If you recall our three-for-all engine build and test, "Three-Way Mousefest" (Aug. '08), we built and tested three radically different mills (327ci, 355ci, and 383ci) and showcased what could be done with today's modern off-the-shelf parts. Our Misfit 327 churned out an impressive 391 hp on pump juice for around $4,000. Now it's time to add some zip to the little mule. To recap our combo, we utilized a cast crank and rods, flat-top hypereutectic pistons, a hydraulic flat tappet cam, a Dart Iron Eagle top-end kit, and a 2-inch Wilson manifold spacer-nothing crazy by any means.
For this edition, we talked to Weiand, a division of Holley, which offers this 142-series blower. It's the smallest blower they offer and produces up to 5.5 psi of boost. For our mill, it's a perfect combination. To put it simply, the blower kit comes complete with everything you need and installing it is as simple as a manifold swap. To make sure our breathing stays as efficient as possible, we also swapped out the old lifters in favor of a set from Comp Cams, along with a nitrided blower specific grind. When we discovered the 1.7:1 ratio rockers were causing the little 327 to be down on power, we reevaluated the situation. Basically, the larger 1.7 ratio was causing the cam to actually lose lift in the dyno pull. However, on hand was a set of smaller Comp 1.65:1 ratio rockers, which we swapped in (although Scorpion does offer rockers ranging from 1.3 to 1.7:1). The new ratio got our lift back and cooperated well with our blower grind 'stick. How much did it add? Sixty horsepower and 52 lb-ft-impressive indeed, but read on to find out the juicy details.
A cam and lifter swap with a blower on top
Big power for little cash
This conversion, as trick...
This conversion, as trick as it may seem, only requires you to complete a manifold swap. Using a 3/8-inch closed wrench, we removed all the bolts and our Dart dual-plane manifold.
The most difficult part? Removing...
The most difficult part? Removing all the old gasket material from the intake ports on the cylinder heads. Be sure to place paper towels or rags in the lifter valley, including the intake ports on the cylinder heads, to prevent any material from entering.
Once they were removed, we...
Once they were removed, we inspected each of the lifters for wear and damage. It's worth the time it takes as it'll inform you of potential oiling problems; in our case, they were fine.
We then popped off our two-piece...
We then popped off our two-piece timing cover from Comp, which allows for easy cam swaps with the added benefit of not having to drop the oil pan.
Organizing Flat tappet lifters...
Flat tappet lifters all wear differently so it's a good idea to label and keep them in order. These lifters are still in perfect condition and will serve as a backup should we decide to use them again.
We pulled the old timing gear...
We pulled the old timing gear and chain off the front and pulled the cam out as well. Be careful when pulling the cam to avoid nicking the cam bearings.