Technical Distributor alignment w/o points

[the hobbler]

My bad luck just keeps going. New Mahle pistons with pre-installed rings went in fine. I had to use a Gates-style hose clamp to compress the rings to slide the cylinders down on top of them. Worked perfectly. Neither of my ring compressors would have been removable after this, but the hose clamp was. Put it all back together and in the car. I get 129 psi on #1 and 1 psi on #1. Leakdown test shows the intake valve is leaking, so I can only assume the new valve seal is causing it to jam/stick open. I'll have to do the rope trick to hold the valve closed, to attempt to remove the springs and replace that seal. But, geez, can't a guy catch a break?

Back to my original post: I'm still wondering about the distributor orientation. Can someone show me how theirs looks? The body of the distributor (mine has the wiring notch facing the coil), the rotor at #1 TDC (pointing at that same wiring notch?), and the cap (my cap is marked I and II, with the I (#1) aligned with the wiring notch in the distributor body. So, with #1 at TDC (both valves closed, crank pulley mark pointing at the case marking for TDC), the rotor should be pointing at the cap's I (#1) which is pointing toward the coil mounted in the right rear flank of the engine bay's stock location. Right?

I would be very surprised if it was the valve-seal holding the valve open against the power of the valve-spring----why would 1 do it and not the other? Did you re-lap-in the valves when you had the head off, and did you do a valve-seat leak test? (head level, upside-down with both valves in place. with springs on, and spark-plug in----fill combustion chamber with paraffin or similar)
With regard to the distributor---the distributor-cap will only, properly, fit in one place as there is a 'female' notch in the the distributor body and a 'male lump' on the distributor cap. As long as you have the tdc mark on the pulley aligned with the mark on the timing-cover, the rotor-arm pointing towards "No1" on the distributor cap and the No1 lead going to the spark-plug nearest the timing cover (i.e. rear OF THE CAR), your timing will be close enough for it to fire into life. Perversly, in "Fiat-talk" the front of the engine(and therefore No1 plug) is at the back OF THE CAR!
Have you built this engine up from scratch? If you have, did you get the timing marks for the camshaft sprocket aligned correctly with the timing mark on the crank-shaft sprocket? IfI am "teaching you to suck eggs", I apologise but the situation is getting to the point where one has to look at the 'not so obvious'!

 

[fiat500]

My bad luck just keeps going. New Mahle pistons with pre-installed rings went in fine. I had to use a Gates-style hose clamp to compress the rings to slide the cylinders down on top of them. Worked perfectly. Neither of my ring compressors would have been removable after this, but the hose clamp was. Put it all back together and in the car. I get 129 psi on #1 and 1 psi on #1. Leakdown test shows the intake valve is leaking, so I can only assume the new valve seal is causing it to jam/stick open. I'll have to do the rope trick to hold the valve closed, to attempt to remove the springs and replace that seal. But, geez, can't a guy catch a break?

Back to my original post: I'm still wondering about the distributor orientation. Can someone show me how theirs looks? The body of the distributor (mine has the wiring notch facing the coil), the rotor at #1 TDC (pointing at that same wiring notch?), and the cap (my cap is marked I and II, with the I (#1) aligned with the wiring notch in the distributor body. So, with #1 at TDC (both valves closed, crank pulley mark pointing at the case marking for TDC), the rotor should be pointing at the cap's I (#1) which is pointing toward the coil mounted in the right rear flank of the engine bay's stock location. Right?

In my experience, that is exactly right with the 594 and 652 engine and the later distributor. The attached image shows my engine at exactly the point you describe, (ie. firing on cylinder 1 as defined by Tom @the hobbler ), but my rotor faces the engine block and the distributor cap is embossed "2", which is technically wrong but makes no difference to operation of the engine.

Looking at the distributor caps for the 499 engine, (I don't have one to hand), I think the numbering is in reverse of this and that the HT lead for No. 1 cylinder should be nearest the block.. Again, it doesn't matter as long as you have the HT lead connected to the distributor socket to which the rotor arm is facing when at TDC.