for several different engines with different gap settings.
lpg plugs
Try Keith at http://www.wtv-uk.co.uk. He now has some silver electrode plugs at reasonable prices.
Read his section on spark plugs to see why he recommends them.
The NGK number ending in QUP suggests it's a platinum tipped plug, which is best avoided as stated previously.
The copper equivalent is BKR6EK which should be fine. WTV has a silver tipped equivalent to this.
I've never used silver tips, but the theory behind it appears sound.
Only reason I recommended copper is that it's served me well in my own cars, so I can speak from personal experience.
I also have negative experience with platinum...
Read his section on spark plugs to see why he recommends them.
The NGK number ending in QUP suggests it's a platinum tipped plug, which is best avoided as stated previously.
The copper equivalent is BKR6EK which should be fine. WTV has a silver tipped equivalent to this.
I've never used silver tips, but the theory behind it appears sound.
Only reason I recommended copper is that it's served me well in my own cars, so I can speak from personal experience.
I also have negative experience with platinum...
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uncouth
I am currently using some DOR15LGS Brisk plugs as recommended by Keith, at first they were fine but now (6,000 miles later) they're misfiring like crazy, especially at around 80mph. (The LPG mapping has not been changed)
Keith did say to me at the time that the jury was still out on some of the silver plugs as some he had tried had started to coke up.
I'm gunna swap em. out and I'll tell you if it was my silver plugs causing the problem.
Keith did say to me at the time that the jury was still out on some of the silver plugs as some he had tried had started to coke up.
I'm gunna swap em. out and I'll tell you if it was my silver plugs causing the problem.
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jalfrezigazee
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junkcatcher
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Copper core plugs have nothing to do with electrcal conductivity ---- the HT system wouldn't even notice the difference. Copper cores were invented by NGK to improve the thermal conductivity of the nose of the sparking plug --- which allows the plug nose to be designed cover a much wider heat range.
When Copper core plugs were introduced by NGK in the early 1960s it was a major advance. In the swinging sixties cold fouling of plugs or plug insulation failure due to over heating was pretty common but copper cored plugs and projecting nose plug designs to a large extent abolished the problems.
99% of spark plugs are now copper cored or double copper cored
With every engine cycle the tip of the electrode of the spark plug gets eroded, this causes the plug gap to increase putting higher voltage demands on the HT system. Because of this no conventional copper core plug (ie a plug without a platinum or iridium tip or a multi-gap plug) should be expected to survive more than 15,000 miles even when running on petrol alone.
In the late 1970s and early 1980's car manufacturers put pressure on spark plug manufacturers to stretch plug life without re-gapping to 20,000+ miles as they wanted to stretch service intervals. The plug manufacturers already had the answer; Platinum tipped Lodge plugs had been used in piston aircraft engines and British military vehicles for decades but because of material costs they were very expensive to manufacture. However it was discovered that the amount of platinum required could be reduced to a tiny speck so keeping costs down to reasonable level. Iridium tipped plugs are just development fork from Platinum plugs however many believe Iridium plugs are more suited to the conditions in LPG fueled engines.
Bosch adopted an alternative approach the multi-gap plug, the idea was that as the spark will always take the easiest route the gap erosion is shared between 4 electrodes. Multi-gap plugs were not a new idea Lodge had made 18mm plugs with 4 side electrodes backin in the 1920's. However a major disadvantage is that due to the side electrodes masking the tip of the nose core multi-gap plugs don't have the same degree of self-cleaning from combustion gases and so are more prone to cold fouling.
With platinum plugs car manufacturers have tried to stretch the plug change interval to ridiculous levels. Just before the folded MG-Rover had the plug change interval stretched to 60,000 miles on the Rover 75/ZT and MGTF models, but the result was often problems with coil pack insulation breaking down at around 40,000 miles due to excessive HT voltages being demanded by the spark plugs.
Conventional copper core plugs should not be expected to last more than 15,000 miles or 1 year on petrol alone, 10,000 to 12,000 on lpg ---- checking the plug gaps at half the mileage is worth doing.
Precious metal tipped plugs I would recommend changing every 30,000 miles. or 2 years For LPG use platinum has a bad reputation but Iridium seems to work.
Reducing the spark plug gap by 12% to 15% on LPG fueled engines greatly helps avoid misfires due to ignion problems.
A rough order of preference for spark plug choice from good to not so good is
(1) NGK ---- world leaders in plug technology
(2) Champion (Unipart and X-part are re-branded Champion), Bosch, Hitachi, Denso
---------------------------------------
If nothing else available
(3) Beru, AC-Delco, Autolite/Fomoco Magneti Marelli*
Magneti Marelli however are only choice for some special Alfa-Romeo applications.
