Engines with Magnetos

[Diederick/DVK]

glad you mention it jimma!
but when running a mag you do need an electric fuel pump. (hint!) 

[Sarge]

glad you mention it jimma!
but when running a mag you do need an electric fuel pump. (hint!) 

sez who?

[Diederick/DVK]

wow! i figured you'd NEED the clamp on a mag.
cool cap too!!

[Fastbrit]

Maybe you should reconsider now that you've got all that book money burning a hole in your pocket.....  

I wish!

[Jim Ratto]

Hey Jim, what´s the theory behind "priming" the system like that? Did you use a separate switch that you flip while running the starter?

Yeah I am still a little confused as to why you it won't want to start after it has been "switched on" 

is it just the shear amount of charge build up 

Hi Lee, if you watch an old Laurel and Hardy movie etc... watch how people got their arms ripped off when trying to hand crank an old car without backing the ignition advance up. That's why all those old timer cars had those levers on the steering wheel. At cranking rpms, a motor doesn't want to light off with 30 degrees advance. In fact, you're trying to turn the crank backwards... that's why the starter "complains". At 7-12 degrees, a good starter/battery isn't going to protest.
I run my car @ 28 degrees locked. When I ran the Vertex in my car for those weeks, we ran it @ 36. Two different motors accepted two different advance amounts (cam overlap, CR, etc....). My current motor fires best if I crank starter and get motor moving, then ignite the MSD. The same thing would happen with ground switch on a mag (locked). When my motor is cold, the little Autostick starter struggles if I try to fire car up with MSD on before I crank, especially if I squeeze the throttle. When engine is warm, no problem, it will start like a normal car. But when it's cold, this is the process:

click on fuel pump/MSD for a few seconds to fill bowls (MSD and fuel pump are on same switch)
turn fuel pump/MSD off
crank engine 4-5 cranks
turn on fuel pump/MSD
open throttle slightly
engine fires, blip throttle lightly to clear
let it warm up for a few moments

off we go

[Diederick/DVK]

thanks for clarifying jim, no i can really see the process!

[wolfswest]

nice one, now I understand it too but still I need more input how other guys their engines' reaction was on this ignition instead of a 009 or something like that...

[lawrence]

Kinda off topic: I do not have a mag, but I recently locked out my mallory unilite at 28 degrees and the car actually started EASIER that my previous setting of 10 degrees initial and 30 total advance. I do not have a seperate switch for the ignition box. Its on when the car cranks over. With that being said the seat of pants meter tells me the car accelerates softer when the advance is locked, but it idles and cruises along much nicer. Like a stocker. No IDAs on/off nonsense. Just my findings.

Does cam duration and compression ratio play a factor in the locked mag thing?

[Jim Ratto]

Kinda off topic: I do not have a mag, but I recently locked out my mallory unilite at 28 degrees and the car actually started EASIER that my previous setting of 10 degrees initial and 30 total advance. I do not have a seperate switch for the ignition box. Its on when the car cranks over. With that being said the seat of pants meter tells me the car accelerates softer when the advance is locked, but it idles and cruises along much nicer. Like a stocker. No IDAs on/off nonsense. Just my findings.

Does cam duration and compression ratio play a factor in the locked mag thing?

Big time. High static CR and low duration would make it harder to get it to fire
Low CR and big drag cam would make it easier.
At least on paper. Now you have to figure real world factors too, like how well the carbs are set, plugs, plug gap, fuel quality, condition of motor.

Just adjusting your valves tight (too tight) will allow the starter to whirr away like you've got no plugs in the thing.
Want to piss somebody off, like an ex girlfriend with an air cooled VW that you built a bitchin motor for and then turns out to be a real bitch... ? Climb under her car when she's asleep and tighten their valves up, nice and snug...  hahah try and get to work tomorrow NOW, in your squareback... 
Or you could just simply take the pushrods out of the motor. that works well too.
Sorry.... got off topic...

[Jim Ratto]

 If my 'new' car didn't already have an MSD and two-step etc, I'd run a mag in a heartbeat.

Maybe you should reconsider now that you've got all that book money burning a hole in your pocket.....  

I'd like to know how guys were able to get away with stock fuel pipe and pump and so on with these 11 sec cars.

