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Discussion Starter #1
this may sound like a dumb question but ive never removed a distributor..ive only put in a couple..

is it really necessary to put the engine to tdc for the number #1 cylinder when removing the distributor ? cant you just mark the position of the distibutor shaft to the intake or block..and then just mark the position of the rotor wherever it is??

im assuming you find tdc for number #1 first because then when you put the distibutor back in, you just make sure the rotor is pointed to number #1??
 

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As long as you mark where the rotor is when you take it out, and put it back in the same place it is no problem.

If you turn the motor over at all with the distributor out and move the orientation, then you should find TDC to reinstall it at the #1 cylinder.
 

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Close, but I haven't seen a reply hit it right yet.

First, scratch a mark of the dizzy body in relation to the block.

Next, take a marker and mark the rotor tip position in relation to the plastic body. This is where it needs to be *after* you install it again. Undo the hold-down clamp, then pull up on the dizzy. The rotor will turn. Once it is finished turning, mark the rotor position in relation to the plastic body again. You now know...

1) Where the rotor should be when you start to stab the dizzy back in.
2) Where the rotor should be after the dizzy seats.
3) Where the timing should be (real close) so that it starts okay.
 

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Discussion Starter #5
thanks for the help!
 

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I'm in the same situation, I recently bought a new short block assembled up to the heads, but I'm not sure if the 1st cylineder is at TDC. How can I tell/ change it so that it is?

Thanks!
 

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Discussion Starter #7
its pretty much general practice in engine building to set the motor to TDC for the number 1 cylinder.

you can try calling the engine builder and asking him...otherwise you can install the engine, and then put a breaker bar on the crank pulley and turn it clockwise. while doing this, have someone put their finger over the hole where the number one cylinder spark plug goes. you should feel pressure and air try to escape the hole as the piston comes up to TDC.
or....

you can have someone turn the motor over in short bursts without starting it. before you do this, , disconnect the number one spark plug wire at the plug and cover the boot with your hands so its dark. as the engine hits the Number 1 cylinder, you will see a spark in the boot of the wire.
 

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If the valve cover is off, bring the damper to zero degrees and watch the rockers of #1. Both should be closed when you reach zero.

Or, as mentioned, take out #1 plug, place your finger over the hole (you don't have to plug it up tight or anything), turn the engine with a ratchet and scoket (breaker bar better NOT be needed). When you feel the air puch on the finger, you are on teh compression stroke. You should also be close, or coming up on zero which will be TDC. Go ahead and turn to 10 degrees BTDC then drop the dizzy in and point the rotor to #1. Should fire right up.

When dropping the dizzy in, there may be that 1/8-1/4" more that it won't go. This is because it's not engaging the dizzy shaft. I can sometimes turn the engine by hand and get it to drop, sometimes I have to bump the starter.

P.S. All of the above is done easiest with the spark plugs out.
 

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I don't worry about finding TDC to pull the distributor, I just make a note as to where the rotor is pointing. I write down things like, pointing to the right bolt on the front of the intake, stuff like that. You will then notice if is going to rotate 1/4" or so counter clockwise when you remove it to make up for the gears at the bottom. Just remember to account for that quarter inch on the way back in. Another thing to notice is that the plug on the distributor is usually facing at around 5 oclock looking down on the distributor. You can put it in wrong and have the car run alright, I did it once by earing it to initially set the timing. Went to set timing with the gun and noticed that it was way off, had to advance a tooth. I always find TDC if needed by turning the motor over with your finger sealing the hole to #1 cylinder. There is a lot of pressure there and is very noticable, you won't be mistaken. From there get as close as you can with the harmonic balance to 0, moving the distributor makes up for the rest of the slack in time.
Good Luck.
 
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