Engine: Easiest way to find 'Top Dead Center' on a 259

[4hawks]

What is the easiest technique to find 'top dead center' on a 259 motor? has anyone used a 'T.D.C Stop' from Summit Racing?
Thanks!

[345 DeSoto]

Pull the number 1 spark plug, hold your finger over the hole and have someone carefully roll the engine over (or use a remote start button). When the compression pushes your finger off the plug hole, that's it.

[PackardV8]

Are we discussing a short block? A TDC stop is just a steel strap with two holes for head bolts and a bolt in the center. You can make one in about five minutes at zero cost.



jack vines

[Lynn]

Depends. Is the engine assembled? Or is it just the short block assy?

[altair]

With the valve covers on remove #1 plug, line up the timing mark, look in with a flashlight or insert a straw, with valve covers off wiggle the rockers if they are both free that is #1 TDC.

[Lynn]

With the valve covers on remove #1 plug, line up the timing mark, look in with a flashlight or insert a straw, with valve covers off wiggle the rockers if they are both free that is #1 TDC.

I am guessing you meant "with the valve covers off" and not "with the valve covers on"

Also, to be clear, if both rockers are loose then you will be at approximately TDC, but TDC on the EXHAUST stroke, not the firing stroke. It will be 180 degrees from TDC firing.

Also, this method is only an approximation of TDC. I have no idea if the OP is wanting an exact TDC location. If so, this won't do it. If, on the other hand he is just trying to figure out how to stab a distributor, then yes, this is close enough.

[Mike Van Veghten]

Need more details..!
Depends on whether you want to know..."exactly", down to the tenth of a degree, or just close for a valve adjustment.

So...how close do you need it to be ?

Mike

[4hawks]

[QUOTE=Mike Van Veghten;n1817065]Need more details..!
Depends on whether you want to know..."exactly", down to the tenth of a degree, or just close for a valve adjustment.

So...how close do you need it to be ?

Mike[/QUOTE

Thanks everyone for all the info! I am in the process of lining everything up so I can set the timing.

[PackardV8]

While this is not exactly the OPs question, it is good to remember there are more than one Studebaker V8 timing cover and more than one Studebaker V8 front balance damper. Anytime an engine is rebuilt, TDC should be confirmed with a piston stop before the heads are installed. We've seen more than one assemblage of random parts where the pointer on the timing cover was not aimed at the TDC mark on the front damper.

jack vines

[arkusvt]

for true top dead center on a short block make a simple bracket as jack suggests, bring the piston up and mark the damper, turn the engine the other way until piston hits bracket again, mark the damper and find the exact center between the two marks; that is what we are looking for. on an assembled engine you could use a dial indicator thru the plug hole and accomplish the same thing. learned this from my flathead ford mentor 50 odd years ago. works every time!

[4hawks]

for true top dead center on a short block make a simple bracket as jack suggests, bring the piston up and mark the damper, turn the engine the other way until piston hits bracket again, mark the damper and find the exact center between the two marks; that is what we are looking for. on an assembled engine you could use a dial indicator thru the plug hole and accomplish the same thing. learned this from my flathead ford mentor 50 odd years ago. works every time!

Thanks for the post!

[tim333]

I bought a whistle for a few bucks off Ebay, put in number one cylinder and turn the engine over til the whistle blows. The timing marks will just about be lined up, then you can turn it slow to line up TDC perfectly.

[Dwain G.]

The beautiful thing about using a whistle is that it won't make a noise when #1 cylinder is coming up on the exhaust stroke, only when coming up on the compression stroke.
Also if the pointer is on the UDC mark and you can feel clearance in both rocker arms of #1 cylinder, you ARE on TDC firing position. Distributor rotor should point forward at that time.
I should probably also explain that if you have the front cover off and the cam and crank gear marks aligned, the engine is actually at #6 cylinder firing position. One full turn of the crankshaft will put the cam gear mark 180º away from the crank gear and put #1 cylinder in firing position. (One full turn of the crankshaft causes a half-turn of the cam shaft.)
DG

[bezhawk]

I bought an adapter that screws into the spark plug hole, and you mount a dial indicator on it.