As SOON as I put 48's on my car, the carbs starved at high rpm/load, even with raising float levels and going 3.00 needles. I lost a crucial street race against "schteev" in front of all my friends, a real blow to the ego. It took a Holley pump and regulator and AN-6 hose all the way back to allow me to keep my foot in it.

How you guys get away with it?

[Sarge]

 If my 'new' car didn't already have an MSD and two-step etc, I'd run a mag in a heartbeat.

Maybe you should reconsider now that you've got all that book money burning a hole in your pocket.....  

I'd like to know how guys were able to get away with stock fuel pipe and pump and so on with these 11 sec cars.

As SOON as I put 48's on my car, the carbs starved at high rpm/load, even with raising float levels and going 3.00 needles. I lost a crucial street race against "schteev" in front of all my friends, a real blow to the ego. It took a Holley pump and regulator and AN-6 hose all the way back to allow me to keep my foot in it.

How you guys get away with it?

I'm wondering if your tank vent might be plugged or crimped.  Of course there's the pick-up screen in the tank, but I'd bet you've looked at that.  As for how we did it, back then there were very few choices so we made due with what we had.  The only guy I knew in DKP with an electric fuel pump was Greg Aronson and all but Ron Fleming ran 010 or 009 distributors.

[2manytoys]

I love the magneto. I run an MSD (Mysterious Spark Disapperance per Lanny) in the DRKC ghia, but for HOT spark the Mag is the way to go.



I have one or two motors with Mags, always will.

[stealth67vw]

Just adjusting your valves tight (too tight) will allow the starter to whirr away like you've got no plugs in the thing.
Want to piss somebody off, like an ex girlfriend with an air cooled VW that you built a bitchin motor for and then turns out to be a real bitch... ? Climb under her car when she's asleep and tighten their valves up, nice and snug...  hahah try and get to work tomorrow NOW, in your squareback... 
Or you could just simply take the pushrods out of the motor. that works well too.
Sorry.... got off topic...

Remind me to never piss you off. 

[wolfswest]

Okay, I searched the net for some magneto / vertex / scintilla options...

I suppose you are nothing with a scintilla unless you prep (send them to joe hunt or another iginition wizard dude) them for your hi-po engine?

what about a vertex with vw/audi logo on it?

+ When do you need to lock it out or when do you need an advance curve and which advance curve?

I don't care if my car starts worse I just want to go faster...    but I like to keep a smooth driving engine, not a no hp @ low rpm drag engine...  Hope you guys understand me...

[Fastbrit]

OK, I first used a magneto on the recommendation of Dave Kawell when I built my first turbo engine back in 1989. The mag was locked out and the advance set at 24° BTDC - the standard timing for a turbo engine at the time. The engine always fired right up and never suffered any misfires. The only reason I eventually changed to an MSD 7-AL system was for its versatility and the fact that, with a crank-trigger system, there was absolutely no 'scatter' when setting the advance with a timing light. There is always some scatter when using a mag or distributor/points, which is not a real problem on a regular motor, but you want perfect timing on a high-boost turbo motor running a shot of laughing gas..

On my street engines, I largely ran a magneto for the mojo, as Darrell Vittone so neatly described it. But, the engines always fired up, never suffered a misfire and the mag looked way cooler than any MSD ever could. Two of the mags I used were former military industrial motor ones, with an advance curve originally set to suit a low rpm, low load motor running at constant speed for hours on end. These are the type that most commonly show up at swap meets. They will work on a hi-po street engine but the advance curve isn't really that great – you might as well have it locked out as the advance is usually all in by about 900rpm! The other problem is that the internal coils break down with time and a former NATO military magneto which has been sat in a bunker somewhere for 40 years will usually work but, when it gets hot, the engine won't restart until the mag has cooled right down. They are often fitted with a rev-limiting rotor arm, too, set at about 2500rpm...

I had my magnetos rebuilt by Bill Morris here in the UK, but I'm not sure he is still around. He was mainly a motorcycle guy but very knowledgeable on all things Vertex. I used to send him the mag, along with an old Bosch 010, and ask him to reset the mag advance to match that of the distributor. It worked for me.

I used the mags in the Chop-top and Flashback with a pair of AutoMeter Pro-Controls, one set as a rev limiter, the other to control a shift-light.

