Chrysler Hemi 1/4 scale

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Dec 25, 2011
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Very nice. What material did you make your model crankshaft from?

Too bad about no pics, hope you document the rest of your journey for us because its a very admirable project.
Can you describe some of the tooling you used - ex parting tool to rough? home cut HSS tools to finish? any lapping?
Thanks Cogsy
And the metal I used for the crank came from a shaft from the draw works on a water well drill rig I once owned. I roughed out the crank on the mill with rotary table and tailstock with a fixture on each end to index rod journals then ground journals to final dimension on the lathe with tool post grinder. As my father owned an automotive machine shop for 52 years I have reground hundreds of crankshafts so it made sense for me to do it this way. I’ll post pics of fixtures next time I go to shop. Thanks for your interest.
Very nice work there. Will be following this one with interest. I worked in a Chrysler factory back when a hemi was the hot money.
Finally back on the Hemi getting the block roughed in, got past the nerve racking part as all the cylinder bores ended up in the proper alignment with crank center line and main bearing webs. Now need to finish hogging out crankcase then the lifter valley will have to be hogged out as well. Then cylinder bores taken to near finish bore for liners then the main bearing caps will be milled away and new ones made. Then align bore the main bearing bores. Now some questions like has anyone used split rod and main bearings? Is so what material was used? Used the washer that is approx same diameter as crank to check for enough clearance for crank the side walls of crank case will also be milled thinner as well.
I don't think there is any other way to make trapped bearings other than to split them. I turn the bearing inserts to size then part them off and finish the length. From here there's 2 ways to go. First you have to make a fixture to hold them then you can split the with a very thin slitting saw and not worry about the small gap produced or you can split each bearing so that one half is perfectly cut in half and discard the other half. This method requires making twice as many pieces but you get perfectly split bearings. I then drill the cap and one half of the bearing for a brass pin to keep the insert fram spinning.
I have also used a third method which involves taking 2 pieces of rectangular stock and soft soldering them together leaving one piece a little longer so that when set up in a 4 jaw chuck the exact center can be established. First the inside is drilled and bored to size. I don't like reaming because sometimes the pressure of reaming will split the solder joint. Now the O.D. Is turned and the insert parted off. Now it's heated until it separates leaving just a minute space where the solder was.
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Not wanting to hijack your thread I'm going to start another on how I machined the connecting rods and split bearings for them. It will be in Tips and Tricks.
Question if I may.

The only engine that comes to my mind when I read "Chrysler Hemi" is the 426 CI hemi from the late 60s. That would make this a 106.5 CI engine, which is still pretty big for a model.

Is that right?
I read George’s split bearing thread first, and then saw yours. That is a fantastic looking job to this point, and I look forward to seeing the remaining steps in your build.

Beautiful work!
John W

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