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Starting a Cadillac V8 That Sat for 93 Years Is Very, Very Hard

There's something compelling about trying to bring a decrepit engine back to life.

As far as wrenching exploits go, there’s seldom anything as satisfying as getting a long-neglected engine turning over and humming once more. Jennings Motor Sports is a YouTube channel that specializes in just that, recently taking on its biggest challenge yet: resurrecting a 1917 Cadillac V8 that had been sitting for a full 93 years.

The engine sits inside a rusted-out shell of a car, with the engine and transmission pretty much the only surviving parts other than the frame rails and some sheet metal. The clutch was also suspected to be stuck to the flywheel. As for performance, the 314-cubic-inch Cadillac L-head V8 made between 70 and 80 horsepower back in its day. The old-fashioned design doesn’t really have heads in the traditional sense; instead, the whole cylinders can be unbolted from the block if one desires to do a full rebuild. 

YouTube/Jennings Motor Sports

Regardless of age, the method for getting an old engine going typically starts the same way. The oil must be drained and the spark plugs removed, and then the cylinders can be filled with various fluids in order to loosen up an engine that’s frozen solid. 

It’s important to get everything cleaned up and freely moving before trying to crank the motor over. Else, there’s a risk of damaging piston rings that are stuck in the cylinder. For an engine like this old Caddy V8, parts are hard to find, so it’s crucial to take things slowly and carefully. Even simple parts can cost hundreds of dollars for this old engine, and that’s if you can find them at all.

No starter motor makes turning the engine over hard work., YouTube/Jennings Motor Sports

The oil was dumped out and despite the age of the car, it still looked vaguely brown and oil-like without any obvious water in the mix. Amazingly, the spark plugs mostly came out okay; having been parked out of the elements with the hood on, the threads hadn’t rusted too badly. The cylinders and crankcase were then filled with diesel to loosen everything up, then Marvel Mystery Oil, and finally with brake fluid. 

At last, the engine was sorta free, and it was hooked up with a battery to try and get it started once more. After hours of turning the hefty hand-crank, though, the towel was thrown in. Further investigation showed that the camshaft might’ve broken; without a working valvetrain, the engine was never going to start. One suspects that may be why the car was originally parked almost a hundred years ago.

While this wasn’t an easy win, the video still serves as a great guide for going about rescuing old engines. The same techniques are just as applicable to modern motors, even if more wiring and electronics might be involved. We’d love to see this old V8 get a rebuild, too; there’s something powerful about a century-old engine still chugging along.

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