The best I can say is that a magneto will give you a fat spark when you most need it: at high rpm under load. And because it is totally independent of the car's electrical system, you don't need to worry about a failing battery. MSDs hate low battery voltage... This is an important thing to remember when your car runs two big fuel pumps, a nitrous system and the ignition system, all off a single battery. The situation is made even worse if your race car doesn't have a charging system.

Running a locked-out mag on the street shouldn't be a major problem unless you floor the throttle at very low rpm – then your motor will 'ping' like a samba band. Most distributors are 'all in' by 1800rpm, or so, meaning that once the engine's above that rpm, it won't know if you have a locked mag or not. That's assuming you have a mechanical-advance distributor (009, 010 etc) – a vacuum-advance distributor is a whole different ball game...

[jick]

great info keith,

Bill morris has retired now but he recommends a guy called Tom Dark, who's near oxford.

he's going through my magneto at the moment, he does a lot of drag race/street VW mags, including all the ones that Ian clark has used.

[wolfswest]

Keith, very nice!   I'm getting to know my way in the dark woods called: magnetos.  thx!!

Dem

[wolfswest]

great info keith,

Bill morris has retired now but he recommends a guy called Tom Dark, who's near oxford.

he's going through my magneto at the moment, he does a lot of drag race/street VW mags, including all the ones that Ian clark has used.

Can you provide me the contact information for tom dark please?

Dem

[louisb]

Keith,

So for a NA street engine do you recommend an 010 advance curve over locking out the mag?

Thanks,

--louis

[Fastbrit]

That would by my preference. 

[wolfswest]

Keith,

So for a NA street engine do you recommend an 010 advance curve over locking out the mag?

Thanks,

--louis

is there a big difference in a 010 and a 009 ?  Technically, besides the good looks...?

[RedEx]

Two pictures of two engine combos out of 4 (all with magneto) on the Muppet Racer.

[jick]

great info keith,

Bill morris has retired now but he recommends a guy called Tom Dark, who's near oxford.

he's going through my magneto at the moment, he does a lot of drag race/street VW mags, including all the ones that Ian clark has used.

Can you provide me the contact information for tom dark please?

Dem

sure thing.......Tom Dark...01993 868 840.

[axam48ida]

Well here is a solution to those who want the magneto "mojo" but have a need to run an msd
These units are identical to a magneto. housing, cap and even come with a Hunt Magneto metal ID tag
just like a traditional magneto. I have had these available for some time. we made some changes over the past year or so
like the rotor is in the same postion for number one as any vw distributor.
So if you want that traditional look with an electronic ignition here is a option.
the units have a 40,000 volt coil inside the unit, so all one sees are the wires going back to your msd box under the back seat.
I have spoke with a business in england that may be soon stocking them
otherwise I can ship them any where.
thanks
 Merry Christmas and Happy Holidays!

[jyri eramaa]

gotta put this in here, my 2520cc 911s motor, with a vertex mag that i ordered from vertex usa...

[Sarge]

gotta put this in here, my 2520cc 911s motor, with a vertex mag that i ordered from vertex usa...

  !!  Nice, Jyri!  Years ago I had a job working at Scott's Independent Porsche.  Scott's delivery truck was a sweet '69 Double Cab with a '71 mechanicaly injected 911-E motor stuffed in the back.  Always a treat to run errands.

[Zach Gomulka]

Keith,

So for a NA street engine do you recommend an 010 advance curve over locking out the mag?

Thanks,

--louis

is there a big difference in a 010 and a 009 ?  Technically, besides the good looks...?

010 has a quicker advance.

[Jim Ratto]

Running a locked-out mag on the street shouldn't be a major problem unless you floor the throttle at very low rpm – then your motor will 'ping' like a samba band.

That is true. I have noticed that if I drive my car with no discipline, and give it the boot way down low, like under 2000rpm, it will ping, if it is hot out. So I roll into it just as I know the motor will take it. I think running damn near 9.8:1 on California-piss gas might have something to do with it too....

[Peter]

here you go!

[wolfswest]

let us say that when you are above 2500 rpm there is no more advantage or am I wrong?  the mag functions the same above let us say 2500 RPM ?

IF you have a car with a locked mag and one with an advantage curve in it will there a difference @ 3 - 4 - 5 - 6000 rpm?  Or is there only a difference under 2500 rpm?