Mallory Unilite Distributor and first start.

[cliffords]

Well another couple of hours this evening trying to get the first start on my Sbc and nearly but not yet. The fuel problem now sorted I think with a pressure regulator fitted but now engine fires and dies immediately I release the cranking.

Did not crank much as now getting quite concerned about eating the cam.

Tonights question. With the Mallory unilite distributor does anyone use a specific coil and ballast resistor . I have a Bosch 12v and a standard ballast resistor. Is it possible after cranking , when I come of the crank the distributor is not getting enough to maintain the spark ?

[fastco]

Originally Posted by cliffords

Well another couple of hours this evening trying to get the first start on my Sbc and nearly but not yet. The fuel problem now sorted I think with a pressure regulator fitted but now engine fires and dies immediately I release the cranking.

Did not crank much as now getting quite concerned about eating the cam.

Tonights question. With the Mallory unilite distributor does anyone use a specific coil and ballast resistor . I have a Bosch 12v and a standard ballast resistor. Is it possible after cranking , when I come of the crank the distributor is not getting enough to maintain the spark ? YES

[Purple AK]

Ahhhhhhhhhhhhhhhhh!!!!!!!!!!!!!!! Just remembered That was the other anomoly in the AK loom I kept meaning to tell you about but never remembered The Purple/Black (Coil+) is not connected at the dash end of the loom, You need to connect it to either the feed of the starter button or the Run position on the ign switch! At the moment you are only getting ign + by virtue of the feed from the starter to the ballast. Once you stop cranking it will die!

[cliffords]

Chris

Thanks however my trusty assistant Craig did work this out for me today and we connected it to a live.

Unfortunately to no avail it still dies after cranking.

Still after the users of this distributor to let me know about coils and ballast resistors

Thanks though for the thought >

[dinosoar]

Mine runs a ballasted coil.
It is usual to have a shunt circuit that will supply full voltage to the coil during cranking (which will have dropped to perhaps 9v) and then disconnects when you release the starter and the coil then uses the ballasted supply (About 9v).
The shunt circuit will come from the starter solenoid and is only live during cranking.
HTH
Andy

[cliffords]

Andy

What sort of coil do you run ?

[TINKA]

Firstly if you are running a ballast resistor then you should have a 9v coil because as soon as you stop cranking the supply will go through the resistor and drop the feed to the coil to 9v. Secondly ( and probably very unlikely ) does the positive feed to the coil that you added , stay live when you stop cranking. Silly I know but when I first fitted my Mega squirt system I wondered why it would not start and it took ages to realise I had given it a supply which switched off when cranking the engine

[cliffords]

Thank you for the reply

The positive supply we added was straight off a good battery , we added it as a temp measure whilst we looked for the route of the problem.

The coil is a 12v one so maybe wrong.
I just spoke to real steel and they say the mallory coil and specific ballast resistor are needed/ recommended.
Could not quite get them to say it was essential rather than a nice to have.

Anyone on the list with this distributor able to tell me specifically what coil you are using

thanks

[craggle]

Even looking through the Mallory catalogue doesn't seem to give much more information away.

Just a quick run down of what we achieved last night........

We are fairly certain that the coil is a standard Bosch 12V coil. It says 12V on the label.

It is running through a ballast resistor.

The purple and black cable was not supplying 12V in the ignition on position. We ran a cable direct from the battery to the ballast resistor until David sorts this out behind the dashboard. We do get 12V at the coil when cranking.

I was tempted to try 12V direct to the coil but the instructions for the Mallory distributor advised against this.

The engine does try to start and run but then quits as soon as the key is released.

We need to know if there is a difference between 12v coils and the type that should run through a ballast resistor. If we have a 12v coil and are only supplying it with 9V then presumably it will not charge itself fully before trying to spark?

Craig.

[TINKA]

There is a difference between these coils. Ballast resistors were first used to aid cars to start easier. They work by running the feed direct to the coil when starting the engine which allows for the drop in voltage due to the load placed on the system by the starter ( which could drop the voltage as low as 9v ) but once the engine is running the supply goes through the resistor to drop the voltage whilst the car is running to 9v+ or -

Hope that makes sense