Ignition Timing

[Robert Hutcheson]

I've got a standard 2.0l GTE CIH. I was doing some work on it today and setting the timing was one of the tasks. My question is, what is the correct timing on this engine? I've heard people say 10 degrees advanced with vacuum off, I've heard line up marks, I've heard retard by 5degrees due to unleaded fuel. Any one know the correct set up? Advance or retard, with or without vacuum. Thanks.

[Snowy]

It depends. Are you asking how to set up the static timing or the dynamic timing (when it is running)?

 

On the none 2.0E engines the mark on the crank pulley means 5 degrees BTDC. On the GTE engines the mark means 10 degrees BTDC.

 

So if you have the correct pulley for your engine, the older ones from memory are pressed steel where as the GTE is a big cast lump, the mark is 10 degrees BTDC.

 

The timing in the books will not be correct as they assume you will be running leaded fuel. If you are then great leave it alone. If you are running on Unleaded like the rest of us try around 5 degrees BTDC. Then just keep adjusting it either way a little until it doesn't pink under load.

 

Now it has been a long time since I worked on a CIH so someone may come on here and correct my memory.

 

Thanks

[Robert Hutcheson]

I'm trying to set the timing when the engine is running. It's got the big cast iron pulley. At the moment I've set the timing with the vacuum removed. Using a strobe I've use it so the mark on the pulley is about 5 degrees before the mark on the block. Is this right?

[Snowy]

I'm trying to set the timing when the engine is running. It's got the big cast iron pulley. At the moment I've set the timing with the vacuum removed. Using a strobe I've use it so the mark on the pulley is about 5 degrees before the mark on the block. Is this right?

That sounds like a good starting point. But you'll have to adjust it by ear now.

Does it pink or not under load?

Edited October 12, 2014 by Snowy

[Robert Hutcheson]

I'll need to test it under load. If it pinks will I advance it slightly?

[cam.in.head]

No retard it.ie turn distributor clockwise.

[Robert Hutcheson]

See what I mean! 1 says one thing and another person says different lol arrghhh. I'm puzzled.

[Snowy]

We are all saying the same thing. Start at around 5 degrees BTDC, In fact start where you like as long as the engine runs. Adjust by ear until the car doesn't pink under load!!

 

Unleaded takes longer to burn than leaded petrol. That is why you have to play around with the timing.

 

• The way I used to do it was start the car and get it warm.
• Disconnect the vacuum to the dissy and plug it so there are no vacuum leaks.
• Turn the dissy all the way clockwise until the engine started to stutter.
• Turn it all the way anti clockwise until the engine started to stutter.
• Stick the dissy half way between these two points and go for a drive - plugging the vacuum back in!!
• Keep adjusting the dissy until the car just started to pink.
• Then adjust the dissy back a fraction.

I hope that helps.

Edited October 12, 2014 by Snowy

[dynamytedan]

once you get fed up of twiddling your dizzy (some of us will never tire of that  )

for more accurate, more reliable ignition timing you could look at something like this .... 

http://motorsport-electronics.co.uk/electronic-ignition-megajolt-nodiz-pro.html

[Julian]

Snowy you have put it exactly as I would have, it is the well tried and tested way that I have always used. Your own ear will beat any meter or whatever modern gadget. I used to have one of those balance thingy's for balancing the twin carbs on a jag, well any twin carbs engine, but found it far more reliable to use a bit of washer pipe, disconnect the link between the carbs and adjust each separately by listening to the carb sucking the air in with one end of the pipe in the carb and the other end in my ear, your ear would tell you when they were both equal, then link them together.

Edited October 13, 2014 by Julian