My eagle has been sitting in the yard for over a year. While I was driving her, she overheated, and all signs pointed to bad radiator. Got that replaced, big difference in temperatures, until the new found pressure of the good radiator blew my head gasket, warped my head, gunked up the engine... general badness.
Anyway, I pushed her into the garage and started tearing it apart. My AC never worked in the first place, and honestly I don't want it, so I tore it out. Need to figure out how to mount the alternator without the AC. Any ideas?
Found a 4.0 head on craigslist, not sure what it comes with, just says "refurbished". Trying to get more info. 7120 casting. Owner agreed on $100, but I'm not sure if a bare head with no hardware is worth that. Will update with more info when I get it.
In the case that it is a bare head, what do I need to purchase? Can my 258 valve springs be used? I'm on a very tight budget and I just want the thing running again. Nothing crazy. If I do end up needing to purchase new valves, new springs, etc, I will just rebuild the whole :censored: thing and throw a better cam in. Do I match the cam to a 4.2 or a 4.0 with the new head? Not sure how that works.
That's it for now, I suppose. Thanks!
It has springs, do the 4.0 and 4.2 share rockers?
If you're on a real tight budget, your cheapest option may be to just find another 258 engine and swap it in. You can generally find one that runs for around $300 on Craigslist. You could then sell your old crank, rods, and pistons to somebody that wants to build a stroker and get $100+ for it. Good luck.
Well, the reason I'm doing the head swap is because I'm tired of the 258 being a slouch. Otherwise I'd spend $40 getting my 258 head machined flat and call it good.
I just wrote alot of good information in another thread today that you should read through.
http://forums.amceaglenest.com/index.php?topic=37553.msg306546#msg306546
Here are pictures of several rocker arms next to each other. The one on the far left is a 1992 4.0, the one in the middle is a 1982 4.2, and the one on the right came with my Spirit on a 4.2 with a 4.0 head. It looks like it used to be the original 4.2 rocker and it got put on the 4.0 head without a problem. My conclusion is that they are slightly different but directly interchangeable along with the springs.
You need to match lifters with pushrods because 4.0 pushrods are shorter to go with the longer 4.0 lifters. Its likely no problem using 4.2 lifters but you should replace your camshaft with new 4.0L lifters and pushrods.
A 4.2L camshaft is dramatically different than a 4.0 camshaft. It is the secret that let AMC take a 115 HP motor and get 190 HP from it while reducing its displacement at the same time. The lobes are considerably bigger. A performance camshaft like the Crane RV cam I buy has small changes to the 4.0 cam to make it better at low RPM, but they are neglibile differences (except that a Crane cam comes with a lobe for the option of using it with a mechanical fuel pump in a 4.2, while the 4.0 eliminated that lobe). Make sure you replace the original camshaft while the engine is apart.
(http://i1181.photobucket.com/albums/x427/captspillane/Eagleweb%20Postings/Oct20110633.jpg)
(http://i1181.photobucket.com/albums/x427/captspillane/Eagleweb%20Postings/Oct20110635.jpg)
(http://i1181.photobucket.com/albums/x427/captspillane/Eagleweb%20Postings/Oct20110636.jpg)
(http://i1181.photobucket.com/albums/x427/captspillane/Eagleweb%20Postings/Oct20110637.jpg)
Quote from: NoCoEagle on February 06, 2012, 08:35:18 PM
I'm on a very tight budget and I just want the thing running again.
Sorry, I thought you were looking for a true low cost option. Good luck.
Pulling the engine and installing an entirely different 258 that will cost $300 is a lot more expensive than swapping on a good head from a 4.0 as long as I can reuse the cylinder head hardware from the 4.2 head...
I'm picking up the 4.0 head (with springs, no rockers, so I'll reuse mine), a 4.0 block, and a 4.0 crank (all newly refurbished, crank is still wrapped up) for $100 today. No use for the block and crank but hopefully I can sell them and come out on top!
Sounds like a good deal! You may also need a 4.0 exhaust manifold and some exhaust mods, according to this thread:
http://forums.amceaglenest.com/index.php?topic=37161.0;all
From the 3rd post in the thread (BenM)
"The only necessary parts are a couple of head bolts, possibly a sleeve set if you have the smaller bolts, the exhaust manifold, and some exhaust pipe bending to clear the front differential. Don't forget gaskets.
You need to notch the intake to fit higher and mess with some brackets, but that's just some time, not money. You're throttle assembly rides along on the intake and just needs the kickdown adjusted for the slight difference.
The only thing to beware of is the exposed casting holes that don't always seal."
I may have gotten an even better deal than I thought! The head is indeed a 7120 casting, and is clean as a whistle. The crankshaft came wrapped up, but the tag on it (from the crankshaft shop) reads: MAKE: AMC MODEL: 258 MAIN SIZE: 010 ROD SIZE: .010
Is this a 258 or 242 crank? The block looks like it was dipped, too, so I should be able to sell it.
Unless that tag is wrong you have most of the makings of a stroker engine
Checked out the casting number, 3235477. Looks like I've got a brand new crank to put in! :hello2:
I'm a huge novice when it comes to the bottom end of engines, what advantage will I see using this crank over the one that's installed? If any?
... you could reference the casting number on the crank to verify... a quick google of that casting number would tell you what it is for certain
That's an 81-86 258 crank, building a stroker is a WHOLE 'nother can of worms & research at least to do it right. See www.jeepstrokers.com for lots more information & reading with a few conflicting opinions thrown in from time to time.
