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GT/E Ignition timing

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A couple of questions but Firstly some background as to the work completed.

I have static timed my GT/E so that the crank pulley mark lines up with the casting mark on the timing case when No1 is at TDC and the line on the edge of the distributor lines up with the centre line on the rotor arm. This I believe is the "starting point" for ignition timing.

(1) I am going to get hold of a ignition strobe but what is the idle & total advance figures for the standard ignition system? Or is there only a idle figure and if so what is it?

(2) The Head is a P2E, so I'm using super plus unleaded fuel. By using super plus unleaded, does this make any difference to the degree figures in question 1


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If your using super plus it should be roughly what 4 star was, so std timing should be ok. 

IIRC static timing is 12 deg and then with revs advances up to about 30 ish.

I did get a good piece of advice off a guy years ago. He said listen to the starter motor as the engine is cranking over, if it sounds like its kicking back change the timing so that it sounds like itsits cranking freely. Your timing should be spot on then. Mine was 12 1/4 deg when i did it this way.

Every engine is different so you have to listen to whether its happy or not. Just as an example i have a highly tuned CIH and i awas going to have a custom cam ground up so i took measurements every 10 deg of where the piston was in the bore so that max lift and timing could be determined. The readings for the piston on the way up were different to on the way down, and by a few mm. The reason.......the crank is offset in the block, only a touch but its probably on max tolerance. So you can time your engine to where the piston should be as designed but it could be 2-3 mm away from that position in reality. Hence listening to the engine is alwaya good indicator.



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The different quality of feul and different compression of engines forces us to set the ignition unique on every engine.

By the way: on a CIH 20E the crank pully mark is 10°, a good starting point.

And I use also the highest octane feul.

I turn the dizzy bit by bit to more advance on a testdrive with low rounds and high gear to wait until the engine pings, than I turn it 

something like 2° later. But be carefull: pinging (detonation) kills an engine.

Last year I visited England with my "400" and needed feul. I asked the bollywood guy behind the counter what octane his feul had.

He shook his head and didn't know.

I filled the car with the best feul and 500 yards further I disconnected the vacuum-tube from the dizzy cause the engine was pinging like hell.

Later at Castle-Combe they tolled me I filled it with 97octane, only a bit lesser than in Belgium...

The idle (20E) is 800rpm and as Chris wrote advance almost 30°.

Personally I like to set the idle a bit higher, 850-900rpm.

Grts, Herman

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