All our Roller profiles are designed with our exclusive Inverse Radius technology.
Our Inverse Radius designs produce a slow initial opening of the valve, then increases the lift rate as needed per engine specifications.
This design gives you more area under the curve at the same lift and duration then a normal flat flanked roller profile.
The result is less air being lost to the overlap process, and more air being retained in the cylinder.
This makes the engine more efficient, increasing both torque and Horsepower.

SR Roller Series

Introducing our new SR Series mechanical roller profiles for Street/Strip performance. All our new SR Series profiles are designed with our exclusive Inverse Radius technology. These profiles give you the ultimate in performance and reliability for your street/strip application. These profiles are for use with Mechanical Roller tappets with a .750″ diameter wheel. The SR Series Mechanical Roller profiles are for use in both street and racing applications, and require the use of our Mechanical roller lifters and high-rate springs.

 

Duration
Lobe
Valve Lift
Part #
Advertised
 @.050″
Lift
1.5
1.6
1.7
SR66340
240°
212°
.340″
.510″
.544″
.572″
SR66365-11
242°
217°
.365″
.531″
.566″
.601″
SR67296-9
244°
213°
.296″
.430″
.459″
.487″
SR67340
244°
216°
.340″
.510″
.544″
.572″
SR68350
248°
220°
.350″
.525″
.560″
.595″
SR69350
252°
224°
.350″
.525″
.560″
.595″
SR70360
256°
228°
.360″
.540″
.576″
.612″
SR71360
260°
232°
.360″
.540″
.576″
.612″
SR72370
264°
236°
.370″
.555″
.592″
.629″
SR73365
268°
241°
.365″
.547″
.584″
.620″
SR73370
268°
240°
.370″
.555″
.592″
.629″
SR74344
272°
241°
.344″
.516″
.550″
.585″
SR74347
272°
246°
.347″
.520″
.555″
.590″
SR74365
272°
243°
.365″
.547″
.584″
.620″
SR75345
276°
244°
.345″
.518″
.552″
.587″
SR75365
276°
246°
.365″
.547″
.584″
.620″
SR76347
278°
250°
.347″
.520″
.555″
.590″
SR76363-7
276°
245°
.363″
.545″
.581″
.617″

 

Asymmetrical I.R. Rollers

EPSON DSC picture

Our Asymmetrical I.R. Intake profiles utilize the same design characteristics as our famous Inverse Radius profiles, but with a faster opening
ramp to create more power, and a slower closing ramp for more stability at higher RPM’s. These Intake profiles are for use with Mechanical Roller
tappets with a .750″ – .825″ diameter wheel. The Asymmetrical I.R. profiles are for use in racing applications only, and should only be used as
Intake profiles.

 

.Seat
.050″ Duration
Lobe
Net Lifts
Part #
 Duration
Opening
Closing
Total
Lift
1.5
1.6
1.7
R75428A2
302°
129°
125°
254°
.428″
.627″
.668″
.710″
R76418A
304°
127°
126°
253°
.418″
.612″
.652″
.693″
R77435A
308°
132°
128°
260°
.435″
.637″
.680″
.722″
R77452AS
308°
130°
128.5°
258.5°
.452”
.660”
.704”
.748”
R78418A
312°
131°
129°
260°
.418″
.612″
.652″
.693″
R78421AR
312°
131°
129°
260°
.421″
.617″
.657″
.699″
R78452AS
312°
131.5°
130°
261.5°
.452”
.660”
.704”
.748”
R78367A2
314°
131°
129.5°
260.5°
.367″
.535″
.571″
.606″
R78450A2
314°
133°
131°
264°
.450″
.660″
.704″
.748″
R79390A
316°
131°
130°
262°
.390″
.570″
.608″
.646″
R79421AR
316°
132°
131°
263°
.421″
.617″
.657″
.699″
R79452AS
316°
133.5°
132°
265.5°
.452”
.660”
.704”
.748”
R80420A
320°
136°
132°
268°
.420″
.615″
.656″
.697″

 

Inverse Radius Rollers

image002

Our Inverse Radius Roller profiles produce a slow initial opening of the valve, then increases the lift rate as needed
per engine specifications. This design gives you more area under the curve at the same lift and duration than a
normal flat flanked roller profile. The result is less air being lost to the overlap process, and more air being retained in
the cylinder. This makes the engine more efficient, increasing both torque and horsepower. These profiles are of
ruse with Mechanical Roller tappets with a .750″ – .825″ diameter wheel. The Inverse Radius Roller profiles are for
use in racing applications only, and can be used as Intake or Exhaust profiles.

