Removing Cylinder Head 1960 18hp Lightwin.

[cprodave]

Working on this neglected locked-up motor for my brother in law. Lower spark plug was seized to head but came loose after 1 week soak with various penetrants. Much to my surprise the Thermostat Cover came off easily, although Thermostat is missing! Also surprised 8 of 10 Head Bolts came loose easily, 2 required soak for 2weeks but are now loosened/removed. Head is stuck to Block. There is a Gasket but doesnt appear to be any Gasket Compound or Sealant holding up disassembly. In the past on other motors i have been able to remove stuck Heads using a twisting motion with my bare hands. Not successful thus far. I am thinking to put 2 wooden dowels in 2 holes (opposite sides of Head) then laying a steel rod across the Head to get a stronger twisting motion that i can exert with my bare hands. I have also used sharp wood chisels in past to start separation, but this often causes slight damage thai has to be surface-ground out.
Anybody know any good tips on this problem of separating Head/Gasket/Block?

 

[F_R]

Chose a protruding place on the head (such as the thermostat housing) and use a large screwdriver as a pry bar between there and the block.

 

[Chris1956]

Hold a hammer in your hand, and using a downward motion, smack the bottom of the wooden handle (never the steel head) against the side of the head. The shock should crack it loose.

 

[Crosbyman]

I use a common putty knife and hammer blows chisels are to thick but a putty knife has a fixed thickness and wedges in between surfaces

try warming things up a bit with a heat gun ( no propane torches) just plain heat say 250 deg

 

[cprodave]

F_R, thanks i will give it a try. I was unsure what areas of the Head are strong enough to use as a pry point.

 

[cprodave]

I used a heat gun, tried various pry points, tried whacking alternate sides with hammer handle. No go. But the putty knife and hammer worked great--i was surprised how intact the Gasket stayed.
Now the bad news. Cooling channels look like engine was not flushed on a regular basis, if at all--although water could probably still circulate. The top of pistons and cylinder walls have a crumbly residue (plus various penetrants i had applied through the spark plug holes).
Based on photos do you think this powerhead can be made functional? Have you seen/fixed worse?
Meanwhile i am soaking fasteners to drop Lower Unit, assess if Driveshaft/Crankshaft are seized together, Water Pump fitness, etc.

 

[racerone]

Take this motor all apart for inspection.-----There is no short cut for this motor.

 

[F_R]

Ugh. Sick.

 

[Crosbyman]

well.... it is a nice project looks like a good canditate for a 3hr flush
how about peeking inside if you takeout the reed plate behind the carb
if the innards are just as bad give it back to your b.i.l.

 

[cprodave]

Thanks All for the input...still working to take the carb and reed plate etc off.
Meanwhile i ponder what might have caused all this, particularly rust in the cylinders, one spark plug was rusted/seized until i soaked it 1 week. When my nephew delivered this motor to the pickup location it was in the back of his truck standing upside down. This motor cannot be flushed with muffs--must be flushed in a tank. At the cottage on coastal Virginia brackish river where this motor "lived" i see no signs of a flushing tank. If the motor wasn't flushed with fresh water, then stood upside down and stored for several years is there any way brackish water could have gotten into cylinders, crankcase, etc? I know the motor wasn't fogged etc stored properly but am still surprised at the internal rust...

 

[racerone]

Rain water would simply drain down into the engine block / cylinders via the exhaust housing.

 

[cprodave]

Thanks Racer, that is what i was thinking too. I am quite sure this engine was stored in a garage or shed (where engine would not be exposed directly to rainwater). However any residual brackish water around the bottom/inside of exhaust tube could trickle back down into the exhaust manifold and as far as the cylinders.

 

[racerone]

I have worked on lots of motors.-----That amount of rust indicates water / moisture was in there.-----How it got in there and over how many years is hard to tell.

 

[Chris1956]

I had an IL6 Merc powerhead sitting upright on it's mounting studs, in the garage, and one cylinder's piston rings rusted to the cast iron liner. I was able to free it easily, with a brass drift thru the spark plug hole. That motor was flushed and drained before the powerhead was pulled and stood up on the garage floor. I have to assume it was condensation that rusted it.