MSD box Instead of the CDI??
#16
RL Technical Advisor
Originally Posted by Charles Navarro
Steve, what do you think of Mallory's equivalents to the MSD boxes? Mallory does make an awesome unilite distributor for the type 1/4 / porsche 914 (can be fitted to a 12v 356/912) that is fully adjustable and I was wondering if their ignition boxes were up to par.
I've not used the latest boxes from Mallory so I really cannot say for sure. If I get a chance, I'll try one on the dyno, back-to-back with the MSD 6AL and see what happens.
I've had several Crane Hi6 failures so I've stuck with the MSD's that has worked very well for me
for many years.
#17
RL Technical Advisor
Hi Loren:
Thank you for your input, wisdom, & experience in this matter.
Everyone is entitled to their opinions and I'll defend your right to express yours.
Thank you for your input, wisdom, & experience in this matter.
Everyone is entitled to their opinions and I'll defend your right to express yours.
#18
"at opposite ends of the same issue..."
From what I read of this, Steve is presenting his actual experience. My understanding is that he has been doing this for a while and has a decent sample size. So I would call it more than anecdotal reports, but not a fully controlled statistical sample as in a scientific study. More like a clinical study I'd say.
Loren is presenting some likely effects based on a mechanistic analysis - i.e. theory (and that's in a positive sense, not a prejorative one).
IF this was science, we would want to pursue both approaches and ultimately rationalise them. Then we would have a clear understanding (tho I hasten to add we still have people in some areas of the US who don't accept the data and theory for evolution).
Another important issue is bais - whether conscious or not. Loren rebuilds the Bosch CD boxes, and so competes economically with MSD and others. He wold be well advised to disclose this and to alter his manner - it only does him harm. Nontheless he does have valuable information about electronic ignition systems.
Now, an example: #4 I think, is the idea that more complexity means less reliability. This is an empirical generalization. It is often true but not always true. Suppose for example, that components are in parallel - then additional componenets means more reliability not less. Even when true, this effect may well be swamped by other effects, hence unimportant. For example, the MSD is a newer design than the 35 year old Bosch boxes. Are newly intorduced type components used? If so, they may well be more reliable than the old ones.
All this points up the importance of getting real world data -- experiments or something close to it.
From what I read of this, Steve is presenting his actual experience. My understanding is that he has been doing this for a while and has a decent sample size. So I would call it more than anecdotal reports, but not a fully controlled statistical sample as in a scientific study. More like a clinical study I'd say.
Loren is presenting some likely effects based on a mechanistic analysis - i.e. theory (and that's in a positive sense, not a prejorative one).
IF this was science, we would want to pursue both approaches and ultimately rationalise them. Then we would have a clear understanding (tho I hasten to add we still have people in some areas of the US who don't accept the data and theory for evolution).
Another important issue is bais - whether conscious or not. Loren rebuilds the Bosch CD boxes, and so competes economically with MSD and others. He wold be well advised to disclose this and to alter his manner - it only does him harm. Nontheless he does have valuable information about electronic ignition systems.
Now, an example: #4 I think, is the idea that more complexity means less reliability. This is an empirical generalization. It is often true but not always true. Suppose for example, that components are in parallel - then additional componenets means more reliability not less. Even when true, this effect may well be swamped by other effects, hence unimportant. For example, the MSD is a newer design than the 35 year old Bosch boxes. Are newly intorduced type components used? If so, they may well be more reliable than the old ones.
All this points up the importance of getting real world data -- experiments or something close to it.
#19
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Originally Posted by randywebb
"at opposite ends of the same issue..."
All this points up the importance of getting real world data -- experiments or something close to it.
All this points up the importance of getting real world data -- experiments or something close to it.
and fwiw I've seen tons of various ignitions come and go in favor over the years.. except a factory installed unit or the MSD.. whatever.
and for Mallory fans.. I've found that they released a return style fuel pressure regulator. It replaces the MAL-4309, and MAL-4310. The replacement is MAL-4307M, 200gal flow, 4-25 psi, three 3/8 ports, + 1/8 ga port, multi-fuel, lists about $190, retails about $90, re-build kit 3178.
enjoy...
#20
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Isn't the MSD a CD unit with multiple spark? I believe their website states that. I think that after a certain RPM the spark is continiuous because of the speed of the ignition cycle.
I'm a Drag race guy. I have done a lot of American cars and bikes. My experience is that with MSD after the install the vehicles would pick up 4-6 hundredths of a sec with no other change. This conversion was on several cars that were very consistant. So I know that it did make a difference. In some cases it allowed slightly more jet in the carb and slightly less timing enabling further modest improvements.
My want is the rev limiting factor plus a better (I think) ignition. I lot of aftermarket components are better designed and perform better the OE.
Manufacturing is always cost first then weight. I'm sure that Porsche feels that their ignition is adequate, but is adequate good enough when you are pushing the limits of the combustion process by increasing comp ratio and cam overlap?
I'm a Drag race guy. I have done a lot of American cars and bikes. My experience is that with MSD after the install the vehicles would pick up 4-6 hundredths of a sec with no other change. This conversion was on several cars that were very consistant. So I know that it did make a difference. In some cases it allowed slightly more jet in the carb and slightly less timing enabling further modest improvements.
