Short background story. A lady gave me a 1956 Chevy 3100 pickup if I would haul it off. It has seen its share of rain, hail, and heat sitting in a backyard for at least 40 years. I've tackled breaking the truck down completely, frame off restoration, just trying to remove as much surface rust as I can. I did get the 235 engine to run and it sounds good, though it only ran for about 2 minutes. Now that I have it out and looking at it I wonder about spending time trying to restore this engine. There's a lot of water jacket corrosion to contend with. Check the attached pix of the thermostat housing after sitting in CLR solution and the general appearance of the engine. I've flirted with doing an engine swap now that everything is off, but my son and b-i-l both want me to clean up the engine and put it back in original
I really worry about the leak at what I think is a cam cap at the back of the engine, as well as the water jacket corrosion. My question is what is your opinion of proceeding with this engine versus doing a swap now?
That leaky plug at the back is in the water jacket. The cover plug for the cam is lower, and on the passenger's side of the engine behind the pushrod cover.
Any engine that has been running recently is rebuildable, as long as there are no serious cracks anywhere. You'll need to do a complete teardown to bare bones- - - -block, cylinder head, crankshaft, etc. Measure everything, including cylinder taper, crankshaft journal diameter, bore size, etc. Do whatever machining is necessary to rebuild it properly- - - - -don't take any shortcuts. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
To just add to what Jerry said above, I don't think you are going to find the block and other cast iron parts all that rusty actually. The internal coolant passages are going to be rough as that's how they were cast, so don't let that misguide you that the block, head and other cast iron parts are going to simply fail from rust. Absolutely replace all the coolant passage block core plugs, but before you do, be sure to give those passages a thorough look and cleaning, especially behind that rear plug and the one on the driver side rear most plug opening as those area are known to collect/build up junk and debris which can seriously restrict and even block the coolant passages. Be sure to remove and clean out the drivers side block draincock/plug at the same time.
The other thing to inspect closely is the engine tins. Oil pan, timing gears cover, block side cover and valve cover are just thin sheet metal and can rust through if left alone for as long as your truck has sat.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)