Oxymoron. Webster's dictionary defines this word as: "a combination of contradictory or incongruous words (as cruel kindness); broadly: something (as a concept) that is made up of contradictory or incongruous elements."
Besides "cruel kindness" here are some other examples: adult male, authentic replica, honest politician, jumbo shrimp, and military intelligence. For a long time, people would put the phrase "budget big-block" in there, too. But a little research proved there are very good values out there for those building a Rat with an eye on cost conservation.
In the last issue of Super Chevy, we went down the list of cylinder head manufacturers and got the latest dope from each company on their most popular off-the-shelf small-block cylinder heads. Mind you, we also informed each company that our aim was to search out their best "cost-conscious" cylinder heads. This month, we searched out those same parts for Chevy's fabled Rat motor. Yes, it's true that when one dives into the big-block waters, budget is a word that seldom comes to mind. Budgets, however, are like waist sizes-they vary from person to person. If only our wallets were akin to our waist sizes, what a wonderful world this would be.
It turns out that purchasing a set of BBC cylinder heads won't require you to sell a kidney on the black market; they're more affordable than you may think. When purchasing a set of cylinder heads, most DIYers prefer the out-of-the-box, preassembled units. Unless you're running some insanely wild cam, the springs and valves in the preassembled heads are capable of delivering some great performance numbers over the OE-spec heads. In no particular order, here are the companies we contacted and the information they provided.
Merlin Cast Iron 269cc BBC Cylinder Head, Merlin III Cast Iron 320cc BBC Cylinder Head
World has a couple of BB heads that are perfect for the budget builder. The first one is the assembled Merlin oval port cast iron head, with a 269cc intake volume, a 119cc combustion chamber, 2.300x1.88 valves and 11/32 guides. Out of the box these heads run about $720. The next step up is the Merlin III. This head features a 320cc intake chamber and opens up to a 345cc intake chamber. The combustion chamber, valves and guides are the same as the Merlin. An assembled set of the 345cc heads will run about $1,459.
Racing Head Service
Pro Action Cast Iron 320cc Cylinder Head, 360cc BBC Cylinder Head
Racing Head Service knocked one out with its Pro Action cast iron heads. The Pro Action heads come in a 320cc and 360cc intake runner. Both heads feature a 119cc combustion chamber with intake valves (with hardened seats) that measure 2.250 and exhaust valves that measure 1.880. A pair of assembled 360cc heads built for a hydraulic roller cam runs about $1,810. The same set built for a mechanical roller runs about $2,064.
Summit Racing Equipment
Square Port Iron 308cc BBC Cylinder Head
Millions have ordered parts from Summit Racing, but some may not be familiar with the fact that Summit also offers its own line of cylinder heads for the Chevy big-block. Summit has set of cast-iron heads that are ready to run from the moment you open the box. The Summit square port iron heads feature a 308cc intake runner with a 119cc combustion chamber, a 2.250 intake valve and a 1.880 exhaust valve with hardened seats. A pair of assembled heads runs about $1,291.