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I'm having a problem trying to adjust my timing pointer. I bought a proform piston stop to find tdc. With it installed, i can turn to motor over and it wont hit the piston stop. I have flat top pistons and trick flow heads. Is there anything i can do or make because i dont have time to pull the head because i have to go to the track on friday. thanks
I had the same problem with my Sportsman II heads. The threaded part wasn't long enough so I got a piece of threaded rod, cut it off about an inch longer than came on my piston stop, and used it - worked fine!
Next question - if you go one way and mark the stop point, then turn the motor over the other way to the stop point, TDC should be EXACTLY the mid-point between the two marks, right? If so, my pointer is off about 4 degrees....
This is kind of a rigg job way but it will work . Take a pice of wier and feed it down the # 1 tube bend acordingly . You want the wier long enoghf so you do not loose it and have a few inchs left. Take another pice of wier and make a loop that can be in a fix position atatch to head somewhere . Feed the the up down wier though the loop . Take a marker and mark the stops . Not the correct way but it get you close .
Originally posted by vernw
Next question - if you go one way and mark the stop point, then turn the motor over the other way to the stop point, TDC should be EXACTLY the mid-point between the two marks, right?
Correct. That's why you should be using a degree wheel. After turning one way then the other, you calculate half way between the 2 stops. Turn the engine over until that mark is at the pointer you used for the degree wheel. Adjust the adjustable timing mark to indicate TDC. Using an adjustable timing pointer, you should be using a marked balancer or timing tape on the balancer to set your timing.
The first engine I put together years ago ran fine but I was worried about the 50+* of timing I had it set at. When I finally checked TDC I found I was actually out 8*.
Don't believe your timing marks unless you find TDC with a degree wheel first.
I've seen factory pointers off by as much as 8*. Every motor I put together now gets checked and most end up with aftermarket pointers or re-located stock pointers b/c they're off.
Well, since my mid-point comes out to 4*BTDC, then I guess I'm really only running 2*BTDC base timing since I set it for the "normal" 6*BTDC initial. Thanks, Folks!
I got this one from some BMW guy:
Gut a spark plug and fit a piece of clear tubing in it
thread the plug and put the other end of the tube in a can of oil
to find TDC, turn the motor untill the oil is neither pulling or pushing
worked for me because my dampener was so rusty I couldnt see the timing mark
hmm... anyone actually find some nasty marks ontop of the piston from the piston stop? Or break a piston stop in half dropping it into the cylinder? or... strip the spark plug threads because of the pressure applied to the piston stop? I just turned the crank while whatching the pushrods to see which stroke was the fireing stroke. Worked fine, timing is perfect now with those caculations.
Last edited by redbird_400; 09-22-2005 at 11:28 AM.
Timing is like any other accuracy. thermometers, tire pressure gauges etc all have variance. Try finding 2 watches with the exact same time.
Someone builds an engine and asks what the timing should be set at. Just because one engine like 36* total timing doesn't mean it's accurate. It also doesn't mean your timing marks are accurate. Once you set the timing mark for TDC, any timing adjustments you do are as correct as you can make them.
Even different timing lights can give different readings. I've tried an advance timing light and wasn't accurate enough. Since my balancer has the degree marks on it, I just use a normal, cheap craftsman, point at marks type. The multifire ignition causes the timing to jump around at low rpms but my distributor is locked at full advance so it doesn't matter what rpm the engine is at when I check the timing. It's always the same.
Originally posted by redbird_400 hmm... anyone actually find some nasty marks ontop of the piston from the piston stop? Or break a piston stop in half dropping it into the cylinder? or... strip the spark plug threads because of the pressure applied to the piston stop? I just turned the crank while whatching the pushrods to see which stroke was the fireing stroke. Worked fine, timing is perfect now with those caculations.
Some people should just stay away from cars.
You don't use the starter motor to rotate the crank to find TDC. There is no need to use excessive force to turn the crank by hand.
