finding tdc when installing dsII
- Thread starter kuhlou
- Start date
http://www.jegs.com/i/Comp%20Cams/249/4795/10002/-1
The description says its only a 14mm but in the picture it looks like it includes the 18mm we need also.
If you can find an 18mm bolt that is threaded far enough it would work also.
grocery getter
Famous Member
i've had good luck with using a piece of wire.
remember to remove all the plugs, for ease of turning
remember to remove all the plugs, for ease of turning
If you are just swapping your old (still working for the most part) dizzy for a DS2 you dont have to know where TDC is. BEFORE you take anything apart get your timing light and tach out and see where the timing is running at idle and at various rpms. Disconnect and plug the vac (unless its a load o) and note where it runs that way also. Put this note in a safe place so it does not get lost. Remove the cap (but leave wires connected for now). Look at where the rotor is positioned, look for a good sight line and make a mark if you have to (maybe even write it down on your note sheet). If you cant sight it to something good you can still bump the starter to get it lined up with something that is easy to see. Now disconnect the battery. Set the cap back on and remembering where the rotor was pointed and see which terminal (spark plug wire) it is pointed to, take note. Now you can remove the cap and wires if you are replacing them. You can now remove the old dizzy. Notice as you lift the dizzy out the rotor will turn a bit. Note where it stops turning as you are lifting and when installing the new one turn the rotor to that position so as it drops in it will rotate and end up in the proper position (that you sighted and noted earlier). If it does not drop in all the way you have to pull it back out and with a 1/4" drive socket on an extension rotate the oil pump shaft slightly and then try reinstalling the dizzy. If it does not drop all the way again remove and rotate the pump shaft slightly again. Once you get it dropped in all the way so the rotor is pointing to the same spot it was before you can put the cap on and get the terminal in about the same spot it was before and then put the wires on with the proper one where the rotor is/was. You then do the rest of the wiring/ mods. Its then start up time. Set the timing back to where it was and you should be at least as good as you were before.
grocery getter
Famous Member
fordconvert":35r0iege said:
many people miss this step, Good Stuff !
You can mark this rotor location with a white felt tip marker on the dizzy housing.
I use the 'Dutch Boy Method' to find TDC by sticking my finger in the #1 hole and turning the crank until there is pressure. If you use the probe only, you can get the top of the exhaust stroke and be 180* off. Using the DBM, once the pressure starts to build around your finger, THEN insert your probe and turn until it stops rising. That is TDC.
At this point, use the white marker to put a new tick on your harmonic balancer so you can time it accurately in the future. (Often the ring has slipped on the rubber membrane and the original marks are off.)
I use the 'Dutch Boy Method' to find TDC by sticking my finger in the #1 hole and turning the crank until there is pressure. If you use the probe only, you can get the top of the exhaust stroke and be 180* off. Using the DBM, once the pressure starts to build around your finger, THEN insert your probe and turn until it stops rising. That is TDC.
At this point, use the white marker to put a new tick on your harmonic balancer so you can time it accurately in the future. (Often the ring has slipped on the rubber membrane and the original marks are off.)
I prefer to get to TBC before swapping the dizzy out just for that reason. The chances of making sure you are dead on again is not worth it. I actually have one of those magnetic wands that makes this easy.
I really need to do a demo of this and write it up. It works like a charm.
1) Remove the valve cover
2) Remove #1 Spark Plug
3) By hand, rotate the crank the normal direction of rotation. Rotate it until you see the intake valve close. The piston should then be on the way up on the compression stroke.
4) When the piston becomes visible through the plug hole, put the magnetic end of the wand into the cylinder to rest on the center of the piston.
5) I then place a long board across the hood of the car. From there, I hang a drafter's T off that board (or any kind of stick/yard stick that will lean up vertically against that board).
6) I then slowly rotate the crank by hand, which will cause the end of the wand to go down. My vertical stick is right behind the end of the wand.
7) Once I see the end of the wand go back up, I know that end point. I mark that point on my vertical stick. I then reverse direction and turn the crank opposite of normal rotation causing the wand to go down again. I also note the relative angle of the crank.
8) Rotate the crank opposite normal direction until the wand goes back up to the place I marked in the previous step. I again note the relative position of the crank.
9) At this point, you should be able to estimate the total number of degrees you rotated between steps 7 and 8. One thing that can help, is to mark the crank angle with a small mark on the block or timing plate in steps 7 and 8. I then rotate the crank to be half way between those 2 angles.
That is pretty much dead on, TDC. The method sounds really involved but it's relatively quick and I've found to be extremely accurate.
I then just put the dizzy in by putting the rotor facing the direction I want #1 wire to be and then just put it in.
I really need to do a demo of this and write it up. It works like a charm.
