| Thumpr Cams Used and Subsequent Dyno Results |
1. Baseline result before
Thumpr install |
| Peak power | 318 hp,355 lb-ft torque |
| Average power | 265.9 hp, 327.7 lb-ft torque |
| Vacuum noted | 15 inches |
2. Thumpr Cam (PN 12-600-4);
279/297 duration;
2,000-5,800-rpm range;
lift: 0.479 intake / 0.465 exhaust |
| Peak power | 357 hp, 387 lb-ft torque |
| Average power | 292.4 hp, 358.9 lb-ft torque |
| Vacuum noted | 9 inches |
3. Mutha' Thumpr Cam
(PN 12.601-4); 287/305 duration;
2,200-6,100-rpm range;
lift: 0.489 intake / 0.476 exhaust |
| Peak power | 376 hp, 393 lb-ft torque |
| Average power | 299.5 hp, 365.6 lb-ft torque |
| Vacuum noted | 7.5 inches |
4. Big Mutha' Thumpr Cam
(PN 12-602-4);
295/313 duration;
2,500-6,500-rpm range;
lift: 0.500 intake / 0.486 exhaust |
| Peak power | 390 hp, 395 lb-ft torque |
| Average power | 302.9 hp, 368.3 lb-ft torque |
| Vacuum noted | 5.5 inches |
Thumpr Flat-Tappet Camshafts Currently AvailableSmall-block Chevrolet'55-98 model years, 262-400 cid
Small-block Chevrolet'87-98 model years,OE hydraulic roller-equipped
Big-block Chevrolet'65-96 model years, 396-454 cid
Small-block Ford Windsor'69-95 model years, 221- 351W
Small-block Mopar'64-00 model years, 273-360 cid
With the first of the Thumprs...
With the first of the Thumprs installed, the guys also swapped out the OEM rockers for a set of COMP Magnums that was used for this and all subsequent testing.
The original carb was found...
The original carb was found to be lacking, so the guys at Westech swapped it out for a 750-cfm unit and tuned it appropriately to rectify the problem. The unit was used throughout all the testing.
The ignition timing was checked...
The ignition timing was checked and set to parameters in sync with each profile after each cam swap.
All testing was, of course,...
All testing was, of course, completed on the same dyno (although, Westech has more than one engine dyno at its huge facility) and comparable conditions for accurate results.
The collective info on the...
The collective info on the comparable testing speaks for itself. Not only did we gain impressive measurable results with all combinations, but we were rewarded with the signature Thumpr sound with each cam. Now, not only do you have the opportunity to improve the horsepower and torque of your street rod engine, but you'll also enjoy the thumpin' sound of a race car at the Christmas tree. Check out the sidebar at right for more specifics.