I'm looking for recommendations on what to do during a rebuild of my 4.6L Romeo in a 1998 F-250.

When it died on me, about a year ago, it slowly lost power over a few mile distance until it just wouldn't go any more. The temperature gauge at the time read a normal reading, but I've learned not to trust those things. There was no smoke from the tail pipe that I noticed. The check engine light had been on for about a month. It just seemed that everything was running OK and never got around to stopping at the local parts store to borrow a code reader to see what it was griping about. I now have my own code reader btw. When the mechanic inspected it, he found coolant with the oil and thought it was, perhaps, a blown head gasket, or worse. I opted to have it towed home with the intent to rebuild it. That time has come.

I should also mention that some months prior to it crapping out, I pulled the dash and installed a new heater core. I was a bit suspicious of the rotating pipe on the heater core, but assumed it was normal and installed the thing as is anyway. I kept an eye on the coolant levels for a couple days after that, but then stopped.

When I got the valve covers off, I saw that one of the roller followers was off the valve. I didn't even see the valve stem. I found the roller follower, in pretty good shape, along with a broken spring. Once I got the heads off, I saw the extent of the damage, as seen in the pics below. It seems, when the spring broke, the valve fell in the chamber and got chewed up, poking a nice hole in the piston along the way. What I'm holding in the pic is what was left of the valve. You can see a bit of the valve embedded in the chamber above the open hole.

From what I can see though, the piston walls don't look too FUBARed. I'm thinking about yanking the block next and putting in a new piston. At the moment, the crankshaft won't even turn. I'm assuming its from the rust buildup. Hopefully, its not from bits of valve wedged between the piston and the cylinder walls.

I'm thinking about grinding down the combustion chamber, where it got beat to hell, to smooth it out, getting a new valve, guide, seal, and spring, cleaning everything up, and relapping all the valves. From what I can see of the beat up chamber, it looks like valves could still get a good seal. I'll also have the head planed if it turns out to be warped. I haven't checked yet. The head gaskets were fully intact. That makes me wonder how the coolant was getting into the oil so easily. It was a full on water fall and mocha latte fest when I pulled the oil pan plug some time back.

My suspicions are that the heater core leaked, the engine overheated, the heads warped, and then the heat caused the valve spring to break, causing the other damage.

I'm looking for recommendations of stuff I should DEFINITELY do while I'm there.

I was certainly planning on doing new valve seals and exhaust manifolds, since they are rusted to hell, but I don't want to dump several hundred dollars into this thing. Its a fun learning experience for me, but a used engine at the junk yard will run about $750 and I'm on a budget.

Should I be concerned about all my other valve springs potentially going?

Was I supposed to solder the pipe on the heater core I put in?

What will be the result of expanding the combustion chamber a bit by grinding it down to make it smooth again?

What other stuff would I be crazy not to do while I'm in there?

Many thanks,
-Steve

Kissimmee, FL

 

That's a mess - I'd look for a junkyard engine or a reman.

 

First off, love Kissimmee, FL!

Second, that engine is not worth rebuilding. Junkyard or reman as stated before. Find yourself a PI 4.6.