Need some help on my old '85 Ford pick-up...

[SS Killer]

... I know I'm in a GM Truck forum and someone probably took high offense to the word "Ford" but I still need some help with it.

It's got a 300ci straight six bored .040" over, RV cam, Headers, Offenhauser dual plane intake and a Holley 390cfm.

If you start it from cold, it starts without issue. If you shut it down after it reaches operating temperature it will not restart. Instead, the motor turns 180 degrees before almost locking in place.

I tried to spin the engine with the starter after I unplugged the coil assuming the timing was too advanced but it behaved the same way.

Any thoughts?

[Frenchy]

Vaporlock?

[SS Killer]

Timing too advanced.

It wouldn't even spin when the spark plugs weren't firing.

[tanz45]

That is a weird one. Turn over easy with wrench?

[SS Killer]

Vaporlock?

I've already re-routed all the fuel lines to make sure we don't have to deal with that.

The issue here is the motor won't even turn over if it's hot. Like physically won't turn anyfurther than maybe half a rotation.

[SS Killer]

That is a weird one. Turn over easy with wrench?

Haven't tried that yet...

[RedHeartbeat]

Sounds like a blown head gasket.

[SS Killer]

Sounds like a blown head gasket.

Like coolant is leaking into the cylinders and seizing them?

[Slimsilverado]

Might be a weak starter or weak starter noid... Take them to autozone for testing... Usually after a old starter or noid gets hot they dont wanna work anymore until they cool down

[RedHeartbeat]

Check the starter first then next time it dead locks up on you, pull the plugs out and see if you get coolant or gas out of the spark plug hole when you crank it. I'm sure you're hydraulic locking which can lead to bent connecting rods if you have too strong of a starter. It can be the carburator draining all the fuel into the engine once its shut off or its water seeping into the cylinder through a head gasket or crank in a cylinder wall. Are you losing water?