Oldsmobile 455 Big Block Engine Build - 511-LB-FT, 445HP 455 Rocket Olds

With our Rocket 461-inch motor assembled, it will be an easy evening's work to swap in our lighter and more powerful Edelbrock aluminum-headed 461ci thruster using a set of coated 1 3/4-inch Dick Miller Racing headers.

With our Rocket 461-inch motor assembled, it will be an easy evening's work to swap in our

On the street, torque is king. One of the best and simplest ways to make gobs of frame-twisting torque is with cubic inches. Among the torque kings in the GM world are the Buick, Pontiac, and Olds 455ci twisters, but it's often the Olds that wins out. While the good Dr. Olds factory variants have been the staples of Rocket performance building for decades, Edelbrock's aluminum head contribution has made building one of these big-blocks enticing and weight conscious. So when it came time to freshen up the tired 455 in our budget '64 F-85 Olds project, we learned a few assembly tricks for our fat-block we thought we'd pass along that will ensure our Olds lives a long and prosperous life-and makes some acceptable power, too.

The plan was a much more street-conservative approach versus our usual max-out horsepower effort-more of an everyman's big-block. We wanted a daily-driver engine with pump-gas-friendly compression and a Comp flat-tappet hydraulic cam to enhance the Olds' already legendary torque. We really enjoy cruising the F-85 with its patina paint, so future plans include either a tight converter combined with a California Performance Transmissions 200-4R overdrive automatic, or maybe we'll retain the TH400 and just slip a 2.56:1 rear gear behind it. Either way, our recipe called for a motor that would make stupid low-speed torque while still pushing our F-85 to mid-12 quarter-mile times. All this was also with an eye toward not destroying what was left of our meager car budget.

After cleaning the block, Barrington bored the block 0.030 over and torque-plate-finish-honed each cylinder to fit the 4.155-inch-bore-size hypereutectic pistons.

After cleaning the block, Barrington bored the block 0.030 over and torque-plate-finish-ho

Since we had never assembled an Olds motor before, we relied heavily on advice and assistance from Don Barrington at Barrington Engines and Dick Miller Racing (DMR), whose Mississippi-based shop offers tons of options for the Rocket engine builder. Barrington and Miller helped us avoid the common assembly mistakes on our 461ci street engine, and much of the success of this engine is due to their significant contributions.

Search and Destroy
While it would have been cheaper to rebuild the existing 455 in the '64 F-85, we knew the build would take some time, and we wanted to continue to drive the car. We found a used 455 short-block on Craigslist that got us started. The crank was wasted, but for $200, we bought the short-block and an extra crank that we discovered had a trashed thrust surface. Engine and Performance Warehouse in Anaheim, California, repaired our ailing crank and gave it a perfect 0.010-under treatment. We then took the block, crank, rods, and pistons to Barrington Engines where Don Sr. and Don Jr. cleaned, bored, and torque-plate-honed the aging jet-boat motor. West Valley did the balancing act.

One trick Barrington and Miller suggested was replacing the stock Conestoga wagon-era rope rear main seal with a neoprene lip seal from a 460 Ford. Next, the guys encouraged us to add cam bearing restrictors that direct more oil to the mains. Our next surprise came with the rear main bearing clearance measuring a wide 0.0041 inch. Barrington says this was factory intentional to flood the rope seal with oil to prevent it from overheating. Barrington suggested we retain the clearance because it would require expensive line boring to repair, so we followed his advice. We've also outlined a couple of other Olds-specific assembly techniques that can save you some grief when assembling a street Rocket.