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[Arpy]

Had a problem with lpg when switching from cold ok when put foot down so went to a specialist who is going to clean the matrix injector block and service.
He has recommended a spark plug I have never heard of just wondered if anyone used them
they are Brisk high performance and have 4 electrodes.

[tunnie]

4 electrodes is really OTT for the Omega, even more so for a 4 pot.

I also have a 2.2 LPG Omega, I have had no issues using standard GM twins, i suspect the "specialist" is attempting to sell you some expensive snake oil 

Is the vaporiser nice and hot when switching over?

[Arpy]

he agrees with me that first port of call making sure the matrix is clean as it is only erratic when  it first switches to lpg after a long spell of not being used ie overnight.
It can still do it when engine warm but not been used for a little while it is intermittent and sometimes i didnt even notice it because once you get going the car runs absolutely fine.
Thanks for advise on plugs

[symes]

Do not use brisk plugs-unless you want to change engine Makes it too lean I tried them in a old v6-not good-but at least I made up for it as coffee table Which made me ££££££s 

[TheBoy]

I thought the concensus here was quad electrodes were for longer life, at the expense of slight performance loss due to the electrodes shielding the spark?

I would (and do myself) stick to GM twins on both of my LPG Omegas.


Additionally, I think its revealling that the big name spark plug manufacturers such as NGK use single electrode plugs on their LPG specific plugs...

[symes]

I thought the concensus here was quad electrodes were for longer life, at the expense of slight performance loss due to the electrodes shielding the spark?

I would (and do myself) stick to GM twins on both of my LPG Omegas.


Additionally, I think its revealling that the big name spark plug manufacturers such as NGK use single electrode plugs on their LPG specific plugs...

+1 works well on mine

[Kevin Wood]

No reason to deviate from using standard GM plugs on these cars. They are well proven on LPG and last 40k easily.

If it's burning out plugs on LPG, then it's running lean, and fitting harder plugs is a bodge. The issue needs to be fixed before it holes a piston. If it's not eating plugs then it's the usual myth that you need some kind of boutique spark plug on LPG, which simply isn't the case.

Well worth making sure the ignition system, including plugs, is sound before going further, though.

[Entwood]

Do not use brisk plugs-unless you want to change engine Makes it too lean I tried them in a old v6-not good-but at least I made up for it as coffee table Which made me ££££££s 

Sorry, but that makes no sense at all .. spark plugs have NO EFFECT on mixture whatsoever ... if it's running lean then whatever plug you have will cause the same overheating/burnout problems. The only "possible" link is that the "brisk" plugs are capable of withstanding a lean running engine for longer before failing, so the damage done is greater .. but that is the fault of lean running .. not the plug !!!

Just my thoughts .. nowt else ..

[Kevin Wood]

Do not use brisk plugs-unless you want to change engine Makes it too lean I tried them in a old v6-not good-but at least I made up for it as coffee table Which made me ££££££s 

Sorry, but that makes no sense at all .. spark plugs have NO EFFECT on mixture whatsoever ... if it's running lean then whatever plug you have will cause the same overheating/burnout problems. The only "possible" link is that the "brisk" plugs are capable of withstanding a lean running engine for longer before failing, so the damage done is greater .. but that is the fault of lean running .. not the plug !!!

Just my thoughts .. nowt else ..

Agreed. If the plug can withstand a lean condition then the next weakest component will fail. Piston or exhaust valve, normally, but the plug can't alter the mixture.

[symes]

well how come those brisk plugs were in it and when ran exhaust manifolds were white-I dont know nor care to be honest-all I know is they were no good and engine ran whole lot happier on vx plugs and yes plugs can effect a lot thats why they come in different heat ratings

[Entwood]

Heat range of a plug has nowt to do with the temperature of the exhaust gases or the "explosion" of the power stroke .. but purely a function of how hot the tip of the plug is ALLOWED to get.

Controlled by the characteristics of the insulator, a "cold" plug conducts heat away from the tip faster, a "hot" plug retains heat in the tip.

Why ??  Simply do do with self cleaning (hotter plugs will clean better), and by this it does NOT mean looking nice... the tip of the plug must remain hot enough at idle to prevent fouling, or the engine stalls due to no spark, however if the tip gets too hot at WOT the tip can melt causing other problems.

The balance is to get a plug that just stays clean at idle and runs "cool" enough at WOT to be safe.

Performance engines cannot always achieve this and run plugs that foul at low rpm, rather than melt at the top end !! Which is why they continually "blip" the throttle to keep the tip hot and clean...

Running too "hot" a plug can lead to pre-ignition (pinking) as the tip stays hot enough to ignite the fresh fuel as it enters the cylinder and before the spark is made ... not a good thing as that damages engines ... lots ..

HTH 

[symes]

mate that helps-just hope OP dont fit Brisk plugs