dstanky

Much appreciated, 59bisquik and 4mula-dlx. I will get a full estimate for 'the works' from my machinist and go from there. Old guys around my area have warned me the thing to watch out for is a cracked or warped head. The previous owner warned me of it overheating a few times. I've got new $30 headgasket ordered and I figure I'll pull the head off and inspect the cylinders for any major wear or problems. Best case scenario is it all looks good, goes back together smooth and I solve one of the engine's problems, worst case is it goes to the machinist in 2 pieces

Thanks Don. I've used a compression gauge, did the oil test and a leakdown and digging through numerous posts on using Marvel Mystery Oil, ATF and other products in both fuel and in the crankcase in case of stuck valves. There aren't any vacuum gauges available in my area short of trying to make one so that wasnt done. The reason I'm leaning more towards a rebuild than just working on cylinder1 is 2 part - the lack of experience in tearing down an engine to get to valves, rings, etc and to fix other problems with the engine like a badly leaking rear seal and coolant in the oil. I figure it will be inevitable that to solve those issues I'll have to have the whole block apart

That's true. Over the past 2 weeks I have been trying to determine the cause of the compression issue. I've checked for stuck valves and they all seem to seat themselves and move freely. I had a friend do a leakdown test and couldn't tell where it was escaping from (He might not know what he's doing though). A local mechanic said that he could pull the block apart but would then have to see if he could get replacement parts and send it off elsewhere if there were problems that required any machining. Bodywork, painting and fabrication are things I'm comfortable with. Mechanical stuff is new for me.

I dont mind spending the extra initial costs of mating up a different engine and transmission to the older truck. My biggest concern is getting the 251 running smooth, any future problems to be prepared for and finding replacement parts. If I get it rebuilt, can I assume that the only costs I should incur are new pistons if milling is needed, rings, valves, guides, and lifters? (edit: plus bearings, seals, etc) Is it likely that the camshaft is worn as well? I know that the transmission has a chewed up first gear also which the machine shop can make a new one for, but again, more money to the pile.

Hi guys, New user here. I recently purchased a 1956 Fargo with an industrial 251 in it and compression is a bit of a problem at 40-80-75-80-90-90. I checked valve clearances and they are around .014 for both types of valves. I pulled the intake and exhaust manifolds off and a large handful of rust shards came out of exhaust manifold right near cyl1. I dont think its the lining of the cylinder based on the size of the rust shards but rather the heat riser in the intake rusted out - there are 2 large holes in the heat riser that exhaust is escaping from. So cyl1 still needs attention and I need a new intake manifold. I haven't rebuilt an engine before and frankly would probably get overwhelmed so I'm going to leave it to professionals. So long-short, I spoke to a local machine shop willing to rebuild the engine and the estimate is between 1-3k to have it rebuilt (not including any surprises that may come up). I'm not too bothered by the fact its an industrial engine but the costs of repair may eclipse the cost of a new crate engine. I found a single carb intake but will likely need a new exhaust as well based on the rust pouring out of both. Ebay has intakes and exhausts listed for a cheapest combined total of $600 after shipping. Couple those with the cost of rebuilding the engine, in your opinions would it be more economical to swap to a crate engine now or begin sinking money into the flathead 6 and pay a premium for any replacement parts that may come up?