A guide to the high-performance red, blue and black straight sixes..
"If you get careless or go romanticizing scientific information, giving it a flourish here and there, Nature will make a complete fool out of you. It does it often enough anyway even when you don't give it opportunities." Robert Pirsig, Zen and the Art of Motorcycle Maintenance
These pages are an attempt to provide some information and guidance for those wanting to build a higher output six cylinder Holden engine - specifically the red, blue or black straight sixes. They are based on my own admittedly limited experience with these engines, plus what I've been able to glean from others. Reliable information for these old engines isn't easily available, and as usual anything you read in magazines should be taken with a big grain of salt - after all their primary responsibility is to their advertisers. The stuff you find on the web isn't necessarily any more credible, so use common sense and carefully consider anything you read before implementing it. Of course, that includes what's written here.
You'll notice that the information here isn't particularly detailed; it's more of an attempt to steer the reader in the right direction. You'll also notice that I tend to mix metric and imperial units - you'll just have to convert them yourself if that's a problem.
Naturally, a site like this can never be complete, and I welcome suggestions and corrections. It's aimed at the builder with a limited budget, and is therefore focused on using the original Holden major components - eg. block/crank/head. Mainly we will discuss naturally aspirated engines, though we may touch briefly on issues related to blown engines.
This site is updated semi-regularly, so you may want to check from time to time. Some people like to have a printed copy; there is a PDF version that's better for offline reading or printing.