MSD's and such, When to use them, and why? |
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MSD's and such, When to use them, and why? |
Razorbobsr |
Aug 4 2011, 07:20 AM
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#1
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Member Group: Members Posts: 282 Joined: 6-June 10 From: Terre Haute Ind Member No.: 11,813 Region Association: Upper MidWest |
I have a HP 2L carb 44 IDF 914 that runs great above 3K, Porsche mach of some 30 yrs says I have a very solid rebuilt engine with a hotter then stock cam, the exhaust sys in too big past the collecter but header is a damn fine unit. He also says the exhaust sys has nearly no back pressure and wants to size it down from 2inch to 1 5/8 or 1 3/4, and I need to dump the TOO damn loud cherry bomb muffler. The porsche guy builds racing engines for the local Indy market, has his own dyno and flow bench, grinds his own cams, and seems to know his stuff as he only works on Porsche's. After talking to him yesterday, he thinks I also need a hotter/better eng sys, like a MSD, rather then stock 009 sys. Gents........... Your thoughts??? Questions?? Bob
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J P Stein |
Aug 4 2011, 08:17 AM
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#2
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Irrelevant old fart Group: Members Posts: 8,797 Joined: 30-December 02 From: Vancouver, WA Member No.: 45 Region Association: None |
I could bore you to tears with the why/fors of using an MSD *set-up* but will just generalize.
Carbs need to run rich to force a flat Porsche engine to run properly. Throw in a hotter cam & it gets worse....particularly on the idle circuit(below 3500ish rpm) With the proper MSD (or its ilk) set-up.....which includes a hot coil, fat wires, and wide gapped plugs.....will "burn throgh" this rich mixture. The distributor is your problem. I would recomend talking to Mr. Raby for his recommendtion (I doubt that is a 009) cause I don't know shit about T-4s. |
carr914 |
Aug 4 2011, 08:47 AM
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#3
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Racer from Birth Group: Members Posts: 118,721 Joined: 2-February 04 From: Tampa,FL Member No.: 1,623 Region Association: South East States |
On my past 4 cyl cars, I used the MSD Igntion, MSD Coil & MSB Billit Dizzy. It worked well as a system and eliminated all the flat spots
T.C. |
Razorbobsr |
Aug 4 2011, 08:49 AM
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#4
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Member Group: Members Posts: 282 Joined: 6-June 10 From: Terre Haute Ind Member No.: 11,813 Region Association: Upper MidWest |
I could bore you to tears with the why/fors of using an MSD *set-up* but will just generalize. Carbs need to run rich to force a flat Porsche engine to run properly. Throw in a hotter cam & it gets worse....particularly on the idle circuit(below 3500ish rpm) With the proper MSD (or its ilk) set-up.....which includes a hot coil, fat wires, and wide gapped plugs.....will "burn throgh" this rich mixture. The distributor is your problem. I would recomend talking to Mr. Raby for his recommendtion (I doubt that is a 009) cause I don't know shit about T-4s. Why do you doubt its a 009?? Bob |
Razorbobsr |
Aug 4 2011, 08:50 AM
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#5
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Member Group: Members Posts: 282 Joined: 6-June 10 From: Terre Haute Ind Member No.: 11,813 Region Association: Upper MidWest |
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J P Stein |
Aug 4 2011, 09:04 AM
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#6
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Irrelevant old fart Group: Members Posts: 8,797 Joined: 30-December 02 From: Vancouver, WA Member No.: 45 Region Association: None |
On my past 4 cyl cars, I used the MSD Igntion, MSD Coil & MSB Billit Dizzy. It worked well as a system and eliminated all the flat spots T.C. That would require the long version. OK another short one. Crack open your carb's butterflies & look down one hole. That 6ish inches you see above the intake valve is all a carb gets to make the mixture correct for that hole throughout the whole rev range. Carbs can't do it. A big, hot, multi spark compensates. Re Raby: I read his stuff |
kevin311 |
Aug 4 2011, 09:49 AM
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#7
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Member Group: Members Posts: 105 Joined: 22-May 10 From: Tampa Bay Area Member No.: 11,752 Region Association: None |
Whatever you end up doing ignition wise just make sure that 009 is properly installed in the nearest garbage recepticle when your done so no other poor soul ends up with it. (IMG:style_emoticons/default/biggrin.gif)
People with more knowledge than me will let you know your options. Kevin |
rick 918-S |
Aug 4 2011, 10:46 AM
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#8
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Hey nice rack! -Celette Group: Members Posts: 20,463 Joined: 30-December 02 From: Now in Superior WI Member No.: 43 Region Association: Northstar Region |
Multiple discharge Spark units aid in firing a wet or large droplet fuel charge at low to mid RPM range. Not needed in alot of applications when good fuel atomization is part of the equation and spark charge is hot and fat. But Carbs tend to be hard to balance across the range. Often they end up fat with fuel in the low to mid range with hi lift short duration carb cams. This is fine if you can keep the plugs firing until you get the engine up in the balance zone. That's where MSD plays a roll. I think... (IMG:style_emoticons/default/unsure.gif)
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Ductech |
Aug 4 2011, 12:19 PM
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#9
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Member Group: Members Posts: 356 Joined: 16-July 10 From: AridZona Member No.: 11,949 Region Association: Southwest Region |
From my knowledge i gained watching a friend fuck around with an msd on an old subaru motor and countless ford v8's.... MSd Cap discharge igniton MOstly will just fire the shit out of your plugs. It should if i remember, increase the sparking duration and increase the strength of the spark.... It will also eat up most stock distrubtor caps and rotors quicker than stock ignition setup. Although for your issues your trying to relieve it might just be the thing you need. I would take someone else's advice and ditch the 009 and get a mallory or msd distrubtor, whoever makes one that fits.
