TDC Question/Initial start-up I have my engine at TDC and at the 0 timing mark. The rotor is just past 1 terminal. Will #1 be the terminal it's just past or the next one? I know this is a no brainer for most, but better safe than sorry. TIA
Should point directly at the #1 terminal and that will get you started. Actually at the point you are at if it's points you should turn the distributor until they just break, or if it's HEI the reluctor and pickup should be perfectly aliegned that is when it fires. And the rotor should be pointing at #1 terminal. That will get you running then time it. Dave B
Get an old distributor cap, a really big drill bit (No, get a bigger one:grin: ) and knock out the #1 terminal, then drill out the hole. Put it on the distributor, and shine a flashlight in there. You'll know beyond a doubt if you're at the #1 on the rotor.
Well I tried firing it up. Got a nice flaming backfire through the carb. Sound like my wires are off? I can't crank on this too much without it starting. This is the first time for my new engine and wiping the cam bearings has me pretty worried.:Brow:
Having a couple wires wrong will make it run lousy. Shouldn't make fire come ou the carb. Sounds to me like you may be off with the distributor and/or #1 piston.
If the wires are crossed and a plug fires before the intake valve closes it will backfire out the carb. I'd take the driver valve cover off and crank it by hand and watch the intake valve, when the valve closes then keep turning it until the piston reaches the top of the cylinder. Your timing mark should then line up or be very close. This is top dead center TDC and #1 is ready to fire, pull the distributor cap and determine where the rotor is pointing. Make this your #1 terminal, it may not be pointing where the book says it should be but that is not important at this time. So make sure the #1 sparkplug wire goes from said terminal to #1 sparkplug. Then follow the wiring order,18436572, going clockwise and it should be close enough to start and do your cam breakin. You do know how the cylinders are numbered, sometimes we take too much for granted and expect a guy to know something that he dosen't. O' don't forget to put the valve cover back on or it'll be real messy. Dave B
Yeah, I know the firing order and the D/S bank is 1-3-5-7 right?. I'll pull the cover tomorrow and start-over. Is the intake valve closest to the front of the motor or the next one? I used one of those whistles in #1 to determine the compression stroke. Not sure how I ended up off. I may have crossed a wire in my frustration. I'll try again in the morning. Thanks,I'll let you know what happens, or doesn't happenp
Well of course you are right, Dave. I should have said it's unlikely to happen. I feel that the chances of this being wires is small compared to the chances of this being the distributor because the wires are easy to check and I have to assume he did double check that after the backfire, as it's the logical and easiest step in troubleshooting. I can see one case where I would think the odds of this being wires is high: In some manuals, like Chilton's, both the HEI and the points distributors' firing orders and a diagram for wire position are illustrated. Both have the same firing order, BUT the physical position of the #1 is slightly different on the two. After that, the order is identical. The HEI diagram shows four hold down screws, the points diagram shows two- but are not labeled by type of distributor. If you use the points diagram for wire position on your HEI or vice versa, it is easy to become confused and while your order of wires is right on the money, you are actually one terminal off on each and every wire- but the wires will be in correct position according to the diagram. There are no indications on the diagram itself, referring to the type of distributor, you must look at the number of hold-down places on the cap in the diagram to determine which is which. Use the hold down places as a reference, not clock face positions, too. after that, I feel the issue is less a case of being 180* out on the timing, and being more of a potential of the distributor being a tooth off- or - becasue of this - "Actually I'm at about 5* so I'm assuming the one its coming up on will be #1. Sound right?" - which I am not 100% clear on....5* off from the terminal? 5* off the timing mark? But if it were HEI, it should be right on, and if points, is this 5* the location were the points break? THAT I'm not sure of but 5* doesn't sound right to me....let me think this out loud so to speak...360 divided by 5 (the # of degrees) is 72, so 8 plugs would make that a multiple of 9, four strokes....are there 36 teeth on the distributor gear? If that little rationalization is right, then the points should open at 5* before the terminal, right? To tell the truth, that little brainstorm I just had doesn't seem sturdy enough to hold up to scrutiny, to me. I think I'll write that out and do some thinking on it... I would make a guess that when installing the distributor, there was a very common mistake. One that I have made and not even realised it: I lined the distributor up properly but forgot the gear will make the rotor turn as I installed it. So I was actually off when I installed the distributor. This is why I suggested getting an old cap and knocking out the #1 terminal. Just my 2 cents and I've been wrong many times, but I gotta think the wires were checked immediately after the backfire.
