cruiser
Well-Known Member
How have my Mobros been sleeping lately? Soundly, I hope. Of course we all struggle to fall asleep sometime, so here is my latest installment to facilitate your somnolence. If you're like me (and I know I am) you probably enjoy walking up and down the rows of lovely Mopar iron at car shows. The hoods are always open of course, and the first thing that I look at is the guy or gal's engine bay. I love a tidy, clean and correct motor compartment and have restored my 1974 Duster to look as factory as I can make it. When I bought my car in April of 2019, it had the original A-904 tranny but a replacement 1974 model year slant six. The replacement motor that came with the car looks exactly like the original engine but was pretty ratty, so I'd like the share the details of my recent engine resto and encourage you to do the same if you're so inclined. First, the engine was pulled and placed on a stand while I cleaned up the inner fenders and firewall (see first photo). All of the engine accessories were removed and then the block was washed several times with a degreasing cleaner. Suffice to say that it took a while to remove 34 years (the replacement motor was installed in 1988) of grime and oily crud from the block. This presented the opportunity to correct several small things, such as removing the hardware store cooling jacket drain bolt and installing a correct drain bolt from a salvage yard, and also installing a correct manifold assembly fastener set. I then had the exhaust manifold and its ten keepers sandblasted and ceramic coated in the color "Tungsten", which was the closest available color to natural iron. And yes, I know that the manifold was painted blue from the factory which burned off right away. But I wasn't keen on a lifetime of looking at rusty blue burned paint on my manifold, so I went with ceramic and it looks great. Check out the before and after photos of the manifold. Next, we painted the block in two coats of the correct corporate blue with Bill Hirsch spray paint in rattle cans. It took four cans to do the engine, which was preceeded by two coats of epoxy primer. There were many paint options, but the Bill Hirsch option was the best for my car. One downside of this product is the two week cure time, during which the engine could not be started. The intake was sandblasted, epoxy primed and painted, then reassembled to the completed exhaust manifold. The intake/exhaust assembly was then installed with the ten keepers and a correct set of fasteners that I found at a salvage yard. The fastener set included two brass slide washers and their associated cone nuts for the forward and rear ends of the exhaust manifold, and the dome washer in the center of the intake manifold. (Note: The photos below were taken before the installation of the correct manifold fasteners). Great care must be taken to not over-tighten this assembly onto the engine. More than 10 foot pounds could cause the cast iron mounting ears to break off. You've probably all seen this warning molded into the top of the slant six intake manifold. The valve cover needed a bit of attention, so I removed and bead blasted away three previous layers of paint. I pounded out a dent at the right front end, then Bondoed over and sanded the dent back to its original contour before reinstalling it with a new gasket (see before and after photos of the valve cover). Next, the cleaned up engine accessories were mounted on the motor and the engine bay was prepped for reinstallation. I removed and discarded the two 5/16" rubber fuel lines (one in the metal fuel line under the right front subframe, the other from the metal fuel line to the intake side of the fuel pump) and their incorrect screw clamps. The rubber line on the right front subframe was original to the car. The new low pressure rubber lines went in with correct 5/16" Keystone crimp clamps. Next, we carefully reinstalled the engine after replacing all three motor mounts. The power steering pump bracket was refinished in satin black and the pump/bracket assembly went back onto the motor, as did the rest of the accessories. The oil and filter were changed, the throttle, transmission kickdown linkage and cruise control cable went back on as did the refinished fan and fan pulley. We briefly started the engine to adjust the timing to 10 degrees BTC and then shut it down to allow for the two week curing period. When that was over, it was back to driving it and dialing everything in. There were a lot of small adjustments to be made, but I love the way it looks and it'll stay like this. The Bill Hirsch paint is far superior to the single coat of engine paint that went on at the factory back in the day. Yeah, it was a lot of work but now I get to look at my clean and freshly painted engine for the rest of my life. I hope that you've enjoyed Part 30, and stay tuned for Part 31 later this year which will cover the restoration of the wiper motor. The final photo is of the Duster on a winter day in northern Minnesota when I was enjoying the cold clean air, pristine lakes and birch forests. Now have your glass of milk and go upstairs to bed. Good night!
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