I don't know really. Rod bolts are the most stressed bolt in the whole engine. I looks like the bearing was getting eaten away, so that says it was probably tight. BUT nothing turned blue. Tight=friction=heat=discoloration. Again IDK someone needs to get slapped.

 

I agree on the slapping. But the bearings that you saw being worn away were on the semi good rod, not the tore up one lol the bearings from that one are the shrapnal in the pan. I thought the bearing wear was from it being uneven since the other rod was crap but Idk and it doesn't really matter I guess just fun to try to guess what went wrong, hmmmm yup I'm settling on stupidity as the key factor in this engine failure do you concure? lol

 

On my 350 can we make any assumtions as to what will be bad?
so upon the assumption that the only thing thats wrong is the cam is bad maybe flat, that the lifter got past it, and went through my pan from the crank hitting it just right.
What would be the necessary things to do? should I completely strip everything and have it checked at a machine shop or just leave the rotating assembly in and replace the cam, lifters, rods, and pan? I think it'd be best to not set myself up for a fall and have everything checked.

 

LOL Well IDK, but if you look at the 400 laying there upside down. You'll see the cam shaft. Now how in the world would the lifter get past it to hit the crank? It was catastrophic failure, if it did.

 

Yeah I've been looking at that. The only thing I could think of would be the cam breaking of that specific node, or flattening down and letting it past but idk I'm just pretty certain it was a lifter cause I remember the bottom was solid and part of the way up that I could see sticking out of the oil pan had the not smooth dark ring part like on a lifter. so it's probably gonna be another interesting tear down.

What do you guys recomend taking the engine and tranny out as one or just the engine then the tranny out the bottom? I'm gonna be fixing the speedo gear plus probably new clutch.

 

The reason I said the engine is toast is that when a rod comes apart and takes away part of the bottom of the bore it's a hard hit. Having the bottom of the bore gently ground away is a totally different scenario, and one that wont cause shock fractures like the explosion of that rod did. Fractures often send cracks up through the bores that can't be seen to the naked eye, and only hot tanking and magnifluxing will find them. But even if they don't show you'll still need a good shop to relieve the damaged area and then re-magniflux it to be certain it didn't open up after the grinding. Most machine shops will just tell you to get another block and not waste more money on this one, but I guess you can take it to one and ask them for their opinion before going further.
I think the 350 length stroke in a 400 block does make a 377, but it takes a special crank that has the same sized mains with 350 rod journals to do it. I'm not sure you can just drop a 350 crank into the 400.
I'd agree with Damon's idea of taking that engine back to the seller and getting the $200 back if possible.
As for what caused it to come apart; well considering the guy made so many errors in assembly, it's quite possible he simply didn't torque it correctly and it let loose. I'd guess the lifter damage was subsequent to the rod damage. Probably the piston let loose and when the valves hit the piston it allowed the rocker to get loose and that dropped the pushrod off the lifter, which let the lifter come out of it's bore and go away. The strange part is what happened to the lifter? No way for it to go down past the cam unless the cam broke too and allowed it to drop into the bottom end and get mixed into the rod damage.

 

The lifter we were referring to was from the 350. He thinks the hole in that pan came from a lifter. It is the right size, but like you were saying. HOW.

 

yeah taking it back wouldn't do me any good, I was the first one to tear into it he didn't know how bad it would be and he told me that it might be scrap.
I new I was buying a possible bomb but I still wanted to try it, I'll probably try to take it to a shop to see What they think, I'm hoping it'll work out since the bad block Is basically the only thing I can reuse cept maybe the crank which I could use to make a 383 I guess but that would take just as much work machining for clearance as having the 400 worked on

 

Hey guys what goes into removing and installing a cam? my dad keeps saying I have to have special tools to do it but doesn't it just go in and pull out by hand? shouldn't the only tools I need be degreeing tools for lining up the timming?

I think I'm pretty settled on what I want to do now, I'm gonna wait till I get my engine stand which is gonna be around christmas. Then depending on how bad the snow is pull the engine, I'll probably have to wait till spring But I'll get it pulled and looked at and If I can't find any damage to anything in the lower end I'll replace the cam, lifters and pushrods and see if thats all thats wrong cause I'm not wanting to rebuild the engine after thinking I still want to sell it in spring to get an older one.

but If the engine is bad I'm just gonna sell it and the 400 for rebuilders and get a gm crate long block to put in since that'll just make selling it even easier then when I get a 70-73 like I want I'll rebuild an engine for that since I will be keeping that one.

But on another note what would be the difference between the cam in the 400 and the one in my 350? since my 400 heads are 350/400 heads the cam should be fine for a 350 right? as far as lift and duration I'm just thinking of low budget ways to test some theorys of mine as to what will work for the 350.

 

You need a harmonic balancer puller to remove the balancer. Other than that you need to pull the distributor, intake manifold, valve covers to loosen all the rocker arms, then pull the balancer, fuel pump, timing cover, timng chain and sprockets (need a puller for the crank sprocket!)
That's pretty much it for pulling it apart. The new crank gear (I always replace the timing chain set!) will need a driver or pushon tool to seat the crank sprocket. I like to heat them and tap them on before they cool and shrink. A good 1.5" ridgid pipe coupling and a piece of pipe will drive the crank gear on if you're carefull and keep it straight.
Make sure the engine is at top dead center on compression stroke for #1 piston before pulling it apart, and make sure it doesn't move while you're pulling the crank gear! TDC for #1 is when the timing mark lines up on the cover, and both rocker arms are fully up with little or no spring tension.