I'm contemplating changing to a msd setup due to the cam I installed at rebuild and would like suggestions on doing this. I still want to retain the stock look including the original braided wires and chrome dist cover.
the overall concensus is the cam is pulling too much fuel and there is just not enough spark in the system to burn the fuel. Does this sound right??
I assume my guys know what they are doing since they build engines and race in NHRA..
I think I am between a rock and a hard place wanting performance with a stock look and using guys that excede 250 MPH as a living... HELP :confused: :confused: :confused:
where would you suggest hiding the MSD box?? and btw the cam I used was the crane cam h-296-2 which I have have found out is pretty stout...


[Modified by 71DropTop, 11:51 AM 2/10/2003]

 

I am using a Crane HI6 which is very similar to the MSD unit. The Crane has rotary dials for the rev limiter where the MSD has to use pills. One advantage of the Crane. I am using the stock distributor that has been recurved. I am using a set of heavy duty points to trigger the box. Mine works very well to 7000+ rpm without a miss. It does run better with this ignition vs the original. I have my box hid behind the map pocket dash pad. A lot have had problems due to heat here but mine has been there for 4 years and is still going strong. I don't have the shielding anymore but that was my doing. It would probably fit fine this way.

 

i just installed an msd 6al.works great.here is where i put it.

 

I just decided to eliminate my problems by going back to the stock cam(or near Stock) 6 mos of BS problems with vac,carb,fuel and bad advice have taken their toll :mad :mad :mad BTW this forum is the only place to get good advice :rant:

 

Their logic is... not logical, but the MSD box will improve performance over a stock ignition system.

Insulate the box from heat and electrical noise.

 

Post your full specs (engine, tranny, axle) and I can recommend you a cam that will give you more power & torque than stock and still drive like a stocker without the low-vacuum BS.

 

NO NO NO!!! Not the stock cam. :iagree: If you don't like the cam it was probably just a mis application. There are a lot of great cams that are way better than stock. Just do a mild upgrade and you will be rewarded with much better performance. The stock cams are old technology .Teh newer ones have much better ramps and usualy higher lift for more power. They are designed to build cylinder pressure and this is what builds torque.

 

Thanks guys for the support and good advise I will try an msd system before a cam Thanks

 

I haven't read the responses yet by others but I really wonder about the guys who are giving you advice. Your cam is putting out too much fuel?. I questions this. I run 2 850 double pumpers and 8-71 blower and this combination still doesn't put out too much fuel for a normal ignition to fire. The carb or your mechanic is at fault. ?Any mixture runnning this rich will wash the cylinder walls plus be way down on power.
Now about the MSD. I have 4 of them in my car. The main MSD-6AL, a timing computer to control the spark curve since my distributor is locked down with no advance, an adjustable timing computer for setting maximum timming while driving down the highway and lastly a boost retart system for the blower. All 4 are tied together and have given me years of service. The rev limiter in the MSD-6AL is very important to me since I regularly bounce off the limit.
A properly set up carb will allow you to run normal plugs and the cam does not dump extra fuel in the motor.

 

I like my MSD system. I have never had any problems with it. I went with the 6AL box and a 8572 Tach drive distributor. The distributor is great....very configurable with no hassles at all changing the mechanical stop and the springs. I mounted my box on the right hand wheel well behind the expansion tank.


One suggestion, to avoid any electrical problems with the box, run a 10 gauge or bigger wires from your batteries + and - terminals to power the box. I have heard that people who wire it to a 12v source other than directly to the battery had problems. The 6AL box is susceptible to voltage variations.
John


[Modified by theandies, 11:09 AM 2/11/2003]

 

It is recomended that you use a noise filter with an MSD box. Not only to clean up your radio reception but most importantly to protect your MSD from voltage spikes and other irregularities in the voltage, especially jump starting. MSD make a nice unit for about $29.95 (MSD-8830)

 

Another plus for MSD, if you have problems with the box you mail it to them, they go through it and test it for a minimal fee compared to replacing the box. Just experienced this myself (found out about it here from you guys). They even sent it back with an instruction manual (wiring diagrams).

 

I am using the distributer and the 6A box. The only problem I have had is that the mechanical advance on the distributer seized up. That was the day I tore my motor apart and decided on the 383/TKO...er thats another story.

Anyways, I sent it to MSD and they sent me a new one for $75. No explanation about what happened.

