What's the best spark plug gap to use on Bosch Super W8DC's (Made in India) going into a euro no emissions high compression (premium fuel) 117 V8 500 SEL engine?

Is rounding up the square tips with a file (old racer tip) produce better spark?

The gap is 0.9mm or 0.036in. Torque to 15 ft/lbs./20Nm.


As an aside I’d pass on the made in India Bosch and go for some made in Germany Beru 14 – 7Ds.

I've always been advised to square up the tips..

That aside, I run all my V8's @ .042..typically helps keep a nice idle.

Jonathan

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Blue Ridge Mercedes
Jonathan Hodgman
http://www.blueridgemb.com/
Enthusiast Service, Restoration & Tuning.
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Located in the Atlanta area
Specializing in all pre and post merger AMG's including Hammers and DOHC M117 engines.
Mercedes Repair Atlanta

No need to reinvent the wheel.

Install the Bosch plugs recommended by Mercedes.

These plugs will be correctly gapped as you remove them from the box and that gap will be indicated on the box. Check it, of course.

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Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles

Perhaps not, but older Benz V8's are not renowned over for their idle quality.. Opening up the gap some is a generally accepted way to improve said idle quality.

Jonathan

__________________
Blue Ridge Mercedes
Jonathan Hodgman
http://www.blueridgemb.com/
Enthusiast Service, Restoration & Tuning.
Follow Us on Facebook!
Located in the Atlanta area
Specializing in all pre and post merger AMG's including Hammers and DOHC M117 engines.
Mercedes Repair Atlanta