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Valve cover t-bar hold-downs were popular dress-up items on engines from the 289's era, and a set for the model was machined next. The full size versions were chrome plated, but the model's were machined from polished stainless steel. Their machining was straightforward and included a handful of...

https://www.homemodelenginemachinist.com/threads/another-knucklehead-build.27584/

From a machining perspective the manifolds are organic parts with no convenient work-holding surfaces and so were designed to be machined through the front and rear faces of a rectangular workpiece. The workpieces included a framework around each manifold to support the semi-finished parts...

After some sketchy band sawing, the 2"x4"x10" starting workpieces for the manifolds wound up being the last of the large chunks of my 25 year old 7075 treasure find. There's no particular advantage in using 7075 for the exhaust except that it was the only material I had on hand that met the...

The dipstick ... The dipstick was the last item on my 'loose ends' list. Located in a busy area on the 289, the dipstick tube snakes down the front of the passenger-side head behind the alternator, through the lower corner of the timing cover and into the oil pan. A realistic looking dipstick...

Although the alternator will tension the fan belts, it's mostly a cosmetic addition. The goal was to come up with something realistic but substantial enough to be driven by the engine. The final assembly included a half dozen machined parts. The most interesting piece was the armature shaft's...

The water neck returns coolant to the radiator and is part of the thermostat housing bolted to the front of the intake manifold. Its small boubous shape and neck exiting the housing at a compound angle makes it a challenging part to machine. Due to an oversight in my manifold design, access to...

In my experience you'll want to keep the manual mill around. CNC is great for making multiples of the same part or complicated parts that require coordinated moves among two or three axes. However, there are lots of simple operations that will become too cumbersome and time consuming to perform...

To be honest, I don't remember where I got them. I've had them for over thirty years and probably bought them at some company surplus sale. - Terry

The insanely high temperatures and daily warnings about our shaky (Texas) power grid limited my shop time to a handful of midnight hours during the past few months. Long CNC operations are still pretty risky, and so for the next few weeks I'm focusing on loose ends and simple parts that don't...

Houston, we have a problem ... The first photo shows the highest outdoor temperature I've experienced in my entire 75 years, and that includes three years spent in the Mojave desert. For you metric guys, that's 45.5 celsius. When this photo was taken, it was 99F inside my shop, and I was...

Before starting on the main bearings, a few loose ends need to be tied up on the block including the machining of the cylinder liners. Once they're installed, the decks can be finish machined and the main bearing work will begin. Since the backup material purchased for the crankshaft wasn't...

Wrapping up the crankshaft ... The sections were clamped horizontally in the vise so the alignment flats on each end could be machined. For these operations the rod journals in the front and rear sections were oriented straight up at twelve o'clock, and a gage pin between the journal and the...

As mentioned earlier, I'm probably trading one set of problems for another ... The distortion left in the workpieces by the rod journal roughing operations wasn't surprising, but since I'd used Stressproof its magnitude was disappointing. In any event, the rod journals were finished with...

Continuing on with the pieced-together crankshaft ... The first step was to bandsaw four workpieces from a length of Stressproof purchased specially for this crank from Speedy Metals. The crankshaft's o.d. was designed around precision ground 1-5/8" diameter material sold by Speedy. The...

Kimmo, et. al. Thanks for the interest and comments. What happened in my tests is that one half of the joint was held fixed in a vise while the other half was twisted until something broke. What broke in all my cases was that the facing flats of two halves opened up and applied enough pressure...

Minh-thanh, It's not my only reason. You might have missed my 'rant' post #125 just above my post with the photos. - Terry

Although it may be a swap of one set of problems for another, the current plan is to machine the 289's crankshaft as four separate pieces. Its tenon'd ends will be coupled together inside Loctited sleeves doubling as the main journals. A custom alignment fixture will be used, with each bearing...

I hate making crankshafts ... The odds of machining a ten inch five bearing solid crankshaft that spins freely in a block are stacked against a builder without a dedicated grinder. I've adapted two different tool post grinders to my lathe, but when it comes time to using them on real...

A handful of small parts still remained in the way of starting work on the crankshaft. A model of the crank (less its counterweight details) was created last summer and verified in a SolidWorks assembly that included the block, pistons, rods, and camshaft. Placeholders were used for the nose and...