TOP DEAD CENTER Ford 1946

[Harylufa]

Dear Friends!
I have just read in various article about how to set TDC. I took my cylinder heads out and re install. It work great, but today I read about to set TDC with the head on removing the spark plug #1. As mine has no mark.
What is the best and precise method? as I ca not see the piston when it is high top. I read a lot over there but I need simple words to understand it. I found this picture and my car needs Flywheel degrees piston position 4º degree btdc.

Please try to help me, It is important to set the correct TDC my dist is all ok now.

Harylufa

[Old Henry]

Originally Posted by Harylufa

Dear Friends!
I have just read in various article about how to set TDC. I took my cylinder heads out and re install. It work great, but today I read about to set TDC with the head on removing the spark plug #1. As mine has no mark.
What is the best and precise method? as I ca not see the piston when it is high top. I read a lot over there but I need simple words to understand it. I found this picture and my car needs Flywheel degrees piston position 4º degree btdc.

Please try to help me, It is important to set the correct TDC my dist is all ok now.

Harylufa

I'm not sure what you are trying to set by TDC (top dead center). Since you only removed your heads and put them back on you didn't change anything affected by TDC and have nothing to adjust.

If you are trying to set the timing on your distributor that is another thing. To be accurate to have the second points open at 4 degrees before TDC that fires the coil you have to take the distributor out and follow the instructions below. Personally, I don't think timing is that critical and just set my adjusting screw that's on the side of the distributor in the middle of the slot. Anytime that I have set the timing with the distributor off that's where the screw ends up so I just use that spot.

If you're trying to set something other than distributor timing let us know because that is all I can think for you to set under your circumstances.

[Straightpipes]

I think he wants to put a timing mark on the pulley.......

[Old Henry]

Originally Posted by Straightpipes

I think he wants to put a timing mark on the pulley.......

If that is the case. He would have been much better off making that mark before putting the heads back on. Then he really could see what TDC was. Now, I don't know how he'd do it without removing the one head again.

I think most optimize the distributor timing with a vacuum gauge as described here: http://www.btc-bci.com/~billben/timing.htm That's what I would recommend.

ADDENDUM: I had never actually tried timing my distributor with my vacuum gauge before even though I'd heard of it. I just always left it at 4 BTDC thinking that was probably optimal. But, I just went out and tried it. At 4 BTDC I got 14" of vacuum. I slide the timing plate/screw as advanced as I could (probably made it 8 BTDC) and, low and behold, I got another inch of vacuum and little faster idle! I then went out and tested my vacuum advance screwed clear out as recommended climbing a hill and no ping/knock! I feel better now having optimized my timing and vacuum advance even beyond manufacturer's recommendations. I like it!

[George/Maine]

I saw this in and old book you may want to try it.
When # 2 and 3 are equal in same height distance from top of cylinder head.Use something soft in same lenght.One piston is going down and other is coming up.

[Harylufa]

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Hi!
Thank for information, Straightpipes is right, I want to mark pulley, my dist is already set.
I had the head out and re installed two day before, but as Henry says, is better with the head out.
If I take the head out now can I re install the gasket or I must put another new one?

Thank you!

[Old Henry]

Just in case you missed it. Here it is again.

Originally Posted by Old Henry

I think most optimize the distributor timing with a vacuum gauge as described here: http://www.btc-bci.com/~billben/timing.htm That's what I would recommend.

ADDENDUM: I had never actually tried timing my distributor with my vacuum gauge before even though I'd heard of it. I just always left it at 4 BTDC thinking that was probably optimal. But, I just went out and tried it. At 4 BTDC I got 14" of vacuum. I slide the timing plate/screw as advanced as I could (probably made it 8 BTDC) and, low and behold, I got another inch of vacuum and little faster idle! I then went out and tested my vacuum advance screwed clear out as recommended climbing a hill and no ping/knock! I feel better now having optimized my timing and vacuum advance even beyond manufacturer's recommendations. I like it!

I'm not sure anyone would recommend that you remove the head to mark TDC when you can really get a better timing with the vacuum gauge as described above.

If you are determined to remove the head re-install it with a new gasket.

[Harylufa]

Henry!
Ok, I will try to get the vacuum gauge then?

Harylufa

[Chris Nelson]

By using a large plastic ZIP-TIE, you can find top dead center. Just insert thelarge end of the plastic tie into the cyl and when it stops rising, you have found TDC.

[Old Henry]

Originally Posted by Harylufa

Henry!
Ok, I will try to get the vacuum gauge then?

Yes. Now that I've tried it I think you'll get more optimal timing with the vacuum gauge than a TDC mark. I did.

[V8 Bob]

Originally Posted by Harylufa

Dear Friends!
I have just read in various article about how to set TDC. I took my cylinder heads out and re install. It work great, but today I read about to set TDC with the head on removing the spark plug #1. As mine has no mark.
What is the best and precise method? as I ca not see the piston when it is high top. I read a lot over there but I need simple words to understand it. I found this picture and my car needs Flywheel degrees piston position 4º degree btdc.

Please try to help me, It is important to set the correct TDC my dist is all ok now.

Harylufa

To answer your question, the most accurate method of finding TDC is the piston stop method, and can only be done with the RH head off. A 1/4" or thicker steel strap is bolted over the number 1 piston with a bolt installed in the middle that can be adjusted. Install a degree wheel to the crank shaft, and fab a permanent pointer to the front cover, water pump, etc. Turn the crank clockwise, adjust the bolt for about 20-30 degrees, then turn CCW, measure, and remeasure CW, divide by two, and that's TDC. Perform this more than once until the CCW & CW numbers are exactly the same befroe you divide for TDC.
I know many use a vacuum gauge to set initial timing, including me, but you should know what the timing really is, including total timing, which can't be done with a vacuum gauge, only with a timing light.

