valves/plugs

[gatorjaws]

Hey, just set my valves & put in new plugs. I set the valves @.08m intake & .18m exhaust & the plug gap @.032in. I am using Bosh platinum 4016/WR7DP plugs. Does anyone know of a better plug or setting? My car is a 1966 230sl

[hauser]

My shop does not recommend platinum.  I've been running WR7DC with out any issues.

[gatorjaws]

why, & what gap do you run?

[hauser]

The late owner of the shop also had a Pagoda along with a few others he had sold.  He knew these cars very well.  On my first visit there I took the car in for a full service and requested Bosch Platinum plugs.  He cautioned that it would not work well with my car.  Considering his expertise and years of MB knowledge I went with his recommendation.  As for the gap I believe they are preset. 

[ja17]

Hello,

Yes, platinum plugs are not recomended  for these cars.  I believe I have a factory service bulletin on this issue somewhere . Using a non-resistor copper core spark plug is your best choice. I use a .028" gap for the plugs. You will find other deviations listed for the gap. Remember, that the spark plugs have changed construction over the years so the original gap specification may no longer be completely relevant. Check to see if the spark plug manufacturer has a current gap spec for your engine. The NGK website, specs .032" gap for their BP6ES spark plug in the 280SL engine.

[gatorjaws]

Thanks for the info! I will try the plugs you suggest next time

[graphic66]

I wouldn't wait, changing my 230SL to non resistor plugs made a big difference in how it ran, very noticible. I used NGK BP5ES.

[dseretakis]

I agree with the NGK recommendation.  I replaced my plugs once with Bosch resistor plugs and the car barely ran.  Changed back to NGK and that made all the difference in the world.

[gatorjaws]

You know I did some checking on the web & l called some of my road racing buddies & the general consensus is the platinum plugs are fine. They last longer & foul less.The big diff is the cost. When I pulled the old ones the color was perfect. I am running one of those 123 ignition distributers & everything is good. I have  a radio but its not working( no big deal) so I don't need to worry about interference. I'm using 8mm silicone & solid copper wires. I have put 100,000 K on the car with this plug. Who knows.....**** or wheels I guess

[ja17]

Hello gatorjaws,

Whatever works for your car is fine with us.  The plug you are using is a resistance plug as the "R" in the number indicates. As I mentioned, the resistor type plug can work  fine in your engine, depending on how your igniition is configured.   I often wondered why the factory did not recomend platinum plugs on some models.

The best spark plug configuration for most of us is non-resitor, and non platinum spark plugs.

Happy motoring,