Hello all! Figured I'd start a new thread to document the V6 engine swap, collect the various bits of information I've gathered from my own experience, and hopefully provide a bit of insight for others interested. Maybe Ed Mc can add this to his growing compilation package which he distributes to anyone who asks. Many thanks especially to Ed, geoffinbc, and Jerry Lemond for their gracious help (and anyone else who has helped along the way - didn't mean to intentionally slight or exclude anyone).
First, the vehicles:
1989 Trooper "Obi-Wan" - originally had a 2.8L V6, manual transmission, previous owner had done several upgrades to suspension/steering and added a 2" lift kit. Engine had a serious lower-end knock and evidence of having been wheeled through some fairly deep mud when I bought it. It would crank and drive enough to make it around the yard a few times, and maybe down to the mailbox and back. I knew it was going to basically require an engine swap, so I began searching. I had not done much with V6 Troopers up until late 2014, when I bought this one listed on Columbus, GA, craigslist. After searching for information on suitable replacement engines, I located a 3.1L with a blown head gasket from a 1990 Pontiac 6000 (transverse mounted - more discussion on this in a bit), which only had 131k miles and seemed to have been fairly well-treated, based on the condition of the donor vehicle.
It just so happens that this engine already has the correct placement of the starter (driver's side), but it had aluminum heads, and smaller combustion chambers, so it came with "deep-dish" pistons to compensate. In order to bring the compression back up to where it needed to be for this engine to run well with cast-iron heads (larger combustion chambers) from the original 2.8L engine, I installed a set of 1992 Camaro 3.1L pistons.
NOTE: This is the 3.1L transverse-mounted, front-wheel-drive engine, NOT the 3100-series engine. The crankshaft main bearing cap bolts are different on the 3100 or 3400-series engines, and while these engines will work in a Trooper, the oil pan requires significant modification to get it to clear the front axle. Geoffinbc and Ed Mc., as well as others, have documented this information elsewhere (See this thread: Installing a 3400-series engine with oil pan
). I asked my local machine shop about the possibility of retro-fitting the older two-bolt main bearing caps into the newer 3100- and 3400-series engine blocks, and they stated the main bearing caps and crank would have to be line-bored to work properly; not something they wanted to tackle. I suppose you could just use two bolts to hold the main bearing caps in place, but you'd still have to figure out the deep-sump, tin oil pan installation.
The 3.1L engine block has the correct three-bolt bosses for the engine mounts. Only thing I had to do was shim one of them with a washer to make certain the bracket bolted up properly. Forgot to get pictures of that, but might be able to get back under the hood and snap a picture or two.
It also would be a good time to document the availability of these engines:
1989 - 1991 Pontiac 6000/Sunbird
1989 - 1992 Pontiac Tempest/Grand Prix
1989 - 1992 Buick Regal
1989 - 1992 Oldsmobile Cutlass/Cutlass Supreme
1989 - 1992 Chevy Lumina and APV minivan/Corsica/Beretta/Celebrity
1989 - 1993 Chevy Cavalier
All of these vehicles are readily available here in the U.S. from just about any salvage yard. I normally pay anywhere from $125 to $250 for a complete engine with accessories, depending on where I can get one.
I installed the Comp Cams 252 camshaft with new springs and lifters (next time, I may order the roller cam kit instead), shallow-dish pistons, new bearings and freeze plugs throughout, new timing chain, harmonic balancer, larger-bored intake, 5.7L throttle body with 4.3L injectors, and larger intake pipe on the oil pump. Also deleted the smog pump, installed an exhaust manifold from an '85 Chevy S-10, and rerouted the pulley belt while I was at it (pics in another reply below). All of this, including the machine work on the heads and block, came in at a little over $1100 total.
Here's the almost-completed engine, ready for installation. Note the tool I made using the distributor-driven oil pump cap from the 3.1L distributor shaft gear.
Next, a coworker said he had seen this one on his way into work. Went to look at it and discovered it is a 1990 model with only 75k miles on the body, but most of the engine was sitting in pieces in the back cargo area. Interior was in great condition, so I'm now the owner of another non-running Trooper. This one is an auto tranny, unfortunately (yes, I can hear the groans across the interwebs), but the wife likes it, and wants it for her daily driver, so here we are.
Here's a snapshot of the engine parts sitting in the cargo area before I bought it.
The story was that the previous owner had somehow managed to trash the engine and transmission towing a trailer over the years and took it to a local repair shop to swap in a remanufactured engine and eventually have the transmission rebuilt. The repair shop installed a Jasper engine with an Edelbrock intake and carburetor, rather than the original throttle body (at a cost of over $5500, mind you). The owner would just shift manually through the gear selector, since the carb'ed engine setup wouldn't have provisions to control the transmission control module. The shop never could get the engine to idle correctly, so the owner sold the vehicle to the repair shop, since he no longer wanted to dump any money into it. They proceeded to remove the engine and returned it back to Jasper. So, it has been sitting for nearly a year with no engine and a transmission that needs rebuilding, but still has almost $2500 worth of new parts installed.
My plan is to rebuild a 3.4L, which I picked up from a salvage yard today, based on the previous success with the 3.1L rebuild in Obi-Wan.
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How to rebuild a 2.6L 4ZE1 distributor
'89 S Trooper - "Kal-El" - 4ZE1
'88 LS Trooper - "Delta" - 4ZE1
'92 Pickup - "Blacktail" - 4ZE1
'89 S Trooper - "Red Leader" - 4ZE1
'89 SE Trooper - "Vader" - 4ZE1'90 Trooper - "Leia" - 4JG2T swap on hold
'89 Pickup - "Wicket" - 4ZD1
'90 S Trooper - "Nan" - 4ZE1 (possible V8 swap - Ford 302 with 5 speed?)
'94 S Amigo - "Artoo" - 4ZE1, SOLD
'92 XS Rodeo - "Jabba", LH0, 3.1L V6
'89 S Trooper - "Chewie" - 4ZE1, TRADED
'89 XS Trooper - "Red" - 4ZE1, SOLD, bought it back'89 LS Trooper - "Obi-Wan" - LH0, 3.1L V6
'88 S Trooper - "Stormtrooper" - 4ZE1, SOLD
'91 S Trooper - "Ghost" - L32, 3.4L V6, SOLD
'89 S Trooper - "Angry Bird" - 4ZE1, SOLD
'89 S Trooper - "Phantom" - 4ZE1, salvaged
'90 Pickup - "Uno" - 4ZD1, SOLD