Spark Plug Recommendations

Message

go_lpg · #41 Post by **go_lpg** » Fri Feb 23, 2007 8:58 am

Lawrence, this largely concours with the advice I have had from NGK. A different heat range, smaller gap etc. for LPG operation. Others have had conflicting advice. I guess it depends who answers the phone and how much knowledge they have. It may be that those with less knowledge would simply quote stock recommendations out of a book or from a table having no idea of the different set of conditions LPG presents. As for Iriduim or any other long life plug, they will retain their gap for a longer period. This is all very well until the time comes to change them and they won't come out....Wear is not just for electrodes, the thread itself degrades when its protective coating has been burned away. Not good in an Aluminium alloy head! Also consider the brown burn tracks up the porcelain insulator. The longer that goes on, the more the plug will 'misfire'. Standard plugs do not present any of these problems if changed regularly due to electrode gap erosion. Regards Steve <a href="http://www.go-lpg.co.uk" target=_top>www.go-lpg.co.uk</a>

lebesset · #42 Post by **lebesset** » Fri Feb 23, 2007 3:46 pm

the more I read this thread , the more ~I come to the opinion that the best way to spend money on plugs is...little and often fit the cheapest plug that will fit ...for most the basic plugs are very cheap in the hypermarket where I live , chuck them out at 6K of course , with a vehicle that is standard with a special plug ,this wouldn't work as the resistance to the spark is higher with lpg compared to petrol vapour I prefer a slighty smaller gap

go_lpg · #43 Post by **go_lpg** » Sat Feb 24, 2007 9:21 am

I totally agree LB. I phoned NGK yesterday and got someone very much 'in the know'. Not only was I given a single electrode alternative for later BMW V8's (after previously being told that it didn't exist) BKR6E along with the advice that single electrode pugs will reduce misfiring in adverse or difficult conditions. This plug's electrode is made from nothing special. I was advised to reduce the gap from 1.1mm to 0.7mm (.030") which falls in with my own thinking, previous findings and most of the advice I have had from NGK in the past. I have learned not to phone between 12-2pm as it might just be phone-minder territory. For others reading, the NGK hotline number is repeated here - 01442 281000. Regards Steve <a href="http://www.go-lpg.co.uk" target=_top>www.go-lpg.co.uk</a>

bob · #44 Post by **bob** » Wed Feb 28, 2007 7:21 pm

I agree as well. As I said so much rubbish spoken about plugs. I fit new every 6000 miles NGK BPR6ES gap 0.022 inches 8 plugs costs £5.20. I never clean plugs or gap them apart from setting the gap when new. If I take a plug out I fit new. I never get plug problems. The less knowledgeable blame plugs for every engine malfunction when in fact the spark plug is the most reliable bit of the ignition system followed by condensers coil points rotor arm dissy cap and the last being the leads. A mate had this Volvo 240 which kept fouling the plugs up on a cold start. new plugs and it would fire up. He tried allsorts of plugs in an effort to get the car reliable, eventually he stripped a plug thread in the head and I heli-coiled it and fitted a new set of leads and the problems all went. I was immediately suspicious when I saw the leads were non genuine and old. In the boot was about 40 plugs of various grades. I fitted 10mm silicon non genuine leads and another 4 new BPR6ES's. With instructions to leave the plugs alone for 6000 miles then come and see me. If it had gone on much longer he would have kippered the the starter motor and maybe the battery and alternator. Moral of the story change the leads first.

bob · #45 Post by **bob** » Wed Feb 28, 2007 7:32 pm

Forgot I have only seen one faulty plug and it obvious it had no thread, I stuck it to a piece of wood and diplayed it on the counter, eventually it disappeared. The plug rep used to call it the plug that escaped inspection at the factory. (Champion ) Plugs were so cheap then we used to fit N9Ys by the truck load yet some customers insisted that we clean plugs to "save money " despite my explaining that at 3 bob each ( 15p) it was not worth the effort of shot blasting them and ruining the plug in the process.

go_lpg · #46 Post by **go_lpg** » Fri Mar 02, 2007 7:25 am

Careful guys. If everyone is in total agreement the forum may not be anywhere near as much fun! Regards Steve <a href="http://www.go-lpg.co.uk" target=_top>www.go-lpg.co.uk</a>

lebesset · #47 Post by **lebesset** » Fri Mar 02, 2007 6:50 pm

sorry steve ,lol

go_lpg · #48 Post by **go_lpg** » Sat Mar 03, 2007 8:18 am

LB, <img src="http://www.my90.co.uk/lpgforum/clipart/happy.gif" border=0> whilst you're on, can you tell me what 'lol' means? There are lots of abbrevations in life that are accepted ( WHY, E&OE etc) but rarely explained. The 'net has only made this worse...! Regards Steve

lebesset · #49 Post by **lebesset** » Sat Mar 03, 2007 12:40 pm

laughing out loud ; there is also roflmao of course , but this being a polite forum..... and am sure rtfm comes into your mind from time to time , even if you don't know it!!!

