Anyone here familiar with the old AMC 5.9L engine that was used in Jeeps? I'm looking for size comparisons and known issues (common leaks, oil issues, cooling issues, etc.). Specifically regarding size, how does it stack against the Chevy 350? Only post I've found is that "it's within an inch in all dimensions" of the 350.

For those wondering, heavily considering dropping a 360 in my XJ. Big plus is sharing a bellhousing pattern with the AW4. Figured a rebuilt AW4 with superior clutches and valve body mods, including a big overkill cooler, should manage a modified EFI'd 360 pretty well AND keep all the gauges happy.

 

I built a 360 for my first Jeep. A 1980 Cherokee wide track. I had absolutely 0 problems out of it. The only mod was was an edelbrock intake and carb. A couple things worth noting which you probably already know. One is the distributor is in the front which I liked. The second thing is the oil pump is located in the aluminum timing cover along with the distributor. Oil pump gears are replaceable but if the gear housing is out of spec, the timing cover would need to be replaced. I never had any cooling issues with it but it had a monster radiator from the factory. Btw it came with a Ford ignition system. I bought the Jeep from the original owner who had severely overheated it on more than one occasion from lack of coolant. It ran but was low on compression. As far as longevity and high mileage issues I wouldn’t know. I put about 40k on the engine I installed.

 

As far as comparing it with a 350, they are really two different animals. The 350 breathes better and the torque curve is higher in the rpm band. However ....

Put some 401 heads on it and a mild cam and you will keep up or surpass any 350 of that era. A friend of mine was pretty sharp with engines and took some 401 heads, ported CCed the chambers, balanced the engine, high compression pistons and with a stall converter in the automatic too top eliminator in the late 70s at the Pac. Northwest 4WD assoc regional meet against 427s, glass bodies and anything else you could think of. So you could make something that would be a lot of fun.

And he drove it to work every day

 

Who's going to do your trans work? I know a guy near us who works out of his garage, doing nothing but transmissions, all by word of mouth. Everybody in the know around here knows his work is excellent. He's usually backed up about 6-8 weeks, and he does not R&R. You take your trans to him and pick it up when he's done. He's all cash, too.

I don't know if he does performance builds, though.

Anyway, PM me if you want his contact info.

 

I have just a bit of experience with both the 360 & the 401.

There are a few issues when rebuilding an AMC V8. OK not really issues, but things that need to be looked at.
The first thing is the cam gear oiling hole alignment with the cam. Most new gear sets you will find that the hole on the cam does not align well with the gear. More than likely you will have to do a little milling with the cam gear. Also depending on the timing set you might have to braze over a few of the "oil slinging" grooves on the front face.

The next thing to do is use a factory timing cover if you can. The new ones from China are ALL horrible.
Here is a good thread on how to make sure a new cover is OK: http://www.ifsja.org/forums/vb/showt...11#post1678711
Here is a good thread on how to refresh your old timing cover: http://www.ifsja.org/forums/vb/showthread.php?t=175526

Most over heating issues are from old scale and rust inside the block. Before you send it out to be machined, it is a good idea to take all the freeze plugs out, and really try to scrape as much rust out of the cavities as possible. Make sure you do this on an engine stand, as it will be good for turning it over and over to get the sand and rust out.
Also take all the oil galley plugs out and use a engine brush kit, to clean out the oil galleys.

The 401 heads are the same as the 360 heads. Big wives tale on they are better.
The real difference in heads, are the different year castings, and the size of CC in the years.

There are quite a few Full Size Jeepers that drop an AW4 into their jeeps. That is a great transmission, and will work fine in stock form behind a 360 or even a 401.
I have two 76 Wagoneer's. One is a 360 with efi, and the other is a carbureted 401. Both have the Edelbrock performer manifolds on them, Edelbrock RV cam, and Edelbrock double roller timing sets.
The reason I went with those is Edelbrock did a pretty good job on the cam gear/cam oiling holes.

One other thing to watch out for is the distributor gear & cam to distributor gear set up.
Use the MSD gear sets.
AMC V8's need to have really good oiling, and contact between the two gears, or you will find your AMC V8 will quit running one day, and you will have metal shavings from those two gears wandering through your engine.

There is LOTS of good information over on the AMC forum, or even on http://www.ifsja.org/forums/vb/index.php as well.








Oiling holes on the Edelbrock cam and timing set

401 is not finished yet

 

Hey Kevin, do you have an engine stand? I can loan you mine for a few months. It's an old-school beast I picked up on Craigslist a while back. I won't need it for a while. Maybe mid to late summer....

 

I have built a bunch of AMC V-8s over the years. Much of what is listed above is accurate and helpful.

There is an internal (under the intake in the tappet valley) oil mod to send oil to the rear main bearing with more volume (not pressure).

It is easy to do and you can get kits with flexible hose and hard lines to do it.

This REALLY improves the oiling of the engine.

Also 390s and 401s have steel cranks and rods. All of them. Even the ones in binders and buses.

You absolutely want to use 1971 and up cylinder heads, or the expensive, but awesome, Edelbrock aluminium heads.

Why? The early square port (as opposed to the later dog-leg port) heads just don't flow very well. Even the highly modified Hurst/SS heads don't flow as well as stock dog-legs.

Every 1971 and up block will take any head. There are step alignment dowels available for early blocks (pre-1971) to take later heads.

290/304 heads have teensy valves and relatively large chambers.
343/360 heads have a variety of valve sizes available and chambers. 52cc to 68cc and stops in between.
390 heads have big valves and crap exhaust flow...
401 heads have big valves and smaller chambers 52cc in 1971 and into 1972.

360(some)/390/401 heads can take Chevy 2.02/1.68 valves with a guide change and seat massage. This removes more than one pound from the valve train...

For Jeeps the dual-plane intake is the magic. Try to find a Edelbrock R-4B. It was meant to have the 900CFM 3 barrel Holley on it, and it works well. That is a THREE barrel carb... the notch in the divider on the intake is for the giant secondary butterfly to have clearance.

No R-4B? the current Air-gap from Edelbrock is pretty awesome too.

Lots of header options. Longer collectors (up to ~12-14") adds low-end torque.

That should be plenty to generate questions....

 

I would not recommend you swap in a 360 AMC motor as its more trouble than its worth fabricating mounts exhaust etc etc. You dont say if your Cherokee is a 2 or 4 wheel drive but in either case the AW-4 will not hold up long under that much torque. Folks are getting 300 hp out of a 4.0 these days and thats all you need in a light Cherokee with a AW4. Either way I would source a Torquflite 999 from an early 80s Wrangler. The 999 when built properly is capable of handling 500hp and heaps of abuse..I have a spare 4.0 im building plus a 999 I will use when the current engine and trans are retired. Mine is a 2WD model and the same driveshaft can be used as the AW4 and 999 2WD transmissions are only 1/2" differnce.

I have built many AMC V8s and can help with some of your questions. I currently have a pro street Matador with a tunnel ram 401/727 and a Spriti drag car with a 360/998 besides my 97 XJ

 

Wow. That turns heads, I'm sure