TR2/3/3A Resistor plugs vs. non-resistor plugs?

[GTP1960]

Any opinions out there on which class of plug is best for a 3A engine?

thanks for your input.

Guy

 

[CJD]

It all depends on whether you want anyone within a hundred yards to be able to hear their radio or not! I would recommend resistor plugs and wires.

 

[TR3driver]

I ran the Bosch Platinums for many years, based on a comment from Ken G. that they found another 5 hp on the dyno with them on a race engine. Never could tell that they made any difference in my street engine, though.

But after I had an entire set of them fail, and Ken noted the same failure in one of their race cars; I switched back to the old Champion L87YC plugs. They don't last as long as the platinums, but they are readily available and cheap.

They are non-resistor plugs, but I've never noticed any particular ignition noise from them (I do have resistor plug caps and of course the distributor cap has a resistor in it) even in my own radio. Years ago, when I used a CB radio in a different 56 TR3, the main source of RF noise was the generator (and I added a filter cap on the output to cut down the noise).

 

[GTP1960]

Champion web site does have a resistor L87YC (RL87YC). & it is recommended for 1961 TR4's.
no mention of TR3.

Plug Type: RL87YC
Seat Type: Gasket
Hex Size (Inch): 0.813
Hex Size (MM): 20.65
Thread Size (Inch): 0.551
Thread Size (MM): 14
Thread Reach (Inch): 0.5
Taper Diameter (Inch): 0.31
Installed Height: 2.24
Insulator Projection (Inch): 0.06
Gap (Inch): 0.037-0.043
Gap (MM): 0.94-1.09
Center Electrode Diameter (Inch): 0.1
Center Electrode Material: Nickel Copper Alloy
Ground Electrode Material: Nickel Copper Alloy
Classification: Champion Copper Plus Small Engine
Resistor Plug: Y​

FWIW: when cross referencing the original champion L10S( apparently no longer available), the recommended plug was an L82YC. It appears to be similar to the 87 but has a gap of:

Gap (Inch): 0.03-0.035
Gap (MM): 0.76-0.89​

 

[GTP1960]

It all depends on whether you want anyone within a hundred yards to be able to hear their radio or not! I would recommend resistor plugs and wires.

Well that explains it:
All this time I thought the interference I was getting from the cars next to me was Rapp music.

 

[Andrew Mace]

FWIW, the L82Y is the next colder Champion plug in the series, after L87Y.

 

[TR3driver]

FWIW, the L82Y is the next colder Champion plug in the series, after L87Y.

Well, I don't recall how I got started using them, but L87Y is what I've been using. Maybe the hotter plug was to cut down on fouling.