Words: Mike Aguilar Photos: Tyler McCormack and Enilda Aguilar
Tyler McCormack is the proud owner of a beautiful 1970 Chevy Chevelle into which he’s thrown a Big Block Chevy motor. I ran into Tyler in a group on Facebook quite a bit ago. He’d posted pictures of the car alongside his other car and said he was doing an engine swap on it. I had a chance to speak with Tyler about the car.
As young as he is, Tyler said he’s wanted a Big Block Chevelle “for the longest time.” Once he had the money to buy one, he set the wheels in motion to find the right car for him. That search took longer than he thought it would, but he was successful, with the help of a friend who flips cars, in finding one that was in great condition with the right price.
He wanted a car that would be a great street/strip car with more of a focus on the racing/strip. Although the stock 454 is beefy, it was old and tired, so McCormack decided to build a new engine based upon a 454 Big Block to give him some authority in the racing arena. When we first spoke he was most of the way done building the engine.
As I write, the install is done, although he hasn’t gotten it on a dyno yet. He told me his target with the parts he chose was 500-550 HP and 500-600 pounds-feet of torque. “It’s been a long haul, because I live in New Jersey but go to college in Boston and can only get home one weekend a month.”
The rear end in Tyler’s car is a stock 12 bolt, although he rebuilt it completely and install 3.73 gears. Right now it has the stock axles. However, he did install a custom aluminum driveshaft to help lighten the car a bit. He told me he’s probably going to install a posi in it before summer break. The suspension is currently stock, but he’s working up a list of upgrades that include coil-overs and tubular control arms. It’s got disc brakes up front and drums out back. Those will most likely be upgraded to discs in the future.
When he got it, the engine in it looked excellent for its age and ran quite well, although he could tell it wasn’t putting out the power and torque that an engine its size should. He went out and found a bare 454 block in great condition and had it acid dipped, hot tanked, walnut shell blasted, magnafluxed – the works – to make sure the block was usable. It was then bored thirty over and line honed.
He next stuck in a forged Scat crankshaft with a four inch stroke and a Melling hi volume/standard pressure oil pump that’s been ported to improve the flow. A set of SRP small dome pistons ride on Scat forged H Beam 6.135 inch connecting rods This combination gives it a final displacement of 461 cubic inches. The block sits on a Stefs oil pan that Tyler had to modify to get it to fit the Chevelle’s chassis.
Crank scrapers and a windage tray were added to make sure that no matter what kind of maneuvers he puts it through, it’ll never be oil starved. Up front, a two piece Cloyes timing cover hides a Cloyes competition adjustable timing chain.
You can tell that quite a bit of thought has gone into the 461’s induction system. Here’s an example of what I mean: Tyler went with a Lunati Voodoo hydraulic roller cam. However, he didn’t go with one off the shelf – he came up with a custom grind. Lift and duration weren’t touched, but he had them give him a custom Lobe Separation Angle (LSA). I asked him and he told me he was going to keep those numbers under wraps for the time being.
The heads are GM 781 castings with the large oval ports. These are arguably the best heads available for the 454 block. Some bowl blending and porting was then performed to help smooth out the airflow and get a few more horses and pound-feet out of the engine.
Eight Dart 2.19 inch stainless intake valves and eight Dart 1.88 inch exhaust stainless valves were installed with springs that support a lift of up to .600 inches. The valves were all lapped with a three angle valve job for optimal cylinder sealing.
Riding in a set of Howard’s hydraulic roller lifters are a set of custom 7/16 inch Manton push rods. The push rod tunnels in the 781 heads had to be modified a bit to accommodate the 7/16 inch push rods. Topping the push rods is a set of Scorpion 1.7:1 ratio roller rockers. Tyler thought he was going to use an Edelbrock Performer RPM intake, but decided to go with an RPM Performer Air Gap he already had.
When I asked him about the carburetor, Tyler got a little quiet. The base carburetor is a Holley 850 double pumper. He told me that he custom built and did some things to help with fuel delivery and atomization. He also milled off the choke horn. Looking toward the future, Tyler also tapped the Manley Plasma Moly rings for a minimum 200 shot of nitrous, although that may get bumped up.
To let the engine breathe better, Tyler installed a set of equal length 1 7.8 inch Hooker headers with four inch collectors. These feed into three inch stainless exhaust and a set of Maganflow mufflers out of a newer Camaro. These, in turn, feed into over the axle pipes that terminate under the bumper with flat tips. For use on the track, he also installed a set of three inch exhaust cutouts.
As you can see in the pictures below, Tyler went with the gold anodized look for both the valve covers and the air cleaner because they give it a nostalgic 70s look. He’s not sure about them though. They may get swapped out for either black or chromed parts. It’s also got an aluminum radiator from Be Cool.
