Finally an all brass Marelli distributor cap?

I took the bait and ordered this from China…. anyone else already do it?

Nope, nope, nope. Look close at the photo of the underside and you’ll see it doesn’t have a metal sleeve surrounding the carbon brush. That means it’s a cheap POS, don’t buy it.

I’ve seen parts that are aluminum look golden like that in photos, either due to anodizing or simply due to lighting. But brass or not, without that metal sleeve it is not to be purchased.

Remind me why that extra metal bit is necessary I know you’ve told us before, I just forgot

Without the metal sleeve, the only path for the voltage to take from center terminal to carbon brush is through the coil spring. And sometimes the spring gets jammed in the hole – it’s deliberately wider in the middle to keep it from falling out – and doesn’t actually touch the bottom of the hole. Then the only path for the voltage to take is by arcing within the hole – which very quickly burns a great big gaping hole in the cap, and if you’re not lucky burns your car to the ground.

Fortunately, if you have a cap without a metal sleeve, it’s pretty easy to add one. Drill the center hole out and press or epoxy in a piece of brass tubing with the correct ID to fit the carbon brush. Make very sure the brass tube makes a secure electrical contact with the terminal at the bottom of the hole.

Just looked at a V12 Lucas dizzy cap. The spring and carbon button pull out in one piece with just a slight bit of force. Maybe 2-3 lbs. Wouldn’t it make more sense to be sure the spring/brush is fully seated in the cap and touching the metal in the cap. Tapped in with a punch and verified with an ohm meter. Once the spring/brush is fully seated, and the cap fitted onto the dizzy body, there is no movement of the part…except a one time compression of the spring ? If necessary, epoxy the spring into the cap. Has anyone tried that ? SD Faircloth

Im puzzled by the concern: in the 4+ decades of seeing thousands of dizz caps, very few had any issue with the spring/carbon center.

It wasn’t until just recently I saw the center wallow out, around the carbon brush, in my Rover’s cap.

I’ve never seen a problem in the Lucas dizzy. But a Marelli will burn through in a heartbeat. Perhaps it’s because the Marelli develops that much more energy, I dunno.

I beg to differ. The best new Lucas black dizzy cap you can buy today (BTW, after market black cap with Lucas imprint is identical to oem) seem to start developing hairline cracks early…mine did after 3 years.

$40/3 years isn’t too expensive, I guess.

Maybe I should buy up 7 of them now before price doubles, so I’m set for 20 years.

Excuse me, I meant to say I’ve never seen that problem – burning through the opening for the carbon brush – in a Lucas dizzy. Yeah, we’ve seen our fair share of other problems with Lucas caps, starting with the vent connections coming loose.

The last two black Lucas caps I bought seem to have solved the vent cap issue. They stay put very well, I’ve yanked those vacuum lines off many times.

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I’ve heard worse advice…:grimacing:

Years ago we heard from someone who described refurbishing old caps and rotors. Apparently popular for very old machines, long out of production. IIRC, refurbishing the plastic components involves some sort of varnish or epoxy or something. Perhaps that’d be the thing to do with some of these aftermarket caps right out of the box.

I’m sure I’ve already seen a post from you showing this, but can’t find it now
if anyone has the link ?

on a related subject, still no good option for Marelli replacement rotors ?

Perhaps here:

Aftermarket Marelli cap by Intermotor is the best you can get these days, still aluminum but…

here is a link with pictures:

LU437 is the part number, not sure if the same is sold in France.

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And it works on a Series 3 Lamborghini Espada - that’s your useless knowledge of the day! :wink:

thanks Steve, for some reason I searched for a thread, not “the book”

I’ll double check the types of parts I got when I changed them (iirc I got the cap and rotor from SNG Barrat)

@Jeff_Schroeder I doubt I would have any other way to know that if you didn’t told me
that could be useful is the chances I got an Espada weren’t that slim :grin:

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