Ignition advance

[Lawrie]

Any one have an idea on the total advance when using a 6.2 head.
Lawrie

[bruceincam]

Mine seems to like about 30 deg total.

[Lawrie]

Ok thanks
Lawrie

[Synchro909]

Lawrie, I'm running a 6:1 head and on advice from the forum, I set maximum advance at 22° which has been pretty good.

[Lawrie]

This is on a new engine which we can only run on the engine stand,other wise if it was in a vehicle I could set it easy,
It is one nice engine, new alloy sump and cylinder head,and Burtz block,new Webber carb as well
Lawrie

[Bruce of MN]

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This thread addresses timing:

https://www.fordbarn.com/forum/showt...+cutting+wheel

[nkaminar]

The advance depends on a number of factors. The compression ratio is one. Also the turbulence, design of the combustion chamber, and the squish area gap (should be 1/16 inch). An easy way to find the optimum advance is to run the engine at a high idle speed, about 1,000 rpm, and advance the ignition until further advance does not increase the rpm. That is the knee in the advance curve. Of course, in actual driving, the advance will change depending on the conditions, like going up a grade.

[Synchro909]

Originally Posted by Lawrie

This is on a new engine which we can only run on the engine stand,other wise if it was in a vehicle I could set it easy,
It is one nice engine, new alloy sump and cylinder head,and Burtz block,new Webber carb as well
Lawrie

Is that Charlie's engine? I think he was putting an alloy sump on his Burtz engine.

[Lawrie]

Arnold, yes on the engine.
when is the 22 degs in, what rpm.
Lawrie

[Synchro909]

Originally Posted by Lawrie

Arnold, yes on the engine.
when is the 22 degs in, what rpm.
Lawrie

Lawrie, Mine is a set like you won't see very often. That shouldn't surprise you.
I made an adjustable stop that I screwed to the side of an original A distributor. It has a screw on it like a throttle stop that stops the top plate with no variation. I didn't like the idea of putting a clamp on the steering column quadrant and have all those mushy connections in between there and the dizzy.. Using the Nurex timing scale and with the engine at a fast idle, I set the stop at 22°. Initial timing was by the usual method and checked with the lever all the way up, it read zero degrees.
Around town, I set it at about half way and once on the open road, I pull the lever down and let the stop take care of everything else. Glenda was driving a while ago on the long, flat open stretches of road near Deniliquin. I saw triple figures on the GPS and it was just starting to "sing". I'm not going to meddle with 22°.

[SAXBY2]

Some posters suggest 22, 25, 28 degrees or other numbers. Somewhere it's noted that each quadrant notch is 4 degrees, and if so, pulling the lever down 5 notches would be 20 degrees advance?

[alexiskai]

Originally Posted by SAXBY2

Some posters suggest 22, 25, 28 degrees or other numbers. Somewhere it's noted that each quadrant notch is 4 degrees, and if so, pulling the lever down 5 notches would be 20 degrees advance?

It doesn't really work that way in practice. The quadrants are different shapes on different types of columns, and because there's a linkage, offset, and a 90° rotation between the spark lever and the distributor upper plate, you don't get a 1:1 mapping between small movements on the lever and small movements at the distributor.

[Jim Brierley]

The important thing is to not let it ping. Compression does require less advance, as does the chamber design and plug location. The dyno shows that the head I make starts losing power above 20* total advance, most 6:1 heads can probably use 26*

[Dodge]

Jim,
That sounds like a very efficient combustion chamber. Congrats.
Lawrie,
Most of the aftermarket Brumefield, Snyder type heads like about 26 degrees.

[Bob Bidonde]

I have a 6:1 head on the Model "B" engine in my Victoria. The ignition timing is set with No.1 @ TDC in the traditional Model "A" way. Running on 87 Octane gas, pinging starts when driving with the lever 2/3 down and accelerating. That's about 26.8 Crankshaft Degrees (13.4 Camshaft Degrees).

I think there is a lot of scatter in timing at the onset of pinging because of engine, gasoline and driving habit variations.

[updraught]

The octane rating make a fair difference in my book.
We have 91, 95 and 98 generally. I drove a Cortina bought new by my father in law in 78 for a while with the pinto type engine. It would ping on 91. But add a bit of 95 to create a shandy of one third or one quarter of 95 or even less and it was fine.