Pure Stock Prep School - Part I: Engine

Evaluate Your Pontiac And Your Intentions
It's important to honestly review how you're going to use your Pontiac before you prep it for PS racing. Answering these questions before you start the project will help you balance any compromises needed:

• Will it primarily be a PS race car or will it be used more for cruising?
• Is race gas readily available in your area or do you need to run pump gas?
• What is your e.t. goal?
• What is your budget?
• If you race and cruise your car, how steep of a gear can you tolerate on the road?

Make Your Stock Pontiac Quicker
What follows is the application of the rules (see sidebar) that Dan has laid out for us.

Machine Work
Let's look at several important items individually to give you an idea of what it takes to build a highly-potent Pontiac Pure Stock motor.

First, you need to choose a trustworthy, competent machine shop. From all the stories circulating and the amount of motors we have had to redo for competitors, this may be more difficult than it seems. Try to find someone who understands and has experience with Pontiacs. When you have so few items that vary from factory original, every small detail needs to be addressed, as this is how you will ultimately make all the power these motors are capable of.

Block
The machining must be precise and should start with the crankshaft main saddle alignment. This provides the reference for decking and cylinder boring. We also check and make sure the cam journals are bored dead straight. A torque plate isn't necessary for boring the block, but is mandatory when honing and should be installed and torqued to the proper headbolt specs. This puts the block/cylinders under the same stress as when the heads are installed and will help to create accurately dimensioned and clearanced cylinder walls for the assembled motor.

Crank
The crank preparation will begin with an assessment of its condition. This is most often done with a magnetic check. The machine shop should be able to resize and polish the crank journals, if needed. Careful crank prep requires knowledge and care to maintain proper radiuses at the corners. Additionally, we make sure that none of the oiling holes have burs. After all the necessary machining is accomplished, then the reciprocating assembly must be balanced. Some racers at this time will have the crank Nitride treated, but that isn't a necessity for PS motors.

Rods
Rod choices are numerous and you can let your wallet or durability concerns be the driving factor here. Stock Pontiac rods have unjustly earned a reputation for being weak. This isn't true, particularly for our venue. If they're properly resized and upgraded rod bolts are installed, they can more than adequately handle the requirements of our blueprinted motors. Using the stock rods may save as much as 50 percent of the cost of going to an Eagle rod.

If you choose to buy new rods, we've used Eagle H beams, SCAT and Oliver successfully. The Olivers are the strongest items available and they've worked very well for us, but they can be a budget-buster and overkill for PS racing. They cost at least double that of the Eagles and SCATs. We've also tested CAT rods and they've held up well in dyno testing and racing in one competitor's motor, but we wouldn't recommend them as they took a substantial amount of extra setup time and reworking to get them to repeat the recommended torque setting before installation and match each other. All the additional work wiped out any cost savings that was realized up front.

Even with new rods, we check every measurement and preassemble them until we believe each rod will hold its torque when installed.