sx4 engine troubbles

jonny - moved this into the engine section. Although it's not a 6, it's closer than the transmission area.....
I just did a COMPLETE on a 151 iron duke. Roughly 1 grand for the job for parts and machineshop work - I did all the labor. Included new pistons, crank kit, deck and bore block, etc.
Watch the crankshaft! They are different, and your little Eagle will have a sleeve in the back end of the crank that can't be removed without totally destroying it. There are also different nose lengths on the 151 cranks.

The 82 TSM says there is a two character code stamped on a boss on the driver's side near the upper rear corner of the block. Note that the codes used for AMC engines might not be the same as GM engines. The VIN code is definitely different. The codes are:

Spirit and Concord
4L - manual no AC, 49 state
4M - manual w/AC, 50 state
4S - auto no AC, 49 state
4T - auto w/AC, 50 state
4Z - manual, with or without AC, CA only

Eagle and SX4
4P - manual
4Y - auto
4Z - manual, CA
4K - auto, CA

Eagles were classified as utility vehicles and had light truck emissions. A Concord/Spirit engine will fit but emissions equipment will be different. You have your old engine for that stuff.

You can't use an engine made after 1982. In 1983 GM changed the bolt pattern from SBC to a different one used on front drive cars and their small V-6 models. I would assume that GM changed all of theirs, even trucks, but S-10 rear drive trucks may have changed a year before or after -- hard to tell with the General! You should be able to use a 2.5L four from an S-10 prior to 1983, but check with S-10 sources on the web. Jeep CJ-7 fours from 80-82 will be the same as Eagle fours also. Post office Jeep fours should also have the same bolt pattern.

If it comes down to it you could use a later model S-10 engine and trans/transfer case as long as the case powers the front axle on the driver's side (I think it does). Would take a little work on mounts to get it in and you might have to change driveshaft lengths, but to get an EFI four it might be worth it. Heck, if you're going to do that may as well swap in an AMC 2.5L from an XJ Cherokee or Wrangler though. The six would be nice, but an EFI four would be just about as good and much easier to install.




Edited by farna - Jul/28/2010 at 9:17am

If that eagle of Luke's was my car, it would have a 6 in it.

Edited by billd - Jul/28/2010 at 9:31pm

Going from GM 4 to AMC 4 would be as much work as going from GM4 to AMC6, but with no real gain..............

I think we're on the same page, so I'll just clarify my thought -
The easiest is another GM4, although they are a pain to WORK on, the replacement process would be simpler.
The reason I say that is - if the OP would want to switch to an AMC 4, it would be as complex as switching to the AMC 6 because of the similarities! In other words, moving to any AMC engine, 4 or 6, would require a transmission replacement and crossmember replacement. Because the AMC4 uses mounts similar to the AMC6, they won't mount to the crossmember he has - the GM4 uses a REALLY convoluted motor mout system
Oh, and don't bother looking at rockauto, NAPA, oreillys, etc. - as they are dead wrong on the AMC Eagle motor mounts used on the GM4. They all will sell you the 6 mounts, and those aren't even close!
The TSM has the mount shown correctly, no one else does.
BTW - when pulling the GM4, you have to disconnect everything, raise the engine, then get in and remove the left engine mount bracket as it won't clear the steering column.
BUT, if you get creative, and use a power hacksaw like I did and cut 1/2-3/4" off the end of that bracket, you can work the engine back in with the mount in place.
The motor mounts used with the GM4 in the eagle suck.