Magneti Marelli coils

I switched to the Bosche Blue coils on my GTC.
In my opinion, MUCH BETTER than the Marelli coils.
Bob Z.

 

While we are on the topic of coils has anyone ever used the black or red Bosch coils with the standard "block" resistors that the Marellis used?

If so, were they good? No good?

Right now, I'm using Bosch blues, but with the the resistors removed, and I'm tempted to try and switch to either the blacks or reds to get the stock look back...

 

Alex, before proceeding, you may wish to figure out whether your existing "Bosch" coils or the ones you're considering switching to are externally or internally resisted.
To my limited understanding, most if not all vintage OEM M.M. coils are/were "externally", hence ...
... the external resistor, ...
... while others, including some, more modern ones are "internally" and therefor may not require nor perhaps even benefit from additional (external) resistor.
It's all (or mostly) about the (Ohm) numbers.

As for the older ones being worse than newer ones, one may wish to consider it from a perspective of new vs. used coils as they too seem to "wear out" or more specifically loose their efficiency in use over time.

All the above is just from my personal experiences and may not be agreed by those with better understanding of electrical components than I possess.

 

Hi Timo,

Bosch "blues" have internal resistors.

Bosch "blacks" are speced to need 0.9Ohm external resistors.

Bosch "reds" are speced to have 1.8Ohm external resistors.

Since I have blues, the external resistors are not hooked-up on my car; hence my question; if someone said "I've been using blacks with the Marelli resistors for years, and car starts great, and my points have been fine after thousands-and-thousands of miles", I'd switch to that set up.

BobZ is basically saying "I've been using blues with no resistors, and..."; which indeed I have seen in some other posts, and is the reason I am currently running blues...

-- Alex

 

i suggest contacting adrian at dinoplex.org.
he is brilliant.

 

Alex,
as far as I know or understand (which may not be that much) and to put it simplistically(?), it just simple math…

In recent years, I’ve converted couple of Daytonas (ours and clients) with aftermarket/non-OEM, electronic ignition setups back to points and condenser system, using a brand X coils with OEM M.M. resistors and while both seem to work just as expected, I don’t have enough long term (i.e. mileage) experience from either car to fully endorse the brand X.

 

Alex

I would measure the resistance of your MM resistors and pair them up to the suitable Bosch coil. You have the hard part Ie the specs for the resistor the coils are designed with.

Cheers Jim

 

The Ferrari resistor halfs the battery voltage; so long as you get 6 volts at the points you are ok.

john

 

Ag

Agreed that is common for 12 volt cars with points.

Cheers Jim