Crank Damper Timing Marks!!

[iwantacobra427]

Originally Posted by blykins

Hold up....

I think something else is amiss.

That balancer is used for all SBF's....with a SBF, you can have the pointer in 3 different spots...10:00, 11:00, and 2:00.

I just used that exact balancer on a 445W build up and didn't have any problems.

Here's what I would advise:

Do you have a degree wheel? I would find true TDC with a degree wheel and a piston stop. Then you'll know exactly where TDC is and you can put your pointer in the right spot. Something else is up....and you need to verify that your TDC is correct and then you can put your pointer in the right spot. I bought an adjustable pointer, that way I could put it anywhere in the 10-11:00 positions.

Also, another tip for quick starting.....when you verify TDC and get your pointer lined out, put your pointer at about 20 degrees BTDC (make sure #1 is on compression stroke). Then stab your distributor in and point the rotor at the #1 plug wire.

I had a builder do a semi-long block for me. They installed the pistons, crank, cam, timing set, and heads. I asked them to degree the cam (I don't have a degree wheel but read about degreeing a cam). I did the rest: oil pump/pan, timing cover, water pump, intake, etc.. I put the crank damper on last year as tight as I could without having the flywheel on. I'm pretty sure I did it correctly. I had a few books to reference. I found TDC for No. 1 cylinder, installed the timing pointer at the 10 o'clock position and lined up the '0' on the damper with it. I just got the flywheel on this past weekend and torqued the damper down. That's how I lost the timing mark under the pointer. I still don't understand why the damper doesn't have a scale to the left of the '0' mark. When I go to do the idle timing where is 10 or 12 BTDC on the damper??? That's why I was thinking of running timing tape to the left of TDC. I'm still weeks away from starting up the car.. I'm working on the engine and car at the same time.. I guess it's cheap insurance to double check TDC. Do the spark plug entry piston stops work well? I guess they are less accurately when compared with the head being off and the stop at the top? I definitely don't feel like taking the intake and heads off..
Do I have to take the damper off to use the degree wheel?

[blykins]

OK...the scale for BTDC should be to the right of the 0° mark. Think about it...direction of crank rotation is clockwise as you're facing the engine. As you're rotating the engine over, the pointer is going to come to degree marks to the right of the 0 first....because that's BEFORE top dead center. Make sense? As you turn the crankshaft some more, and the pointer passes the 0, it's going to be AFTER top dead center.

So let me understand something better.....how did you know you were at TDC without a piston stop or a previous harmonic balancer to read off of? You can't really eyeball it and be dead on....you really need to use a piston stop because the crank actually rotates several degrees while the piston is stationary at TDC. Chances are that everything is ok, but I think it would be good insurance to double check everything...and it's not difficult.

Spark plug piston stops are easy to use and they're effective. You can use your degree wheel with the balancer on it.

If you want, PM me and I'll give you my phone number. Sometimes this is easier to explain when someone is talking to you.

[iwantacobra427]

Originally Posted by blykins

OK...the scale for BTDC should be to the right of the 0° mark. Think about it...direction of crank rotation is clockwise as you're facing the engine. As you're rotating the engine over, the pointer is going to come to degree marks to the right of the 0 first....because that's BEFORE top dead center. Make sense? As you turn the crankshaft some more, and the pointer passes the 0, it's going to be AFTER top dead center.

So let me understand something better.....how did you know you were at TDC without a piston stop or a previous harmonic balancer to read off of? You can't really eyeball it and be dead on....you really need to use a piston stop because the crank actually rotates several degrees while the piston is stationary at TDC. Chances are that everything is ok, but I think it would be good insurance to double check everything...and it's not difficult.

Spark plug piston stops are easy to use and they're effective. You can use your degree wheel with the balancer on it.

If you want, PM me and I'll give you my phone number. Sometimes this is easier to explain when someone is talking to you.

Ah.. I see.. that makes sense. There are three separate sets of scales so two of them are BTDC. So after checking the idle timing I estimate the total timing by installing the applicable springs in the distibutor then run the engine at 3000 - 3500 rpm and see if the estimated number shows up with the timing light? I guess a safe number would be 35 degrees? You're right I'll buy that piston stop and double check the TDC. I eyeballed it through the sparkplug hole plus I didn't have the intake manifold on then so I could see the pushrod moving very easily. I'll give it a shot this weekend with the piston stop. Thanks for all your help.. I'm learning a lot! I'll probably take you up on the phone call help in the future!