Small Budget Big-Blocks
“There’s No Replacement For Displacement” is the old saying regarding building bigger engines. Starting in the late 50’s Chevrolet started producing Big-Block engines, but for most the infamous 396 is really the beginning of the story.
Not until 1966 was the Big-Block 396 standard issue in Super Sport Chevelles. The engines became more powerful and had more displacement till the peak in 1970 with the LS6 454. If you’ve ever been in a BBC-powered classic, there’s nothing like it. Building and swapping in these Rat motors is a fairly easy task nowadays.
There are a million different ways to build a Big Block for your ride and it all depends on your goals and how deep your pocket book. Let’s go over some of the cheaper options though.
Seeing how GM produced millions of Big Blocks and put them in everything from cars, trucks, vans, motorhomes, or any other large vehicle, there are a lot of them still out there to choose from. By far the cheapest way is going to be to buy a used BBC and swap it in with little or no modifications.
Going this route you can pick up the necessary items from SS396.com to swap in a Big-Block over the course of a weekend or two. Even a low-horsepower Big-Block is still going to make gobs of torque and shoot you down the road like a rocket. But let’s say you want to get a little more fancy and have a little more power – then what do you do?
Building engines is a slippery slope. You start with a simple cam swap and before you know it you’re porting aluminum heads and installing a stroker crankshaft. You really have to be mindful of your budget and goals here. Luckily these are extremely popular engines and as we mentioned they made millions of them, so parts are readily available and fairly cheap compared to some other engines.
Building On A Budget
The absolute cheapest way to build a big block is to get it for free. But that’s rarely going to happen so let’s look at building one while watching every penny.
With a budget in mind, look at cheaper big-blocks. For example, a big-block out of a late 70’s or 80’s truck or motorhome is going to be a low-performance, smog equipped, and most likely two-bolt main engine. These engines are a great starting point as they can be had for cheap and still be built affordably to create big power. If you’re looking for an all-aluminum 427, be prepared to spend big bucks on it.
Suppose you bought a good running engine that doesn’t need a complete rebuild. Buying one that needs a rebuild would be cheaper, but it will cost more to get it to running condition. However, if you’re building it you can do upgrades such as high-compression pistons and bore it out for more cubic inches.
Taking your basic two-bolt big block, there are a few cheap upgrades you can do to add big horsepower. First, bump up the compression ratio. This can be done by adding a new set of pistons, changing the heads out, or both. The other cheap upgrade is simply swapping in a new performance camshaft that will allow more air into and out of the engine.
Swapping the heads can be a massive gain in power, but can be costly as well. Aluminum heads are generally the choice as they are lighter but have been improved with larger valves, better flow, and increased compression. You can still take apart your basic steel heads and port the intake runners and polish up the valves for a few extra horsepower.
Adding a performance intake and carburetor are also ways to upgrade the performance with a budget in mind. You can find these used or even buy new ones. There are even some companies that sell an intake, carb, and camshaft combo that’s designed to work together and give you max HP. Aftermarket intakes flow better and are usually aluminum saving pounds of weight off the front end.
Adding a set of performance headers and a performance exhaust will also gain horsepower. We’ve covered the perks of a performance exhaust, how to choose a performance exhaust, and how to install a performance exhaust.
Remember that an internal combustion engine is basically an air pump; the more air you can get in it and the more air you can get out of it the more power it’s going to make. Don’t forget about upgrades such as a performance HEI ignition too that will help ignite the extra air and fuel in the cylinders for more horsepower.
There are many options, and like we mentioned, it’s a bit of a slippery slope when building engines. The absolute bare budget would be to buy a used running low-performance big-block. Take that and install a performance camshaft, intake, carb, headers, and HEI ignition. That alone will really wake up the engine and make a big difference.
If you have more budget available, a set of pistons and heads will really make a massive power jump in your big block along with the items listed previously.
Remember to also budget for everything else you’ll need to swap the engine into your ride if it doesn’t already have a big block. Items such as motor/frame mounts, accessory drives, oil pans, radiators, etc. We have all those items ready to go if you need them.
If you have any other questions or need help with your big-block Chevy, hop on SS396.com or give our friendly techs a call at (203) 235-1200!
