I've learnt a lot from this forum over the past 8 months whilst re-building my 500, but now I have my first question.

I have rebuilt the engine and set the static timing as described in the Haynes manual. Engine starts well and runs well so far (250 miles) I'm still running with trad points and condensor and plan to fit an Accuspark trigger.

Prior to fitting the Accuspark I decided to check the ignition advance using a Gunson strobe. With the tdc marker on the pulley painted white and the arrow on the timing cover painted white, I found that I had to set the Gunson advance dial to 40 deg to get the two marks to line up. I guess I was reving the engine over 3000 rpm. The book says 28 deg for max advance.

What are the group's thoughts?

Thanks
Peter

After static timing, check with the strobe that the idle speed advance is 10°, then check that increasing engine speed (to 3000RPM if you have a rev counter) progressively brings it to 28° (max. value).
(Reducing the advance will make the idle speed drop, re-set it at the carb)
To change to Accuspark, simply swap the components, timing should still be in the ballpark and need only minor re-adjustment.

when two marks are line up then you are set to 10 degrees. You have to mark the pulley by yourself at 18 or 28 degrees and then align those new marks with the timing gun. In the end of the day you will end up in a setting based at you ear rather at the manual settings.

lblorbust said:

What are the group's thoughts?

Thanks
Peter

Click to expand...

Assuming that the points gap is correct at 0.5mm + or - a bit and that the distributor weights and springs are intact and not worn (I think you just have to assume that at this stage), I would slacken the distributor clamp-bolt sufficient to allow it to turn with a little force and then rotate it clockwise a little. Then recheck with the strobe and repeat until you get about 28 degrees. If it runs okay at that, then check it's roughly 10 at tickover, but don't sweat if it's a bit out.

gordinir8 said:

when two marks are line up then you are set to 10 degrees. You have to mark the pulley by yourself at 18 or 28 degrees and then align those new marks with the timing gun. In the end of the day you will end up in a setting based at you ear rather at the manual settings.

Click to expand...

The strobe has a variable dial for degrees of advance, and as I understand it, I change the advance dial until the two marks line up with this type of gun.

I'm not sure it's quite clear that the foundry mark on the engine pulley is TDC (0°), not the initial advance (10°) point...

lblorbust said:

With the tdc marker on the pulley painted white and the arrow on the timing cover painted white, I found that I had to set the Gunson advance dial to 40 deg to get the two marks to line up. I guess I was reving the engine over 3000 rpm. The book says 28 deg for max advance.

What are the group's thoughts?

Thanks
Peter

Click to expand...

Wait i got it now, that means that your engine is set at 40 degrees of advance as we speak, you have to set your tool at 28 and then turn the distributor until both lines are line up. (turn it clockwise) and at 3000 rpm. If you let it at idle it will normally drop about 9-10 degrees, again you can set your tool until both lines are line up and then you will see your real static timing related to the 28 degrees adjusted before. Alternative if you measure your pulley and mark from TDC 36mm this new mark will be your 28 degrees, more or less.

giardini said:

I'm not sure it's quite clear that the foundry mark on the engine pulley is TDC (0°), not the initial advance (10°) point...

Click to expand...

The mark on the edge of the pulley (the engraved one) is the TDC but this can be checked easy if you remove one spark plug, set to TDC ( i usually put a pencil inside the cylinder) and then check the mark if it is align.

Thomas

Thanks for the input.

I'm surprised that the engine seems to be running quite well with what appears to be 40 deg of advance, but I'll reset to 28 deg using the strobe and see how it runs.

You might surprised as well if you adjust it to 28 and stop running Well, so before you adjust anything make a mark on the current position so you can bring it back.