Time for a tune up / valve adjustment, wondering what spark plugs everyone is using these days.

My 70 914-6 was upgraded to 911S specs (2.2 or 2.4 liter, sheesh bad memory...)  Stock ignition, still has Marelli Distributor.

Currently running NGK B7EV, in the past had Bosch W225 T35. Not wanting to start an 'Oil discussion', LOL, but curious if there have been updates / changes. 

Really you want to take them out and see how they're burning. Use a plug chart if a nice tan you want to stick with the same plug.

My 3.0 I'm using NGK BPR5ES but it's twinplug 10.1:1 with MSD

I only use NGK or Bosch copper cores, T4 and /6, Beru may be okay just never tried them.

I've been running NGK BP6ES in stock 2.0L 6cyl with stock Bosch Dist and CDI
Runs fine no problems.

This is from the NGK site.
Click to view attachment

NGK BP6ES are the other plugs I have NIB for tuning, just never got around to trying them.

When i tried to get new plugs late last year I found out NGK have actually discontinued BP6ES 7333. Their site recommends BPR6ES 7131 as a direct replacement, but I was told the resistor in them didn't play well with the 123 distributor so I ended up getting BP5ES 7832 instead.

ngk.com/ngk-7333-bp6es-nickel-spark-plug

For racing in my 3.4 L twin plug I used these:
NGK BPR7ES (5534 large 13/16 base), or BKR7E (4644 small 5/8 base)
I mention this because I researched small base plugs with all other parameters equivalent to the large base ones. It always was difficult servicing the lower plugs if I didn't remove the exhaust manifolds due to clearance issues . The small base plugs gave me just enough extra room that the job was easier. One or two heat ranges hotter would be proper for a street engine. I used small base plugs when I had a 944 Turbo for the same reason. Try the small base equivalent plugs in your preferred brand, I think you'll like the change.

movin6, I also have a 2.2E with S pistons and had the same question this last year. I have a bosch S distributer, MSD and 40 PMO, NGK BR6's recommend but if still running rich a hotter plug is the NGK BPR5's. If your NGK 7's look good I would stay with that....only use a hotter plug if you must. Best, Mark

Thanks for the feedback, the plugs are black, not the desired tan, I suspect running rich. I also noted that the Bosch W5 is shorter than the NGKs (The Bosh was installed on a road trip when cyl #2 NGK broke.) Makes me wonder if that is the correct plug?Click to view attachment

Those seem awfully hot for a twinplug. Are you having good success? I just ordered 8s my track car... mainly cause I can’t get 7s, they’re on back order, so I thought I’d go a hair cooler...

I use BCPR-6ES plugs in the 4L engine. They work great.


Clay