ARP 2017 Catalog r3

22 800-826-3045 FASTENER TECH Today, there are literally dozens of different cylinder head and engine block combinations for the more popular applications, and new offerings coming out all the time. It is virtually impos- sible for ARP’s engineering staff to obtain detailed information from all of these various sources, so it may be necessary for cus- tomers to calculate exactly what they have so the correct cylinder head studs or bolts are used. Whether it’s a small block Chevy engine or a Honda VTEC, the procedure remains the same. The illustration on the right shows the nine different variables that come into play when determining the proper fastener for a particular position. Many cylinder heads have different column heights, etc. at various positions, and additional variables come into play when using aftermarket engine blocks (some of which have “blind” tapped holes for attaching the heads that are shal- lower than OEM). It is therefore critically important that you determine exactly how many different bolt/hole combinations exist for the cylinder head installation. GETTING THE CORRECT ARP HEAD STUD/BOLT FOR THE APPLICATION CYLINDER HEAD/BLOCK CROSS-SECTIONAL DATA You must have the following data: A. Depth of cylinder head counter bore_ ________________ B. Diameter (o.d.) of head counter bore _ _______________ C. Column height (net thickness of head) _______________ D. Diameter (o.d.) of bolt hole in head _________________ E. Head gasket thickness (uncompressed) _ ______________ F. Depth of counter bore in block _ ____________________ G. Length of thread in block _ ________________________ H. Depth of hole from surface to bottom _______________ I. Thread size and pitch _ ____________________________