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Discussion Starter #1 (Edited)
I run a lot of static timing plus 8* of non-ported vacuum advance. The engine loves it, low speed performace is great, and the gas mileage is very good. That said, sometimes on startup the engine wants to fire before TDC and stall the mini-starter. I've done the huge wire thing and that helped some. The solution has been to manually kill the ignition with the dash-mounted kill switch while cranking to allow the starter to spin up.

The new solution is an automatic 3/4 second ignition kill (defeatable) on startup.



The circuit is 1/2 of a 556 timer (a 555) configured as a monostable one-shot. It's triggered by the orange wire connected to the starter contact on the ignition switch. One of the white relays energizes when the starter is activated and triggers the timing sequence on the 555 circuit. The other relay's NC contacts are in series between the distributor output and the magnetic trigger input to the MSD box.
When the key is turned to start, the distributor signal in disconnected from the MSD box for 0.7 seconds, enough time to spin up the crankshaft. Then the relay coil de-activates (closes NC contact) and reconnects the distributor to the MSD box, the coil fires and the engine starts. A switch under the dash defeats the box's operation if desired.


More detail on the buildsite: http://www.worldisround.com/articles/123897/photo557.html
Greg
 

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Great Idea!!!

I am running 18 deg static in a 408 and I have cooked 2 starters from kickback. Would the unit work with a duraspark box and where can I get one?
Cheers Greg
 

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1st RFM/FFR Legacy Winner
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Discussion Starter #3
There may be something on the market-off the shelf, that would do exaclty what I designed this little box to do. I had some parts laying around so I whipped it up last night.

Not sure about Duraspark. The idea of the box is to prevent the ignition amp from triggering for 3/4 of a second to give the starter a change to get the cranshaft to speed before the first cylinder fires. If I had more time on my hands I could build some more but that's not going to happen for a while,

Greg
 

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Team FFR Mechanic
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MacGyver at his finest!! Greg, I guess you could build a rocket ship out of a tube of toothpaste, a coat hanger and a battery. Beautiful work indeed!
 

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I am running 18 deg static in a 408 and I have cooked 2 starters from kickback. Would the unit work with a duraspark box and where can I get one?
Cheers Greg
I bet you could accomplish this with a toggle switch for the positive wire to the duraspark. This would allow you to turn the key and once its turning over hit the toggle to add power. Vroom!

Mike
 

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Nice work Greg. Thanks for posting that.
 

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Discussion Starter #7
I bet you could accomplish this with a toggle switch for the positive wire to the duraspark. This would allow you to turn the key and once its turning over hit the toggle to add power. Vroom!

Mike
I agree. I did exactly that for 2 years. Wanted automation....

I'm just an old electronics hack and it's too cold to work on the ABS. I got bored.

Greg
 

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I bet you could accomplish this with a toggle switch for the positive wire to the duraspark. This would allow you to turn the key and once its turning over hit the toggle to add power. Vroom!

Mike
That's a good idea and would double as a decent theft prevention. My car does this also, maybe once every 30 or so starts.
 

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Greg, this is very nice - something you could probably patent/market if you wanted to! As you said, there may be something like this already out there, but I don't recall having seen it. Hot starts have been a bugaboo of motors with significant timing/compression since the beginning of time, more or less...
Charlie
 

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Discussion Starter #10
Hi Charlie,
Patents...I have two 5725402 and 6264513 and I learned early-on that patents are only worth as much as one can afford to spend defending them. Both of my patents are for a wireless means to extend control of the boat's tilt/trim, stereo, disable the engine and trim pump as a security measure, to the steering wheel and to keychain tramsitters for use outside the boat. I could not find an interested party after trying for 6 years even though I have working systems.

As time went on, companies either came up with the idea on their own or stole mine disregarding the patents after they discovered I was a small entity.

I might be open to building a few of these for friends, if enough interest is out there.

Greg
 

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I am far from an engine expert but why wouldn't you just run less initial timeing and more advance that comes in more quickly than usual?
 

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Discussion Starter #12
I tried a several combinations and for my setup crane dizzy has 27 combos of centrifual and vacuum advance curves. 14-15* base timing allows the engine to run better below 1800 rpm with a mixture as lean as 14.5:1, even at idle. With 10* base, it stumbles. I tuned using a wideband for best mpg in cruise mode back when gas was $4/gal and the way things are heading, the tune will be appropriate again real soon :(.

The carb'd E-cam engine runs smoothly and if sesired, can pull steadily using 1/2 throttle or less from 1,300 rpm in 5th gear with a 3.08 rear and never stumble or ping or regular gas. Vacuum advance (MAP sensor in dizzy responds electronically) adds another 8* above 12" of vacuum, and centrifugal advance comes in at 1,800 rpm, adding 22* by 2,800 for a total of 36* plus up to 8* more with the vacuum advance.

The car runs nice and lean, pipes are clean and mpg is as high as 25 cruising at the speed limit of 45-55 in 4th and 5th on the backroads around here. Not bad for a carb'd car.

Greg
 

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Greg, perhaps you should make a remote variable timing control device.:)

In the early days, cars had an ignition advance/retard control, usually on the steering wheel center, which could adjust the timing depending on the starting, and or driving conditions.

Now you could take some of the technology you used for the boat, and use it for the roadster..wireless perhaps.. A solenoid could turn the distributor, as required.
 

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Discussion Starter #14
MSD makes (or used to make) a variable timing module. I run one on my supercharged boat. It's not the Boost Timing Master that returds timing based on manifold pressure, it's a module that you can dial-in, from the dash, +/- 6* from base timing. It goes in between the dizzy and the 6AL box.

Greg
 

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Discussion Starter #15
Tested this today and it works as designed. Engine cranks very fast and at 3/4 second, fires right up without drama.

Greg
 
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