How do you turn the engine over manually?

[MrTucker]

This is probably such a stupid question that I hate to ask, but how do you spin the motor over manually?

I've done it on newer models by simply putting a wrench on the crank pully bolt, but the front of my '53 GMC 228 doesn't have a bolt.

How do you do it?

[tmoble]

it's not what I would call "spinning" but you can use a big screwdriver on the flywheel/ring gear. there's also special tools for turning by the ring gear teeth.

[mr48chev]

If you pull the plugs you can usually turn on over with the fan and fan belt.

If you working on the bottom side such as changing rod bearings turning it with a big screw driver or pry bar on the ring gear works or I have used a wrench on the clutch bolts or torque converter bolts a lot to turn one.

[coralhead]

I use two short bolts in the harmonic balancer pulling holes. Then you can use a bar or screwdriver.

[magicoolbus]

You can also put it in gear and push, espcially if the plugs are out. In absence of a bump starter, I use this to get engines on TDC for setting dizzies. Easy to make uber small adjustments when trans is in 4th. Can't do this with an automatic so I use a flywheel turner sometimes too.

[booger1949]

them motors dont have much compression so if the fan belt is still on it just grab the fan an push r pull it an it should turn right over

[FFredo]

If you pull the plugs you'll have zero compression. If it feels tight thats a good thing because it points to a nice seat on the piston rings.

[MrTucker]

thanks guys. i'll try these tactics out.

fyi - there is no fan belt and it's an automatic. I'll try the 2 bolt/pry bar method

[Dan Bowles]

Not sure on the GMC motors but if you notice on the same era Chevies there is a 1" or so hole in the splash apron behind the grille. They still had the ability to use the hand cranks of old. I happen to have one from an IH Super C that fit in pretty good. It is a 16 mm bar with a pin through the end. It is the same as an old Ford jack wrench my employer used to produce. I use ours now and again and have cranked over our 1 1/2 ton '49 with a 235 to verify the valves weren't stuck! Never tried to crank start one, just turn it over.

[MrTucker]

I'd love to see a picture of that!

[Dan Bowles]

I'll have to take one. My son looked and said "hey, this hole goes all the way through" and the radiator is actually bumped up in the center to clear.