When it came time to build a motor for our '68 Barracuda, we had to think long and hard about what type of engine our combination would require. Some would say that a '68 Cuda requires a Hemi to be respected, and that venerable powerplant did cross our minds. Our car is slated for some serious bracket racing, however, and we want to spend more time at the track and less at the shop during race season. Reliability, ease of maintenance, and economics all dictated that we look at options other than an elephant motor for this build. Given our back-halved car's 3,000-plus-pounds in race trim, and the fact we are shooting for some low-nine-second timeslips, we felt a big wedge motor was really our only choice. Big-inch wedges make killer torque, which is what we need to get our somewhat heavy A-Body moving, and make great power without having to rev the engine to the point of accelerated wear. Also, stroker kits are readily available and reasonably priced for this combination, so a big-inch wedge makes economical sense. We'll need nearly 800 hp to achieve our goal, so our combination has to be dead-on.
As with any engine build, many variables needed to be considered before formulating a final plan. For economical reasons, we are using a stock 440 block bored .060-inch oversize for this build and won't be filling the water jackets with block hardner; our idea is to maximize our power output with the stock block as our biggest limitation. Given the choice of our block, we decided to stiffen up the bottom end with a main girdle from Chenoweth Speed & Machine. We consider this a mandatory upgrade if you are planning on revving your engine above 6,500 rpm or make more than 650 hp. The factory block can hold this power, but cap walk will occur, causing metal transfer from the block to main caps. The Chenoweth girdle ties the main caps to the oil pan rail, considerably strengthening the bottom end and keeping our Eagle 4.150 stroke crankshaft solidly in place. An added benefit of the girdle is its proximity to the crankshaft's weights causes it to act as a crank scraper, aiding in keeping the oil off the crank and where it belongs-in the oil pan.
In addition to our Eagle crankshaft, we'll finish our rotating assembly with JE-forged pistons and Eagle H-beam steel connecting rods as we will sacrifice rotating weight for endurance. Eagle rods were chosen because of their durability and price. Our engine would have accelerated quicker, and we could have made a few more ponies using aluminum connecting rods, but running them would require us to pull the engine and change the rods every 150 passes or so, and we'd rather be at the track racing. For pistons, we chose JE small-dome forged units to achieve a 13.1 to 1 compression ratio with our Indy heads. Our crankshaft, rods, and pistons were balanced and installed with Clevite race bearings and Perfect Circle medium tension piston rings.
One of the tricks we're using in this combination is the use of a Moroso crankcase vacuum pump. There are many benefits to a vacuum pump in a race motor, including improved ring seal, prevention of blow-by, and a less contaminated intake charge. An additional benefit is the elimination of valve cover to header vacuum lines for a cleaner-looking engine bay. The Moroso unit is billet aluminum and requires very little horsepower to drive. The kit we ordered was complete, easy to install, and included an adjustable vacuum relief valve. The main benefit that we've noted by running a crankcase evacuation system is the ability to achieve ring seal with lower tension compression rings. The reduced friction of a lower tension ring frees up more than enough power to drive the belt-driven pump with power to spare for the back wheels.
As far as an oiling system, our experience dictated that a serious wedge engine-revving in the area of 7,500 rpm-benefits from a Milodon dual-line external oil system with a swinging pickup and rear sump pan. The Milodon system has been the standard for race wedge and Hemi motors for more than thirty years-and aside from a dry sump system-it's the best race oiling system that we've seen for a big wedge. The system is so good and so frequently used, some of our parts were back ordered. If you plan to use the Milodon system, call early so that you can get the parts in a timely manner. We always run a windage tray, so a special Milodon unit with additional clearance for our extra stroke was ordered. In addition to chamfering the oiling holes on our crankshaft's journals, we had our crankshaft knife edged and scalloped so that it would shed oil quickly. No other special oil-system modifications were performed, other than plugging the internal pickup and removing the casting flash from the valley and heads to aid the oil's return to the pan.
For cylinder heads, Indy was our only serious option. Indy Cylinder Head offers a great selection of aluminum street and race heads for every power level and budget, and a quick call confirmed the aluminum SR heads, ported to Max Wedge size, would be the best selection for our engine. We won't be revving this engine above 7,500 rpm due to our stock block, so we couldn't justify the extra flow and cost of the 440-1 heads for our combination. In engines larger than 500 ci or in applications revving higher than we plan to rev ours, the 440-1s are a great choice, but for our engine we'll maximize the SR heads. The ported SR's flow numbers are very close to the 440-1 numbers, and the SR heads offer a great, heart-shaped, quench area in the combustion chamber, large 2.19/1.81-inch valves, and shorter intake runners than the 440-1 heads. An added benefit of the SR heads is the ability to use factory style rocker arms, shafts, valve covers, and intake. The exhaust port of the SR head is also the factory pattern, but is raised slightly requiring custom headers in some applications. We will be using Hooker Super Competition fenderwell headers for this project, which actually fit quite nicely in a big-block A-Body with SR heads and without modification. Aside from expensive custom-made race headers, the Hooker fenderwell pieces pretty much set the standard for race exhaust.
