Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Spark Plugs

Hi

Thought I would change the spark plugs !!!. When I removed the existing ones that have been in since I purchased the car 6 months ago they are NGK laser platinum Motorcraft AGFS 22FE13J

Went to Halfords and they identified Morgan 4/4 1997 on their computer and got me the new plugs - they ar totally different from the ones in the car. The ones in the car are much shorter. The length of the thread is 17mm from the shoulder and the plug length from the shoulder to the end of the plug is 23mm.

Checked the Ford ZTech 1997 on Halfords list and this agrees with them.


So I have two possibilities - the lists in Halfords are wrong

OR - someone has put a different plug in with a shorter thread.

I am reluctant to try the longer plug before I can confirm exactly whats going on BUT I am now a bit concerned about running on a shorter plug.

I have done abour 4000 miles since I bought the car with no probs.


The Morgan handbook gives yet another set of numbers for Champion

Could you please tell me what plugs you are running on.


Thanks

Chris

Hi Chris,my engine is a 2000reg ZETEC 'SilverTop', I'm using NGK- take a look here:
http://www.sparkplugs.co.uk/pages/pricing/ccp/NGK-cars-ccp.asp
The length over the thread, from the 'top' of the chamfered seating (where it's at it's widest) to the end of the plug (at the combustion chamber end) is 25mm.
Hope this is helpful, Gerry.

Thanks thats useful info.


After very careful measurement with a screwdriver down the plug holeI have put in Champion 704 which is what Halfords recon is correct. These have a thread length of 25mm.

All seams fine.

Set off for another 500 mile trip tomorrow so fingers crossed.


Cheers

Chris

I would not place too much weight on the Halfords recommendation myself.

Their battery listing for a 2000 model year Defender is wrong (too small) and the listing for a Plus 8 is the 4/4 (smaller capacity) type.

My feeling is they tend to list things they stock, or have a higher profit margin on.

NGK publish or did a proper book (mine is 1990!) and any decent factor should have a copy and will probably let you peruse it.

In this case, Halfords look to be correct as a plug should occupy all the threads in the head.

You can download the full NGK catalouge here....

Note it is 18Mb....

Thanks, link acted funny but I got to the bottom of it. Pooter is now downloading it as the 1990 application list I have has been very useful over the years.

It's worth learning what the various letters mean, especially if you have either a tuned engine and need to alter things, or in the case of my JAP LTOW, you have 14mm inserts fitted and are needing plugs not even invented when the engine was!