The engine block was machined from 6061 T6 aluminum in three main parts, the crankcase and the two cylinder banks. The crankcase was machined to size and all the milling work completed, then mounted to the lathe cross-slide table and rough drilled for main bearing journals, a between the centers boring bar was setup for line boring the journals. Split phosphor bronze bearings were turned in the lathe and mounted in the three center main journals. The bearing caps have a hollow pin which locates the bearing and prevents them from spinning in the bores; oil enters these bearings from a manifold attached to the tops of the center three caps. Two sets of thin section roller bearings are fit at each of the end bearing bores. Drill rod was used for the studs that mount cylinder blocks to crankcase. These were cut to length and threaded with a geometric die head in the lathe. A die head is great for making studs quickly, you simply clamp the material in a collet and feed the head onto the material, the die head pops open when it has reached the length of thread you set it up for.
The cylinder banks where machined to size and all the bores and stud holes where located and drilled or bored to size on the Bridgeport mill. The blocks were then clamped to the lathe faceplate and the water jacket recesses were bored, all the water jackets are connected by holes drilled from the ends of the blocks. The cylinder liners were made from centrifugally spun cast iron, first the outside diameter with a raised shoulder at the head side was turned and the center bored to +0.001 inch and finished with an expanding brass lap. Liners were then coated with Loc-Tite retaining compound and pressed into there bores.
Well here it goes, it may take some time to get this page looking right but it's a start. I first must let everyone know that I have been getting tons of e-mail from a lot of different people thinking my engine is a Challenger, or a Challenger hybrid of some type? I have had questions about how I did the Hemi head conversion for the Challenger engine? Sorry guys this engine has nothing to do with the Challenger V8's. It is not based on any type of scaled down full size engine, no castings were used in this engine, this engine was constructed based on ideas I thought would look neat and be fun to machine. I do like the Challenger engines but I wanted to do something a little different. The pictures on this page will be redone by tomorrow night; I am going to try something different. This page is going to take some time since every part is going to be placed on here; this was simply a place to start.
CRANKCASE AND CYLINDER BANKS
FRONT AND REAR DRIVE HOUSINGS
These are the front and rear housings for the cam gear drive system and the rear dual distributor drive. I choose to build this engine in a modular fashion so if something did not work right I could make changes very easy, if I decided to build another V8 based on this prototype I would make the engine block and a lot of these extra pieces from one solid billet of aluminum. This design has worked well for the prototype, I have not had any problems with loose parts or oil leaks.
The crankshaft was turned from a length of stress proof steel; I first turned the crank to the finished outside diameter and finished both of the end bearing surfaces with the blank mounted between centers of the lathe. I then made the two of the fixtures in the picture below to locate the rod center journal positions. These were first turned and bored on the lathe and then set up on the rotary table of the mill for center drilling and reaming the rod journal centers, so now we have two fixtures like in the picture but without the flat machined on them yet. I then took both pieces and passed four ground pins through the journal locating center holes; with both fixtures clamped together in the mill vise I milled the flat across the bottoms. The fixtures were pressed onto the ends of the crankshaft blank and the assembly was carefully indicated true along its length, with the flat's of the fixtures against table it was clamped down on the mill table. Holes were drilled and reamed for tapered pins to lock the fixtures to the crankshaft blank.
I mounted the assembly between centers of the rotary table and tailstock setup on the mill, I located and milled the majority of material away from the journal areas, back in the lathe the journals were all turned to finished diameter +.001 inch. I covered all parts of the lathe with plastic sheeting and used a tool-post grinder to finish the journals to size. I have had several people tell me I could not get a good finish without using flood coolant with the tool-post grinder, I didn't seem to have any problems running it dry, I got a very nice ground finish with no vibration or chatter patterns on the journals.
The area between the journals was milled away to make the counter weights. The next step was the part that had me the most worried, drilling all the oil passages without breaking a bit. I first used a .065" endmill and made a flat where the hole positions were to be, a very long and tiny spotting drill was then used to get the drill started, I ran the rpm of the mill very high and kept the feed pressure low, the drill was backed out often and cleaned of chips. This step didn't turn out to be as hard as I had thought it would be, at this stage I removed the fixtures from the crankshaft.
The flywheel was added because I wanted my engine to be able able to have a low idle rpm, it was pressed on the back of the crankshaft, the flywheel is so small I don't think it really has much of an effect. The rear of the shaft was splined and the front was cut for a keyway to lock the timing gear and front drive pulley. That's it, done.
PISTONS, CONNECTING RODS, AND RINGS
The pistons were turned on the lathe from 2011 low expansion rate aluminum; the pistons were sized to .001" smaller than the bore size. The ring grooves were turned with parting tools made from sections of slitting saw blades. The compression rings are 0.025" wide, and the oil control rings are 0.054" wide. The wrist pin bores were located, bored, and reamed. The internal profile and the radius on the piston skirt were done in the milling machine. I purchased a custom ground tool for turning the retaining ring or circlip's recess in the wrist pin bore.
The connecting rods were made from 6061 T-6 aluminum, first eight rectangular blocks were machined to size, the rod bolt holes were located, drilled, and threaded for 5-40 fasteners, the cap section was cut off with a slitting saw, with the caps bolted back on the rods, and a 0.020" shim between them the bearing journals were located and bored to size taking into account the .010 inch thick pure silver sheet that is used for the split shell bearings. The wrist pin holes were located, drilled, and reamed for phosphor bronze bearings before removing from mill vise.
The profiles of the connecting rods were done on the milling machine with a rotary table. The silver sheet was sandwiched between two aluminum plates, and cut to the width of the connecting rod, with a slitting saw. The strips of silver sheet were formed by clamping the connecting rod and cap around a mandrel, now with the bearing shells in there final position, I drilled through the silver material for the rod bolts.
The piston rings were made following the advice of George Trimble's article in Strictly I.C. magazine. I made my rings exactly the way he said to do it and they have worked great. The bottom pictures to your left are the ring's heat treat fixture. I have made the oil control ring's but I have not installed them on the pistons yet, I still have not drilled the piston oil ring groove for the oil return hole's, the video of my engine running is without oil control ring's installed. I will install them when I reassemble the engine.