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HAM Inc |
Aug 4 2011, 01:51 PM
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#10
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Senior Member Group: Members Posts: 846 Joined: 24-July 06 From: Watkinsville,GA Member No.: 6,499 Region Association: None |
On our 1.8 F-Prod engine we ran with a MSD 6-AL and also tried the comparable Mallory with our mallory dist. After we fell out of a race at Barber (while leading) when the mallory box crapped out I rigged up a back-up ignition system that used just a coil and no MSD box. We could switch it on the fly so next time the box crapped out (as they are prone to do from time to time in race cars) we could at least keep racing.
When Jake and I dynoed the car the first time with the two systems in place (which included the new 6-AL) we switched on the fly and the MSD box showed 0% more torque from 5000-8000rpms. That's Zero torque increase. The two graphs lay right over each other. And this was on his chassis dyno that has repeatability within 1%. We were so surprised by this that we did multiple runs and tried different timing for the two systems and the results were the same. I removed the box and sold it. Less crap to fail and less wt to carry. At the '05 runoffs the Finch FP car (winner that year) had a 009 with tiger-stripe points! Jake and I saw it with our own eyes. I'm not saying the msd boxes don't have their place, but our testing on our 4cyl race car at our revs (with 12.7:1CR) showed it was no help at all. That's my .02 worth. |
rick 918-S |
Aug 4 2011, 02:25 PM
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#11
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Hey nice rack! -Celette Group: Members Posts: 20,463 Joined: 30-December 02 From: Now in Superior WI Member No.: 43 Region Association: Northstar Region |
On our 1.8 F-Prod engine we ran with a MSD 6-AL and also tried the comparable Mallory with our mallory dist. After we fell out of a race at Barber (while leading) when the mallory box crapped out I rigged up a back-up ignition system that used just a coil and no MSD box. We could switch it on the fly so next time the box crapped out (as they are prone to do from time to time in race cars) we could at least keep racing. When Jake and I dynoed the car the first time with the two systems in place (which included the new 6-AL) we switched on the fly and the MSD box showed 0% more torque from 5000-8000rpms. That's Zero torque increase. The two graphs lay right over each other. And this was on his chassis dyno that has repeatability within 1%. We were so surprised by this that we did multiple runs and tried different timing for the two systems and the results were the same. I removed the box and sold it. Less crap to fail and less wt to carry. At the '05 runoffs the Finch FP car (winner that year) had a 009 with tiger-stripe points! Jake and I saw it with our own eyes. I'm not saying the msd boxes don't have their place, but our testing on our 4cyl race car at our revs (with 12.7:1CR) showed it was no help at all. That's my .02 worth. That makes perfect sense. The MSD is only effective and functioning at low and mid RPM's. I think you guys were looking for something measure-able in a controlled environment that simply isn't there. It's not a HP enhancer like NOS or water injection. On a race engine that is well tuned and not idling through traffic or running long distances at say 15-1800 RPM's around town, the plugs will not have a fouling effect or cylinder loading. Drag cars benefit the most from the use of an MSD as they go from staging with huge amounts of raw fuel being dumped into the cylinders to WOT and the need for instant precision cylinder work. On a track car the only benifit would be to keep the plugs clean while idling around some off track excursion that the saftey crew is cleaning up. The noticable gain will be experienced when you dash for the first turn at green flag time. |
J P Stein |
Aug 4 2011, 02:34 PM
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#12
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Irrelevant old fart Group: Members Posts: 8,797 Joined: 30-December 02 From: Vancouver, WA Member No.: 45 Region Association: None |
+1
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Razorbobsr |
Aug 5 2011, 05:37 AM
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#13
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Member Group: Members Posts: 282 Joined: 6-June 10 From: Terre Haute Ind Member No.: 11,813 Region Association: Upper MidWest |
On my past 4 cyl cars, I used the MSD Igntion, MSD Coil & MSB Billit Dizzy. It worked well as a system and eliminated all the flat spots T.C. That would require the long version. OK another short one. Crack open your carb's butterflies & look down one hole. That 6ish inches you see above the intake valve is all a carb gets to make the mixture correct for that hole throughout the whole rev range. Carbs can't do it. A big, hot, multi spark compensates. Re Raby: I read his stuff |
Razorbobsr |
Aug 5 2011, 05:41 AM
Post
#14
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Member Group: Members Posts: 282 Joined: 6-June 10 From: Terre Haute Ind Member No.: 11,813 Region Association: Upper MidWest |
Multiple discharge Spark units aid in firing a wet or large droplet fuel charge at low to mid RPM range. Not needed in alot of applications when good fuel atomization is part of the equation and spark charge is hot and fat. But Carbs tend to be hard to balance across the range. Often they end up fat with fuel in the low to mid range with hi lift short duration carb cams. This is fine if you can keep the plugs firing until you get the engine up in the balance zone. That's where MSD plays a roll. I think... (IMG:style_emoticons/default/unsure.gif) Thats part of our prob, fat mix at one rpm level[low] lean at higher. This guy knows more than most and I dont think kes that keen on spending MY money foolishly. Bob |
