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A very strange question about testing ignition timing


Unclejake

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Gents,

I have been re-building my Mk1 Cortina 1500 pushrod and I have completely re-wired it.

I need to do some testing without risking the engine. The engne is several months away from complettion.

I wish to roughly test the ignition curve WITHOUT using the engine. To test the ignition system to achieve what I need to achieve (which sadly is a secret that I will only post in Leet) I must take the engine speed to over 6,000rpm.

I have the wiring loom - including the rev counter. I have the distributer, cap and leads. I have an electric drill that spins to 3,200rpm (which should if connected to the dizzy driveshaft equate to an engine speed of 6,400rpm?)

I have two timing lights. One adjustable and one fixed.

Hooking the drill up to the dizzy shaft seems obvious. Monitoring the 'corrected' RPM via the rev counter seems obvious.

How do I safely and sort of accurately see what the timing is doing?

Don't forget - all this with no engine :?

Chur

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Guest vvega

mark tbc on your drill chuck and the ref point on your drill case .. you should be able to work out distance to 10 deg - 20 deg- 30 deg etcb from points position...unless yoru not useing them anymore then you just work off pickup position

make sure you have a plug in each lead and they are grounded to the comon earth

make some jig...hold in 2 vices dizzy etc and go for you life just graph the results

keen for pm of secrets if your willing to share

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My dizzy has no mechanical or vacuum advance.

BDA - there was a similar machine in Wellington at Car Therapy but it is broken. As far as I can tell there are no others in the region BUT such a unit will not achieve what I want to achieve as the timing is handled by 'computers' mounted in the car rather than the dizzy. I need to spin up the dizzy physically near the immoveable car and connected to the installed wiring harness.

I think a white line drawn on the drill chuck will work.

I will make up a jig in the next few days and will post photos. It will be a fun project.

Our mutual friend with the Rover tested his arrangement using the motor and AFAIK bent the crankshaft because he didn't have it set-up right. I wish

to avoid that risk :shock:

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^ nah load of poos - Leggless never bent a crankshaft in his chevs - (unless it was early 327 days back when Adam was a cowboy) - but since he has been running a 406 hes always run a Scat crank - read suitable for big NO2 shots or supercharging - a bit extra timing don't mean nuttin.. a lot just means it won't fire or have enough compression to cause drama

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^ As said - only hearsay. Perhaps he broke the starter motor, or a nail. Perhaps it was all in someone's mind. Dunno.

My electric drill powered dizzy test rig will rule. Dare you to hold the spark plugs for me :)

I start to build it tonight (if my dizzy has arrived in the mail)

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^ As said - only hearsay. Perhaps he broke the starter motor, or a nail. Perhaps it was all in someone's mind. Dunno.

My electric drill powered dizzy test rig will rule. Dare you to hold the spark plugs for me :)

I start to build it tonight (if my dizzy has arrived in the mail)

hold them in my teeth- you bet - will be round at pinkys for wiring chores at 6ish

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the timing is handled by 'computers' mounted in the car rather than the dizzy. I need to spin up the dizzy physically near the immoveable car and connected to the installed wiring harness.

What flavor computer?

Hall effect or reluctor pickup?

Why don't you just test it in the car with the spark plus out of the engine and the fuel disabled once things are ready?

Do you have access to a decent oscilloscope?

If you do connect the probe to the trigger lead of the ignitor (assuming the ignitor is dumb) run the drill at a consistant speed and tweak the display so that you are getting a stationary wave form. Then as you increase the revs on the dizzy you'll see the freq increase, you should see the advance as the whole wave form sliding from left to right..... or is it right to left... I did this when I having some ignition issues on my capri about 10 years ago...

Most jappers have a port you can access to look at the ignition signal have a go on the Mrs car first to see what should be happening :wink:

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the timing is handled by 'computers' mounted in the car rather than the dizzy. I need to spin up the dizzy physically near the immoveable car and connected to the installed wiring harness.

Why don't you just test it in the car with the spark plus out of the engine and the fuel disabled once things are ready?

:

Spinning the engine to 6,000rpm plus would be a challenge.

Soft Iron reluctor.

MSD

No ocilliscope - and I don't need one. I just need to observe the presence of advance and retard. Not the exact values or the pluse shape.

Chur.

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