The 427 is one of Ford’s most successful and iconic engines. With its 4.630-inch bore spacing and characteristic deep skirted block, the 427 slots right into Ford’s FE family of engines. But unlike its brothers, this powerplant was designed specifically for racing.
When it was first introduced in 1963, the 427 took the racing world with a bang. That first year, Ford won 23 races in NASCAR — including the Daytona 500 — with the brand-new engine. That was four better than any other manufacturer with their established engines.
Unfortunately, a serious weakness in the 427’s design was discovered fairly quickly. The block routed the oil first to the camshaft before it eventually made its way to lubricate the crank journals. During extended high-rpm operation, the lack of priority oiling to the crank would sometimes lead to a spun bearing.
Obviously, this was no good for NASCAR competition, which is all about pushing an engine to its limits for several hundred miles at a stretch. So Ford updated the original 427, the “top oiler,” to the side oiler in 1965. The side oiler prioritizes oil supply to the crankshaft first before feeding the cam and valvetrain, and that solved the 427’s issues for NASCAR racing. The side oiler is easy enough to identify because it has a hump in the block casting for the oil gallery on the driver’s side running lengthwise just above the pan rail.
Still, the 427 top oiler isn’t a bad design.
If you aren’t planning on spending a few hours making laps at Daytona, the top oiler is actually an excellent engine. Plus, if you are trying to source one they can often be had cheaper than the more famous side oiler.
Recently, we spent some time at KT Engine Development in Concord, NC, as they restored and upgraded a top oiler 427 that will be going into a classic 1964 Ford Galaxie. The owner — like most of us — wanted a bit more power, but he also wasn’t willing to sacrifice the bone-stock look that went with the rest of the car.
So KT Engines set about stuffing an absolutely ridiculous amount of inches into the block without changing anything on the outside of the engine. What they wound up with is a 427 with an astounding 498 cubic inches of displacement that is capable of gobs of torque and very respectable horsepower — all without a single exterior clue that this is anything but a tame stock rebuild. Even with the stock iron cylinder heads and dual OEM four-barrel carbs, this beast produces an astounding 500-plus ft.-lbs. of torque all the way up to 5,000 rpm and hits its peak 471.9 horsepower at 5,300 rpm. And while the less informed may poo poo the top oiler for its more famous side-oiling brother, this engine package will produce reliable performance in a street machine for years before needing a rebuild.
To see how the 498-cubic-inch top oiler came together, browse the slideshow at the top of this post.