We're in the home stretch with the buildup of our resident '93 Cobra a.k.a. project Stolen Goods, and this month we will assemble the top half of our D.S.S. Racing-built, Boss 347 engine.
These goods certainly aren't stolen, but they'll be really hot once they're assembled.
While the new Boss block from Ford Racing Performance Parts is quite capable of handling high horsepower and high rpm, it was never our intention to spin the motor to the moon in search of peak horsepower. What we wanted was a fun-to-drive powerplant that put out something north of 400 hp at the flywheel. In order to come up with a usable combination, we called Rick Anderson of Anderson Ford Motorsport (AFM) in Clinton, Illinois, to see what he thought about our goals for the engine and what the best way to achieve them would be.
His first recommendation was a cylinder head and intake manifold package from Trick Flow Specialties. A set of Twisted Wedge small-block Ford heads (PN TFS-51400004) and a Trick Flow Track Heat intake manifold (PN TFS-515110002) were sourced from Summit Racing Equipment. The cylinder heads feature a uniquely twisted combustion-chamber design with a 2.02-inch intake and 1.60-inch valves.
These would not go on the Boss untouched, however, as Anderson opted to give them AFM's Stage III port job in addition to a set of AFM Hi-Rev valvesprings to support the B-41HR camshaft that Anderson also provided. In order to allow the AFM cam and spring set to work together, we called Comp Cams for a set of its Pro Magnum 1.6:1 ratio roller rocker arms, replacement roller lifters, and Hi-Tech pushrods.
"For what we are doing, we want to keep the port velocity high," Anderson says. "Bigger runners might be suitable for drag racing where your rpm range might be only 1,500 rpm wide, but they would be lazier in other areas under the curve. For getting in and out of the corners, we want to keep the velocity up to provide more horsepower and torque down low. I like the Twisted Wedge heads the best because of the combustion-chamber design and how the flame front travels across the combustion chamber."
Jon D. Carls of JDC Engineering handles all of AFM's hand-port work and performed a Stage III porting of our Twisted Wedge heads. Hand porting was chosen over CNC-machining to keep the runners on the small side to promote better midrange flow numbers. This keeps the horsepower down low and pulling hard all the way up the powerband.
The Stage III work costs $1,050, and Carls shapes the intake and exhaust ports for maximum efficiency. This includes the runners, the bowl area under the valves, and the valve guides, as well as polishing the intake and exhaust tracks. The combustion chambers are shaped, polished, and blended to the valve seats, intake ports are matched to a Fel-Pro 1262 intake gasket and the exhaust ports to a Fel-Pro 1415 gasket. The valve seats and valves receive a performance multi-angle valve job as well.
We mentioned before that we'll be using Anderson's B-41HR camshaft, and while we would like to give you the specs, we were asked not to. "The B-41HR is designed to give more power through the midrange, but the hi-rev design will pull all the way to 7,000 rpm without falling off," Anderson says. "From 3,500 to 4,500, it will pull really hard with a smoother transition. Cams that come on hard don't work well when you're at the limit in the middle of a turn." According to Anderson, the AFM cam profiles are constantly updated, so you get the latest technology when you order one.
As for the intake manifold, Trick Flow has three to choose from, all of which have different runner lengths to match the powerband of the engine. "The Track Heat intake will make more power through the midrange versus the R-Series," Anderson says. The Track Heat power range is 1,500-6,500 rpm and features a 12-inch runner length versus the Street Heat's 15-inch length.
Our D.S.S. Racing Boss 347ci bullet arrived at HP Performance, and the crew there opened i
Here you can see some of the millwork on the lifter bosses that D.S.S. performed, as well
We sent the crew at D.S.S. our one-piece Fel-Pro oil pan gasket that came with our PN 2816