Ok, since I picked up the 400 on Friday, Ive already started tearing it down. Ive found some good things, and as expected, some not so good things.
It was interesting in that in taking off the heads I discovered that prior people had drilled holes in the side of the heads (likely for mounting assessories), and it ended up going into the cylinder head bolts. I suspect that they used the wrong depth head bolts or they simply went too deep in their drilling. Either way, those bolts will need to be replaced.
For the push rods, Ive seen two different types of pushrods used. One is long straight rod with just the oil hole in the tips, and the other rod has ball ends. Not sure, but I suspect that a few rods were replaced sometime in the past 40 yrs. For me it probably makes sense to replace them all and go to one type.
For the pistons, the wear/carbon build up was minimal, and I didnt note any .20, .30s etc on the piston tops, so Im wondering if this block has never been bored.
The cylinders looked pretty good, no obvious channels, or major ridge issues, although on the top area of the block surface area, I did note that the circular area looked a bit oblong in some cylinders. Is that normal?
If the piston is all the way to the top of its rotation, you can see its not perfectly round, which makes me wonder if someone was going to bore it, and rounded a little of the top, or was it just made that way? Not sure if that affects performance or not.
*If someone could post some good and bad pics of the top surface area completely surrounding the piston, I might be able to compare. Otherwise, I suspect Ill be taking it to the machine shop and get a professional opinion on the condition. If its never been bored, then I would suspect no problem in boring a bit, slightly bigger pistons and reassemble.
The cam has the usual varnish on it, but I didnt see any major flat spots or eroded lobes. Im still looking at replacing the cam anyway, but just trying to guage what type of life this engine has had.
The valve lifters Ive been able to remove so far look ok, just a bit of varnish, but no concave sections. If Im replacing the cam anyway, it makes sense to replace lifters at the same time if part of a kit.
From what I can tell, it looks like the engine was probably used within the last year or two as the cylinder walls still had oil, and the coolant passages still had proper colored green coolant in them. My guess is that someone simply pulled the motor to replace it with another one, and then set it aside. But at least they knew enough to tape off the intake ports, lubed the cylinder walls, put coolant in the passage ways, etc..