1) Remove the valve cover
2) Remove #1 Spark Plug
3) By hand, rotate the crank the normal direction of rotation. Rotate it until you see the intake valve close. The piston should then be on the way up on the compression stroke.
4) When the piston becomes visible through the plug hole, put the magnetic end of the wand into the cylinder to rest on the center of the piston.
5) I then place a long board across the hood of the car. From there, I hang a drafter's T off that board (or any kind of stick/yard stick that will lean up vertically against that board).
6) I then slowly rotate the crank by hand, which will cause the end of the wand to go down. My vertical stick is right behind the end of the wand.
7) Once I see the end of the wand go back up, I know that end point. I mark that point on my vertical stick. I then reverse direction and turn the crank opposite of normal rotation causing the wand to go down again. I also note the relative angle of the crank.
8) Rotate the crank opposite normal direction until the wand goes back up to the place I marked in the previous step. I again note the relative position of the crank.
9) At this point, you should be able to estimate the total number of degrees you rotated between steps 7 and 8. One thing that can help, is to mark the crank angle with a small mark on the block or timing plate in steps 7 and 8. I then rotate the crank to be half way between those 2 angles.
That is pretty much dead on, TDC. The method sounds really involved but it's relatively quick and I've found to be extremely accurate.
I then just put the dizzy in by putting the rotor facing the direction I want #1 wire to be and then just put it in.
pedal2themetal45
Famous Member
You don't realy have to find TDC to swap out dizzy's.. NOW BEFORE YOU JUMP ME.... 
If you have the old dizzy still in the motor pull the cap and rotate the motor by hand untill the rotor is pointing at eather 3, 6, 9 or 12 o'clock Then pull the old dizzy and install the new dizzy with the rotor pointing to the same spot.. noticing how much the rotor turns as you pull the old one out well help in instaling the new one..
This is just one of many ways to do it..
tim
If you have the old dizzy still in the motor pull the cap and rotate the motor by hand untill the rotor is pointing at eather 3, 6, 9 or 12 o'clock Then pull the old dizzy and install the new dizzy with the rotor pointing to the same spot.. noticing how much the rotor turns as you pull the old one out well help in instaling the new one..
This is just one of many ways to do it..
tim
grocery getter
Famous Member
yeah, that gets back to fordconvert's post. I think the reason for this thread though was to verify the balancer hasn't moved.
grocery getter
Famous Member
kuhlou":hqani140 said:grocery getter":hqani140 said:
actually, have never done this before, so get the detail from beginning to end, along with everyone's favorite tips is especially valuable info.
This is terrific, keep 'em coming!
do a lot of searching, there is a ton of info here....
as you have read, there can be issues but, most of these upgrades go without a hitch 8)
I forgot to add that on a manual transmission car its critical you dont have it in gear for all of this because if you bump the car the motor could turn and then all this which way its pointing and marks no longer mean anything and you then need to find #1 compression stroke and start from scratch.
The thing with the stopper bolt thing is just to find and verify the exact point for the marks on the balancer. I personally dont care what the number is I just want to know the range. Thats why if your engine is running now its worth some time with a timing light, tach, and note pad to know where you are at before you start messing. I have one car that runs great showing 10*after at the marks, must be some mismash with the parts. Not worth my time to figure out and fix. I just know that 10after* is the number I am shooting for as a starting point when I take things apart.
The thing with the stopper bolt thing is just to find and verify the exact point for the marks on the balancer. I personally dont care what the number is I just want to know the range. Thats why if your engine is running now its worth some time with a timing light, tach, and note pad to know where you are at before you start messing. I have one car that runs great showing 10*after at the marks, must be some mismash with the parts. Not worth my time to figure out and fix. I just know that 10after* is the number I am shooting for as a starting point when I take things apart.
kuhlou
Well-known member
c4 tranny here. Pull all the plugs to be able to turn over the motor? bolt stopper thing procedure would be to rotate engine to bolt stop, then keep backing out the bolt a turn, rotate engine, etc, etc, until piston does not touch bolt. That establishes tdc? Don't know if I'll use that method, since there are many other tips here as well. Need to satisfy my curiosity.
Thats more or less the theory behind using the stop bolt.
IMHO the only time you really need to find the exact TDC is when degreeing a cam. At that point you usually have the head off so it is easily done with a dial indicator. The stop bolt could also be fairly accurate but on some engines the angle of the plug hole is less than optimum. The rest of the procedures are pretty much only good for getting you close enough to do something like drop in a distributor.
IMHO the only time you really need to find the exact TDC is when degreeing a cam. At that point you usually have the head off so it is easily done with a dial indicator. The stop bolt could also be fairly accurate but on some engines the angle of the plug hole is less than optimum. The rest of the procedures are pretty much only good for getting you close enough to do something like drop in a distributor.
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