McLearran Racing dyno-tested the new Classic Inlines aluminum head on Kelly's 10-second Falcon sedan drag car with a turbocharged, intercooled 273ci six and a C4 transmission. Here's what happened at IA Performance in Tucson.
Kelly's first pass on the dyno using a North American iron Ford head with log manifold yielded the following results:
|Run ||Peak HP ||Peak TQ |
|1 ||283 at 4,800 rpm ||416 at 2,700 rpm |
|2 ||270 at 4,800 rpm ||437 at 2,575 rpm |
Will says air/fuel ratio was stable at 11:1 running on E85 Ethanol fuel with a 450-cfm Holley two-barrel carburetor. The improvement in torque on the second run came from a timing retard and increase in boost. Note that horsepower fell, yet torque increased. Torque is what matters most.
Whenever you're boosting cylinder pressure via a turbocharger or supercharger, the block d
This husband and wife team work closely together. Here, the couple installs the piston and
McLearran checked deck height during the mock-up phase. He'll check it again during final
Here's what happened when the McLearrans installed the new aluminum head from Classic Inlines:
|Run ||Peak HP ||Peak TQ |
|1 ||323 at 4,800 rpm ||480 at 2,700 rpm |
|2 ||318 at 4,700 rpm ||502 at 2,650 rpm |
The common denominator is tuning and torque. Everything else remained the same except for a cylinder-head swap. The Classic Inlines aluminum head has given this 273ci stroker a broader torque curve on top of more horsepower and torque. This swap has yielded 40 hp and 64 additional lb-ft of torque. The McLearrans want to lean the mixture just a pinch to improve horsepower, in addition to 17 pounds of boost. A cam swap is also in the works. We'll keep you posted.
Other Ford-six buffs have noted even greater improvement in performance using a 500-cfm Holley, richer jetting, and ignition-timing tweaks. Much depends on camshaft profile, elevation, temperature, relative humidity, and good old-fashioned tuning know-how.
Because Winterboer has fitted his SportsRoof with a fuel-injected 273ci six-stroker, we don't know what to expect. When he puts this beast on a dyno, we'll bring you the results.
Rod bearings get the same treatment as the mains-with dry surfaces between bearing and rod
A Good Support System Because Winterboer wanted an adequate electrical system to support
McLearran is pretty grassroots in his methods-fuel-line hoses make terrific journal protec
McLearran studs the block deck for much the same reason he studs the main caps-strength an
In the Clutch Winterboer opted for a Centerforce Dual-Friction clutch and zero-balance fl
McLearran Racing does a quick engine fit check just to see how our 273ci turbo screamer me