 

 Duration
Lobe
Net Lifts
Part #
Seat
.050″
Lift
1.5
1.6
1.7
R64352
256°
210°
.352″
.511″
.545″
.579″
R68400
272°
226°
.400”
.582”
.621”
.660”
R70400
280°
233°
.400”
.582”
.621”
.660”
R71390
284°
236°
.390″
.568″
.606″
.644″
R72350
288°
236°
.350″
.508″
.542″
.576″
R72380A10
288°
239°
.380”
.555”
.592”
.629”
R72395
288°
240°
.395″
.575″
.614″
.653″
R73346
292°
238°
.346″
.503″
.538″
.572″
R73400
292°
243°
.400″
.584″
.624″
.664″
R73401
292°
244°
.401″
.586″
.626″
.667″
R74347DP
296°
246°
.347″
.505″
.539″
.572″
R74375-10
296°
245°
.375”
.548”
.584”
.621”
R74406
296°
248°
.406″
.593″
.634″
.674″
R74425
296°
248°
.425″
.622″
.664″
.707″
R75425
300°
252°
.425″
.622″
.664″
.707″
R75438
300°
254°
.438″
.641″
.685″
.729″
R76347DP
304°
250°
.347″
.505″
.539″
.572″
R76358
304°
252°
.358″
.521″
.557″
.593″
R76412
304°
254°
.412″
.602″
.643″
.684″
R76417
304°
255°
.417″
.610″
.651″
.693″
R76424
304°
255°
.424″
.620″
.662″
.705″
R76424BW
304°
254°
.424″
.620″
.662″
.705″
R76434
304°
256°
.434″
.635″
.678″
.722″
R76442
304°
256°
.442″
.647″
.691″
.735″
R77315
308°
252°
.315″
.457″
.488″
.520″
R77385
308°
255°
.385″
.562″
.600″
.639″
R77424
308°
258°
.424″
.620″
.662″
.705″
R77425BW
308°
257°
.424″
.620″
.662″
.705″
R77425
308°
260°
.424″
.622″
.664″
.707″
R77434
308°
260°
.434″
.635″
.678″
.722″
R77444
308°
260°
.444″
.650″
.694″
.739″
R78322
312°
254°
.322″
.467″
.499″
.521″
R78372
312°
256°
.372″
.542″
.579″
.616″
R78390
312°
258°
.390″
.569″
.608″
.647″
R78398
312°
259°
.398″
.581″
.621″
.661″
R78410
312°
262°
.410″
.599″
.640″
.681″
R78417HC
312°
262°
.417″
.611″
.651″
.692″
R78421
312°
261°
.421″
.616″
.658″
.700″
R78424
312°
262°
.424″
.620″
.662″
.705″
R78425
312°
264°
.425″
.622″
.664″
.707″
R78430
312°
262°
.430″
.629″
.672″
.715″
R78437
312°
262°
.437″
.640″
.683″
.727″
R78453
312°
264°
.453″
.664″
.709″
.754″
R79388
316°
262°
.388″
.567″
.605″
.643″
R79392
316°
262°
.392″
.572″
.612″
.651″
R79425
316°
265°
.425″
.622″
.664″
.707″
R79429
316°
266°
.429″
.628″
.670″
.713″
R79431
316°
264°
.431″
.630″
.673″
.717″
R79450
316°
267°
.450″
.657″
.700″
.744″
R80346
320°
260°
.346″
.503″
.538″
.572″
R80362
320°
262°
.362″
.526″
.561″
.596″
R80367HC
320°
262°
.367″
.535″
.571″
.606″
R80393
320°
264°
.393″
.573″
.614″
.644″
R80412
320°
268°
.412″
.602″
.643″
.684″
R80417HC
320°
269°
.417″
.611″
.651″
.692″
R80424
320°
272°
.424″
.620″
.662″
.705″
R80432
320°
269°
.432″
.631″
.673″
.715″
R80444
320°
266°
.444″
.650″
.694″
.739″
R80465
320°
270°
.465”
.680”
.725”
.770”
R81332-10
324°
261°
.332″
.483″
.515″
.547″
R81437
324°
273°
.437″
.638″
.680″
.723″
R81538
324°
277°
.538″
.789″
.842″
.894″
R82362
328°
268°
.362″
.527″
.563″
.599″
R82401
328°
272°
.401″
.585″
.626″
.666″
R82412
328°
273°
.412″
.600″
.640″
.680″
R82426
328°
274°
.426″
.623″
.665″
.708″
R82436
328°
276°
.436″
.638″
.681″
.725″
R82448
328°
277°
.448″
.656″
.701″
.746″
R82465
328°
277°
.465”
.680”
.725”
.770”
R82495
328°
278°
.495″
.727″
.776″
.826″
R83373
332°
272°
.373″
.544″
.581″
.618″
R83436
332°
279°
.436″
.636″
.678″
.721″
R83472
332°
282°
.472″
.692″
.739″
.786″
R83538
332°
284°
.538″
.789″
.842″
.894″
R84363
336°
272°
.363″
.529″
.565″
.601″
R84389
336°
277°
.389″
.568″
.606″
.645″
R84412
336°
280°
.412”
.600”
.640”
.680”
R84436
336°
282°
.436″
.636″
.678″
.720″
R84472
336°
288°
.472″
.691″
.737″
.783″
R84488
336°
286°
.488″
.716″
.765″
.814″
R84500
336°
285°
.500”
.732”
.781”
.830”
R85373
340°
278°
.373″
.544″
.581″
.618″
R85510
340°
289°
.510”
.747”
.797”
.847”
R86397
344°
282°
.397″
.579″
.617″
.656″
R86406
344°
284°
.406″
.593″
.634″
.674″
R86436
344°
288°
.446″
.638″
.681″
.725″
R86446
344°
290°
.446″
.653″
.698″
.742″
R86465
344°
291°
.465″
.680″
.725″
.770″
R86495
344°
296°
.495″
.725″
.774″
.823″
R87335
348°
288°
.335″
.487″
.520″
.557″
R87389
348°
290°
.389″
.568″
.606″
.645″
R87465
348°
294°
.465″
.680″
.725″
.770″
R88373
352°
288°
.373″
.544″
.581″
.618″
R88455
352°
298°
.455″
.667″
.712″
.758″
R88528
352°
300°
.528″
.774″
.826″
.877″
R89351
356°
288°
.351″
.511″
.546″
.581″
R89455
356°
300°
.455″
.667″
.712″
.758″
R89480
356°
302°
.480”
.702”
.749”
.796”
R90530-2
362°
310°
.530″
.777″
.829″
.881″
R91480
364°
309°
.480”
.702”
.749”
.796”