go_lpg · #50 Post by **go_lpg** » Sun Mar 04, 2007 8:19 am

Thanks, obvious when you know! I admit that wtf is the first thing I think of when presented with a broken gas system.

lebesset · #51 Post by **lebesset** » Sun Mar 04, 2007 10:38 am

and rtfm is similar when advising someone to read the manual

bob · #52 Post by **bob** » Sun Mar 04, 2007 1:21 pm

A mate has just this minute turned up on a Suzuki 600 sports bike. Very nice, except the plot is not running right. It is rough on tick over and appears to miss fire when revved but goes ok on the road. He says the plugs needs changing. I put my hands over the exhausts and said you have a hole in the exhaust. Off with the belly pan and there is a rust hole in the collector under the g/box. About right for a 4 year with 10k miles on the clock. Bodged up with gungun to prove the point. Bike now good and much faster--- he was surprised at how slow the bike had become with out him noticing. Well it was until the wad of gungun fell out He is going to fit a whole new exhaust system. ( road legal only is my advice ) when people can't pinpoint the problem they blame the plugs.

speed · #53 Post by **speed** » Tue Jul 03, 2007 8:31 pm

In Japan all Taxis are on LPG. There fore, for the FIRST TIME in history !!!!!!!!(LPG-Plugs did not excist!!!!!), NGK designed a (petrol/)LPG plug!!!!. Sory, could nog find English documentation. Fitted these in my 1.6 16V Clio. Very good. <a href="http://www.ngk.de/fileadmin/downloads/k ... uere_D.pdf" target=_top>http://www.ngk.de/fileadmin/downloads/k ... e_D.pdf</a> or: <a href="http://www.NGK.de" target=_top>www.NGK.de</a>

dory · #54 Post by **dory** » Sun Aug 12, 2007 10:07 am

My bi-fuel Vauxhall Omega is currently fitted with the standard NGK plugs (BKR6EK) but it's time to change them. According to Steve from go-lpg I should switch down to a 5, but NGK Australia told Lawrence to switch up from a 6 to a 7. This is presumably because everything is upside down in Oz! Until this forum gives a definitive answer I've decided to stick with my 5 plugs. Yesterday I followed Steve's example and reduced the gap to 30 thou with no discernable difference to performance.

dory · #55 Post by **dory** » Sat Aug 18, 2007 9:06 am

Oops, I meant "stick with my 6 plugs".

dory · #56 Post by **dory** » Mon Aug 20, 2007 12:18 pm

NGK-UK just wrote back saying "Unfortunately NGK do not have a listing for the above dual fuel vehicle". Not much help there then!

supercharged_buddy · Tue Aug 21, 2007 8:21 am

Dave, we're not quite upside down in oz <img src="http://www.my90.co.uk/lpgforum/clipart/biggrin.gif" border=0> Australia has a diffrent climate to the UK, so we have diffrent plug,oil, etc,etc, recomendations for our engines, but the AU NGK site says to go one heat range cooler (one number higher) when running LPG as LPG has less cooling effect than petrol. The 2nd function of a spark plug is to remove excess heat from the combustion chamber. If in doubt stick with your standard plugs.

stubeedoo · #58 Post by **stubeedoo** » Thu Oct 04, 2007 4:11 pm

I'm soon going to be replacing the plugs in my BMW320i. When I fitted the LPG system, I stuck with the standard Bosch WR8DC's and gapped them 0.1mm less than recommended by BMW for the engine on petrol.
While trawling through the internet today, I found this on the NGK website.....

The unique V-grooved centre electrode requires less voltage to produce a better quality spark. This results in better cold starting, more complete combustion, improved exhaust emissions.

I was particularly drawn by "more complete combustion".
Would this be the case when running on LPG, with respect to the higher electrical resistance of the LPG/air mix than that of petrol/air mix?
Put another way..... Is there anything to be gained by me fitting these NGK V-grooved plugs for running on LPG?
Or is it just the usual sales schpiel to get mugs to spend more money?
TIA
Stuart.

stubeedoo · #59 Post by **stubeedoo** » Tue Oct 09, 2007 1:42 pm

No-one any experience/comments/opinions then?

MarkJones · #60 Post by **MarkJones** » Tue Oct 09, 2007 5:18 pm

go for ngk iridium ...not v-grooved ...
as ngk iridium is what ngk themselves recommend for lpg.

all the best.mark