Well, I think the time's finally come to rebuild the engine I pulled out of my Bronco last year.

To recap, I installed a performance cam in the engine about a year and a half ago, but unfortunately one of the lifters didn't agree with the cam and it ate a lobe off within 500 miles of the install.

Luck would have it that a guy locally had a running '78 300 for $50 on craigslist. Unknown (albeit original) miles, unknown condition, just that it ran when pulled 5 years prior.

I pulled the engine with the bad cam, cleaned up the craigslist engine, and dropped it in. It's been running great for a year know with great compression, but it's noisy. There are lots of rattles, clacks, and unexplained squeaks (fortunately no knocks), so I can definitely tell it's 34 years old.


So, I'm starting in on rebuilding the engine I pulled out. I disassembled it this weekend and am getting all the main components ready to go to the shop.

I'm in NO hurry on this rebuild, so pictures may not be very regular. I'll be taking my time and doing little pieces here and there when I can.

Here it is on the engine stand. It's been sitting there since last November.



Most of the bearings were showing the gold/copper color. It's probably a good thing I pulled it when I did. Almost every bearing in the engine looked like this.




None of the pistons would come out the top of the block. The cylinders had worn and the rings wouldn't let the pistons move past the lip.




The crank is out. Once all the main and piston rod bearing caps were off it came right out. Not as heavy as I was expecting, but then... I have been working out.



LOTS of copper color on those bearings, especially on the piston rods.
Looks can be deceiving too. It looks like those pistons should come right out the bottom. They don't.




Some of the main bearings weren't as bad as others.



This was a fun chore! Dropped the pistons into this bottom chamber and had to reach in and work all the rings off. As much as it looks like they might, they simply don't come out the bottom. It was about ten to fifteen minutes per piston getting the rings off. Not a lot of room to work with.




Nothing like a good cardboard box to keep all your parts together.


Not a whole lot left before it's ready to go. Have to remove the oil filter and the lifter cover off and take the remaining lifters out. Should only take a few moments, but my hands were cut up from the rings, so I was done for the day.

 

That's a 500 mile engine? Something isn't right.

 

No, I only got about 500 miles on the cam I put in it before it got chewed up. I have no idea how many miles are on the engine, just that it's been rebuilt once before.

 

It was 500 miles...at Talladega.

 

Did you do new lifters when you changed the cam, or reuse the old ones?
I'd be hostile if I installed a new cam and it went out in 500 miles.

 

Sorry, duplicate post somehow.

 

Yes, at the time we imagined it went down like this:

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Yeah, it had new lifters, springs, rocker arms, etc. Break in oil, did the whole start up procedure to a T. I discussed the whole ordeal with a machine shop here and they said there wasn't a whole lot more I could have done correctly. The final verdict was a lifter with a defect.

 

Haha, yes.
Pretty spot on.

 

On the plus side, when it's all said an done you'll end up with a sweet new engine.

What kind of head do you have? Since you're not in a rush you should look for an early 240 head. I picked up a core engine with a '68 240 head and the ports are so much nicer than the '72 240 head I ported was when I started. No AIR hump on the exhaust side plus the intake runners are a little bigger and match up to an Offy intake better. The 240 head has a nice little quench area too.

 

Wow! Congrats on the project, Justin! You'll learn a lot.........................

 

well done AbandonedBronco! I've seen some other posts of yours throughout the forum and i'm pretty impressed with your wealth of knowledge on these engines.

I am going to be attempting my first ever rebuild with a 240ci out of a 1967 Ford Econoline Falcon this fall. My hope is to replace the 240 innards with (possibly new if i can find them) 300 crank, rods, and pistons.
I pray that i don't run into the problem you had with the cylinder rings wearing the chamber so much that they dont want to come out... but even so, the bores will have to be machined ever so slightly to ensure the longer stroke of the 300 pistons dont hang up anywhere.

Any advice you want to give to someone who is attempting this? Once i begin, i will start my own thread... not trying to hi-jack this one :P

 

way to go man...sounds like a ton of fun. can't wait to rebuild mine in my 81. i'll definitely be following this thread with a fine toothed comb. congrats!

 

I've thought about that, but I have no idea where I'd find one. I don't think I've seen a 240 around here before.
Either way though, the head I have on the engine is pretty new and I port and polished it myself last year. I also like it because it has the newer style setup for the rocker arms with the bolt hole instead of the stud:
It allows me to swap to screw in studs pretty easily if I so desire.



(P&P)



I removed the air bumps inside while I was at it. Made quite a difference.

I can imagine! It'll be my first rebuild. Fortunately, I've learned enough before hand that nothing'll really surprise me. It's just a matter of doing it and doing it correctly.

That'll be fun to do! I've heard it's pretty simple to go from a 240 to a 300, but I don't think anyone's ever documented it on this site. That'd be great to see!

Getting the rings off while it was still in the engine was a pain, but it wasn't that big of a deal. I pulled them down into the block and used a pair of pliers and a flat bladed screwdriver to slide them out. On the two top compression rings, it was easier to just get one of the ends to raise up a little bit, grab a hold of it, and snap it off. The oil control ring was a little more frustrating, but I found that if I was able to grab a corner of it with the pliers, I could work it out around the piston. Just keep the piston from laying on it or pinching it against the block.

As for any other advice, it's my first rebuild, so I'm learning as I go. Just use lots of break in lube, follow the break in procedures to a T, and use break in oil. New oils don't get along super great with new flat tappet cams and lifters.

Hopefully this thread'll be a lot of help to you, unless it takes me forever. I can't wait to have it done though, my Bronco's always had a high mileage 300 in it so it'll be fun to have a fresh one.

 

AB--
There is a ridge remover for such times....

I'd also like to bring up one variable that seems to have avoided suspicion: The ebay cam. Didn't you buy it on ebay for a very good price? From what I have read due to the defects reported in cams, there are many aspects to making them that if not done correctly could cause a quick melt down.

I think the only advice I would give to possibly help you avoid my own mistakes would be to tell you to be sure your magnaflux the block. Also, the quality of machine work has alarmingly dropped. I would pay good money to a well-researched machinist who is going to turn crank, rods, bore, etc.

Huh...I may know a guy with a nice Eddy 500 and cal. kit. Cheers.