Dizzy's making me dizzy

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Aug 7, 2010
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Location
McDermitt, NV
My Car
1973 Convertible H Code, 351C 2V FMX
OK, took the newly rebuilt Cleveland back the the builder last night because I can get her timed properly. He (actually there were 4 guys gathered around) swore a bit and unplugged a couple of the vacuum hoses) and tried to adjust the dizzy with poor results. Looked at the points and swore a bit more, took a file to them and tried to adjust the gap. The 351 ran a bit better but couldn't get a decent spark. He said the dizzy was shot and I said I was thinking about a Pertronix II and he said that sounded good.

I reread most of the dizzy threads and have narrowed it down to either a Pertronix II or an MSD. I'll be doing burnouts and driving the vert as often as possible, and take it to the strip a couple of times. I'm gonna take a break from auto mechanics after the engine rebuild and mostly work on washing and waxing, so the engine guy will be doing all the work. What do you guys think? MSD or Pertronix?

Doc

 
I'm assuming you are looking for a plug and play that doesn't require an additional "ignition box". As I've said before, I'm not a fan of pertronix for performance work above 5700 RPM. Trigger becomes unstable above that RPM and from what I've seen, a significant "infant mortality" rate. If the choice is just between those two brands I'd pick the MSD. You might consider this as a third option. http://www.summitracing.com/parts/SUM-850306-1/?rtype=1 It is cheaper and looks to be MSD or MSD copy but does not have a rev limiter. I would call Summit and ask a few questions. Not matter what you pick consider tach compatibility, cap style (male or female), coil primary resistance needed, curve adjustability, and voltage required at the coil (full 12VDC or reduced voltage through factory resistance wire or after market "ballast resistor". Everyone has an opinion. This is just mine. Chuck

 
MSD or old HEI is hard to beat for reliablity and good strong spark at high rpm....I hear the HEI cap doesnt fit well if you got ram air hooked up thou....Not a worry for me thou..Sence i got a 73 mach 1..lol

 
Dizzy's can make you dizzy.

A have run a pair of P2's for probably 60k miles over 6 years, no issues(outside of a couple of installation issues with a tach and a 12V ignition system).

However, as you know, your distributor has 2 components to adjust the timing based on engine conditions: a vacuum pod and springs. These components must be adjusted to suit the way you drive as well as the mods you have made to your engine. For example, a typical NEW OEM Engine will have 20 pounds of vacuum to the distributor. Our rebuilt motors with a little more power due to a different cam only have maybe 15 or 16, sometimes 12. So right off the bat, there is an adjustment that needs to be made. Additionally, although you can't see much, these things do wear out over time, and distributor inner workings can get worn as well.

For my new motor, I am going HIGH ENERGY, which the P2 definitely is not and MSD may be depending on which one you get. If you get a new billet distributor, beware the height and diameter does not match stock and there are often clearance issues.

If you are interested in the high energy solution I am using, see http://www.davessmallbodyheis.com/. I will not have any fitment issues. And, most importantly, any component that breaks will be available at my local auto parts store. Cannot say that for any billet distributor.

I agree with you. Once I get my baby running, I am washing and waxing and beer drinking.

Good luck.

 
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I used MSD, (pt no. 8477), with 6AL & Tach adaptor but beware the MSD billet distributors have clearance issues if you are running with Ram Air.

I took the trouble to double check & recheck before ordering including contacting MSD sales tech & they still got it wrong so had to butcher the stock air cleaner can to accomodate the Ram Air, fortunately its not something easily spotted if done carefully.

037-1.jpg


That said the rest of the install was a breeze, set up was straight forward thanks to plenty of help from the guys here, no problems so far & made a world of difference to the performance.

_MG_1790.jpg


HTH

 
Roger, did you get the dizzy/ignition module/coil in a kit, or buy them separately? This is the route I'm thinking about going. My current setup is all stock. And by all stock, I think everything (including the coil) are original to the engine. The coil is in horrible shape with what looks like discoloring and maybe even hairline fractures in the case!

I'm thinking of going with the 6477 distributor (Pro-billet Street), 6425 ignition module (6AL), and 8202 coil (Blaster 2).

 
I used MSD, (pt no. 8477), with 6AL & Tach adaptor
mmm...Tach adaptor.

I am assuming this item allows you to use your factory tach with the MSD.

What does that look like?

How is it wired in?

Can you provide a wiring diagram?

MSD billet distributors have clearance issues if you are running with Ram Air. I took the trouble to double check & recheck before ordering including contacting MSD sales tech & they still got it wrong
You think they never sold one of those distributor to a guy with a 71-73 Mustang with Ram Air.

Isn't that crap?

Don't you think, after 40 years, they would have a little note to the sales literature: DOES NOT FIT RAM AIR SYSTEMS WITHOUT MODIFICATIONS, and then detail the modifications.

Here is an interesting post on MSD:

http://www.msdignition.com/forum/showthread.php?t=14749

It says to expect to hear a HUMMING noise!!! lol

Please help us in understanding the workings of the tach adapter with a factory tach and how to properly wire it in.

 
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I used MSD, (pt no. 8477), with 6AL & Tach adaptor
mmm...Tach adaptor.

I am assuming this item allows you to use your factory tach with the MSD.

What does that look like?

How is it wired in?

Can you provide a wiring diagram?

MSD billet distributors have clearance issues if you are running with Ram Air. I took the trouble to double check & recheck before ordering including contacting MSD sales tech & they still got it wrong
You think they never sold one of those distributor to a guy with a 71-73 Mustang with Ram Air.

Isn't that crap?

Don't you think, after 40 years, they would have a little note to the sales literature: DOES NOT FIT RAM AIR SYSTEMS WITHOUT MODIFICATIONS, and then detail the modifications.

Here is an interesting post on MSD:

http://www.msdignition.com/forum/showthread.php?t=14749

It says to expect to hear a HUMMING noise!!! lol

Please help us in understanding the workings of the tach adapter with a factory tach and how to properly wire it in.
The tach adapter lets you run your stock tach in the car. Its just a little box that you wire up to your tach instead of running tach to the coil. Really easy to instal and i completely hid mine under the dash behind the tach. Hers a link to the wiring instructions.

http://static.summitracing.com/global/images/instructions/msd-8920_frm28572.pdf

And this is the dizzy im running http://www.summitracing.com/parts/MSD-8577/ Havent got to see if it will fit with ram air yet.

 
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I don't have a tach so it's not an issue for me.

I wonder how that would work with the Rocketman tach, or some other aftermarket deal? Hmm.
I believe that most new tachs are magnetic triggered and will work fine without the tach adapter. The older tachs read off of the points set up and thats why the adapter is needed with the new electronic dizzy.

 
I don't have a tach so it's not an issue for me.

I wonder how that would work with the Rocketman tach, or some other aftermarket deal? Hmm.
I believe that most new tachs are magnetic triggered and will work fine without the tach adapter. The older tachs read off of the points set up and thats why the adapter is needed with the new electronic dizzy.
Good info as always, thanks Chuck!

 
Ones as good as the other IMO but why not just put the Ford unit in it ? Just as trouble free and if you are ever 50 miles or more from home and something stops working you can buy any part for it at any parts store.

 
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