With modern ignition systems on you can generally use a plug one or two grades harder/colder than standard.
If doing so be aware that with some manufacturers (ie Champion) a lower number is a colder plug but with others (ie NGK & Bosch) a higher number is a colder plug.
When Copper core plugs were introduced by NGK in the early 1960s it was a major advance. In the swinging sixties cold fouling of plugs or plug insulation failure due to over heating was pretty common but copper cored plugs and projecting nose plug designs to a large extent abolished the problems.
99% of spark plugs are now copper cored or double copper cored
With every engine cycle the tip of the electrode of the spark plug gets eroded, this causes the plug gap to increase putting higher voltage demands on the HT system. Because of this no conventional copper core plug (ie a plug without a platinum or iridium tip or a multi-gap plug) should be expected to survive more than 15,000 miles even when running on petrol alone.
In the late 1970s and early 1980's car manufacturers put pressure on spark plug manufacturers to stretch plug life without re-gapping to 20,000+ miles as they wanted to stretch service intervals. The plug manufacturers already had the answer; Platinum tipped Lodge plugs had been used in piston aircraft engines and British military vehicles for decades but because of material costs they were very expensive to manufacture. However it was discovered that the amount of platinum required could be reduced to a tiny speck so keeping costs down to reasonable level. Iridium tipped plugs are just development fork from Platinum plugs however many believe Iridium plugs are more suited to the conditions in LPG fueled engines.
Bosch adopted an alternative approach the multi-gap plug, the idea was that as the spark will always take the easiest route the gap erosion is shared between 4 electrodes. Multi-gap plugs were not a new idea Lodge had made 18mm plugs with 4 side electrodes backin in the 1920's. However a major disadvantage is that due to the side electrodes masking the tip of the nose core multi-gap plugs don't have the same degree of self-cleaning from combustion gases and so are more prone to cold fouling.
With platinum plugs car manufacturers have tried to stretch the plug change interval to ridiculous levels. Just before the folded MG-Rover had the plug change interval stretched to 60,000 miles on the Rover 75/ZT and MGTF models, but the result was often problems with coil pack insulation breaking down at around 40,000 miles due to excessive HT voltages being demanded by the spark plugs.
Conventional copper core plugs should not be expected to last more than 15,000 miles or 1 year on petrol alone, 10,000 to 12,000 on lpg ---- checking the plug gaps at half the mileage is worth doing.
Precious metal tipped plugs I would recommend changing every 30,000 miles. or 2 years For LPG use platinum has a bad reputation but Iridium seems to work.
Reducing the spark plug gap by 12% to 15% on LPG fueled engines greatly helps avoid misfires due to ignion problems.
A rough order of preference for spark plug choice from good to not so good is
(1) NGK ---- world leaders in plug technology
(2) Champion (Unipart and X-part are re-branded Champion), Bosch, Hitachi, Denso
---------------------------------------
If nothing else available
(3) Beru, AC-Delco, Autolite/Fomoco Magneti Marelli*
Magneti Marelli however are only choice for some special Alfa-Romeo applications.
With modern ignition systems on you can generally use a plug one or two grades harder/colder than standard.
If doing so be aware that with some manufacturers (ie Champion) a lower number is a colder plug but with others (ie NGK & Bosch) a higher number is a colder plug.
I could recommend Beru plugs, which tend to be found ex-works rather than afterfit.junkcatcher wrote:
If nothing else available
(3) Beru, AC-Delco, Autolite/Fomoco Magneti Marelli*
I found a set in a Tickford LPG converted LT35 (Merc Sprinter engine) with 120k on the clock. It was running fine, so you can imagine my astonishment when I removed the plugs to find the centre electrodes worn below the insulators and gaps of about 2.5mm to what was left of the side electrodes!!
They showed no signs of damage or overheating, so there was every reason to believe that these were the original factory installation and had never been touched. Maybe the relatively low compression ratio had helped them to last so long?
Also had good performance from AC Delco, which turned in 40k in a V6 Omega LPG without any problems. I replaced these with NGK which freshened it up a bit, but that would be expected after such mileage.
I've stated previously that my first choice would be NGK copper which seem to be consistently reliable in whatever LPG application I have used them.
I've heard and read mixed reports about iridium from various places. I have formed the opinion that they seem to be more fussy than copper, but more forgiving than platinum. Perhaps it just depends on the individual application?
