Now that our 1993 Jeep Cherokee’s 4.0-liter inline-six engine has been disassembled, Davin has some prepping to do before it heads to paint—specifically, removing the casting shrapnel from what he calls “a poorly designed mold.” Using a die grinder to clean up the mess, Davin’s time-consuming task was becoming a bit tedious. Then he had an idea: Why not try a tool that’s designed to remove rust? Moments later, a descaler is making quick work of the shrapnel.

With that job finished, Davin cleans up the block in the wash cabinet, blows it out, and begins taping it for paint. That’s when he offers another time-saving tip, showing that he made plastic coverings on a 3D printer that slide nicely into the core plug holes. And off we go to Traverse Body & Paint to “let Darryl do his magic.”

With the parts laid out on stands, Davin offers his RockAuto.com Tip of the Day: “If you want paint to stick to anything, the surface cannot be smooth, and it needs to be oil-free.” That means, for example, the coating on the oil pan needs to be scuffed up, and then it needs to be wiped clean to remove any finger prints/oil residue.

Check out the results for yourself and also be sure to subscribe to the Hagerty YouTube channel so you never miss an update.

Thanks to our sponsor RockAuto.com, an auto parts retailer founded in 1999 by automotive engineers with two goals: Liberate information hidden behind the auto parts store counter (by listing all available parts, not just what one store stocks or one counter-person knows), and make auto parts affordable so vehicles of all ages can be kept reliable and fun to drive. Visit RockAuto.com to order auto parts online 24 hours a day, 7 days a week, and have them conveniently delivered to your door. Need help finding parts or placing an order? Visit RockAuto’s Help pages for further assistance.

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Enjoy Engine stories, opinion, and features from across the car world - Hagerty Media

In the latest Redline Update, Davin gets us up to speed on the Cadillac 365 V-8 and Honda Trail 70 projects.

First off, he inventories the Cadillac parts that remain after he disassembled the mill. The lifters show varying levels of wear, with the worst offenders displaying significant dishing. Those won’t be reused. New parts will join the original camshaft, which is being reground. Davin was surprised to find a new water pump; the big casting is pretty complicated, so it’s good to know that the cooling system will benefit from fresh components.

Plenty of the original Cadillac parts will be put back in service, however, and Davin reviews some of the steps used to restore them. For example, the V-8’s pushrods went through the parts washer and then through a tumbler filled with solvent and stainless rods to remove the baked-on oil. Now, they look brand-new. The rocker shaft assembly shows what the valvetrain parts looked like before that treatment. The shaft and its components are going into the ultrasonic cleaner before it heads to the tumbler. Due to the wear on the rocker tips, the rockers will need further work, since the ridges left by the valve stems need to be ground smooth.

Besides the tumbler and other parts washers, Davin and the Redline Rebuild crew rely on a media blaster. A quick trip to that part of the shop shows the valve covers getting stripped and readied for the same paint that will eventually coat them and the rest of the engine.

On to the Honda Trail 70, Davin lists all the new parts that he’s already collected, including clutch plates and a rebuild kit for the stator, plus brake shoes, sprockets, a battery, and an OE chrome engine guard. More and more original parts are going into the bin that’s destined for Jason’s Chrome, which will re-plate all those components in addition to polishing all the aluminum bits, including the intake manifold. Other aluminum parts, like the side case, will be sandblasted and Cerakoted. We also get a peek at the stamped steel frame, which is stripped of its stickers and nearly ready for sandblasting. The rusty split rims are also ready to get sandblasted. If they’re not too pitted, they’ll be powder-coated, but Davin’s lined up replacements just in case.

Next, the video team heads to Thirlby Machine Shop, where the heads get disassembled before being thoroughly cleaned along with the block. As previously discovered, one of the exhaust manifolds is cracked from the center port almost all the way to the collector; Davin plans to drill out the crack and weld up the cast iron. Luckily, the block passes its magnetic crack check with flying colors. Mike at Thirlby will handle boring, honing, and decking the block, making sure to leave the stamping on the deck surface intact. Compared to some of the other projects Davin has brought him, this Cadillac should be a cakewalk.

Finally, Davin reconditions the stock rods by pressing in new bolts, cleaning up the rod caps, and resizing the big end. As parts continue to show up, including the pistons and back-ordered fuel-pump rebuild kit, we’ll continue to bring you progress reports. Make sure you’re subscribed to Hagerty’s YouTube channel so you don’t miss a single one.

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Enjoy Engine stories, opinion, and features from across the car world - Hagerty Media

Most folks tend to think about a rebuild as comprised of two phases: taking it apart, and putting it back together. The facts often tell a different story, and rarely is a rebuild that simple; but regardless of what percentage of the rebuild Davin accomplishes in today’s update, he’s making solid progress on the 1937 Ford dirt track racer that he and Tom Cotter began to tear down last week.

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