My want is the rev limiting factor plus a better (I think) ignition. I lot of aftermarket components are better designed and perform better the OE.
Manufacturing is always cost first then weight. I'm sure that Porsche feels that their ignition is adequate, but is adequate good enough when you are pushing the limits of the combustion process by increasing comp ratio and cam overlap?
#21
RL Technical Advisor
Originally Posted by randywebb
"at opposite ends of the same issue..."
From what I read of this, Steve is presenting his actual experience. My understanding is that he has been doing this for a while and has a decent sample size. So I would call it more than anecdotal reports, but not a fully controlled statistical sample as in a scientific study. More like a clinical study I'd say.
From what I read of this, Steve is presenting his actual experience. My understanding is that he has been doing this for a while and has a decent sample size. So I would call it more than anecdotal reports, but not a fully controlled statistical sample as in a scientific study. More like a clinical study I'd say.
I would tell you that everything I've learned on this subject comes from hundreds & hundreds of hours on an engine dyno.
In these cases, one tries things like different ignition settings, equipment, plugs, plug gaps, etc and the dyno records the results. No mixture or other induction parameters are altered so no other variables are different during the tests. One tries one thing at a time and the dyno's instrumentation and software records the results. The dyno runs are all automated so there are no operator-induced factors.
Our Superflow engine dyno has a resolution of 2 HP so thats as small a difference I can accurately see.
I do not generally publish detailed dyno reports due to the competitive nature of our industry and these represent a VERY significant investment in time and capital.
All I can do is offer the general findings of many years of R&D and hopefully, someone reading this will find something useful.
#23
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Steve, or others. Not getting into the msd vs bosch discussion is their any real benifit in going to the electromotive crank set-up. My 69 911 has a 2.7 in it with 40 ida webers. This winter it gets a new backdated exhaust and a new ignition. The exhaust seems like an easy choice but ignition systems seem to run the gamut depending on who you talk to
Thanks
Thanks
#24
Check out Steve's web page - re plug gaps and power gains from that.
BTW, it looks like a guy on Pelican is just about to start making a cheap way to get 12 wire dist. caps.
BTW, it looks like a guy on Pelican is just about to start making a cheap way to get 12 wire dist. caps.
#25
RL Technical Advisor
Bryan:
My best advice to you regarding ignitions for your carbureted 2.7 would be to run it with the OEM Bosch CD ignition and then try the MSD-6AL (and matching coil).
LOL,...In this fashion, you'll soon see the differences for yourself without having to decide who knows what they are talking about on this particular subject.
My best advice to you regarding ignitions for your carbureted 2.7 would be to run it with the OEM Bosch CD ignition and then try the MSD-6AL (and matching coil).
LOL,...In this fashion, you'll soon see the differences for yourself without having to decide who knows what they are talking about on this particular subject.
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for entertainment purposes I bought 3 sets of NGK BPR 9 ES.
As soon as I do the Mallory install, ordered today, a set will be installed. I've been running 8 ES for a couple of thou and ithey're squeaky clean so I'm gonna push the limit on the coldest R NGK pulg that's street doable.. for some strange reason I think it may be doable this winter. Temps are starting to drop below 40deg.
btw.. I'm rich at 60 idles @ 2 1/2 turns & a modified rich acceleration circuit.
... cheap thrills
As soon as I do the Mallory install, ordered today, a set will be installed. I've been running 8 ES for a couple of thou and ithey're squeaky clean so I'm gonna push the limit on the coldest R NGK pulg that's street doable.. for some strange reason I think it may be doable this winter. Temps are starting to drop below 40deg.
btw.. I'm rich at 60 idles @ 2 1/2 turns & a modified rich acceleration circuit.
... cheap thrills
#29
I've been running an MSD 6AL with its matching MSD coil for several years now, and am very happy with them. My MSD unit has been totally reliable; as Steve pointed out, properly installing it is vital.
This debate has been conducted a number of times over at Pelican, with Loren always holding out as the flat-earther of the board (as he also does with ECU chips). The simple reality is that Steve has decades of real-world experience tuning 911's, and knows firsthand what works and what doesn't. He has no financial stake whatsoever in MSD, and would not recommend the product unless it was a genuine improvement over the stock component.
This debate has been conducted a number of times over at Pelican, with Loren always holding out as the flat-earther of the board (as he also does with ECU chips). The simple reality is that Steve has decades of real-world experience tuning 911's, and knows firsthand what works and what doesn't. He has no financial stake whatsoever in MSD, and would not recommend the product unless it was a genuine improvement over the stock component.
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Well the real reason for me changing is that my whole ignition needs replacing as far as I am cincerned. Todays technology is probaly better in 99% of all things made, thus I figure that the MSD unit must be better tham a system almost thirty years old. I know the first response will be from someone who will say that I took off a more modern CIS and put on webers but I am old school and just plain love carbs. For what they cost I could of easily upgraded to a different injection system.My thinking is that I will go with the MSD unit. I am also planning a camshaft swap so I really won't have a great indication of the ignition gain if any