Packard Merlin Spark Plugs

[Taz]

Anyone got a part number or detailed spec of sparkplugs required for the -7 Packard Merlin. Seen discussions regarding NGK vs Champion on this site. Need to get a few quite quickly without being near the engine to have a look

Thanks!

[51fixer]

Anyone got a part number or detailed spec of sparkplugs required for the -7 Packard Merlin. Seen discussions regarding NGK vs Champion on this site. Need to get a few quite quickly without being near the engine to have a look

Thanks!

What does the engine run now?
What kind of harness ends are installed?
That has to be known.
If you run Champion Aircraft Plugs then the harness has ends that a 7/8" wrench will fit and a 7/8" socket is used on the plug.
If it uses original British Lodge style plugs then I believe a 13/16" wrench will fit on the harness nut and a 13/16" socket is used to remove the plug.
If it has a Roush PMA replacement harness and Spark Plug system then the plugs have an automotive style harness and you pull the cap off and it is a 13/16" socket to remove the plug.
The use of a NGK plug is only on an Experimental registered aircraft and I don't know what plug number it would be. Even the Roush Plugs are Champion Auto Racing Plugs but need to be purchased through Rouh for the PMA to be legal for use on Limited Category Registered Aircraft.

[Taz]

Rich,

Thanks a lot. I'll get down there and have a look!