The Amsoil/Mopar Muscle Engine Challenge - Tech

The Amsoil/Mopar Muscle Engine Challenge is one of our favorite events to cover here at Mopar Muscle because each year it gives us the opportunity to highlight the performance of a great Chrysler engine. In years past, our Engine Challenge has featured stroked Hemis, stroked big-blocks, and stroked small-blocks, and all these engines impressed us with their power numbers. In each of the past Challenges, the engine builders had to follow the basic rules, factoring the engine's cost and limiting displacement, and they all had to run on the same 93-octane pump fuel, but otherwise anything was fair game. This year we decided to change it up a bit and require all the builders to use the same basic parts to build what is commonly termed a spec engine.

When deciding which engine combination to feature in this year's Challenge, we took many factors into consideration. Rather than coming up with an exotic combination, we decided since one of the most common bracket and street car engines is the 440, that it made sense to feature the 440 in this year's contest. With the engine picked, we decided to keep it simple this year and limit the builders to a .060 inch overbore, and stock stroke. This is a typical short-block that pretty much anyone can build, and is the same basic engine that many of our readers have in their street or bracket cars.

Because this year's rules call for a spec engine, all of the builders had to use the same Indy SR cylinder heads to top their 440s. Indy Cylinder Head has been supporting Mopar racers with fantastic aftermarket engine parts for many years, and their SR head is a great choice for the Chrysler 440. The SR head is moderately priced, offers large valves, an efficient combustion chamber, and plenty of port volume for the flow needed to feed a 440, but doesn't require specially offset rocker arms. Also, the SR cylinder head is available in a CNC ported version with max-wedge size intake ports which most of this year's builders took advantage of.

Otherwise, the rules of our contest were pretty simple. Builders could choose one of two aftermarket oil pans, or use a factory pan, and induction was limited to 1,350 cfm. Any camshaft could be used, and all of this year's competitors chose solid roller cams for their engines. We again ran all the engines on Rockett Brand 93 octane pump fuel, which kept the compression of most motors around 11:1. Amsoil was our major sponsor again this year, and again we had no oil related issues with any of the engines. If you haven't tried Amsoil's full line of synthetic lubricants, you should. More than one of this year's engine builders commented on how clean their engines looked after being run on Amsoil.