For those who've had good results with a particular brand or electrode type then best advice is to stick with it and maybe tell us about it...
after years of experimenting ~i found the solution for me...even the cheapest plugs will last 6K .. so buy them and change at that interval ..takes me about 15 minutes
frankly I found that with even the best plugs you can get the odd failure at low mileage , and it causes a lot of hastle ...if you always have a new set of plugs fitted you have eliminated one possible problem
last set I bought cost me £4 at a supermarket , so am probably saving money as well ! and in my experience , a lot of trouble shooting time as well
frankly I found that with even the best plugs you can get the odd failure at low mileage , and it causes a lot of hastle ...if you always have a new set of plugs fitted you have eliminated one possible problem
last set I bought cost me £4 at a supermarket , so am probably saving money as well ! and in my experience , a lot of trouble shooting time as well
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junkcatcher
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- Joined: Mon Apr 21, 2008 4:54 pm
[quote="lebesset"]after years of experimenting ~i found the solution for me...even the cheapest plugs will last 6K .. so buy them and change at that interval ..takes me about 15 minutes
frankly I found that with even the best plugs you can get the odd failure at low mileage , and it causes a lot of hastle ...if you always have a new set of plugs fitted you have eliminated one possible problem
last set I bought cost me £4 at a supermarket , so am probably saving money as well ! and in my experience , a lot of trouble shooting time as well[/quote]
A set of standard copper core NGK plugs only costs a tenner or less -- Some high volume Champion copper core plugs can be found for fiver or less for a set of 4 but ---- cheap brands of plugs should be avoided, the bigest names in the plug world NGK, Bosch and Champion have massive research facilities and choose exactly the right plug for an application, other manufacturers work purely on equivalence list our plug xk6e is roughly equvalent to a Champion RN9YCC so we will list it for ever engine Champion N9YCC is listed for --- this may or may not be OK Plugs made by NGK in particular are renown for having a wider heat range than "equivalent" plugs from other manufacturers. A plug with wider heat range is more likely to continue working no matter what the conditions or state of wear of the engine.
frankly I found that with even the best plugs you can get the odd failure at low mileage , and it causes a lot of hastle ...if you always have a new set of plugs fitted you have eliminated one possible problem
last set I bought cost me £4 at a supermarket , so am probably saving money as well ! and in my experience , a lot of trouble shooting time as well[/quote]
A set of standard copper core NGK plugs only costs a tenner or less -- Some high volume Champion copper core plugs can be found for fiver or less for a set of 4 but ---- cheap brands of plugs should be avoided, the bigest names in the plug world NGK, Bosch and Champion have massive research facilities and choose exactly the right plug for an application, other manufacturers work purely on equivalence list our plug xk6e is roughly equvalent to a Champion RN9YCC so we will list it for ever engine Champion N9YCC is listed for --- this may or may not be OK Plugs made by NGK in particular are renown for having a wider heat range than "equivalent" plugs from other manufacturers. A plug with wider heat range is more likely to continue working no matter what the conditions or state of wear of the engine.
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junkcatcher
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- Joined: Mon Apr 21, 2008 4:54 pm
[quote="lpgelite"][quote="junkcatcher"]
If nothing else available
(3) Beru, AC-Delco, Autolite/Fomoco Magneti Marelli*
[/quote]
I could recommend Beru plugs, which tend to be found ex-works rather than afterfit.
I found a set in a Tickford LPG converted LT35 (Merc Sprinter engine) with 120k on the clock. It was running fine, so you can imagine my astonishment when I removed the plugs to find the centre electrodes worn below the insulators and gaps of about 2.5mm to what was left of the side electrodes!!
They showed no signs of damage or overheating, so there was every reason to believe that these were the original factory installation and had never been touched. Maybe the relatively low compression ratio had helped them to last so long?
...[/quote]
I think you will find the original factory fitted plugs would have been Bosch rather than Beru
If nothing else available
(3) Beru, AC-Delco, Autolite/Fomoco Magneti Marelli*
[/quote]
I could recommend Beru plugs, which tend to be found ex-works rather than afterfit.
I found a set in a Tickford LPG converted LT35 (Merc Sprinter engine) with 120k on the clock. It was running fine, so you can imagine my astonishment when I removed the plugs to find the centre electrodes worn below the insulators and gaps of about 2.5mm to what was left of the side electrodes!!
They showed no signs of damage or overheating, so there was every reason to believe that these were the original factory installation and had never been touched. Maybe the relatively low compression ratio had helped them to last so long?