Well here's where I stand today. Rotated the engine until the intake valve closed,then a little more to 0 on the timing mark. Pulled the distributor cap(HEI), rotor at 8 o'clock, which I used for #1, carefully numbered all my wires as I put them back on. Doubled checked everything and cranked it over. NO FIRE. At this point another backfire would have been fine, and freaked out my helper(read wife) againp, which was pretty funny. I checked my voltage and have a full 12V to the HEI, so I'll put a new module in it and see what happens. I'm starting to think there is some kind of divine intervention going on here.....
Andy- later on, when I'm done with my housework:af: I will dig up my Chilton's manual and duplicate the diagram for the distributor. What I am thinking of is that your wires are perfect, but the cap is in the wrong place. the diagram references the cap to the engine, and the wires to the cap.
HEI caps can only go one way. They have the notch that fits on the rim of the distributor, unless I'm misunderstanding you. I'm going to drop a new module in and see what happens in the mean time. With my luck I probably managed to fry it somehow.o No:
You are misunderstanding me. I do not mean the distributor cap might be on wrong. If you give me a chance, after lunchtime, I can post the two diagrams and explain. If you used the points diagram to put on your wires, you may be one post off and not know it, and you can put the entire distributor in wrong, still have the rotor point to the #1 terminal, and have the wires correct- but the wires will be in the factory location while the entire distributor faces the wrong way. that's why I would make sure the distributor is referenced to the engine, and not the clock face.
OK, here is the diagram for the points distributor. Note the cap gives two reference points for the wires- they are the cap hold down screws. if the cap were turned 90* (possible but unlikely, this is an example) if you were to put on the wires by simply using the clock face as a reference, the wires would be wrong. Reference them from the hold down screws- but ONLY for a points distributor. Your HEI would have the #1 at 12 o'clock if you only refer to a clock face. If you use this diagram to psosition the #1 on an HEI distributor, you would put the #1 at 11 o'clock by mistake (I am not exaggerating the positions of the terminals in these diagrams to prove my point, this is were the diagrams show them in my Chiltons manual that covers points and HEI distributors- they got the diagrams from the manufacturer. I might not have perfect spacing here, I whipped this up- BUT the #1 should be immediately to the right of the points window, and the #8 should be next to it, to the left of the hold down screw. The #1 should point at 11 o'clock on the diagram) I will post the HEI diagram next.
Here's the HEI. Note that the #1 is now at 12 o'clock in this diagram. If veiwed from the front, this would place the #1 at almost exactly 9 o'clock on the clock face, not 8 o'clock. On your HEI, the #1 should be right on the rotor at TDC. At any rate, this is the method I have used over a dozen times with no problems with an HEI. Knocking out the #1 terminal on an old cap and installing it is cheap and simple assurance you're dead on the #1. HEI diagram:
Whenever I have had the tach/bat connections sticking out at around 9 o'clock on the clock face, the hold down screws for the HEI look like this diagram. Now that I have the entire distributor referenced to the engine, I can be confident that when I put the rotor at #1 and then put the #1 wire on the right terminal, I am indeed going to fire the #1 when I should. Like I said, I'm not sure if this is the issue, but this is what I mean by referencing the distributor to the engine. otherwise, you could be a post off on every single wire and it would still look right. I bet you can guess how I discovered this issue:laugh: Hey it only took me three hours to figure it out.
I see what your saying. My cap and rotor are just like your pic when I brought it up to TDC last time. Sooo..I went back out and using the handy dandy whistle tool this time(didn't feel like pulling the v- cover) I brought it to what should be TDC.. again. Pulled the cap and now its showing me I'm 180* off from watching the intake valve. My whistle must be lying, or my helper(wife again) was watching the wrong valve and doesn't want me to get it started, which, at this point and time is entirely possible. I just don't get it. I'll re-do everything again tomorrow, TDC,index the distributor to#1, new module. Thanks for letting me try your patience. Maybe I'll have results tomorrow instead of more Q's.
Andy, just guessing but your "helper" is probably innocent of malicious wrong doing with your engine. If anything it's lack of experience. I have had plenty of "helpers" in my garage with a wife and two daughters over the last dozen years or so. When one has to explain and show what bumping over an engine means 15 times it might be time to rethink the "help" (like I did). Of course, I was to blame for lack of patience with my wife. That is why I now work alone even if it involves doing four handed jobs by myself. Less rework to do... More importantly less grief. good luck! George
