Here’s the camshaft, oriented just like the diagram. Not so helpful, as you end up guessing which way half of them should go, and hoping they line up correctly with the valves, so they’ll open and close them. Unfortunately, half of them aren’t visible in the diagram due to the orientation of the sketch. There are indicator lines on the cams to indicate which way they should be installed. Here’s one that shows the camshaft with the cams lined up a certain way. The instructions were decent for the most part, but the diagrams could’ve used some work. The plastic is thin and malleable (not really a good thing… cheap “feel”), so applying some pressure to it for a few minutes was enough to bend it back to the right position and make it stay. The valves need to slide back and forth (open and close) freely. The upper hole didn’t quite line up with the lower, so the valve (purple pin) would stick instead of springing back. It happened to us when we inserted the valve into the cylinder head, seen below on the lower-right. One of the most common complaints was misaligned holes. There were about 60 screws in the set, and only 2 left over, so no room for error. That worked out well, since it was tough to apply enough force to not strip the head, while applying the minimal force necessary so the plastic didn’t crack (which almost happened a few times). Luke would start the screws, then I’d finish them up. The cheap kind with the heads that strip while you’re screwing them in. It was mostly screwing everything together in the right order… lots and lots and lots of tiny screws. Our set had all the right pieces in the right quantities, not something you should even have to worry about. It wasn’t an overly difficult model, and we lucked out. Plenty of helpful suggestions in there before you get started. if you've got one and you're feeling intrepid, read on! Hopefully I can help you avoid a few issues.

I’d be hesitant to buy another similar toy with their label on it.Įnough of that. The Smithsonian is a respected name, but obviously partnered with the wrong manufacturer.

Amazon ratings are abysmal, mostly because of thin/cheap/missing parts. I wouldn’t recommend ever buying this at full price. The concept is awesome, but the materials are not. The girls were at a play and the toddler was napping, so it was the perfect time for a little father/son bonding over a cool project. I’d shelved it for a rainy day and completely forgotten about it, then rediscovered it last weekend during an overdue cleaning session in the basement. Once built, it’s supposed to model a 4-stroke internal combustion engine.

Last summer, I found this “Smithsonian Motor-Works” set for $5, which I figured was a steal. Garage sales are great for finding random, interesting things to do with the kids, usually for dirt cheap.

Combustion 4 stroke