Spark plugs searchable catalog & random talk

[AndreyB]

Today I've learned about spark plugs with threaded stud terminal like this pictured Denso 4116 (OMG why?!).

Does anyone know a searchable spark plug catalog for me to find a plug like that in Miata specs - 14 mm thread size/19 mm reach?

That's for me to use spark plug extenders - the ones I've got a designed for this kind of the terminal. Testarossa uses 12 mm thread size and I would prefer not to use a thread adapter.

[AndreyB]

Problem solved - some or most spark plugs have a removable bullet end revealing those style threads, I did not know!

[Simon@FutureProof]

Most NGK plugs are like that with a screw on cap.

A lot of Bosch plugs have a fixed bullet end.

[AndreyB]

Last time it was about Ferrari 124792 spark plug extenders, today @andreika is forcing me to look into 8mm spark plugs.

CR9E is 10x19mm

ER8EH and ER9EH are 8x19mm

aliexpress has these cool images for their version of ER8EH

[AndreyB]

They say that's the kind of spark plugs used in NASCAR? Note the unusual central electrode layout with no cavity. Why? What are the pros and cons?

[AndreyB]

NGK 5946 is interesting due to Thread Size: 10mm and Reach: 26.5mm (1.04") and Hex Size: 9/16" (14mm)

DENSO 4162 Thread Size only 8mm!

This is related to https://rusefi.com/forum/viewtopic.php?f=3&t=1630&p=35122#p35122 project, better discuss there.