The ritual was always the same – before firing up a freshly rebuilt small-block Chevy for the first time, you dug around in the bottom drawer of the toolbox to find that junkyard distributor shaft (no store-bought tools for you, when you could make your own!) so you could spin the oil pump with your drill and pre-oil the engine. Assembly lube is great and all, but you’d still spin that pump, give the crank a quarter turn, spin again, and repeat until fresh oil had made its way to every nook and cranny.

Then, you started building LS engines, with their crank-driven oil pumps, and suddenly pre-oiling the engine presented a new puzzle. Enter YouTube user AGearHead4Life, with a pretty straightforward solution; a DIY primer that uses air pressure to force oil through the system. We’ve seen his work before – a while back we showed you his DIY head porting video series – and this latest video is a good addition to his library of helpful tech tips.

We do have one issue, though. His homemade tank is crafted from large-diameter PVC pipe, which should never, ever be used with compressed air. While it might be rated to a certain PSI limit, that’s for water, not air. Water is incompressible, meaning that a crack just means a leak. But because pressurized air acts like a spring, the stored energy in that tank pumped up to 70 pounds per square inch makes it a potential bomb. We’re especially concerned about the fittings drilled and tapped into the end caps, which can cause stress concentrations and places for cracks to start. One good smack and sharp fragments of PVC pipe will be looking for your tender flesh.

Far better, then, to repurpose something designed to hold compressed air, like an old-but-not-rusty portable air tank, to use as the reservoir. Overall, we’ll call this a good idea with one major flaw in the execution.