Want to time my 71 crewcab tomorrow and the crank wheel has to marks at tdc. What one do I use?!? Hmmmm
Just 2? You're lucky. The dimple is TDC. If you really are lucky, 45mm round clockwise from TDC you might find a full advance notch.
Wish it was that simple zed. My pulley only has two marks to the back of the pulley and no dimple. It does have three cut outs on the pulley at 180* but they are at the front of the pulley. I'm thinking the left mark at tdc is tdc and the right mark is 10* but I'm not sure. I shall take a pic in the morning.
I have a special spark plug. It has the guts drilled out and a piece or theaded bar jammed in to make it longer. I put it in 1 or 3, turn engine until the piston hits the plug and mark the pulley in line with the case joint. Then I turn the engine the other way and repeat. Halfway between the marks is TDC. Very accurate.
Doesn't help me though does it . I know its your birthday but no need to show off your fancy toys. On a serious note, my dizzy has no vacuum advance and dual carbs. Do I time at idle speed and the fancy flamethrower thing and carbs will do the rest? Also is it still 7.5* cause I've been reading the bleeding net and there stating all kinds of different timing. Confused.com ATM. On a good note, there was no bush in the bell housing for the starter so I replaced that along with the starter and she starts great now.
You can make your own "special" spark plug. Use a bolt then cut the end off. It only needs to be 10-15mm longer. You can read as much as you like about timing, but until you know what the marks are it won't help. Start with 7.5 as a base setting, then set to 30 degs full advance. How far apart the marks are would offer a clue to what they might be.
Ta for that pic with arrows Zed ,that tiny little dimple ? there is one on my bus pully (along with a lot p /o of home made chop marks),I have eyed it suspiciously for quite some time ! going to take another look later today.
I'd guess that in the first pic you have TDC and a timing mark to the right. In the second pic, judging from the sq hole in the pulley, these marks aren't opposite the "timing" marks (which they would be to set the valves) so look like damage to me, not marks. Edit to add - the marks in the 1st pic look a bit far apart for TDC and timing. I think you really need to verify TDC for yourself.
