Thermal paste for spark plugs

Re: Thermal paste for spark plugs

by Rhett Mitchell » 13 years ago

Rhett Mitchell

8 99 0

http://www.rotax-owner.com/rotax-forum/4-general-discussion/4306-spark-plug-paste

Re: Thermal paste for spark plugs

by Dennis Hannon » 13 years ago

Dennis Hannon

0 2 0

Radio Shack's paste is great for applying to components such as transistors or 3-terminal regulators mounted on heat sinks for thermal transfer, but it is not designed to handle the high temperatures of an operating engine.

Re: Thermal paste for spark plugs

by bill martin » 13 years ago

bill martin

10 757 0

Wacker P12 has a themal conductivity rating of 0.81 W/mk and heat range of -22 to +392f.

Radio Shack (made by NTF Electronics) has a thermal conductivity rating of 0.80 and heat range of -40 to +400f.

NEITHER product is made for spark plugs. Both are made specifically for electronic applications. My guess is that Rotax in europe just has easier access to Wacker; as we have easier access to Radio Shack. I've used both for years with no problems from either one.

Bill.

Re: Thermal paste for spark plugs

by Mike Kopacki » 13 years ago

Mike Kopacki

37 62 11

I'm sure I know less than anyone else here, so I just read and try to understand.

Bill has provided numbers. I don't know what W/mk means and how important the difference is between .80 and .81.

The Radio Shack stuff has a wider heat range which I would think is a good thing.

Two questions - Bill, what is W/mk and how important is that difference; second, what is the name of the RS product?

Re: Thermal paste for spark plugs

by bill martin » 13 years ago

bill martin

10 757 0

Mike,

W/mk is watts per meter kelvin. Its just a system for measuring thermal conductivity. Same as BTUs.
The Radio Shack product is Thermal Grease. It is about $3.50 per tube. Its a tiny tube but good for four or five plug changes. They also have another brand which is supposed to be better called Arctic silver. It is much more expensive; about $12.00. I've never used it but computer clockers swear by it.

There are dozens of heat sink products out there and they are all basically the same thing. Silicon grease with zinc oxide and small amounts of silver added.

Be very careful and very sparing when you apply this stuff. Put it ONLY on the threads and DON'T apply it on the last two or three threads nearest the electrodes. Unlike anti sieze, this stuff does not conduct electricity well and too much can affect the plug grounding and foul the electrodes.

I'm told that the difference between 0.80 and 0.81 is not enough to even consider.

Bill.