Resistor plugs stop a significant amount of back-EMF being generated as the spark quenches. This probably helps stop electronic ignition amplifiers from being fried, and is definitely necessary to stop ECU damage in vehicles that drive their coils direct from the ECU.
But I'm with you on the interference issue - my SII is running BP6EY plugs on the end of copper leads with crimped on ends - no suppression in sight (also no radio so the point is a wee bit moot). :-)
To check the cr it's stamped on the head 50mm below the head bolt that's between the middle tow spark plugs on the nearside bank.
AJH
On or around Tue, 15 May 2007 19:54:45 +1200, EMB enlightened us thusly:
I bet the neighbours love you...
I've not had one that drives the coil from the ECU. I suppose the Thor engine does that.
My comments were really about old contact-driven systems, which had much lower voltages than the new stuff, and sometimes carbon-core leads, resistor caps and resistor plugs made for a crap spark.
I'm not too worried about these 'modern' systems on the 101 :)
Right badger, I've bought a set of these but they are longer reach than the ones that came out (there is about 5mm more distance between the washer and the end of the plug). Is this going to cause me any hassle? or does it not matter?
I can turn it over by hand and its not obviously hitting stuff..
could do with finding out so i can go out in it tommorrow! :)
On or around Wed, 23 May 2007 17:42:55 +0100, Tom Woods enlightened us thusly:
It's not meant to have short plugs, is it? the ones with only about half an inch of thread? The older V8s have 'em.
Long ones won't, IIRC, foul pistons, but be aware that the thread is exposed inside the cylinder and if it collects gunge of any kind it can make them difficult to remove again, or even risk damaging the head. Should be OK short-term. I've seen engines with short-plug heads and long plugs fitted, and no sign of damage to pistons, especially as it's a fairly low compression one, the piston crowns are machined deeper anyway.
The early ones in champion terms are S rather than N, ISTR. Not sure about NGK, though.
Email sent.
Thanks badger+austin
it appears my 101 does indeed have the earlier head. They stopped in
76 according to what i can find and my 101 is a 77.. did they nick the 101 bits off the production lines and stash em till they built them?i was hoping one someone would know the part number for the short version of the bpr6es as im not sure the guy in the shop will know - we usually just get stuff in by looking at the proper listing for the car... and the bpr6 isnt even the proper one for the RR as im assuming it is a 'better for LPG' one..,
id rather not risk buggering the threads on heads ive just had reconned!
ok.. ngk themselves list bp5hs for the pre 76 engines, then bpr6e for the later ones..
a bpr6hs also exists.. could the H be short reach?
to carry on talking to my self..
from here:
also
"A BP5ES is hotter than a BP6ES and a BP7ES is colder than the 6.
"The 5 has a larger surface and dissipates heat slowly. The 7 has a smaller surface and dissipates heat quickly."
since lpg burns hotter than juice in the cyls, should i still go for the bp6 over the bp5? (recommended) as i gather that causes it to stay at a more suitable temperature in there.
From memory I'd be using a B8ES in that application. But go and check one against what came out cos I'm away from my reference material about things automotive (and running on a steep learning curve about brand new IBM x-series servers)
Sorry... not thinking well.... B8S is what you want.
found this which is cool
and from that table the difference between bpr and bp is 'resistor type'.. im assuming the resistor types are for leccy ignition.. which i am going for soon so might as well get em in advance..
a very one sided thread tis this!.
resistors apparently help stop electrical noise and electric ignition need em. might as well have them.
im going to order some bpr6hs's and go do some work!
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