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When I was rebulding my 1940 Chevy truck, I acquired a 1955 235. I was told that the engine had been rebuilt but never run and had sat for 20 years. I noticed that there was "nesting material" in the intake and exhaust manifolds. I pulled the water pump off and flushed out the block and got an assortment of acorns and other "stuff" out of the block. Next I pulled the oil pan and checked the internals out. I could see that new pistons had been installed. I oiled everyting up and reinstalled the pan.
The engine was installed and fired up without issue.
However I had a nagging overheating issue. All the usual suspect things were checked, water pump, thermostat, radiator, ignition timing. I was getting to the point of banging my head up against the wall.........................
Then I got thinking, did I really get all of that nesting stuff out of the block. So I pulled the head and low and behold, about half of the water ports between the block and and head were clogged up with acorns along with the water passages in the head.

So, if you ever take an engine out of long term storage and you see signs of "nesting", pull the head and check the water passages. It is a lot easier to do when the engine is out of the truck.

John Gott

wow. amazing story.
good tip. thanks.
leonard

A nesting incident doesn't have to be that obvious! Back when I ran a dirt tracker in California, one of my competitors had the bad luck to scatter an engine one night. No sweat- - - -he's got all the bits & pieces of his backup engine under a tarp in the corner of his shop. He assembled the engine, installed it in his race car, and fired it up. About 5 minutes into the cam break-in runup, it burned a rod bearing. We found evidence of a mud wasp nest in the crankshaft oil gallery going to that bearing!

Conclusion- - - -never assume anything is clean until you make sure it's totally contamination-free!
Jerry

I had a 51 at the cabin that a mouse got in the block and it never ran cool ever since,it was not worth tearing apart due to the motor being very tired and the truck was rough and I ended up giving the truck to someone down the road before the property was sold. We could not keep radiators in our lot trucks up there when we were not up there since the radiators would disappear and I forgot to plug up the motor. Jeff

Final update:

After putting the head back on the engine and putting everything back to togather, it still ran hot, not as hot, but 210 degrees. I was ready to pull my hair out. I ran it with and without the thermostat (165 degrees) I tested the thermostat. I was sat my wits end.
The set up was a 235 (1955) with a the short shaft water pump (which sits 3 inches lower), A smaller fan to fit inside the fan shroud and a 1954 crankshaft pulley.
I removed the short shaft water pump, reinstalled the adapter plate to run the 1954 water pump (which put the fan squarely in the fan shround)
Now if you did not know, the water pump pulley is smaller on the 1954 water pump than on the 1955 water pump. .

Well it turns out the the water pump was not "turning" fast enough. When using the 1954 crankshat pulley to turn a 1955 water pump (lager diameter) pulley, it was turning to slow.
So, using the "correct" pulleys (1954 crnakshaft pulley with a 1954 water pump) the ratio was correct.

So with all the "crap" cleaned out of the head and block, she is now running 180-185 degrees under load, and when idling she is right at 180 degrees.

So, again, if you ever get an engine that had been sitting for awhile, pull the head and water pump and clean all the nesting material out, and you will save yourself alot of headaches.........

John Gott

IHC v8s are bad about that, they will have 2" of crud in the bottom of the block. Never put rtv on the freeze plugs, the'll rust out in 9 months, electrolysis.....