Spark plugs

[what2do]

Been supplied with some Bosch WR 78 plugs for nowt, they're not what I normally use and I was wondering if they'll be ok. I can exchange them if necessary but that would involve returning to Eurocarpartsparts on the other side of town and I can't be arsed.......

Thoughts please. Thanks, Mitch.

[Ralf85]

Check the wiki above. It explains all.

[itchyfeet]

A quick google says they will fit at least one post on here where somebody fitted them

Some lpg experts claim multi electrodes are bad some say they are ok

who knows what to believe, I don't use them as I was advised not to

http://wiki.club8090.co.uk/index.php/Al ... park_plugs" onclick="window.open(this.href);return false;

[what2do]

Fair enough, I'll get them changed. Not going to cost me anything.

[SamsBus2012]

First time I serviced my van i discovered I had multi terminal plugs fitted. Used Bosch +1s ever since. No issues either way from my point of view as the van seemed to be running fine with either type. I dont have LPG though.

[California Dreamin]

I had a look to see if they crossed referenced to the Triple electrode W7TDC but couldn't seem to make a direct link. If these are indeed 'super fours' and the same heat range (that's the 7 bit) then they will likely be fine...but...the uncertainty is enough that I would advise the swap to something you definitely know fits.

If you're on gas, single electrode does seem to be the way to go. However, there are lots on here use multi electrode plugs with good results.
I guess it all depends on what ECP stock.

Safe bet: Bosch WR7DC single electrode.

Martin

[Ceirion]

I have just put them in my van seem great so far, makes sense to have multi electrodes to me, again not log though.

[what2do]

Things are never straight forward with van ownership - are they??? I envy the ignoramus that just drives their van without the knowledge gleaned from forum membership!

[California Dreamin]

I pretty sure that 'historically' when VAG group started extending their service intervals (mid to late 80's with the advent of synthetic oils) they began using 'extended life' stark plugs. In the case of the T25 wasserboxer engines, this meant migrating from Bosch W7DC's (non resistor single electrode plugs at that time) to W7TDC's (triple electrode plugs) which lasted much longer.
The 'Super Four' and I'm guessing this incarnation of the Super Four, are just evolution's of that triple electrode plug.

My only concern with using these (and I have used the triple electrode ones before with good results) is the inability to adjust the spark plug gap, which is pre-set and not adjustable.
As the advised gap for LPG is 0.6mm (from Steve at Gasure) the fixed gap of somewhere 0.8 or 0.9 (from memory) maybe too much of an air gap for these to run optimally on gas.


For those on GAS (LPG) ..Bosch have designed a platinum/iridium tipped plug that they say is particularly suitable for LPG and gives enhanced performance on standard petrol engines as well.
The Bosch WR7DP, which is the same heat range and physical dimensions as a standard plug, (also has the ability to adjust the gap) BUT with tapered earthing electrode and Platinum long life center electrode....several times the life compared to the standard WR7DC.
These are a bit more expensive but LONG LIFE so cheaper in the long run...and admitedly not on the 'list' of recommended plugs because of there expense. However, my recommendation because of there superior start capabilities (always an issue on gas particularly)
http://rb-aa.bosch.com/aa-uk/en/sparkpl ... atinum.htm" onclick="window.open(this.href);return false;


Martin

[what2do]

That's it. The inability to adjust the electrode gap is the deal breaker, I'm going to return them as I am running LPG. Like I said, it's no biggy as they were free from Eurocarparts anyway.

Now, I'm off to bury my head in the sand as I believe it's the better method to ensure 'trouble free motoring'.........

[CovKid]

Resurrected thread. Mine had the multi-electrode plugs, was getting lumpy. Old plugs. From what I can glean those plugs are a fiver a shot. Went to single electrode WR7DC+ (marked Russia?) this time. About £7 for all four. Started on the button anyway.

Personally I don't mind swapping them out more regularly if thats the routine. Nothing like a fresh set of plugs for livening up starting.

[silverbullet]

I detest those multiple electrode plugs. The longer they are fitted and undisturbed, the more likely they are to sieze in any engine.
I have LPG specific (tiny tiny centre electrode) NGK's in the SA iirc. Not cheap when buying 5, but its never fouled a plug on either fuel and its been on petrol only for a while now. Starts on the button every time.

[CovKid]

Aye. Despite the hype I've never found them to last longer OR run any better than single electrode. The question you have to ask is:

"If it needs FOUR electrodes - whats the matter with the plug???"

[itchyfeet]

I can't help thinking modern plugs are good for 20, 30, 40,000 miles, can't remember ever having a plug fail.
Don't bother changing mine too much in the van or cars.

[silverbullet]

Apparently the logic is that the spark will always jump the easiest/smallest gap, so manufacturing tolerances will always favour one until it burns backnor becomes sufficiently contaminated, then the spark will find the next easiest route to earth.
The downside is that (as I understand it) the messy plug design rather impedes the initial flame front that initiates combustion.
Somewhat self defeating.