distributor caps

Ellis Kinney · Dec 12, 2011

All through the 80s and 90s it was virtually impossible to buy a brass distributor cap. I would always ask at the IH dealer for brass and they only had aluminum. I am assuming that brass is the better choice and it was just cheaper to make aluminum ones. Lately brass has been available again. Which is the better choice and why? Thanks, Ellis

mike1972chev · Dec 12, 2011

Brass is a better conductor of electricity,I believe?

Where can I get a brass cap for my IH distributor ??( Super M )

AG in IN · Dec 12, 2011

I'm sure someone will say it's the conductivity of the material or the melting point of the material that makes one superior over the other. Their answer is probably correct.

My answer is that aluminum caps can corrode sitting on the store shelf. They'll corrode sitting on a tractor sitting in a shed. I have considerably fewer problems with brass contacts in the caps. I avoid the aluminum ones when ever possible.

I live in a high-moisture area. Humidity most of the time. Tractors sweat in the summer in the shed. Maybe in a drier climate this isn't a problem, but here it is.

AG

AG in IN · Dec 12, 2011

(quoted from post at 16:07:05 12/12/11) Where can I get a brass cap for my IH distributor ??( Super M )

Mike, I get mine at NAPA. Cost $15+ and US made if I remember correctly. They fit properly, too.

AG

Ellis Kinney · Dec 12, 2011

Mike, Lately (last 4 or 5 years), the Case IH dealer near Louisville, Ky. only sells brass. I suggest you call the dealer in your area, or Steiner, 1 800 234 3280 Ellis

Anonymous-0 · Dec 12, 2011

Brass is primarily copper and therefore is a better conductor. As many have already stated it has better oxidation resistance.

big fred · Dec 12, 2011

Actually, brass is a poorer conductor of electricity than aluminum. it's only about 28% as conductive as copper, while aluminum is about 61% as conductive as copper. Even though the alloying elements are a small portion of the mix, they have a large impact on the conductivity.

Anonymous-0 · Dec 12, 2011

Did the google thing and yes you are correct. Also thought gold was slightly better than silver, but it again said I was wrong. Apparently the only advantage for gold must be oxidation resistance as it is for brass.

mike1972chev · Dec 12, 2011

The one thing I DO know is the aluminum contacts in the caps are MOST likely to conduct OXIDATION !!!! I have had TOO many caps(on ALL makes of vehicles) grow white "crap" on the poles in the caps.My Blazer almost quit running because of it.Pulled the cap,and it looked like it "snowed" in the cap! Same with My Super M.Had to take a knife and scrape them out! an good after that.

TMonton · Dec 12, 2011

Brass is a softer metal and less corrosive to airborne elements. Aluminum tends to chalk up after awhile. Metal to metal contacts will also arc and pit with normal wear. Jumping electric currents between two bodies is basically a low power welder. Aluminum being a harder metal, is more brittle will wear and dirty up quicker.

For the same reason the high quality gold relays are more expensive is for the contact metal. Silver is the best conductor but is again .. a hard material. Moving or brushing softer metals together with the in-out action of the contacts will offer some self cleaning, longer wear and an over all more stable contact.

There are 29 electrons in copper and 47 in silver and can coeval with more free electrons thus ... the better conductor.

distributor caps

Ellis Kinney

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mike1972chev

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AG in IN

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AG in IN

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Ellis Kinney

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Anonymous-0

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big fred

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Anonymous-0

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mike1972chev

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TMonton

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