Razorbobsr |
Aug 5 2011, 05:51 AM
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#15
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Member Group: Members Posts: 282 Joined: 6-June 10 From: Terre Haute Ind Member No.: 11,813 Region Association: Upper MidWest |
On our 1.8 F-Prod engine we ran with a MSD 6-AL and also tried the comparable Mallory with our mallory dist. After we fell out of a race at Barber (while leading) when the mallory box crapped out I rigged up a back-up ignition system that used just a coil and no MSD box. We could switch it on the fly so next time the box crapped out (as they are prone to do from time to time in race cars) we could at least keep racing. When Jake and I dynoed the car the first time with the two systems in place (which included the new 6-AL) we switched on the fly and the MSD box showed 0% more torque from 5000-8000rpms. That's Zero torque increase. The two graphs lay right over each other. And this was on his chassis dyno that has repeatability within 1%. We were so surprised by this that we did multiple runs and tried different timing for the two systems and the results were the same. I removed the box and sold it. Less crap to fail and less wt to carry. At the '05 runoffs the Finch FP car (winner that year) had a 009 with tiger-stripe points! Jake and I saw it with our own eyes. Not looking for more HP, just want spark that will better allow us to set up carbs across the driving range, and not foul plugs. Bob I'm not saying the msd boxes don't have their place, but our testing on our 4cyl race car at our revs (with 12.7:1CR) showed it was no help at all. That's my .02 worth. |
carr914 |
Aug 5 2011, 06:36 AM
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#16
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Racer from Birth Group: Members Posts: 118,721 Joined: 2-February 04 From: Tampa,FL Member No.: 1,623 Region Association: South East States |
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Jake Raby |
Aug 5 2011, 06:55 AM
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#17
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
We stopped selling ignition components 3-4 years ago retail. We of course still install them on turnkey engines. Selling ignition components retail is like asking for customer relations nightmares.
Capacitive Discharge Ignitions have a place with these engines, however until you reach 12:1 CR the benefits are not as great. With CR in the 13-14 range I have had to use them, because with CR increases the load on the ignition system also greatly increases. A CDI system will allow more spark plug gap to be ran and will generally equate to smother performance at lower RPM. Note that "MSD" only allows for multiple spark discharge at below 3K RPM. Typically a quality CDI unit will give 4HP and 6 lb/ft of torque in a 150HP 2270cc Engine. When applied to my 175HP 2270cc Performer we can see up to double those figures across the board. The higher the CR and better the chamber filling the more benefit you will see from more intense ignition. |
Jake Raby |
Aug 5 2011, 06:55 AM
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#18
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
We stopped selling ignition components 3-4 years ago retail. We of course still install them on turnkey engines. Selling ignition components retail is like asking for customer relations nightmares.
Capacitive Discharge Ignitions have a place with these engines, however until you reach 12:1 CR the benefits are not as great. With CR in the 13-14 range I have had to use them, because with CR increases the load on the ignition system also greatly increases. A CDI system will allow more spark plug gap to be ran and will generally equate to smother performance at lower RPM. Note that "MSD" only allows for multiple spark discharge at below 3K RPM. Typically a quality CDI unit will give 4HP and 6 lb/ft of torque in a 150HP 2270cc Engine. When applied to my 175HP 2270cc Performer we can see up to double those figures across the board. The higher the CR and better the chamber filling the more benefit you will see from more intense ignition. |
yeahmag |
Aug 5 2011, 11:43 AM
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#19
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Advanced Member Group: Members Posts: 2,422 Joined: 18-April 05 From: Pasadena, CA Member No.: 3,946 Region Association: Southern California |
The biggest reason I run them is for the soft rev limiter function...
That being said you will never foul a plug and a carb'ed car starts much easier. I run the Mallory 6AL so I can just dial in the rev limit without having to buy pills (like the MSD) and I've never had one fail. |
Razorbobsr |
Aug 5 2011, 12:31 PM
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#20
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Member Group: Members Posts: 282 Joined: 6-June 10 From: Terre Haute Ind Member No.: 11,813 Region Association: Upper MidWest |
The biggest reason I run them is for the soft rev limiter function... That being said you will never foul a plug and a carb'ed car starts much easier. I run the Mallory 6AL so I can just dial in the rev limit without having to buy pills (like the MSD) and I've never had one fail. Plug fouling has been another prob, keep the revs above 3 k and NP, below that and plugs start to fouling around town. Bob |
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