Topping this combination off with an intake manifold also allowed us to show off one of our tricks. It's a given that for an engine of this size, we'll need a 4500 series carburetor. in fact, we've chosen a Barry Grant 1095 King Demon for the build, so a 4500 flanged intake manifold is what we need, right? Wrong. The guys at Indy discovered their 440-2 intake (4150 flange), combined with a 2-inch-tall adapter and mated to a 4500 carburetor, makes 12-to-15-more horsepower than the 4500 flange intake by itself. This combination does place the carburetor significantly higher, however, so if hood clearance is an issue, you may need to opt for the 4500 flanged intake. In the next of our two-part series on this build, we'll do some intake swaps at the track to see which intake really works best, but for our baseline we're going to use the 440-2 Indy unit with the spacer.
Now for the million-dollar question-what camshaft do we use to make the most of this combination? We assure you we don't take cam selection lightly, and much thought was put into which camshaft would optimize the parts we had selected for this build. Keep in mind, this engine is not a Dulcich dyno mule. It is going in a race car that will see regular duty nearly every weekend at the track, so it needs to have broad torque and power curves. As we stated earlier, our stock block will limit us to about 7,500 rpm, so we need to consider that, as well. Also, our car is no lightweight at 3,000-plus pounds, so an extreme, peak horsepower cam profile is out of the question. Also remember that consistency wins in bracket racing, and we still shift our own gears in this car so our cam needs to be somewhat forgiving if we miss a shift point by 100 or so rpm. Even though we had calculated our combination and had a good idea of the cam profile to run, we never make a cam selection without advice from the experts, so we called the engineers at Crane Cams to help us with our decision.
Crane has been in the camshaft manufacturing business since the first days of hot rodding. The engineers at Crane have designed cams for nearly every application you can think of, and their wealth of knowledge can greatly benefit your camshaft decision. For our combination, we already knew that we needed lift numbers in the high-.600 to low-.700-inch range just to make our engine breath properly. Going with a higher lift could make slightly more power, but would sacrifice longevity due to accelerated valvespring wear. The engineers at Crane also agreed that duration at .050-inch numbers needed to be in the 280- to 290-degree range to make the power we were asking from this motor. After further discussion with the guys at Crane, we decided on a custom ground solid roller stick with .715-inch lift on the intake side and .688 inch on the exhaust, and 284-degrees duration at .050 on the intake, and 296 degrees on the exhaust. Lobe separation is a wide 112 degrees, which our big-inch wedge should like, especially since it launches at 4,600 rpm and only sees lower revs than that when idling through the pits or staging lanes. This camshaft will make power at a fairly high rpm, but will still make the torque required to get our car moving out of the hole. Since we also use this car in local Quick 16 races and sometimes use nitrous oxide, this cam should be a great choice making good torque and power on the motor, but still taking advantage of the torque created by the nitrous when we squeeze the button.
Since we were on the phone with Crane, we decided to use their recommended valvesprings, along with their 10-degree retainers and locks, and gold roller tip rocker arms to actuate our Manley stainless steel valves. To spin the cam in its journals, we ordered Crane's billet double-roller timing set with a Torrington thrust bearing and cam button. Always remember that camshaft manufacturers do extensive research to match their valvetrain components, so taking their advice when it comes to matching springs to a cam is usually the best choice. We have always found Crane camshafts to be very precisely ground with each cylinder's lobe lift and position identical. Most engine builders degree a cam based on the number one cylinder's specs; on a race engine we actually check multiple cylinders to make sure the entire cam is ground properly, not just the lobes for number one. Our Crane camshaft checked perfectly and was installed with its matching lifters and valve gear.
With all of our decisions made and our parts accumulated, there was only one thing left to do-assemble the motor. Be sure to tune in next month when we'll install it, fire it up, break it in, and take it to the track to optimize the tuning and race it!
What do you think about our combination? Do we have what it takes to consistently run low-9s on the motor in a nearly 3,100-pound race car? E-mail us at mopar.muscle@Primedia.com and let us know what you think.
