First thing, easy way to see if the engine runs. Throw some ether starting fluid into the carburetor, turn the key, and then crack some beers cause the engine is running. Well that isn’t what happened.
The starter clicked but the engine didn’t turn over. It was locked up. I pulled the plugs and put down a bore scope.
Well that is not good.
Remember this is an AMC 121 engine that is basically a Audi EA831. This block is aluminum silicon. The head is aluminum. Where did all this rust in the cylinders come from? This is cylinder 3. Looking on the porsche 924 forums, the head of this engine has stainless valves but steel valve seats. That is where the rust has to have come from. So we are dealing with rusty intake valves but the engine is frozen.
Over a couple days I soaked all the pistons in a mixture of ATF, acetone, and brake fluid. This mixture really creeps and loosens stuff up. I just poured it down the sparkplug holes. After a couple days of hitting the starter it finally broke free and started spinning.
We got an engine that spins! With the plugs out lets test the compression.
110lbs
90lbs
0
90lbs
So uh, cylinder 3 with all that rust is not happy at all. We either have a bad head gasket, valves are trashed, or rings are cracked. That engine head has to come off to properly check and fix the problem.
Lets see if we can get the engine to actually run before tearing it apart though. The carburetor needs to be rebuilt and the Jeep came with 2 rebuild kits and a spare carburetor for parts.
This is my “new” 1979 DJ-5G Dispatcher Jeep. I picked it up near the end of May.
Posing with the “kill” :) Yes its painted with zebra stripes…. or what is left of the stripes.
Once I got it home I put it up on jack stands and started to really dig into what it this Jeep is.
This is a “G” model of the Dispatcher, which was a really short lived variant. The big difference between this Dispatcher and other models was it has the AMC 121 2.0L i4 engine.
This is a very interesting engine and the history behind how these ended up in AMC vehicles… and the Dispatcher Jeep!
The EA831 engine, also known as the “Audi EA831,” was developed in the late 1960s. During the late 1960s, Audi sought Porsche’s engineering expertise to develop a new range of engines. Porsche, which had a strong reputation for engineering and performance, worked on several projects for Volkswagen since the 40’s, including the EA831 engine.
In the early 1970s, AMC was seeking to modernize its engine lineup to stay competitive in the automotive market. They had the small, light weight compacts that the gas crisis needed but not the engines.
In 1973, AMC struck a deal with Audi (then a part of Volkswagen Group) to use and license the EA831 engine. This engine was adapted for use in the AMC Gremlin, Hornet, and later the AMC Spirit. As part of this agreement, AMC was not to use the VW or Audi names when referring to the engine.
They also changed how the engine was run, Porsche was pushing fuel injection but AMC did not want that added complexity nor could burden the costs of developing a system. Thus, AMC went with a 2 barrel carburetor with a traditional points distributor. This is what became the AMC 121 engine.
Audi and Volkswagen ended up not using this engine, it was in the Audi 100 and the Volkswagen LT van. Porsche on the other hand had to pick up the pieces of the 924 fall out with Volkswagen and kept this engine there.
Basically if I need to get parts for the engine. Porsche 924 parts work and fit!
Back to the DJ-5G. AMC used it in a couple vehicles like the Sprint but it ended up being in a weird price point. The overhead cam engine was more expensive then the larger straight six and four engines that AMC was using at time. The engine was more fuel efficient then the old push rod designs but the extra price put it in the bracket of the V8 powered options. Economy at the time (and still now i suppose) was cheap = fuel efficient and expensive = powerful. So an expensive inline 4 that got good gas mileage occupied a weird spot in the market.
AMC used it in the Dispatcher jeeps but did not use the engine for long. Once AMC could get out of the deal they did. The post office also didn’t really like the small inline. You really had to rev the engine to get torque and drivers would just red line it all the time.
My copy of the DJ-5G is in ok shape. Frame is solid and the majority of the body is clean for its age. It does have one bad rust spot that will have to be fixed.
The drip rail here is rusted through which compromised the seam sealer. This ended up rusting out the upper roof frame.
This will need to be addressed but the first call to action is to get the Jeep driving again.
I got the pieces for the Checker’s battery box from sendcutsend earlier this week. Laser cut out of 1/8″ Stainless. Everything fit together really well and was easy to get it tacked together with the tig welder as the tolerance and fitment of the panels was really good.
And here is the test fit inside the trunk of the Checker. Still need to finish that rust repair before I can install this :)
The battery will need to be relocated on the Checker to the trunk. Not enough room up under the hood with all the turbo and A/C equipment. I will build a box to fill the area where I cut out the spare tire wheel well…. once I fix all the rust in the trunk sheet metal.
The box itself is 12″ wide, 21.5″ long, and 8″ deep. Same depth as the gas tank. Parts will be lasered out of 1/8″ 306 Stainless and then tig welded together. I designed a double flange system so the box will squeeze the sheet metal. Hopefully this will be more then strong enough keep the trunk sheet metal from ripping apart!
Now this box is bigger then the group 21 battery I am planning on running. Perfect place to store tools and extra fluids!
The leaf spring hangers turned out great looking. The bolt / threaded part was plated with zinc and the hanger section was painted with the AG111 chassis paint system. Should last longer then the rest of the Checker.
I also ordered replacement bolts and nuts for the suspension. Part links to McMaster below.
I should get one of those inflatable paint booths someday! This is my first paint project with my new 3M Accuspray Paint Gun that my Mother and Father gave me for Christmas. Should do a “review” of it at some part. Maybe when I try to paint something other then thick chassis paint?
Worked on the rear leaf springs on the Checker today. This is what the brackets and leafs looked liked after coating with Metal Prep and using a brass wire wheel to remove the Metal Prep crust. Metal Prep is a zinc phosphate based solution that promotes adhesion to the primer and protects the surface by leaving a thin zinc coating behind. Primer can go directly over it if its not all flaky.
Now the rear leaf spring hangers have welded in bolts where the bushings ride. The bushings will just rub through the paint eventually so I am going to zinc plate the bolts and threads. Will zinc plate the leaf spring center bolt as well.
This is my simple zinc plating setup. Chemicals are from Caswell. I use inexpensive sous vide heaters to agitate and keep the chemical baths at proper temperatures.
Here is the leaf spring hangers and leaf spring center bolt before plating. These have been blasted with 220 grit in the vapor hone, treated with Metal Prep, and then wire wheeled.
Now I only want to plate the bolt and threaded section of the hangers and then paint the rest of it. I used a special 3M tape (3M 470 Electroplating tape) to mask off the sections I didn’t want to plate.
Here is one of the parts in the electroplating bath.
Here is the leaf spring center bolt after zinc plating and black chromating. The hangers are currently having the rust sealer painted on the none zinc’d parts.
This isn’t completed but the general shape and assembly for the Cat Feeder Unreminder is going to look like this. A 3D printed enclosure with a grove in it that the solar panel slides into. Then the PCB fastens to the front which captives the solar panel. Then on the PCB there will be soldered threaded inserts where a plexi front panel will fasten to.
