V8 Head Tightening
Page created by T Mar 5th 2009:
V8 Head Tightening:
Broken Head Bolt Holes:Ben Simpson has pointed out that there is a correct procedure for tensioning Holden V8 Head Bolts.Failure to observe it results in broken Head Bolt Holes as per the image.
253 Head Bolt Thread:
ben simpson on Wed, 04/03/2009 - 16:44.dont worry, if the rest of the engine is in re-usable condition, these bolt holes are not required. did you know the late model blocks do not have these holes at all??? these 2 are commonly broken as many people dont read the proper torque specs, and this is the result of them being torqued to the same as the main head bolts.
Blind Inner 4 Head Bolt Holes:
By Another_HQSS 24/07/14@21:34The 4 inner head bolts are also "blind" holes, don't put any sealant or oil in them, the hydraulic pressure can be enough to crack the bosses of the block. Clean the threads properly and use some air to make sure they are dry before assembly. The EFI blocks didn't have them drilled, and I have seen opinions that you don't actually need to even fit them, but I don't think I would do that if I had a choice. But I do have a 253 with one of the bosses broken off, it has never blown a head gasket even though there is no bolt so that may be true but I don't think I'd use the block for an expensive build.End of submission by Another_HQSS.
Blind Exhaust Side Head Bolt Holes:
By HQJeff 25/07/14@00:40 LetsCruise 6112Of the five head bolt holes on the exhaust side (short bolts) numbers 2, 3, and 4 are also blind holes that require no sealant. Lightly oil these bolt threads and the underside of the bolt head before installing. JeffEnd of submission by HQJeff