[Old Henry]

Originally Posted by Chris Nelson

By using a large plastic ZIP-TIE, you can find top dead center. Just insert thelarge end of the plastic tie into the cyl and when it stops rising, you have found TDC.

Just be extra careful not to drop the zip tie into the piston. Then you would be removing and re-installing the head again.

[V8 Bob]

Originally Posted by Juergen

The most accurate way to get top center is to hollow out an old spark plug and replace the center with an extended bolt which will hit the cylinder top a little before top dead center. Rotate the crank by hand in one direction till it hits the "plug". Mark this spot. Now rotate the crank by hand in the other direction until it hits the plug. Mark this spot. Top dead center is in the middle of these two marks.

You can't do that on a Ford flathead, 'cause the exhaust valve is under the plug.

[lee34]

The best way to find tdc you need a degree wheel and a dial indicator.set the dial indicator so you can stop the piston in the exact same spot coming up. It is better if you use a place that is at least a 1/4 inch btdc.Secure a degree wheel to crankshaft,rotate crank until top of piston moves your indicator to a number (can be any number) record that number.make a pointer to show where degree wheel is stopped.(a coat hanger works) record position of degree wheel that pointer is indicating.Rotate the crankshaft in opposite rotation until piston contacts dial indicator and moves it to the same number as before.See the degree on the degree wheel that the pointer is at.TDC will be half way between the two readings.You can mark pulley etc.accordingly Lee34

[Harylufa]

Hi!
yes , i can see the exhaust valve, no piston. So, i must take the head out? You mean that could be better than vacuum gauge? if I do not want to take the head out.

Harylufa

[Harylufa]

Originally Posted by lee34

The best way to find tdc you need a degree wheel and a dial indicator.set the dial indicator so you can stop the piston in the exact same spot coming up. It is better if you use a place that is at least a 1/4 inch btdc.Secure a degree wheel to crankshaft,rotate crank until top of piston moves your indicator to a number (can be any number) record that number.make a pointer to show where degree wheel is stopped.(a coat hanger works) record position of degree wheel that pointer is indicating.Rotate the crankshaft in opposite rotation until piston contacts dial indicator and moves it to the same number as before.See the degree on the degree wheel that the pointer is at.TDC will be half way between the two readings.You can mark pulley etc.accordingly Lee34

Hi!
This is without taking the head out? am I right?
Harylufa

[Harylufa]

Originally Posted by V8 Bob

To answer your question, the most accurate method of finding TDC is the piston stop method, and can only be done with the RH head off. A 1/4" or thicker steel strap is bolted over the number 1 piston with a bolt installed in the middle that can be adjusted. Install a degree wheel to the crank shaft, and fab a permanent pointer to the front cover, water pump, etc. Turn the crank clockwise, adjust the bolt for about 20-30 degrees, then turn CCW, measure, and releaser CW, divide by two, and that's TDC. Perform this more than once until the CCW & CW numbers are exactly the same befroe you divide for TDC.
I know many use a vacuum gauge to set initial timing, including me, but you should know what the timing really is, including total timing, which can't be done with a vacuum gauge, only with a timing light.

HI!
I read how to set TDC when my head was reinstalled, I feel no good for this, I lost the chance to do everything right, But I realized after, God!

[Randy]

Originally Posted by Chris Nelson

By using a large plastic ZIP-TIE, you can find top dead center. Just insert thelarge end of the plastic tie into the cyl and when it stops rising, you have found TDC.

That's a partial description of a method to find TDC, but absent more detail will find you one of two things: 1) when the piston to head clearance equals the thickness of the zip tie that you use, or 2) that the piston to head clearance exceeds the thickness of the zip tie.

Going off the top of my head, the instructions are roughly this: Fix a timing pointer to the timing cover that overhangs the crank pulley. With a thumb over the spark plug hole, rotate the engine by hand until the compression forces the thumb off the hole. Rotate the engine by hand in reverse about 1/4 turn. Put a zip tie or a piece of small rope down through the spark plug hole until it rests on top of the piston. Rotate the engine again clockwise, by hand, until the rope stops the piston from rising. Put a chalk mark on the pulley in line with the pointer. Now reverse the rotation, by hand, of the crankshaft until the piston goes all the way down and then all the way back up and until the rope once again stops the piston. Again mark with chalk the pulley in line with the pointer. The point exactly in the middle of the two marks you have made will be TDC. It's important that the rope on top of the piston remains in the same shape, mass and position when making the second mark as it was in when the first mark was made.

[TomO]

Here is a link to an easy way to find TDC.

http://www.wikihow.com/Find-Your-Eng...ad-Center-(TDC)

A variation is to put oil in the tube and then mark the high point going forward, then go past TDC and mark the high point coming backward. TDC will be exactly in the middle of the two marks. They will be about 1/8" apart, depending on the size of the tubing used.

[Harylufa]

Originally Posted by TomO

Here is a link to an easy way to find TDC.

http://www.wikihow.com/Find-Your-Eng...ad-Center-(TDC)

A variation is to put oil in the tube and then mark the high point going forward, then go past TDC and mark the high point coming backward. TDC will be exactly in the middle of the two marks. They will be about 1/8" apart, depending on the size of the tubing used.

Hi!
I read that putting a tube full of oil, what happen with valve? because in spark plug hole I see valves. Not the piston itself because is below.

Thanks

Harylufa