What Spark Plugs for 911SC

[keynsham1]

I have a 1978 911 SC Targa ROW (UK spec) and I need new spark plugs. There seems to be lots of info about what are the correct fitment, but a lot of it is contradictory.

Does anyone know what the best plugs are to fit?

[KiwiJohn]

Your car is identical spec to mine.
Normal driving, (not track), I use WR8DC+.

[rsscotty]

I quit using the WR8DC after having a bad pinging problem under load up hills. I know they recommend the WR8DC for early year SC cars, but the later years like 82 & 83 went to a WR5DC+. I feel the 8's are way too hot. The switch to 5's took care of the pinging and they do not foul. On our stock spec. track engines we use a 4 heat range, just to be safe. The car mentioned above had the correct ignition timing curve.

[DaddyGlenn]

Originally Posted by rsscotty

I quit using the WR8DC after having a bad pinging problem under load up hills. I know they recommend the WR8DC for early year SC cars, but the later years like 82 & 83 went to a WR5DC+. I feel the 8's are way too hot. The switch to 5's took care of the pinging and they do not foul. On our stock spec. track engines we use a 4 heat range, just to be safe. The car mentioned above had the correct ignition timing curve.

+1

I don't remember were I learned it but the 5's are correct for an RoW.

[theiceman]

so here we are years later with advances to iridium and other precious metal for Plugs. In efforts to gain longer service intervals and the ever present heart stopping risk of stripping out a plug have people begun to move to these Plugs ? Or are we still sticking with the dinosaur Copper plugs ?

i have a 78SC so W8DC Bosch are my go to and BP6ES on occasion when i see them . Just thought before firing in another set i would find out if people are going with modern alternatives these days.

cheers

[franklinstower]

I just searched the NGK site, I prefer NGK to Bosch,
They now recommend BPR8EIX Iridium plugs for a 78-79.
Anyone use these?

[HaroldMHedge]

Wayne's Rebuild & Modify book lists the 1978-79 911SC (Europe) plug as W5D.

[franklinstower]

Originally Posted by HaroldMHedge

Wayne's Rebuild & Modify book lists the 1978-79 911SC (Europe) plug as W5D.

It sure does, however that book is coming up on 20 years old and I would think spark plug advancements might supersede a recommendation from circa 1999.

[HaroldMHedge]

Originally Posted by franklinstower

It sure does, however that book is coming up on 20 years old and I would think spark plug advancements might supersede a recommendation from circa 1999.

Ok

[drewr]

I have a 1977 Targa with a 1982 3.0 L engine. I just put in NGK BP7ES plugs in it. Copper core. I think the Iridium plugs are going to have a hotter fire.

[AndrewCologne]

Originally Posted by franklinstower

I just searched the NGK site, I prefer NGK to Bosch,
They now recommend BPR8EIX Iridium plugs for a 78-79.
Anyone use these?

I use them for years – although I have 930.16 engine – but should do the exact same job in a 78-79 model.

[Bill Douglas]

I've just referred to the manual. 1979 UK spec car - same engine as yours.

So you want the equivalent of Bosch W 225 T 30 (W 5 D) or Beru 225/14/3 A (14-5 D)

[BER]

Originally Posted by theiceman

so here we are years later with advances to iridium and other precious metal for Plugs. In efforts to gain longer service intervals and the ever present heart stopping risk of stripping out a plug have people begun to move to these Plugs ? Or are we still sticking with the dinosaur Copper plugs ?

i have a 78SC so W8DC Bosch are my go to and BP6ES on occasion when i see them . Just thought before firing in another set i would find out if people are going with modern alternatives these days.

cheers

Good question Iceman.

I installed new plugs in my 84 911 about 6 months ago. This time I broke out of the "dinosaur" mentality and installed NGK Iridium (BR7EIX) plugs. So far, I have been very pleased. Engine runs strong and smooth...no misfires, stumbling or hiccups. Be interesting to examine them after a couple thousand miles and see how they look.

https://ngksparkplugs.com/en/products/ignition-parts/spark-plugs/iridium-spark-plugs

[RSTarga]

Originally Posted by BER

Good question Iceman.

I installed new plugs in my 84 911 about 6 months ago. This time I broke out of the "dinosaur" mentality and installed NGK Iridium (BR7EIX) plugs. So far, I have been very pleased. Engine runs strong and smooth...no misfires, stumbling or hiccups. Be interesting to examine them after a couple thousand miles and see how they look.

https://ngksparkplugs.com/en/products/ignition-parts/spark-plugs/iridium-spark-plugs

I’ve been using these for a couple of years in my 2.7 mfi great plug

[Bill Douglas]

I just googled NGK Iridium plugs and it came back with a whole lot of info on how to spot fake ones. Society is so full of fakers and thieves.

[Flojo]

received my Bosch WR5DC+
Made in Russia
well... nearer to Europe than China...

[Jonny042]

Originally Posted by RSTarga

I’ve been using these for a couple of years in my 2.7 mfi great plug

I agree.

I've been using BR6EGP (Platinum) in the 3.2 MFI hot rod - nice and hot and in combination with the CDI+ will fire 11.0:1 mixtures (still tuning!). However they seem to be discontinued and have been replaced by the EIX Iridiums.

I'm trying to dial the fuel curve in and keep it on the rich side for now. I will lean it out over the whole range once I'm satisfied. At that time I will change to BPR7EIX, A little cooler for when I'm a little closer to the edge, mixture-wise.

To answer the OP's question, I would say any NGK plug with a 6 heat range would be good.

If you are committed to making it the best it can be, a CDI+ ignition is a great investment.

[john walker's workshop]

NGK BP6ES is discontinued apparently. I'm assuming BPR6ES is about the same.

[Walt Fricke]

To confuse things more, didn't Bosch change its way of coding plugs sometime 20 or so years ago? Not just extra stuff like what the center wire was, but the heat code? Causing issues with using factory specs from back then? Or am I dreaming this.

[ty901]

a timely topic as I'm looking for something other than OEM Bosch as well. my application is far from stock; 2.7L w/ Webers, mod-Solex cams, C/R ~ 9.5:1, 004 dizzy & MSD

Originally Posted by john walker's workshop

NGK BP6ES is discontinued apparently. I'm assuming BPR6ES is about the same.

I see both still available. possibly old inventory still in the supply chain ?