Hey guys, i recently found a good deal on an 83 f-250. everything on the truck is near perfect but the 460 is seized up. the guy i got it from said that it ran great for a long time and then developed a rough idle...but it would smooth out when getting into higher rpm's. then one day it just died while driving it normally. he dragged it home and it turned over really slowly, if i remember right, but after letting it sit for awhile, it got to the point that it would not turn at all. i got it home and put a wrench on the crank and tried at first to spin it forward. it didnt budge at all but when i tried spinning it backwards it went easily for about 20 degrees and then froze solid again. it could then go back and forth but thats the only movement it would make is about 20 degrees. any thoughts on what it might be? if all else fails a friend will sell me a 429 that he has sitting around, but itd be cool if i could fix it myself. do you think its possible that the timing chain snapped and is now jammed in the gears? or does is sound more like a spun bearing or a rod poking through a cylinder or something like that?

 

Does it make a noise when it stops spinning? Where does the noise come from? Does it stop abruptly, or slow to a stop? Does it stop in exactly the same spot every time? These should help to narrow it down without tearing the engine apart...

-Andrew
f250_64(No Email Addresses In Posts!), same for yahoo messenger

Nothing, and I mean nothing, stirs the soul, saying I'm a bad **** like lettin'em rip with a window shaking, fuel gulpin, carbon monoxide belchin, attention gettin, V-oh my LORD!-8!

 

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This may come off harsh, but given that history you'd be a bonafide fool trying to figure out what went wrong without opening that engine up. Sounds like it may have overheated or suffered from oil deprivation. You may or may not be able to salvage the engine. What do you have to lose? Initially, just your time for the tear down and a little investigating. However, you stand to gain some valuable experience and perhaps, with some luck and well spent money, have a nice truck with a strong 460.
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I agree with StockMan but you can do a quick check on the timing chain. Pull off the distributor cap and rotate the crank while watching the rotor. If it doesn’t turn, bingo!

Barry

 

ya, it goes back and forth stopping in the same exact two spots each time and makes no noises. i figured there would be no way to really tell for sure what it was, but i want to save as much unnecessary work as possible...i was hoping i could get an idea before pulling the engine . anyway, thats an excellent idea barry. why dont i ever think of these things? i guess i just go brain dead sometimes. =)

 

ok just got back in from the cold. checked the chain and its good...or there at least (the rotor moves). i forgot to mention that the crank doesnt come to a slow stop...it comes to a sudden stop both ways. thats all for now, does that help at all? what could be wrong with it...i would think that if something burned up do to oil problems or over heating, it would likely not spin at all, that or else spin a little and come to a slow stop. anyway, ill probably end up pulling it and tearing it down once it warms up, but anyone have any ideas? thanks a lot

 

I once had a 289 that the timing chain streched so much that the timing was off enough to make the valves hit the pistons and not let the engine turn over.Pull the timing cover and find out.

 

If I had to guess, I would say you lost a rod cap, and the crank it hanging up on the rod but who knows. I think I would drop the pan and take a look up in there.


1977 F-100
300 I-6 / C-4
Offy intake w/holley390
Hedman headers w/duals
MSD6
Whiter whites/Brighter brights

 

[font size="1" color="#FF0000"]LAST EDITED ON 14-Feb-01 AT 10:34 PM (EST)[/font][p]I also agree with stockman, I bought a 460 and a 429 from a guy for $100. He said they were shot, I just wanted something to rebuild, when I got them tore down the only thing wrong with the 460 was a headgasket, and the 429 had a spun bearing, both realativly cheap fixes compared to the crate motors he bought! I say open it up and check it out youll only gain experiance if nothing else.

 

There could be many different things wrong, tear it apart and rebuild it before you hurt it more.
Anthony DiPietro
79 F150 Ranger

 

I'm betting its a broken timing chain.

 

Ok, the rotor moves which means the chain is not broken. Next guess is the chain stretched and first jumped a tooth, then later it jumped several more teeth like thenkel2 says. That’s probably what it is from the way you said it died. You can jump one tooth and still run, although real crappy. I don’t think a 460 will freewheel. Looks like its time to bite the bullet and tear it apart.

Barry

 

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It could be some "compound" failure related to one or more components, but I still expect to see a cylinder related failure based on the way it turned over slowly, then not at all, then only partially. I reckon' we'll waste more time speculating on what it is than it would take to tear it down and rebuild it twice.
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is the truck a manual or automatic. i have heard of torque convertors breaking, and locking up an engine. i have no idea of how to check for this problem though.

 

Bob, Just in case you ever get the oportunity to check one out, there is a dust cover under the rear of the engine/bell you just remove the bolts and there it is. :-)

John
jowilker
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66F100s Rule
In the cool still quite of night you can hear chevies rusting away.