Special Firing Order camshafts were first offered by Crane Cams some 30-plus years ago, but recently there has been quite a bit of media attention focused on “4/7 Swap” cams for a number of racing applications. For this reason, Crane’s engineering and manufacturing team has added a half-dozen new cam cores to the company’s already formidable roster.

Crane’s most recent SFO introductions include cast iron cores, small base circle steel cores, and steel 55mm cam bearing cores for the small block Chevy. Also added to the availabilities are cast iron cores for big block Chevys, steel billet cores with 60mm or 2.125” cam bearings for Chrysler’s 426 Hemi, and steel cores for the 429-460 c.i.d. Ford.

These cores can be translated into literally hundreds of special cam profiles from Crane’s industry-leading database of 80,000 lobes.
By changing the firing order from the stock 1-8-4-3-6-5-7-2 (Chevy and Chrysler) to the alternate 1-8-7-3-6-5-4-2 (or 1-5-4-8-6-3-7-2 for the Ford) is has been demonstrated to obtain nominal power gains due to improved fuel distribution (especially in open plenum intake manifolds) and “smooth out” the torque curve. Oval track racers especially like this because it makes the car easier to drive.

Personalized technical assistance can be obtained by calling Crane’s tech personnel at 386-258-6174, or writing to Crane Cams, 530 Fentress Boulevard, Dept. _____, Daytona Beach, FL 32114. Detailed information on camshafts and related valve train components can be obtained at: www.cranecams.com.

Click below to download:

	"4/7 Swap" Camshaft Image (300K - 3M)
	"4/7 Swap" Camshaft Text (2K)