Who is running MSD Ignition coil and what do you think?

[thefaculty]

Before I get slammed I have read almost every thread on the MSD Ignition coil here and wanted to try to get a collective view on it before I order one:

My coil, the notorious silver Bosch crapped out, so I need a new one to get running again. I am about to press GO on the MSD High-Vibration Blaster Coil (8222) unit sold by our host but have read about it melting or catching fire: My 911 on fire! Burning MSD coil

So what are your thoughts? I am running:

• Stock Bosch CDI (0227300004)
• Current coil reads 0.6Ohms primary and 645 Ohms secondary.
• I will probably replace my ignition wires to Clewett or Magnecor (do you have a preference?)

Would really appreciate any thoughts you guys may have here. I guess I just want to be sure that this setup will work and is safe and does not need any modifications or changes that I am unaware of to make it work properly.

Thanks guys!!

Dan

[john walker's workshop]

MSD 8222. Use it a lot. Heatgun the lable off. 8202 oil filled works too. It's red, so paint it. Both fit the original coil bracket.

[thefaculty]

Originally Posted by john walker's workshop

MSD 8222. Use it a lot. Heatgun the lable off. 8202 oil filled works too. It's red, so paint it. Both fit the original coil bracket.

Thanks John - and no need for concern with compatibility with the stock Bosch CDI or dizzy?

[john walker's workshop]

Nope.

[smadsen]

I've used the 8222 for 10+ years on my '82. Works perfect.

Be aware the 8222 may have a different diameter wire receptible than the distributor cap. I seem to remember fabbing up a wire that was 8mm on one end (for the coil) and 6 or 7mm on the other for the distributor. Others have on this board reported arcing when the small wire (stock) rattles in the big receptible.

Just check when you do the install.

[HaroldMHedge]

Another option is the Partsclassic (replace c's with k's) CDI coil.

Reviews can be found on the Early 911s Registry.

[Flojo]

MSD 8222 is top! No issues since install years ago.
Got the black version. Stripped the MSD sticker and gave it a Bosch look.
Housing is longer than the black/silver Bosch

Here is a picture from 2013 after setup

[eastbay]

Originally Posted by Flojo

MSD 8222 is top! No issues since install years ago.
Got the black version. Stripped the MSD sticker and gave it a Bosch look.
Housing is longer than the black/silver Bosch

Here is a picture from 2013 after setup

Nice job, looks great. Looks better than the 8222 I am running with the MSD stickers. Will have to put those original style coil stickers on the buy list.

Don't see the coil cover used very often. Might motivate me to install the one I have in my parts stash.

[thefaculty]

Originally Posted by Flojo

MSD 8222 is top! No issues since install years ago.
Got the black version. Stripped the MSD sticker and gave it a Bosch look.
Housing is longer than the black/silver Bosch

Here is a picture from 2013 after setup

This looks great! Thanks everyone - I think this pretty much made up my mind - it's already ordered, hopefully this gets me running again!

[thefaculty]

I cannot tell you how happy I am to report back that the new coil arrived today, it went in and she started faster than ever before!!!

I cannot thank you guys all enough for your help, experience, wisdom and patience with me! For most of you this is simple stuff but for a newbie like me it's a milestone. Taking a car from a non-starter to a nice clean start without taking her to a shop is a big deal for me and I couldn't have done it without this forum!

THANK YOU EVERYONE!!!! And now enjoy the sweet sound of success!!

[rw7810]

What makes the original black coil different or required for CDI box

[Frog76S]

Originally Posted by rw7810

What makes the original black coil different or required for CDI box

The original Bosch black OEM coils are great. When the black ones fail, don’t buy the silver Bosch coils, they’re absolute junk. I went thru three of them in less than 1k miles before this forum enlightened me about the silver coils substandard quality. I run the MSD coil with great success.

[Flojo]

Originally Posted by rw7810

What makes the original black coil different or required for CDI box

The Brazil-made BOSCH coils had a production period up to 2017 and NOS from that tended to fail. and they failed quickly.

a 2018 or younger should be good now (check production date).

but compared to AD-prices the MSD 8222 is a no brainer (and even better, as it is epoxy filled (not oil).

[zedsn]

I didn't use the round MSD coil. I used the red square one that mounts on a plate and never had an issue and I used the msd box as well.

[tirwin]

I’ve been using the MSD 8222 for several years with no issue with the original coil. I did buy a spare one. Found it was DOA when troubleshooting another problem once. Too late to return it. Lesson learned... install the new one and put the good one in the road trip tool bag.

[RSR Racer]

How much longer is the housing that the Bosch coil? The Holley site does not provide the coil length. I have a very tight fit under the intercooler!

Thanks!

[1979-930]

Originally Posted by RSR Racer

How much longer is the housing that the Bosch coil? The Holley site does not provide the coil length. I have a very tight fit under the intercooler!

Thanks!

I use it on my 79 930 with a TK Longneck intercooler. It fits the same as the Bosch.

[MichaelSJackson]

Just a point of caution...

I installed my 8222 a smidge too deep in the bracket and closing the lid scraped paint off the bottom edge.

And make sure the distributer wire is seated deeply. Sparking caused a buildup that led to misses.

[RSR Racer]

Thank you both! Great info and very helpful!

[Jonny H]

Ok, I will pitch in here and no doubt get trolled by 'that guy'.

The MSD may well work 'ok' with the Bosch CDI system but isn't optimal. The CDI and coil are part of the same electronic circuit and when circuits are designed, the values of the components are part of that design. If you change the values then the circuit may not operate as intended.

The Bosch black coil is unique in that it has a very low primary resistance (0.5 ohm) and a step up ratio of 90 resulting in an output voltage of around 35kV (depending on primary voltage). This makes the coil VERY fast, delivering a short sharp kick of current and producing an aggressive spark. It also means the coil is difficult to make, since the insulation between the windings has to cope with a large potential voltage between each winding layer. This is why the original Bosch coils are filled with a tar like substance that is in effect self-healing when the coil gets warm.

When coil manufacturers use epoxy to insulate the windings, it is very difficult to get the epoxy to seep in an around the coils and insulation layers. The epoxy must be mixed thin enough to flow well and the process must be done under vacuum to get rid of air bubbles. Failure to get this process correct is the reason the new silver coils fail.

The alternative for the coil manufacturer is to 'relax' the spec of the windings so that there is less voltage between the windings, meaning the insulation is not so critical and the coil is less likely to breakdown. From a performance point of view, this results in a coil that is slower to charge and discharge and therefore the spark is less aggressive and the fuel is not ignited as fast.

The MSD coil is therefore a compromise. It does not have the rapid spark delivery of the Bosch coil since it is slower to respond and delivery the energy to the plug. Although it can 'hold' more energy, once the spark has finished, there is some energy left in the coil which results in lengthy 'ringing' of the coil on the primary winding. This ringing lasts around 700us - 4 times longer than the Bosch coil. This is most likely the reason why MSD ignition units have a multi spark interval of 1000us. With a Bosch coil, you can fire again in 400us, which is what our CDI+ units do.