Help needed with engine decision

Help needed with engine decision
A

AdamH

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Location
Charlotte, NC
Vehicle(s)
'06 Rubicon LJ, '81 Scrambler, '06 Commander
Friday was a bad day for me. My freshly built factory AMC 304 , the one that came in the Jeep from the factory, developed a knock after only 200 miles since the rebuild. I had a shop look at it and it seems my engine builder completely screwed up when he built the engine. The crank has deep grooves, the rod clearances are way off, etc, etc..

Let's not even go down the path of going back to the builder. The builder is my brother in law. Issue is I am going through a divorce so let's just say things aren't good anymore with me and that family. I would rather cut my losses and move on with the engine situation.

Here's my dilema...

Do I put the $$ into the AMC 304 again?

or

I found 2 360s of unknown shape for $800 along with D60 and Dana 44 axles out of a J10.

With the damage done to the AMC 304 along with the fact that if the bottom end was built using the wrong specs, then the top end probably is damaged as well.... wouldn't the cost to build the AMC 304 or the 360 be about the same? Or since I know nothing about the 360s, do I stay away and stick to the original engine?

Any advice is appreciated here.
 
Is the top end fresh on the broke AMC 304 ?
 
as far as top end, yes, is was rebuilt as well but I am worried there could be issues since the bottom end was done wrong. Obviously all this is being said without the engine being torn apart. Just thinking of my options 3 days later...


as for the 360s, you know how things go with buying used engines....


"one 360 has never run since I have had it, 2nd one runs just fine but needs final touches" so who knows

as far as the axles, not sure about them. wouldn't do anything with them right off the bat. would end up either selling them or seeing what it would take to put them under the CJ7 .
 
If it were me, and I had a fresh top end, I would repair the bottom end. Any respectable machine shop can straighten the crank and rods out. You will be out a little machine work, but you will know what you have.
 
I was in a similar boat with my AMC 304 . I would rebuild, as long as the top end is good to go. I would replace the crank, though, not have it machined. Too many engine builders have told me that once you machine the crank down, it won't last as long. If the top end is bad, sink the money into the 360.
 
if you go with the 360 they are relatively cheap to rebuild compared to some other motors...but if your more nostalgic id go with a new crank and bottom end in the AMC 304
 
CJKrawler said:
I was in a similar boat with my AMC 304 . I would rebuild, as long as the top end is good to go. I would replace the crank, though, not have it machined. Too many engine builders have told me that once you machine the crank down, it won't last as long. If the top end is bad, sink the money into the 360.
Click to expand...
there is nothing wrong with having a crank turned, as long as it doesn't have to be turned to much. when i have one machined i try not to use it if i have to go more than .20 under on the rods or mains. i have used one before at .30 but i was in a pinch, that motor is still running great though.

i was thinking if you knew if one of the 360s ran good you would have a bigger v8, plus one to build, and new axles to put under your jeep, all for the money you would spend rebuilding the AMC 304 .

everybody is probably right there shouldn't be anything wrong with the top end, you can take it to a machine shop and have it line bored, just make sure you take the rods as well and have them checked to. when you have a rod knocking, the rods can get oval shaped.
 
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I found an engine shop about 2 hours from me that seems to have a good reputation, CME outside Columbia, SC. I may just go that route and keep the AMC 304 as long as the block and everything else checks out OK.

If it looks like there are way more issues that the last machine shop found, I will then consider the 360 route. Thanks everyone!

on a side note... I have never heard of anything more than a 20:20 turn on a crank, interesting.....
 
Theres some engines that they even make .040 bearings for.
And than you can always weld the crank to build it back up and regrind it.
I've seen this done many times. It works and is done when theres not any cranks to be found. (think old )
 
I used to work for the chevy dealer in newberry, sc. Give the parts dept a call and ask for Dale or Jamie, tell them a guy who worked there said to call and ask about a good shop in or near Columbia. Those 2 are true gearheads like me and can advise you on a shop if they've heard of it.

Hopefully they still work there, lol.
 
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Thanks for the info Brock. I googled and found more than one dealer in Newberry. Would you mind sharing which one? PM is fine if you would rather not share here. Thanks!!
 
AdamH said:
as far as top end, yes, is was rebuilt as well but I am worried there could be issues since the bottom end was done wrong. Obviously all this is being said without the engine being torn apart. Just thinking of my options 3 days later...


as for the 360s, you know how things go with buying used engines....


"one 360 has never run since I have had it, 2nd one runs just fine but needs final touches" so who knows

as far as the axles, not sure about them. wouldn't do anything with them right off the bat. would end up either selling them or seeing what it would take to put them under the CJ7 .
Click to expand...

I recently bought a 360 that had a fresh rebuild with 20k on it....Well I offered AMC 150 .00 and bought it. Mostly going into it I expected I was buying a core to build. And core it is, rod and main bearings scored/grooved. Still OEM pistons with new rings and new bearings were just "thrown" in most likely in that way. So look around and trust no one you dont know. Id wanna see it run for that price.
 
I've decided to keep the AMC 304 . At least I know most of the history of it. Now just have to save my pennies. Thanks everyone!
 
Re: Help needed with engine decision - very interesting turn of events!

So as if I don't have enough on my mind right now.....

I found out yesterday there is a very real possibility I may be moving to Arizona. So of course I start looking at things like housing, etc.. and decided to check on DMV laws.

My daily driver should be just fine (was worried with 37s and flat fenders)

The Harley will be fine (talked to a dealer out there and they gave me tips on what to do if it doesn't pass - no emissions here in NC for bikes)

THe CJ... WOW! It has to pass emmissions?!?!?!? :censored:

What am I to do? I obviously don't want to dump money into fixing the engine if I can't even get it registered there. I read something about even though it isn't a 1966 or older, I could skip the emissions if it is registered as a classic. Is this true? What all does that involve.

This could be a major decision maker as to whether I fix the thing or part it out before I moved out there. Thanks for the help.
 
will start a new thread
 
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