FAQ

What pushrod length is recommended for my AFR cylinder heads?

There are several variables that influence proper pushrod length, i.e. block deck height, head milling, head gasket thickness, camshaft base circles, and even the design of the rockers and lifters. It is necessary to use a pushrod length checker to determine the proper geometry for your application.

Will I have enough piston-to-valve clearance with my new AFR cylinder heads?

Regardless if it is a fresh engine build or a cylinder head swap, piston-to-valve clearance must always be checked for depth and radial interference prior to startup. The use of modelling clay is highly recommended for this procedure. Minimum clearances on depth are .080" on the intake and .100" on the exhaust, radial clearance should be no less than .020" around the perimeter of the valve. If your measurements are below the minimum it will be necessary to notch the pistons or replace them all together. Failure to do so may result in catastrophic engine damage, voiding your warranty.

Will the supplied valve springs work with my camshaft?

All AFR assembled cylinder heads come equipped with high quality valve springs, however it is possible that the supplied springs may not be correct for your application/camshaft selection. All valve springs must be checked for compatibility with your specific camshaft prior to installation and engine startup. Failure to do so may result in severe wear of valve train components and/or engine damage, voiding your warranty. Please consult with your camshaft manufacturer for recommended spring pressures. We also stock a full range of valve springs which can be selected during order process, besides the standard spring package.

Does AFR supply rocker studs and guid plates?

All assembled, stud mount cylinder heads are shipped with ARP rocker studs and AFR adjustable guide plates for optimal valvetrain geometry. These pieces are packed seperately and are not installed. Please make sure to remove all parts from the packaging and confirm no pieces are missing prior to discarding of the box.