If Jesus can turn water to wine...

[Agnem]

Another possibility is that your water pump has worn through the front cover. The obvious and unpopular answer is going to be to pull the engine, pull the oil pan, and pressurize the cooling system and look to see where the water comes from. Wouldn't hurt to pull the valve covers. Could be a cracked head and a weird leak to the top side under the valve cover.

 

[Calder]

Hi guys, been even busier now that the truck is off the road.

Got an 87 7.3 as a backup and a 94 5.9 as well. Pulled the motor and got the heads off. Couple of things I noticed were the rear most head bolt on passenger side was loose. There was a lot of oil leaking past the exhaust gasket on that side as well. The driver side head gasket was not stuck to the block or head between the rear coolant port and the cylinder. The pre cups are all cracked like normal and the intake and valley pan were sealed up tight. The oil cooler gasket looked to be blown out causing my water to oil miracle. I'm going to use RTV next time.

#6 has a hot spot on it, and is not looking good around the edges along with #8.
#7 was washed clean like it had water inside the cylinder at the time of combustion.

I'm going to pull apart the spare 7.3 and see how it looks and go from there.

Here are some pictures for y'all to dissect.

#8 you can see the worn edge of the piston and the fire ring has deformed

You must be registered for see images

#7 This piston was even worse

You must be registered for see images

It was a bit melted

You must be registered for see images

This is the odd texture in the 4 rear cylinders

You must be registered for see images

The part of gasket that didn't seem to be sealed very well

You must be registered for see images

This is cylinder 7 and it was all nice and shiny compared to the rest
The loose head bolt was next to this one

You must be registered for see images

Anyways, good evening to you all. I'm going to get into the other motor in the morning.

 

[icanfixall]

Well from the looks of this engine those textured cylinders looks to be water damage. So this is a new block??? How can that be so because they have not been made is over 20 years. I see the piston has the factory A size on itwhich means its the third size past standard bore.Its measured like this..
Class U is 4.10325 +- 0.00025
Class B is 4.10375 +- 0.00025
Class A is 4.10425 +- 0.00025
Class C is 4.10475 +- 0.00025
Class D is 4.10525 +- 0.00025
Then you go into the 10 20 30 over pistons.
It almost looks like the cylinders were rusted and honed clean but the rust piting was still in the cylinders. The cross hatching looks good. Can't really say why the pistons burned like that other than bad leaking injecters in those culinders. Clearly the water leak was back in that top corner. Somebody did a bad job of installing that head gasket around the head alignment dowel.

 

[Calder]

icanfixall, thanks for the information and the insight. Sounds good, the previous owner of the truck remembers at 40k miles the block cracked and he got it replaced at ford. Since then he put 100k miles on it and parked it. Its been parked since 06. Either way it is not important because it could have been any number of things. The 87 motor does not have any markings on the pistons but #8 has lots of rust so its probably shot.

How exactly is a block deemed good enough for a rebuild?

Would it be possible to sleeve the 7.3 down to a 6.9, and run 6.9 heads?

I reckon the 5.9 is going into the ford at this point. Anyone got conversion parts for sale or a G56/np271?