How to find TDC with heads off engine

[slick5861]

I am installing a MSD Flying Magnet crank trigger on a SBC. The heads are off the engine getting ported. How do I find TDC ? Thanks for any suggestions.

[Ed McLawhorn Jr.]

I have a plate I bolt to block that covers #1 cylinder. Bolt pattern on plate matches up to head bolt holes in block. I drilled a hole in plate over center of piston and installed a bolt with 2- nuts. One on each side of plate to allow adjustment of depth of bolt. I screw bolt down so piston does not quite reach top. Then check TDC just like head was installed. Basically I built a piston stop with a plate bolted to head.

Ed

[kansas stocker]

I have a 1/2" strap that bolts between 2 head bolts with a bolt that protrudes where it crosses the cylinder. I set the bolt down in the cylinder a quarter of an inch or so. With a degree wheel on I rotate the crank until it comes up against the bolt and take a reading. I then rotate the crank the other direction until the piston comes up against the bolt and take another reading. Split the difference and you should be at tdc. Repeat.
I've also used a dial indicator in a like manner at about 050.down. With the dial indicator you must push down on the piston to take up rod clearance.
Both have worked for me.

[dmir55]

Use the positive stop method. There is some dwell time with a dial indicator. If you don't have a degree wheel you use your damper. Mark the spots you stop on and split the difference. Hope this helps and happy motoring.

[George Mirza]

Are you trying to find the compression stroke? Look at the lifters of the number 1 cylinder, when they are both down and the piston is up that should be it. Then you can fine tune tdc with a stop or dial indicator like the others suggested.

[Lenny5160]

Originally Posted by George Mirza

Are you trying to find the compression stroke? Look at the lifters of the number 1 cylinder, when they are both down and the piston is up that should be it.

For crank trigger installation, you don't want actual TDC. If you want 34* of timing advance, you'll want the engine at 34* BTDC to set up the crank trigger.

As George said, watch for the #1 intake lifter to go up and down, then turn the engine until your timing pointer is pointing at 34* on the balancer. Follow the instructions from there.

[slick5861]

Originally Posted by Lenny5160

For crank trigger installation, you don't want actual TDC. If you want 34* of timing advance, you'll want the engine at 34* BTDC to set up the crank trigger.

As George said, watch for the #1 intake lifter to go up and down, then turn the engine until your timing pointer is pointing at 34* on the balancer. Follow the instructions from there.

This is what I was after, I wasn`t sure about the lifter movement, but you guys have clarified that question for me, Thank you, and I moved the balancer to 38 * and set the pick up for the timing.

[Mike Taylor 3601]

If you have any kind of timing or start retard boxes or have ignition box that does,you will have to set crank trigger 4-6* advanced from where you want you timing,they will filter 4-6* of timing out, use timing light to verify your timing.
Mike Taylor 3601