Crusty ’68 Chrysler 440 V-8 gets machine-shop makeover
This Chrysler big-block, picked up a few years ago from veteran dirt-track racer Claude “Snowball” Bishop, will soon be roaring back to life in the 1937 Ford coupe where it belongs. But first, Davin and Hagerty’s Redline Rebuild crew head to Apex Competition Engines in Fenwick, Michigan, where the now torn-down 440 V-8 engine gets all kinds of machine work.
First up, the big Mopar’s cylinder heads get new valve guides. The old ones are bored out and new bronze guides get air-hammered into place, cut to length, and honed to their final size. These will serve as the starting point when Apex begins to machine the new valve seats.
Before that, though, the heads must be carefully squared up and resurfaced. A true cylinder-head surface, along with a true block-deck surface, is key to proper head-gasket sealing. Mill too much and, as Jon from Apex Competiton Engines explains, intake bolt holes start to get out of whack. Of course, there’s also the reduced combustion-chamber volume and the corresponding increase in compression ratio to worry about.
Next, exhaust seats get cut out. New seats, fresh from the freezer, get hammered home and machined to seal up the new valves and flow better than ever. After checking that the exhaust valves were installed to a proper depth to keep lifter preload equal, Jon gives the intake valves some attention, finishing with hand-lapping to ensure a positive seal and keep combustion pressure where it belongs.
Finally, it’s time for the block. The first and only problem in the machining process rears its head: A stubborn dowl pin, which requires a torch and a TIG welder before it cooperates. While the block cools down, Davin and Jon move to the rotating assembly, which consists of flat-top CP pistons, Eagle H-beam rods, and a refurbished factory crank. Since the new parts have a different mass than the stock pieces they’re replacing, the rotating assembly must be rebalanced. After Jon removes metal from the crank counterweights and just a touch from the flywheel and damper, everything gets the green light. Now, it is back to the block, which he decks 0.010 of an inch and bores 0.030-inch over, using a boring bar and then a hone with a torque plate installed to ensure perfect cylinders.
Apex Competition Engines made this project look easy. Hopefully, the assembly of the engine goes just as smoothly. Keep an eye on the Hagerty YouTube channel for the next installment of Redline Rebuilds, where we’ll be seeing this big-block crank out serious power very soon!