Little Demon V-8

LITTLE DEMON V-8
Part one - by Steve Huck

LITTLE Demon is an 8 cylinder, 4 stroke engine designed to run on gasoline. The engine has a 5/8 inch bore and stroke for 25cc with 5.2:1 compression. The valves are ¼ inch opened by roller rockers. The oil system is splash and it is water cooled via water pump and radiator.
Doing a full build article would be as big a job as building the actual engine. There are almost 500 pieces so what I’m planning to do is give you a good start by covering the block and heads. There are many ways to make something. I’m not saying this is the best way to do this, just the best way for me.
When making these 2 pieces they will get spun and flipped and rotated all over the place. It is important to pull all measurements from the same surface. For my block and heads I used the front of the piece and measured from there throughout the entire process
Start the block by squaring up a piece of aluminum 2.728 square and 4.936 long. Drill the coolant passages into the block that run from front to back. Placement being more important than alignment, I drilled from both sides and had the holes meet in the middle. The block was then rotated to the left bank of cylinders. I rough cut the valley with a .875 cutter and then finished up using a .250 diameter cutter. Drill the lifter, breather, and set screw holes. Drill the head bolt holes and drill and bore the cylinder holes. Cut the water jackets into the cylinder holes.
The jackets are formed by using a .625 key cutter. After setting the cutter down in the cylinder to the proper depth, move the cutter in a .125 inch square .0625 off center and then in a cross pattern .094 off center. This will be done multiple times in steps until the proper depth is reached. My cutter is .125 wide so I lowered the cutter in .100 increments until reaching finished depth. Seems like a pain but it goes fast after a few holes.
Now rotate the block to the right bank of cylinders. Cut the valley for the right bank of cylinders. Drill the lifters, vents, set screw, and the water passage holes. Drill and bore the cylinder bores. And again cut the water jackets into the walls of the cylinders. When finished you should have a block that looks like this.

Rotate the block to a 45 degree angle. I used 2 miniature V-blocks that I made out of some ½ inch square stock about 2-1/2 inches long. Cut the top and the bottom of the block to height. Rough out the crankshaft pockets and drill the holes to mount the main caps. Drill the holes to mount the oil pan. Make the main caps and install them. From here finish all the milling to clean out the crankshaft pockets.

Now the oil pan needs to be made. Once that is done the oil pan is mounted to the block. Locate the crank and cam holes and drill and bore the two bores. The oil pan serves as the front and rear main caps.

Drawings can be purchased via Paypal by sending funds to pross396@wowway.com Engine plans are $50USD and contain 68 pages. Blower plans are $25USD and contain 27 pages (Steve has built blower prototypes but not a final version at the time of writing).

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GO TO PART THREE

GO TO PART FOUR

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