I figured it had been rebuilt sometime in the past. It came to me with the factory 4BBL "S" intake (I think with a '68 date code). I don't know if the intake is original to the engine, though (it came with both a 2BBL and 4BBL carbs in the box 'o parts). It also had a "long-tail" C6 transmission attached. I figured with all that, engine and transmission probably originated in a car, and got transplanted into my truck (a '67 F250 2WD) at some point.

I'll definitely need that checked into. A quick check measured the bores at 4.07", plus wear and tear. They would need to be bored at LEAST to 4.08". I also need to have the heads checked. The exhaust valve is sunk in about 1/8" on one cylinder. I don't know if this can be repaired, or if it's even worth repairing; these are only C4EA-G heads.

I didn't know that. I figured all of that would have to be replaced, so I chucked it in the circular file. I did notice that there were numbers stamped into the tops of the pistons; is this another sign of being a factory reman? I'll have to pull that stuff back out to check numbers.

Thanks for the info.

Joseph

 

Yea. sounds like a Frankenstein engine all right. The heads can be rebuilt with new seats, although once you add up the cost of the operations and parts needed, aftermarket heads become the more attractive alternative. Crank can be mic'd to see where it's at, if the undersize isn't already stamped into a counterweight. Look for that on one of the machined flats. Oversized pistons were all stamped in the crown with the oversize. A reman engine would be indicated by the mixed rods only. Most done by an individual or a machine shop wouldn't have mixed parts as a rule.

 

Are you sure that the eighth rod is not C6AE-C? That is a common std short FE rod used on all 1966 390,410 and 428 engines.

 

Yep, you're right. I got the letters swapped. They are C6AE-C and C3AE-C.

I checked the bearings tonight. Clevite for the main bearings, and Federal Mogul for the connecting rods. Both are 0.010 over (or under, depending on your point of view). I couldn't read the pistons; too much crud. Maybe this weekend.

Joseph

 

Best way to clean that crud off a piston is with a wire wheel on a bench grinder or a drill. Run a fingernail across the crank journals, if you feel ridges it'll need turning again. If they're smooth, you may get by with fresh bearings. But having a machinist mic them will tell you more acrurately.

 

I live in a small town, but I'm very fortunate that I have access to an excellent machinist. He's not a gung-ho, gotta-do-it-all type. He's very conservative, careful, and complete. I'll let him check everything out before I move forward.

Another odd realization with the disassembly was the engraved numbers on the connecting rods. The driver side matched the cylinder numbers: 5 - 6 - 7 - 8. But the passenger side was all screwed up: 2 - 1 - 3 - 3. Both #3 rods are C3AE. The deeper I dig, the more interesting my Frankengine becomes...

Joseph

 

That's typical of a factory reman engine. They did several engines at once, dumping the rods in a box and pulling them back out at random. The bigger shops would also affix a tag to the outside of the block with the displacement, overbore and undersize numbers for the crank.

 

It happens more often than one thinks, if rebuilders find a bad part (rod, ect) they grab another of the same style from their inventory and use it.
One time a outfit I was wrenching for had a rod bushing come loose in the 331 truck engine, I dropped the pan and pulled the head from the bad side, jerked the piston and rod out, went to our used parts inventory and grabbed another 331 rod and had the engine back going in a few hours.
Didn't pay attention to what numbers where on the rod, it was the correct length and size so I used it.

 

The pistons were stamped with "30". Some of them had a round recess to show the front of the piston, and some of them didn't. I hope to get this mess to my machinist next week for him to check it all out.

Joseph

 

It's been bored .030 then.

 

Good choice.