Chris

 

How about the Ignition shielding cover for the BB can I still use it :confused:

 

I have said it before and I"ll say it again...the only ignition upgrade worth messing with is the HEI conversion....of course that means change the tach for electronic, unless you spend lots of money....

another thing is MSD does absolutely NOTHING unless you run a rich carb....
then at idle it will help fire off the rich mixture....but at 3k there is no time for extra sparks...and so i'ts just like an HEI....

NOw at higher RPM's yes it can help, IF you want to stay with your basic point dist. body and install some new sending unit....


GENE

 

MSD only uses multi-spark up to a certian RPM (can't remember exactly, I think it is 2500 and the only reason it does this is the multi spark electronics cannot spark the plug to keep up with the high RPM's but multi-spark give you great low RPM throttle reponse) then it like a conventional HEI setup as far as spark is concerned. Rev control is cool too with the 6AL box. The way this works is that the box cuts off spart to 1 cylinder at a time.........example: when you reach the rev of the pill installed say 5800 RPM then the box will not fire #1, the next revolution it will fire #1 to clear out unburnt fuel but won't fire #8 the next cylinder in the fireing order, it continues droping out 1 cylinder at a time untill the revs go down below the rev control limit.....very slick. Like I said before I like my MSD system and am glad I spent the money.
John

 

John, here's something I read over on the NCRS tech board regarding the reason that an MSD ignition generates multiple sparks at lower RPM's. I'm just the messenger here, but I do trust this fellow's technical expertise.

The MSD is a capcitor discharge system and the TI is inductive. CD systems feature a very intense short duration spark, which is good for igniting the rich, dense mixtures that exist at WOT. This is best for a race engine, but street engines have different requirements.

At idle and low speed, mixture density is low (relative to WOT), and it is diluted with exhaust gas, especially on SHP engines. Such mixtures need a long duration spark since they have poorer ignitability than rich, dense mixtures typical of WOT. The spark duration for a TI is about 180 microseconds compared to about 30 microseconds for a typical CD system. MSD gets around this by generating up to three successive sparks at low engine speed, but, of course, only the first spark is timed properly. The addition sparks are retarded due to the time required to recharge the capacitor.

If you have a TI, my recommendation would be to retain it, and you can increase its reliability by having the modern electronic package installed in the external amplifier.

Like most aftermarket "hot rod" parts, MSD igntions are hyped with a lot of advertising and "word of mouth" testimonials from users who have little real understanding of combustion including the ignition requirements for the different mixture characteristics that exist in an operating engine.

GM doesn't spend advertising dollars on 35 year old parts, but in many cases, they are better than "modern" hot rod parts.

If I see one more MSD box on the cowl of a Chevelle at a car show, I'll probably puke.

BTW, the HEI is basically the same design as the TI but features some additional circuitry that adds variable dwell, and it is all packaged in a thick film hybrid cicuit small enough to be packaged in a module (rather than discete parts in an external housing) that will fit in the larger HEI distributor housing. It is completely self contained and only requires a 12 volt power source. HEI replacement parts are readily available and inexpensive, and this along with the HEIs excellent inductive operating characterisitcs make it an ideal ignition system for a street high performance engine.

If the HEI pickup coil wave form is the same as the TI pickup coil wave form an HEI module could easily be substitued for the TI amplifier. The early HEI modules have four pins - two are for the pickup coil input, one is the coil wire and the fourth is 12v power. All you have to do is figure out a dry place to hide the HEI module (I think it's too big to fit in the TI amplifier housing). The wiring harness would have to be modified and the other wild card is the coil as the HEI module might generated more current that the TI coil can handle.

 

Now that we have all MSD issues cleared up and everything arrived yesterday . Who wants to come over and help install.... any takers :D :D :D :D :D

 

Send me a plane ticket and I am there :yesnod: :yesnod:
John

 

I installed MSD system 5 or 6 years ago, on my 427. Used 6200 box & Pro Billet tach drive distributer with vac advance.....very nice , set up, my big/block "used" to crank 5/8 seconds before starting & ran rouugh for a while whle warming up :crazy: after MSD set up starts instantly & runs smooooooooth :steering: very satisfied. has very easy adj advance set up , have not had to touch ignition system since MSD installation. :auto: Worked for me :seeya note, My Vette is a 66, put box behind battery , in pass wheel well area............ :seeya :auto:


[Modified by StrayDog, 9:09 AM 2/15/2003]