How to Prep Your Collectible Car’s Engine for a Supercharger or Blower

So you want some super-horsepower? Many people think you can just “bolt on” a supercharger or a blower. Sure, you can do that--chances are, you might make one pass down the strip. You might even make two passes. You most likely will not finish the third pass.

Depending on the type of blower or supercharger you are installing, you may have to do a little bit of work-or you may have to do a lot of work. Assuming you want to install a roots-type blower, you will need to prep your engine to keep it from grenading.

Difficulty: Challenging

Instructions

1. Start at the bottom end--you will need to install a double keywayed steel crank. The keyway is the key on the nose of the crank that fits into the notch on the harmonic balancer and keeps the balancer from spinning around the crank. The average crank in your collectible car is made of cast iron. A steel crank is much stronger. You also need to take the crank to a machine shop and make sure it is balanced properly.

2. Change your rods to a stronger aluminum rod. Some Chevies came with “X” rods or “pink” rods. While they are not as strong as a medium to high end aluminum rod, they will work with an underdriven blower. For the pistons, you will want to choose a forged aluminum piston. The compression in your car should not be more than about 8:1 or 8.5:1 with a blower. This means you must be able to choose heads, a cam and a piston combination to come up with an overall compression ratio of about 8:1. In the last small block Chevy I built, I used 10.5:1 compression flat top TRW pistons with stock cast heads that had the valves cut out. The exhaust valves were cut more than the intake valves, though they were still smaller than the intake valves. We left the intake valves at the stock 2.02, and enlarged the exhaust valves as much as we could go without breaking into the water jacket.

3. Choose a cam. We used a competition cams nitrous extreme cam with just over a half inch of lift and a longer duration on the exhaust side.

4. Do your research as it pertains to the motor and size you have. You can get much wilder with a big block than you could with a small block. You will also need to do research based on whether you are driving a Ford, Chevy, Dodge--or whatever you choose.

5. Get an MSD 8AL-BTM. This is a multiple spark discharge unit that multiplies the spark-in the case of the 8AL, 8,000 times. The BTM is a module that allows for automatic retarding and advancing of the engine. This particular MSD also has a rev control, where you can plug in different chip. If you install a 7,000 rpm chip, the MSD will cut the cylinders in the engine if you rev over 7,000 rpm. It is very easy to over-rev an engine with a blower on it, so know the “safe” point of your engine and its components and plug the appropriate chip in.

6. Know that installing a blower is not difficult-it is the prepping of the engine, making sure you have the correct components and the correct combination that is the difficult part. You now have a great place to start with your research in knowing what items you must change out so that your engine does not grenade.

Tips & Warnings

• If you are a big horsepower hog, you can also use things like a one-wire alternator, or just take the alternator off, if you are just going down the drag strip. Have a very good battery before doing this.