When using a roller cam, you...
When using a roller cam, you must also use a bronze-type distributor/cam gear on the oil pump driveshaft. We used the Milodon (left, PN 21525) oil pump drive assembly. The Lunati (center, PN 88426) bronze gear could have been pressed on and pinned to the original shaft by a local machine shop. The gear (right) has over 8,000 miles on it. Inspect the bronze gear for wear every few thousand miles.
We were curious to see how quick the R/T would quarter-mile with its fresh stroker combo. We mounted the Hoosier 30x9x15-inch slicks and 26-inch front skinnies before pulling up to the line. At this point the 950 HP and the 3.73s were still part of the R/T's equipment. Out of the hole, the slicks spun and we received a 1.60 60-foot time, but we still ran an impressive 10.70 at 126.40. We pulled around again and heated the Hoosiers again. This pass produced a no-spin 60-foot of 1.50, enabling the big B-Body to boogie to a quicker 10.56 at 126.10 mph! We can't tell you how happy we are to have a 10-second, pump gas, real street car.
Roller cams offer better lobe profiles than flat tappet sticks, thus better performance. We honestly can't say which bumpstick won our test. Using a chassis dyno with a loose converter was not conducive testing. We've heard of racers going quicker using a motor that showed less hp on the dyno. It's always in the combination. If it's in your budget, a roller cam matched to your combo is the biggest winner.
Note: Please read the captions to see the trials and tribulations we encountered to perform this cam test. We hope this prevents others from experiencing valvetrain component problems. Pay close attention and don't be afraid to ask questions on the cam tech line about your intended cam and valvetrain parts combo for your engine.
|Chassis Dyno Results|
Tested at SLP Performance Parts
SuperFlow SF840 Dyno
|Ray Barton 493 with .575-Inch Lift Cam|
|Peak rwhp||524 at 5,500 rpm|
|Peak rwtq||512 at 5,300 rpm|
|Ray Barton 493 with Voodoo .600-Inch Lift Cam|
|Peak rwhp||503 at 5,500 rpm|
|Peak rwtq||494 at 5,300 rpm|
|R/T Quick Specs|
|Short-block||'70 440, Eagle crank 4340-steel forging 4.15 stroke, JE flat-top pistons, Manley/Barton H-beam rods |
|Camshaft||Lunati VooDoo roller, 255/263 duration at .050-inch lift, .600-inch lift|
|Valvetrain||Comp roller lifters, Hi-Tech 3/8-inch pushrods, Pro Magnum roller rockers, dual valvesprings, Titanium retainers|
|Heads||Edelbrock Performer RPM, 2.14/1.81 valves, ported, flow 293/227 cfm at .600-inch lift.|
|Induction||MP M1 single plane, polished plenum, dividers, runners, except floor left as-cast, no gasket matching. Wilson Manifolds 1-inch, 4-hole tapered spacer (PN 004110). Holley 950HP, 78 jets, 40 squirters.|
|Exhaust||2-inch tti headers, 3-inch tti exhaust with DynoMax Ultra Flo mufflers.|
|Drivetrain||Pro-Formance-built 727 with rollerized planetary, Hemi governor for auto upshifts at 6,200 rpm, Dynamic 9.5-inch converter. Denny's 4-inch HD aluminum driveshaft. Randy's Ring and Pinion-built 83/4 w/3.73s and Detroit Locker, Yukon axles.|
|Suspension||FFI and Magnum Force front-end components, Stock leaf springs re-arched with 1 leaf added per side, QA1 shocks, Hoosier 30x9R-15 slicks, 26-inch skinnies, Weld Superlites 15x8 and 15x4.|
|Test Weight||3,850 lbs.|
|Best ET/MPH||10.56 at 126 mph|
With only five miles on the...
With only five miles on the engine after reassembly, we ran into a problem. The rocker on the left seized on the shaft and also damaged the pushrod. This was due to inadequate oil pressure at the rocker arm assembly and the high pressure of the springs.The proper fix was to install rocker arms with needle bearing fulcrums and pushrods (cupped end type) without the oiling hole. We could have used either lifters or pushrods without the oil hole to cure our oil pressure bleed-down problem.
There's no way we could rely...
There's no way we could rely on regular rubber motor mounts for our wild Wedge. Schumacher's Poly-Loc mount (left) features polyurethane construction with internal locking plates (see cut-a-way) to prevent blow-out. They're holding up well!
Back together and running,...
Back together and running, we want to put on a couple hundred more miles before dyno testing. We figured this would be a good time for us to try out two different Holley HP carbs. The 1,000 HP (PN 0-80513-1) exhibits larger venturis compared to the 950HP (PN 0-80496-1). Driving around (mixed city and highway) the 950HP was the hands down winner. At WOT between 5,000-6,000 rpms (top-end charge) was when the 1,000HP shined.
On SLP's dyno, we were surprised...
On SLP's dyno, we were surprised to learn we were down 20 hp at the same peak (5,500 rpms) as the first cam. When the 91/2-inch Dynamic converter locked up at 5,000-5,200 rpms, the VooDoo cam was averaging 25 more horsepower. At 5,800 to 6,100 rpm, the VooDoo cam was making the same power. The older-tech roller cam held its own against the new-tech VooDoo roller. Only if we had tested the previous camshaft for average horsepower on an engine dyno (most average power 3,000 to 6,000rpm), we could have declared a winner in this cam contest.
Mounted on the firewall (where...
Mounted on the firewall (where the ballast resistor once was) is the Performance Distributors Mini VIP 18-volt step-up regulator. It works with most 12-volt electronic ignition systems that can withstand 18 volts. We plugged the Mini VIP into our DUI distributor and realized six more horsepower to the wheels. That would easily be worth a tenth at the track.
While on the dyno, we removed...
While on the dyno, we removed the 1,000HP carburetor and replaced it with the 950HP. We lost five horsepower, but it offered better drivability. With that, the 950 Holley still resides on top of our motor.