Ok this may seem dumb to ask but I have to. I have a SBC 350 with no timing pointer. I have a new Harmonic balancer. The car is running pretty good but I'd like to check the timing. So my question is I know how to find the true TDC on the balancer with the use of piston stop but how do I install an after market adjustable pointer and make sure it's correct since I have no true pointer to go by. Or am I making this more complicated........After sitting here typing this I believe I may be making this complicated. LOL
Bring it up close to tdc then put a long screw drive in the spark plug hole an turn the crank until it comes up all the way.Install your aftermarket timing tab and set it.Most timing tabs are just bolt and go for sbc.
If you want to be more accurate you'll need to buy a timing light (they're cheap) that reads out the timing and adjust your tab accordingly.
make sure you are on the compression stroke, maybe pull a valve cover or feel the compression in the spark plug hole.
Yeah...The timing light can tell you where TDC is. (?!?) Better find TDC with the 'positive stop' method first. ...And check slop in the timing chain while you're at it...
You want to use a stop, the spark plug type...cheap tool or I can tell you how to make one in 5 minutes. SBC is a long rod engine with significant dwell at TDC, so any visual check of movement will only fall into a 2-3 degree range. For finding TDC, ANY pointer already there or improvised from a piece of wire will do the job, then when you have it located you simple match up your new marker to suit. You put in your spark plug based blocking bolt and gently turn engine til piston stops against the tool. Mark that point on your pulley against whatever pointer you have or make. Then you gently swing over engine the other way till it stops and mark that point. A good TDC is exactly half way between your marks. Measure that and mark it at your temporary pointer. Now, without moving engine, put on your new pointer and adjust it to whatever permanent mark you make or already have on the balancer. The point to understand here is that engine IS at TDC so if you don't move anything you can bolt down your new pointer anywhere that corresponds to a permanent mark at this time, and you are done. If your new pointer doesn't get shifted and your mark on pulley is permanent, you now have a permanent TDC until the rubber in the balancer fails. DO remember to remove the stop tool before you hit the starter!!
There are some interesting ideas here for sure LOL Use the Piston Stop to find true TDC, that is the ONLY accurate way to do this with a motor ***embled, in the car. put the stop in the spark plug hole, turn the motor one direction until it hits the stop. Make a mark on the balancer using something for reference, like a bolt in the cover, you can even draw a line on the cover. Now turn it the other direction until it hits the stop and make a second mark on the balancer across from your reference point. measure the distance between the two marks. That is your TDC. Take the piston stop out and rotate the motor until the half way makr lines up with the reference mark. You are now at true TDC. Now set you new adjustable pointer to match TDC mark on your balancer. If the balancer has timing marks, you are Done. Use a timing light to set the timing. It the balancer does not have any timing marks (some only have one big mark), then you need to get some timing tape for the diameter of the balancer.
You will need to use a positive stop on # 1 . The best is to make the stop from an old spark plug with a bit of rod welded where the electrode was, turn motor carefully both ways till it stops on it and mark damper,TDC is exactly in the middle of these two marks. Set your new pointer to this and you are good to go. A timing light can not find it unless you have it already. JW
Yeah I made a piston stop about 10 years ago but lost my degree wheel from 1 house to another. Anyway I will be getting a new pointer and installing soon. Thanks for all the input everyone.
Bruce L and Hotrodon have it right. It may work out that there is'nt enough adjustment on the timing tab, so you just put it in the center and remark the crank damper to match.
For this exercise it Makes no difference if its on compression or over lap. TDC is always TDC and crosses it twice.
31 Vicky. Hey I googled this a sec ago. Easier than explaining. And I do get the dwell statement. I wonder where in that stopped liquid is true TDC? http://www.2quicknovas.com/2qntdc.html
The guy that put that link together needs to edit the last paragraph because he's FOS and a dial indicator doesn't include piston dwell factor. The only way to do this correctly requires a piston stop. Maybe you want a tape or a degree wheel or a pointer or chalk or a ****ing crayon but its not going to be correct without a piston stop.
True - but your first post said "you could also use a degree wheel" and since that wasn't referenced to any other post, by itself the Degree wheel and suggestion are not of much use ....
When you get TDC ,remove the pulley and the keyway will be a 12 o'clock That's close enough. Then mark were you want the mark.
Oh brother !!! TDC is a very precise and finite point in an engines cycle. There is no "close enough" Y'all just stay far away from my stuff.
Listen fenders, you are FOS. TDC is not "simply" when the piston is at the top of its travel. The piston reaches the top of its travel way before the crank hits TDC position and the piston stays at the top of its travel long after the crank p***es TDC position. How many degrees is "way before or way after"? We don't need a cam in a block to find TDC either so any reference to which cycle the cylinder is on is completely irrelevant. Saying "be sure you are on the compression stroke" to find TDC is pointless. Study "piston dwell" for some help on this.
When you put a timing chain on do you put cover on and pulley get TDC then remove. All timing is from keyway 12oclock KISS
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