Basically a 258 crank and a 4.0 block and appropriate pistons/rods gets you 4.5(std bore), 4.6(+.030) or 4.7(+.060) there are two ways to approach it, long rod(4.0) & short rod(4.2/258), the pistons are generally cheaper in the short rod variety as there are cast and Hyperutectic's available while the long rod version are all forged and cost significantly more, you have to watch your recipe pretty close to avoid too high of compression and pinging.
Doc
Is it possible to use 258 pistons in a 4.0 block? I wasn't planning on using the 4.0 block, I think I'd prefer to leave my bottom end alone. The head has new springs and valves, so all I need to do is bolt up my rockers and use my existing pushrods (along with the other head swap details) and I'm set. Not to mention I like running a mechanical fuel pump, which I can't do with the 4.0 block.
My intake already has Gronk's (or something like it) adapter for a Motorcraft carb, believe there's a 2100 on it now. Always seemed to run fine, just a little dirty. I remember the previous owner saying something about converting to HEI as well, although the big ugly orange cap on the dizzy doesn't look like any HEI dizzy I've seen on ebay.
So my next course of action is finding a set of headers (there's a set of stainless steel ones, brand new, on craigslist for $125) or finding a stock exhaust manifold. I'd like to keep cost down so I'm not sure which route to go. The headers for sale are Rugged Rock 17660.01 steel headers for 91-99 wranglers. Will they fit?
I also already regasketed everything on the bottom end while the car was running (with help from member tougeagle), which is another reason why I wouldn't want to use the 4.0 block. Gaskets add up!
No, 258 pistons can't be used in a 4.0 block, they are smaller, you would have 0 compression and lots of noise as the pistons rattled up and down the bores when you spun the starter(it would not run) If you are staying carb'ed then you absolutely can run the manual fuel pump, though putting a generic electric pump and relay on the passenger side of the engine bay in the same general area as the manual pump is now would be easy & work fine(though most E-Pump vendors recommend closer to the tank as they push much better than they suck) I believe that the header you are referring to is a Rugged Ridge, and that is a very good question as to fitment, I have an APN header here taht I bought for my ZJ but haven't replaced yet that I've been thinking about using if it'll fit, my suspicion is that it won't without some serious massaging, the one that seems to work closest without too much work is a 87-90 Renix style 4.0 exhaust often called a "Log" style exhaust
I'll give you a $100 for the crank. I'll be in Denver tomorrow evening till Friday afternoon. Are you in Fort Collins?
Now there's a thought, wish I have thought of it... :)
I'm in the Fort Collins area, yes. I actually live up in Drake. Before I decide anything, though, any insight on my previous question of how the new crank would benefit me? Is it just dependent on the condition of the crank that's in there?
Quote from: NoCoEagle on February 08, 2012, 10:23:34 AM
I'm in the Fort Collins area, yes. I actually live up in Drake. Before I decide anything, though, any insight on my previous question of how the new crank would benefit me? Is it just dependent on the condition of the crank that's in there?
The new crank can benefit you by being able to rebuild another engine while still driving your Eagle with it's current engine. It sounds to me like someone was assembling the parts to build a stroker. 258 crank and rods and 4.0 block and pistons.
If that 4.0 block is truly a machined block and depending on casting number, I may be interested in it for another $100.
I just purchased a brand new stainless steel exhaust manifold for 88 dollars on the evil bay. There was a bunch of the same one for sale. Its got the baffles where the stock ones usually crack. I was impressed with it and it turns out its identical to the one that my Spirit already had.
If you get that one, do not use the gasket it comes with!
When its time to put the head on I use two old 4.0 head bolts instead of buying the spacers. It works much better. I grind the hex head off and flip them upside down so that the 7/16 threads that used to be for accessories go into the block and the 1/2 threads stick up in the air. Slide the gasket down two bolts at opposite corners, align perfectly, then slide the head down the two modified bolts perfectly into place. It's a nightmare to do it any other way because you can't slide it without misaligning the gasket.
The casting # on the block is 53008405.
Quote from: NoCoEagle on February 08, 2012, 07:41:51 PM
The casting # on the block is 53008405.
That would be a 91-95 block.Let me know what you decide to do.
PM sent.
Quote from: captspillane on February 08, 2012, 12:33:36 PM
I just purchased a brand new stainless steel exhaust manifold for 88 dollars on the evil bay. There was a bunch of the same one for sale. Its got the baffles where the stock ones usually crack. I was impressed with it and it turns out its identical to the one that my Spirit already had.
If you get that one, do not use the gasket it comes with!
When its time to put the head on I use two old 4.0 head bolts instead of buying the spacers. It works much better. I grind the hex head off and flip them upside down so that the 7/16 threads that used to be for accessories go into the block and the 1/2 threads stick up in the air. Slide the gasket down two bolts at opposite corners, align perfectly, then slide the head down the two modified bolts perfectly into place. It's a nightmare to do it any other way because you can't slide it without misaligning the gasket.
When I did the swap where the headbolts were wrong diameter, I did similar to what you suggested, but I re-threaded two of the bigger diameter bolts to the smaller thread and cut a screwdriver slot where the head was so I could back them out again.
Pretty sure my '88 head and the 4.0 head both use 1/2 inch head bolts.
Some were 7/16"
They seem to have the same amount of play in the 4.0 cylinder head (tiny bit of wiggle) and the 4.2 head they came off of.