Classic inline six engines are really popular in the world of traditional hot rodding because for years they were the big ticket for making horsepower and zipping down the road or the track. The GMC Jimmy six cylinder, especially the 302ci version could be hopped up to hang with the flathead powered Fords of the day and as we all know, inliners typically run nice and smooth, make great torque, and can be easy on parts.
A few manufacturers over the years have made the leap and manufactured some really legit performance parts of these things. Companies like Wayne made cross-flow, 12-port cylinder heads that really raised the performance potential of the engine and while they were expensive and pretty rare, many of them still exist today. Having driven a vintage hot rod with a Wayne headed Jimmy motor it in several years ago, we can tell you for certain that it made some suds! Enough to have the very light little ‘bucket we were in zipping down the road anyway.
Likely at the top of the Jimmy performance food chain is the cylinder head you can see above and below. This aluminum piece made by Algon is purported to be one of less than 10 ever made by the company. It is a full race head that has never been mounted on car and as you can see, there’s lots of meat to work with to form ports and fine tune these babies to have them be exactly what you want them to be.
Other aftermarket heads, like the Wayne did not have a combustion chamber. They were flat like a diesel head. These have a traditional looking chamber, allowing the user to fine tune his or her combo with more traditional pistons.
This is a pretty bad ass piece and we bet it will be on a land speed car or some sort before too long. At last we hope so!