AK435 Series

The AK435 series Intake profiles utilize the fastest accelerating opening ramps
in the industry to create more H.P. and Torque, while the ultra-smooth closing
ramps make the AK435 series remarkably easy on your valvetrain.
The AK435 series profiles are for racing applications only, and should only
be used as intake profiles.

Seat
.050″ Duration
Lobe
Net Lifts
Part #
Duration
Opening
Closing
Total
Lift
1.5
1.6
1.7
R74435AK
296°
124°
123°
247°
.435″
.637″
.680″
.722″
R76435AK
304°
128°
126°
254°
.435″
.637″
.680″
.722″
R77435AK
308°
130°
128°
258°
.435″
.637″
.680″
.722″
R78435AK
314°
133°
130°
263°
.435″
.637″
.680″
.722″
R79435AK
318°
135°
132°
267°
.435″
.637″
.680″
.722″
R81435AK
324°
137°
133°
270°
.435″
.637″
.680″
.722″
R82435AK
328°
138°
136°
274°
.435″
.637″
.680″
.722″

 New “Sprint Series”

I.R. Roller Profiles

New for 2015 is our line of “Sprint Series” Inverse Radius Roller profiles.
These profiles are designed specifically for the extreme performance
demands of today’s Sprint and Latemodel race engines. Using our
“Parametric Profile” design equation, these lobe profile designs are
optimized for 400-420ci V8 engines.

 

Duration @ Lobe
Part # Seat .020″ .050″ .200″ Lift
R78465s 312° 292° 264° 189° .465″
R78480s 312° 292° 264° 190° .480″
R78453s 312° 296° 266° 190° .453″
R79465s 316° 296° 267° 191° .465″
R79480s 316° 296° 267° 192° .480″
R79450s 316° 300° 269° 193° .450″
R80465s 320° 300° 270° 194° .465″
R81465s 324° 303° 274° 196° .465″
R82465s 328° 307° 277° 199° .465″