SBC cylinder head identification
| Line 1: | Line 1: | ||
{{develop}} | {{develop}} | ||
| + | =Overview= | ||
| + | Most cylinder heads are identified in a general sense from simply looking at them. But just knowing the generic type of engine does not begin to tell the whole story. There are a wide variety of heads for most any given engine type and in many cases there's a lot of difference between them in their potential for performance. | ||
| + | |||
=Basics of cylinder head identification= | =Basics of cylinder head identification= | ||
| + | |||
| + | A big block Chevy (BBC) or small block Chevy (SBC) head is readily recognized by the majority, as are Hemi heads, small block Ford (SBF) heads, and depending on experience and engine preferences, others as well. | ||
| + | |||
| + | To distinguish the nuances, there are several things that can be used to ID cylinder heads: | ||
| + | ;Casting number | ||
| + | :Usually cast into the head as opposed to being stamped, the casting number is usually the best thing to use to tell what a cylinder head was originally used on and its potential for performance use. | ||
| + | |||
| + | :The casting number may be out in the open where it can be easily seen, like the Pontiac V8, or somewhat harder to see but still visible without taking anything off the head, or the number can be under the valve cover or under the head where it's difficult to see without some amount of disassembly. | ||
| + | ;Casting date | ||
| + | :Like casting numbers, the date code is usually cast into the head, and may or may not be visible without removing the valve cover. | ||
| + | ;Secondary identifier(s) | ||
| + | :These are often stamped in instead of cast, like in the case of some 1970's Pontiac heads. | ||
| + | ;Casting identifiers | ||
| + | :This is different shapes that may be (in the case of the SBC) on the end of the heads or elsewhere. | ||
| + | |||
==Chevrolet== | ==Chevrolet== | ||
| + | |||
===Casting numbers=== | ===Casting numbers=== | ||
Located under the valve covers, the casting number is the best way to ID a SBC head. The number along with the date code can be used to pinpoint the heads original application fairly closely. Valve sizes (1.94" intake x 1.5" exhaust or 2.02" intake x 1.60" exhaust) and whether or not screw-in studs and guide plates are in place can further ID them. Be aware that screw-in studs/guide plates were not used on all, or even most, large valve SBC performance heads from the factory, and if present, they could very well have been added previously. | Located under the valve covers, the casting number is the best way to ID a SBC head. The number along with the date code can be used to pinpoint the heads original application fairly closely. Valve sizes (1.94" intake x 1.5" exhaust or 2.02" intake x 1.60" exhaust) and whether or not screw-in studs and guide plates are in place can further ID them. Be aware that screw-in studs/guide plates were not used on all, or even most, large valve SBC performance heads from the factory, and if present, they could very well have been added previously. | ||
===Casting identifiers=== | ===Casting identifiers=== | ||
| − | Through the years, small block Chevy heads have been ID'd by the head's end casting shapes. | + | Through the years, small block Chevy heads have been ID'd by the head's end casting shapes. They don't usually tell the exact details like valve sizes but are useful for telling (at least potentially) a performance head from a non performance head. A casting identifier can differentiate between a large or small combustion chamber volume, also intake port volume, spark plug type (gasketed or tapered seat), whether they were used with a certain type of front accessory arrangement (short or long water pump for instance). |
===="Fuelie" heads==== | ===="Fuelie" heads==== | ||
Your Privacy Choices