Dial indicator easier.
Trouble with Timing Chain install 383
- Thread starter roadrunnerh
- Start date
Here's a good video which clearly explains how to set up a degree wheel and use a piston stop.
Hopefully this helps, see if you can duplicate what he does here.
This is step 1.
Degreeing the cam is more complicated.
One thing he doesn't mention is checking to see where the indicator on your timing cover corresponds when you get the degree wheel at 0 degrees TDC.
It's a helpful thing to know after you get the engine back in the car.
You can also put timing tape on the dampener as an alternative.
Hopefully this helps, see if you can duplicate what he does here.
This is step 1.
Degreeing the cam is more complicated.
One thing he doesn't mention is checking to see where the indicator on your timing cover corresponds when you get the degree wheel at 0 degrees TDC.
It's a helpful thing to know after you get the engine back in the car.
You can also put timing tape on the dampener as an alternative.
There's a lot he doesn't cover. I guess his piston stop stopped the piston without any adjustments?
I'm on to using a dial indicator, and had to go back to my old one. The one with the kit is a POS that moves the needle every time you zero. The "dial" is sticky AF.
I'm on to using a dial indicator, and had to go back to my old one. The one with the kit is a POS that moves the needle every time you zero. The "dial" is sticky AF.
It doesn't matter where it stops the piston as long as it hits before the piston comes to the top.
Huh? I want the piston to stop at it's highest possible point, hence TDC? No?
That should work.
So the dial indicator goes down if you rotate the crank in either direction correct?
Just checked, yes sir.
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This is a simple determination. Don't make it more complicated than it really is. Use a dial indicator, rotate crank until you have the highest reading. Back down until you hit 0.50"; rotate until you have 0.50" the other way. Split the difference and you have TDC. Not rocket science here. Black_Sheep has it right...
Chuck (snook)
Chuck (snook)
Chuck I misread his post thinking he was using a piston stop so I deleted my reply. Although, the same principle applies to using a dial indicator. I prefer to measure .015 before TDC and .015 after TDC and split the difference on the degree wheel.
To the OP, Google piston dwell at TDC, it will lead you down a rabbit hole…
To the OP, Google piston dwell at TDC, it will lead you down a rabbit hole…
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Black_Sheep, the principle is the same, you had it right.
Chuck (snook)
Chuck (snook)
Thanks for the replies.
The dial indicator will be slightly less accurate than the piston stop, from the slack in bearing clearances etc. Very minimal
I may be repeating what others have said, but...
To find true piston TDC, you need something that randomly stops the piston near, but not at, TDC. Turn the engine just past TDC and install the piston stop. Now rotate the engine backwards until the piston (gently) hit the stop. Mark this point on the balancer where the tab shows zero. Now rotate the engine in the forward direction, (almost) 360 degrees until the piston again hits the stop. Again mark the balancer where the tab shows zero.
Measure the distance between these marks and divide by two. This is the exact TDC of the engine. In a perfect world, it will be exactly where it is marked on the balancer. If not, make a new mark where the true TDC is.
Now you can degree the cam.
Hope this helps
To find true piston TDC, you need something that randomly stops the piston near, but not at, TDC. Turn the engine just past TDC and install the piston stop. Now rotate the engine backwards until the piston (gently) hit the stop. Mark this point on the balancer where the tab shows zero. Now rotate the engine in the forward direction, (almost) 360 degrees until the piston again hits the stop. Again mark the balancer where the tab shows zero.
Measure the distance between these marks and divide by two. This is the exact TDC of the engine. In a perfect world, it will be exactly where it is marked on the balancer. If not, make a new mark where the true TDC is.
Now you can degree the cam.
Hope this helps
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Done properly, either way is within an acceptable margin of error. I only use a piston stop if the heads are staying on the motor, like when I had to mark TDC on the aftermarket balancer for my BIL's 340. IMHO the drawback to a piston stop is having to rotate the engine in both directions, even a new timing chain has a little backlash. I prefer rotating the crank in a clockwise direction and using a dial indicator if possible.
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