euro b34 engine - spark plugs ?

[rsporsche]

anybody running a 3.5L euro b34 engine ... with 10:1 compression ... what spark plugs are you running? according to realoem, the early 80's 635csi runs a bosch w9 LC plug. but there is also a note about w8 DC ... which i think is more typical for the US b34.

 

[twistinglane]

What would W+N recommend? They must sell a lot of tune up parts for Euro E24s etc

 

[rsporsche]

good idea ... here is what they have for 635csi
635csi (up to 6/87 with cat) - w9 LC
628csi to 635csi - all years - WR8 DC
635csi (from 6 / 87 up) - W8 LCR
M635csi (all years) - X5 DC

interesting enough, for the e28, they don't list spark plugs
for the e23 - WR8 DC all models.

 

[autokunst]

Any thoughts on using NGK? I recall a thread elsewhere on the site discussing the merits of the BP5ES, I think. Seems it is discussed on the E24 and 2002 forums.?.

https://e9coupe.com/forum/threads/spark-plug-recommendation-pls.14155/page-2#post-192470

 

[bdigel]

Depends more on the ignition system you are using, ie Motronic vs points . Also I run Bosch plugs on all M30's , anything after that NGK

 

[twistinglane]

That info from W+N could be clearer. But sounds like for non-kat M30B34 they recommend the WR8 DC. I bet Walloth would be happy to confirm. And perhaps would have a comment on NGK

 

[rsporsche]

i like NGK ... i am asking the question on which plug is most correct, so that i can cross reference it to NGK.

won't be using points. motronic, but fuel delivery will be megasquirt. no cat either ... its a dirty engine

 

[bdigel]

I ran 8LCR 's in my M30 race motors , Like I said I like NGK in newer stuff, but in old school 2 valve the bosch stuff worked better .

 

[Stevehose]

imho if you choose Bosch search for some nos ones from Deutchland not Brasil or Espania. Otherwise NGK is way to go.

 

[OCCoupe]

Bosch W8DC make sure you buy the copper core otherwise you risk detonation.

 

[sfdon]

Only German Bosch.
No russia, India, Brazil.

https://m.ebay.com/itm/W8DC-Bosch-S...165788?hash=item362e02be9c:g:KNcAAOSwH3haH0Sl

 

[rsporsche]

Only German Bosch.
No russia, India, Brazil.

https://m.ebay.com/itm/W8DC-Bosch-S...165788?hash=item362e02be9c:g:KNcAAOSwH3haH0Sl

Bought - thanks Don

 

[rsporsche]

well, it was going good, except i just got an email from the seller that an R was missing from the description - WR8DC. anybody know the difference between the W8DC and the WR8DC plugs?

 

[sfdon]

Resistor

 

[sfdon]

https://www.ebay.com/itm/10-OE-W8DC...ash=item2f183fd68c:g:n7QAAOSwVqlZ9Iiw&vxp=mtr

 

[rsporsche]

those 10 are not from germany as i remember ... i looked at them. so what does the resistor do good or bad? is it problematic?

 

[Stevehose]

Just get NGK BP5ES they are W8DC equivalent and available at local parts stores. I've been running them for years when I stopped hunting for the German W8's. Resistor was for radio interference and may hold back some spark I guess.

 

[autokunst]

Just get NGK BP5ES they are W8DC equivalent and available at local parts stores.

That is exactly what I did. I love the "idea" of saying I run German Bosch plugs. But you don't see them so appearance isn't a factor, the NGK's work really well (imho), and they are available and consistent.

 

[Belgiumbarry]

after W8LCR i now use NGK ZGR5A , works fine !

 

[sfdon]

Just get NGK BP5ES they are W8DC equivalent and available at local parts stores. I've been running them for years when I stopped hunting for the German W8's. Resistor was for radio interference and may hold back some spark I guess.

Best answer....