Piston Stop and Degree Wheel

[luvmyclassics]

Getting ready to assemble my V8 flathead.

Any suggestions for a good piston stop and degree wheel?

1st time builder.

[J Witt]

I made a degree wheel by copying a circular protractor onto stiff cardboard and cutting a hole in the center that fit the front pulley bolt. A piece of coat hanger wire was used to make a pointer.

Only problem with this is that you have to turn the engine from the flywheel end.

You can buy a metal degree wheel from the various speed equipment guys like Jegs or Summit.

[JSeery]

With the heads off, a piston stop can be a strap of metal with holes drilled on each end to match head stud/bolts and a tapped hole in the center for a stop bolt. Spacers may be required under each end to adjust the stop to clear the piston. The only major requrement is consistency so that the piston stops in the same position. If all you are after is TDC you can just make marks on the pulley, a degree is not required.

[Willit Stop]

Here's a link for a printable degree wheel:
http://www.flatheadv8.org/degree.htm

[shoe box Jack]

Is the degree wheel just for setting the valve clearance?. Jack.

[37don]

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If you have the heads off why can't you just use a dial indicator
Don

[Mart]

On a flathead it is easy to make a piston stop. you don't need anything fancy. A simple piece of steel bolted down to the block face and projecting across the centre of the piston. Roll the engine over one way until the dome stops against the steel stop.

To mark the pulley for TDC you first need a pointer near the pulley. With the piston against the stop, put a temporary mark on the pulley. Roll the engine over the other way, and let the piston meet the stop again. Put another temporary mark on the pulley. Now put a permanent mark exactly half way between the two temporary marks. That is your TDC mark.

For me that is good enough. I use a snap on dial back timing light and can Get all the timing info I want from that.

That's good enough for ignition, for cam work you can attach a degree wheel, as long as the zero is aligned with your TDC, that will be good.

Mart.

[JSeery]

Originally Posted by 37don

If you have the heads off why can't you just use a dial indicator
Don

You can do it that way, but it is difficult to get it as accurate as you can do with a piston stop.

[Ronnie]

Originally Posted by 37don

If you have the heads off why can't you just use a dial indicator
Don

Can be done but there is dwell at the top of the stroke(no piston movement but some crank rotation) and it depends how anal you are. A solid stop is more down and dirty.The dial gauge just requires some addressing the dwell.

R

[Bill OH]

I used Mart's (#7) procedure and used a socket on a head stud - socket has to be large enough to stop the piston. Great for TDC.

[jrvariel48]

A dial indicator will give you the exact stop.

[Frank Miller]

Set up correctly a dial indicator will eliminate the need to feel equal pressure on a piston stop. If you do not have one then a homemade stop can easily be made. Yes, there is dwell at TDC so the stop or indicator needs to be a little below that. Turn the crank in one direction and mark the stop point or zero on on the crank pulley. Turn it in the other until the piston comes to the same position. Make another mark and the md point of the two marks is TDC.

[russcc]

Vern Tardel offer an inexpensive kit to put a pointer on the timing cover, so you can notch the crankshaft pulley for TDC. He suggests, as other have, using a dial indicator on top of the piston to determine actual TDC.

[Mart]

If I were to use a dial indicator, I'd still use it as described by Frank Miller, to get the piston stopped in the bore at a specific height, in either direction. It would be more accurate than trying to guess the exact point at which the rod is going over centre, if trying to detect exact TDC directly.

To be honest, I'd doubt a flathead needs the timing to be accurate to within a tenth of a degree, so "It's all good" as they say.

Mart.

[Ol' Ron]

I use a piece of angle iron bolted to the block. Sometimes a big flat washer. Sometimes you have to start thinking.