Timing question?

[needabronco]

OK this one is embarrasing to ask. I checked my ignition timing today, and I can't figure this out. I've got a slightly warmed up 302 with an MSD dizzy, and with the vacuum port plugged, the light is about 10 +/- degrees out or before the timing marks, and with the vacuum line hooked up it is exactly on 10 degrees? Am I missing something here???? It does run very well with only some slight carb adjustment issues. I did verify that when at #1 TDC the timing pointer is at TDC or 0 on the balancer. If I remember right the balancer is a Summit brand part # SUM-163289. Thanks in advance.

 

[broncnaz]

Sounds like you may just have the wrong balancer for a bronco not really a big deal you can remark the balancer so it reads correct. one other thing to consider is that the camshaft could have been ground different or installed advanced or retarded either way if its running fine I wouldnt worry to much but I would reverify TDC and remark from there just to be sure with your current setup.

 

[pondscum]

You can time by vacuum. With a vacuum gauge hooked up advance the engine timing and watch the vacuum rise and then it will begin to fall back off 1hg from the highest reading and you should be timed quite well for the altitude you are at. Email me if I did not explain the timing thing clearly.

 

[pondscum]

oops!

What I should have said is once the vacuum begins to fall retard the timing until you are at the highest vacuum point and then retard the timing until it is 1hg below the highest point. I need the vacation I am starting tomorrow.

 

[needabronco]

The cam is timed correctly with the crankshaft. I researched the balancer and found out that it is for multiple setups and actually has three different degree marks on it. I can only guess that I put it on using the wrong scale, althoug like I said earlier, when at #1 TDC the pointer is at 0. Oh, well, I'm not tearing it down again just for that.... Thanks.

 

[Johnnyb]

I agree with pondscum

Timing is entirely relative to altitude/compression. At 7000 feet, you are lucky to pull 15"hg. at idle and youe engine is operating at a much lower compression.
If you time by vacuum, you can get the best setting for your location.

-J