Harmonic balancer

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Joel Chapman

Joel Chapman

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So I have 74 360 that I have been putting together for my 71 dart. So far I have swapped the cam shaft on the long block and worked my way up. I am at the point of installing the balancer but 0 and my line are off by about one degree (see picture). I made sure my dots lined up on my timing chain as well as well as degreed the cam. I got a degree of 106.5 when it when comp said it should be 106. I figured that this .5 was due to the pointer landing between the lines while I was reading the whee. Long story short is my balancer being off a big deal? Did I do something wrong with the cam install?

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That's actually 2 degrees at the crank. Each hash mark is 2, not 1. You say you degreed the cam. Why didn't you remark the balancer when you found true TDC?
 
Joel Chapman said:
What do you mean?

so just remark the balancer?
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I mean you needed the balancer when you degreed the camshaft. You would have found the error then and remarked the balancer.

No, you cannot just arbitrarily remark the balancer. You need to find true TDC with a piston stop first. Then you will have a correct reference to make a new mark.
 
How do you know it’s truly on TDC right now?

The timing chain has nothing to do with the balancer lining up with the marks on the timing cover. All you need To find TDC is a block, crankshaft, #1 rod & piston, timing cover and balancer.
 
413 said:
How do you know it’s truly on TDC right now?

The timing chain has nothing to do with the balancer lining up with the marks on the timing cover. All you need To find TDC is a block, crankshaft, #1 rod & piston, timing cover and balancer.
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I'm wondering the same. He "says" he degreed the cam. If that's true, he had to find TDC, but he's not acting like he knows exactly what that is.
 
I wasn't talking about what the timing cover was saying. I was just explaining, maybe for someone else who doesn't know ,that the camshaft is rotating at 1/2 crankshaft speed. 4 cycle engine. Fact.
The timing tape on the balancer also needs to be removed. The TDC needs to be verified with a degree wheel. The balance mark may be incorrect. Balancer ring slippage ? We aren't there. The camshaft mfg. should have given instructions with the cam on how to determine TDC in order to accurately degree the cam. Sounds like part of the story may be missing...
 
MoparLeo said:
I wasn't talking about what the timing cover was saying. I was just explaining, maybe for someone else who doesn't know ,that the camshaft is rotating at 1/2 crankshaft speed. 4 cycle engine. Fact.
The timing tape on the balancer also needs to be removed. The TDC needs to be verified with a degree wheel. The balance mark may be incorrect. Balancer ring slippage ? We aren't there. The camshaft mfg. should have given instructions with the cam on how to determine TDC in order to accurately degree the cam. Sounds like part of the story may be missing...
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Right, which is what I was gettin at. We don't know what he knows or really did. Just trying to help point him in the right direction. Finding true TDC is imperative.
 
A degree wheel is not needed to verify that the TDC mark on the dampener is correct. A piston stop can be used & one can be purchased, or made from an old spark plug. Install the stop in #1 or #6 cyl & rotate the engine CCW slowly until the piston hits the stop. Mark the '0' spot on the damp. Now rotate the engine slowly CW until contact is made with the stop. Mark the '0' mark on the damp. TDC for that dampener is halfway between the two marks. It is a good idea to back off the rockers on the cyl used for testing, to avoid valve/piston stop contact which can occur on some engines.
 
You still need the degree wheel to degree the cam. At the same this will verify if the tdc notch on the damper is correct. A stop will also be needed.
 
Bewy said:
A degree wheel is not needed to verify that the TDC mark on the dampener is correct. A piston stop can be used & one can be purchased, or made from an old spark plug. Install the stop in #1 or #6 cyl & rotate the engine CCW slowly until the piston hits the stop. Mark the '0' spot on the damp. Now rotate the engine slowly CW until contact is made with the stop. Mark the '0' mark on the damp. TDC for that dampener is halfway between the two marks. It is a good idea to back off the rockers on the cyl used for testing, to avoid valve/piston stop contact which can occur on some engines.
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If all you want is to check TDC, true, but why on earth go to that trouble without the wheel? Just makes no sense.
 
My mark on my new balancer was off 8' . I used a piston stop and remarked it. Thought my timing was set at at 16btdc when it was actually at 8.
 
Joel Chapman said:
What do you mean?

so just remark the balancer?
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yup, look up online for how to use the piston stop to determine TDC ( would type it out, but the information is online ). I have had to do it on a couple of engines especially with a/m VD. i had to do it once with a stock 340 set up, not sure why but the vibration damper was off slightly, maybe someone messed up putting it together way back when.
 
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RustyRatRod said:
Right, which is what I was gettin at. We don't know what he knows or really did. Just trying to help point him in the right direction. Finding true TDC is imperative.
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So I used a degree wheel and kit to find tdc and degree my cam. But no where in the instructions I had for the cam degree did it say to install my balancer while degreeing in my cam. I may be new to all this but I am trying to make sure to do everything right and read through and reread through all the instructions before and while doing something.
 
Joel Chapman said:
View attachment 1715753111 View attachment 1715753113 View attachment 1715753114
So I used a degree wheel and kit to find tdc and degree my cam. But no where in the instructions I had for the cam degree did it say to install my balancer while degreeing in my cam. I may be new to all this but I am trying to make sure to do everything right and read through and reread through all the instructions before and while doing something.
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Ok, a couple of issues immediately jump out. You MUST MUST MUST have the dial indicator completely vertical to "whatever" you are measuring, otherwise your readings will not be accurate. In both pictures, you have the indicator totally off center of vertical on the piston and on the lifter. You have the pushrod lying against the cylinder head. That in no way shape form or fashion will ever read correctly. The indicator must be on center and vertical with the lifter bore, just the same as it must be on center and vertical with the piston.
 
Pick yourself up a set of dial indicator extensions. This way you can put the indicator's tip directly on the lifter....because like RRR said above it's critical (if you want accuracy) to have the indicator rod parallel with the lifter and there's no way it's happening with a pushrod between them. It usually takes some fussin' to get the dial indicator set up just right, but careful attention to all those little details is the difference between a good and a not-so-good result.
 
Post #16, verifying TDC with a degree wheel. My post, #15, was based on the statement made by the OP in post #1 that he was changing cams in a long block. Unless the meaning is different between our two countries, a long block engine has the heads installed.
So in this situation [ heads in place ], how does a degree wheel verify on it's own that the piston is at TDC, in order to verify the TDC mark??
 
Bewy said:
Post #16, verifying TDC with a degree wheel. My post, #15, was based on the statement made by the OP in post #1 that he was changing cams in a long block. Unless the meaning is different between our two countries, a long block engine has the heads installed.
So in this situation [ heads in place ], how does a degree wheel verify on it's own that the piston is at TDC, in order to verify the TDC mark??
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It cannot, which is why I've said at least three times now to use a piston stop. Is the meaning of THAT different "down there"?
 
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