Cam A was good for 437 hp at 6,000 rpm, and 409 lb-ft of torque at 4,900 rpm. All three grinds idled well at 900 rpm, with the Thumpr providing a noticeably choppier disposition.īased on specs alone, Cam B would seem to have the advantage on paper since it packs the most duration and lift, but that’s not how things played out on the dyno. The wild card of the bunch was the 227/241-at-.050 Thumpr, which proved to be the best all-around performer in our 347. 050, and the latter with 232/240 degrees at. Both are Xtreme Energy grinds, the former measuring in at 224/232 degrees of duration at.

Two of COMP Cams’ most popular SBF camshafts are PN 35-518-8 and PN 35-522-8. As one of COMP’s Thumpr grinds, Cam C was designed with a lopey, aggressive-sounding idle in mind, and as such, it has a tighter LSA and an earlier exhaust valve opening The wild card of the bunch is Cam C, which measures in at 227/241 degrees of duration at. 565/.574-inch lift, also with a 112-degree LSA. Cam B, the largest of the bunch, features 232/240 degrees of duration at. 555/.565-inch lift and a 112-degree lobe-separation angle.

The smallest of the lot, which we’ll call Cam A for the sake of simplicity, is a 224/232-at-.050 unit with. The challenge was picking three cams that were different enough to show a measurable difference on the dyno, yet similar enough to where variations in horsepower and torque output could be pinpointed to specific differences in their lobe profiles. I have a Sunbeam Tiger with a 347 stroker in it want to change cams was thinking about the small thumpr cam but hear a lot of mixed feelings about it Summit ,Jegs and comp cams themselves all say they make sound no power but according to this they make more power than the other ones so witch is it do they or don't they? A Tale of Three Cams hot rod networkĪs no surprise, a quick call to COMP Cams’ Trent Goodwin confirmed that the most popular grinds in the SBF catalog are relatively mild designs that offer a great balance between sub-6,500 rpm power and low-speed driveability.

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