Project Professional Awesome Time Attack Evo: Part 2 – Engine Details

Project Professional Awesome Time Attack Evo: Part 2 – Engine Details

by Daniel O'Donnell

We last left you with the chassis in progress and weeks worth of prep and fab ahead of ourselves to have the car ready to start bolting parts on to it. While this was going on in our shop, we had a whole new engine project being worked on by Steve Schmidt Racing Engines in Indianapolis, IN. The goal of the new engine was to improve reliability, make more power and try some new ideas we had been tinkering around with in our heads.


While we toiled away in the garage, grinding away tar and sealant in order to stitch weld the chassis the new engine was being assembled at a nearby engine shop.

Now the old engine setup, as you can read about in Part: 0, was a 2.4L 4G64 block/4G63 head hybrid. We were reasonably pleased with this setup, but the block was damaged in the Road Atlanta accident and a new engine would have to be started from square one. As any car enthusiast knows, when life gives you lemons, you max out your credit cards and buy new, better parts to replace what you had in there before. So began the decision making process in switching our setup.


I hope all MotoIQ readers realize the wealth of knowledge to be found in the pages of the unforunately deceased Sport Compact Car magazine. I knew Dave Coleman covered rod stroke ratio in an issue and I knew I had to find it to read up before building the new engine. Coincidently, that issue was July 2002, the first issue I ever purchased!

First, I grabbed the Manley catalog as we always run their performance products where possible because they are great supporters of the team and we’ve never had a single issue with anything they produce. Second, I went searching through my Sport Compact Car archives, which I assume all good readers of MotoIQ have, looking for the July issue of 2002. The significance of that 13 year old issue? Well of course it was Dave Colemen’s Technobabble entitled “Don’t Bother” that covered the importance, or lack there of, of rod-to-stroke ratio. I then brushed up on Kheim’s MotoIQ articles “Does Length Matter Parts 1 and Deux” to ensure I had covered all possible rod-to-stroke ratio bases.


Our previous 2.4L 4G63/64 with MA Performance's EF4 turbo before it got smashed into a wall. This setup proved very potent, although with room for improvement, and went through a few different iterations in its life. In this photo notice the second, external wastegate after the internal wastegate. This was done to support this inital wastegate actuator and hold boost at higher RPM. Eventually we switch the internal wastegate actuator to a Turbosmart design, making the secondary wastegate no longer needed.

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