With everyone going off the deep end these days and drowning in monster cubic inch motors it seemed like a good idea to try and regain our senses if you can call 'em that. It's easy to get carried away when the bench racing gets started or especially after throttling the gas around town in something with ponies to spare and the tires smokin'. But do we all need 600 hp for the street?
Around 10 years ago vintage big-block Chevy motors were in high demand and fetched equal money to restorers as well as hot rodders wanting the high-quality iron for their powerhouses. A couple of presidents and a few hundred horsepower later and you can order something equal to that motor or one that sinks it over the phone that incorporates the latest in new and precision parts-blocks included. Granted, you'll still be out a fair amount of green for something of this modern variety and that's kinda short around here, so what about the motors that are being looked over now like all those vintage Rat motors? We know you automatically get a bunch more cubes if you start a big-block project with a 454, but could a 396 hold its own in today's world? We went to Speed-O-Motive in West Covina, California, to find out.
The staff at Speed-O-Motive knows engines probably better than the back of their own hands and they have the experience to prove it! They can do WHATEVER you wanna do with your motor from hot tanking to dyno services, or you can just order a complete motor to be dropped off at your house. Well, they looked at us a little weird when we told them what we wanted to do, but decided to go along for the ride. We told George Ullrich that we were looking for something that would be streetable and fun to stomp on and could also be easily upgraded as more power was needed.
We wound up with a 4-inch SCAT 454 crank and matching I-beam rods, 0.060" over KB pistons, a whole slew of Edelbrock parts from cam to heads, COMP Cams rocker arms, Milodon oil pump and pan, Pertronix Flame-Thrower ignition, ARP hardware inside and out, Professional Products dampener, Mooneyes valve covers, and last but not least, the vintage 396 Bow-Tie block.
It seems that much of this build could be mirrored for the other displacement big-blocks and went together fairly easily once our core was deemed fit by Speed-O-Motive. Even though all these parts are going into what could be considered an antique motor, it doesn't mean all the companies involved have stopped improving these parts-in fact it's quite the opposite. With all the advancement in computer-aided design and manufacturing, these parts will make older motors run better than ever with more performance and reliability! With these advancements, though, some things like installation methods might have changed since you last put an engine together, so throwing away the directions is not Step 1 anymore and never should've been. It's all in the details. We've tried to touch on some of these examples in the following pages, but our space is limited, so check out these companies' Web sites and paperwork for more cool in-depth tech, theory, and the reasons for these new ideas and products.
In the end, we got what we wanted on the dyno-a solid motor with enough grunt to keep us happy for a while and the room for growth when we're ready for a louder pedal. After six dyno runs we came up with these numbers: the peak torque settled into 472.8 lb-ft at 3,200 rpm. Adding 3 degrees of advance in the timing from the original pull did yield and extended rpm range that went to 5,200 rpm and got us an additional 26.2 hp, making its peak 386 hp at 5,100 RPM. The HP and torque numbers are smooth all the way through its max RPM and shows that we have a stump puller on our hands.
With a solid bottom end, the valvetrain would be the next logical place to beef up and squeeze some more rpms out with a bigger cam and stiffer valvesprings since it pretty much said "no" after 5,200. Like we said, we didn't want the nastiest motor on the block, but still, who on your street has 386 hp and 472 lb-ft of torque to annoy the neighbors with? We do. Mission accomplished!
