Projects In Metal

1/4 Scale Chevy Smallblock

The engine is a very interesting build in a lot of ways. As my photo shows, the block which actually is an aluminum casting, and was line-bored in my milling machine, and has cast-iron sleeves when assembled. The sleeves are machined as a sliding fit in the block. Once I was ready to assemble the sleeves into the block, a thin bead of high-temperature 620 Loctite was applied to the upper and lower mating surfaces of the block and the sleeves. Once the sleeves were in position, the loctite was allowed to cure, and voila! a totaly waterproof joint that will-not come apart any time soon.

When this photo was taken, I was in the process of machining the valve guides for the cylinder heads. Once the valve guides, that were machined from brass were in place, I machined all the valves from 316 stainless-steel. The valves machined from 316 SS, have proven to be capable of with-standing the high-working temperatures they are subjected to.
The machining of the heads made me sweat once or twice, as I turned compound-angles while boring the intake and exhaust-ports, with only thousandths of a inch to spare between them.
The crankshaft is built from 9 different pieces of material, that includes ground crank-journals, and once the alignment of the crankshaft was to my satisfaction, and after being assembled in my arbor press, I drilled and pinned all the crank-joints, with 5 high rpm ball bearing-assemblies in place.

The engine can turn at 12,000rpm and to date has not suffered lower end failure. The camshaft proved to be a interesting build as well. After boring the block for the cam shaft, the lifter holes were drilled and reamed. I then machined the individual lobes for the cam from 1/8th sheet material. Nothing extreme as far as the lift for the valves. The lobes were then heat-treated in my heat-treating furnance. The next step was to insert the cam blank without the lobes, into the block. The crankshaft was in place with the cogged pulleys that drive the cam in place. I installed a degree wheel on the crankshaft, and cylinder by cylinder, I advanced the engine through its firing order. At top dead center for each intake and exhaust position for each cylinder, I inserted a special punch that I had made up, to slide freely into each lifter hole. This centering punch was used to center-punch each intake and exhaust position on the cam-blank. Once the entire cam-blank had been marked all the way through the firing order, I removed the cam blank and mounted the blank in my milling machine where a 1/16th hole was drilled through the cam blank at every marked position. The cam-lobes that had a matching 1/16th hole drilled in them prior to heat-treating, were slid in place and loctited and then pinned in place. The cam has proven to work like a charm.

With a water-cooled engine,you need a waterpump of course. Look close, and you can see the water pump that I sourced from another application. I initially was going to drive the pump with pulleys off of the crank. One day while working on the engine and at that point, I was in the process of maching the cover for the timming belt, a light in my head came on, why not mount the water pump on the timming cover and drive the pump off of the end of the camshaft I thought. In no time flat, that is where I mounted it. You can see the brass fittings on either side of the block where the water is pumped to cool the engine.

conley