...[/quote]
I think you will find the original factory fitted plugs would have been Bosch rather than Beru
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king.module
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junkcatcher
- Member
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- Joined: Mon Apr 21, 2008 4:54 pm
[quote="king.module"]and whilst we're on the subject of plugs...... :roll:
i have a '97 vito (OVML) going in for a service in a couple of weeks so am going to get some plugs in advance for them to put in...
was thinking about getting some 'BPR6ES - NGK Spark Plug' - anyone any opinions??[/quote]
BPR6ES will have the wrong hex size it is roughly the equivalent of a Champion RN9YCC the hex size is the old style 20.8mm
NGK recommended plug is BKRU5ET-10
Thats a fairly special plug
B = 14mm x 1.25 thread
K = Small 16mm hex
R = Resistor
U = Semi-Surface Discharge *********
5 = heat rating = hot/soft side of average
E = 19mm reach (more correctly 3/4" reach)
T = 3 ground electrodes
-10 = 1mm (0.040") Gap
The special feature is the U for "semi-surface discharge" --- I know what surface discharge plugs are (as in Golden Lodge plugs) but have never encountered "semi-surface discharge" type before.
A colder/harder plug the BKUR6ET-10 is listed for other Mercedes models but this is also tri-electrode semi-surface discharge.
If you want to try a conventional double copper core of the conventional NGK plugs the most suitable is probably the plug used in the Rover K series engine up to 1999 the BKR6ES or the single copper version the BKR6E Try a 0.32" (0.8mm) gap setting.
i have a '97 vito (OVML) going in for a service in a couple of weeks so am going to get some plugs in advance for them to put in...
was thinking about getting some 'BPR6ES - NGK Spark Plug' - anyone any opinions??[/quote]
BPR6ES will have the wrong hex size it is roughly the equivalent of a Champion RN9YCC the hex size is the old style 20.8mm
NGK recommended plug is BKRU5ET-10
Thats a fairly special plug
B = 14mm x 1.25 thread
K = Small 16mm hex
R = Resistor
U = Semi-Surface Discharge *********
5 = heat rating = hot/soft side of average
E = 19mm reach (more correctly 3/4" reach)
T = 3 ground electrodes
-10 = 1mm (0.040") Gap
The special feature is the U for "semi-surface discharge" --- I know what surface discharge plugs are (as in Golden Lodge plugs) but have never encountered "semi-surface discharge" type before.
A colder/harder plug the BKUR6ET-10 is listed for other Mercedes models but this is also tri-electrode semi-surface discharge.
If you want to try a conventional double copper core of the conventional NGK plugs the most suitable is probably the plug used in the Rover K series engine up to 1999 the BKR6ES or the single copper version the BKR6E Try a 0.32" (0.8mm) gap setting.
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king.module
- Junior Member
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- Joined: Tue Apr 29, 2008 11:04 am
Thanks junkcatcher
>>BPR6ES will have the wrong hex size it is roughly the equivalent of a Champion RN9YCC the hex size is the old style 20.8mm
opps!!! did i mention i know nothing about these things?!?!?....i had a trawl of the site and came up with those.... of course it didn't even cross my mind that plugs would be different sizes dependant on make/model Etc (blonde day maybe 
)
reckon i'll give the BKRU5ET-10 a try
thanks for your help - very much appreciated
>>BPR6ES will have the wrong hex size it is roughly the equivalent of a Champion RN9YCC the hex size is the old style 20.8mm
opps!!! did i mention i know nothing about these things?!?!?....i had a trawl of the site and came up with those.... of course it didn't even cross my mind that plugs would be different sizes dependant on make/model Etc (blonde day maybe )reckon i'll give the BKRU5ET-10 a try
thanks for your help - very much appreciated
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junkcatcher
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- Joined: Mon Apr 21, 2008 4:54 pm
[quote="king.module"]Thanks junkcatcher
>>BPR6ES will have the wrong hex size it is roughly the equivalent of a Champion RN9YCC the hex size is the old style 20.8mm
:oops: :oops: opps!!! did i mention i know nothing about these things?!?!?....i had a trawl of the site and came up with those.... of course it didn't even cross my mind that plugs would be different sizes dependant on make/model Etc (blonde day maybe :roll: )
reckon i'll give the BKRU5ET-10 a try
thanks for your help - very much appreciated :)[/quote]
On the the other hand the Rover plugs will be an awful lot cheaper and you can set the gaps -- which is just about impossible on the tri-electrode type.
>>BPR6ES will have the wrong hex size it is roughly the equivalent of a Champion RN9YCC the hex size is the old style 20.8mm
:oops: :oops: opps!!! did i mention i know nothing about these things?!?!?....i had a trawl of the site and came up with those.... of course it didn't even cross my mind that plugs would be different sizes dependant on make/model Etc (blonde day maybe :roll: )
reckon i'll give the BKRU5ET-10 a try
thanks for your help - very much appreciated :)[/quote]
On the the other hand the Rover plugs will be an awful lot cheaper and you can set the gaps -- which is just about impossible on the tri-electrode type.