Feature Articles

Flat Tappet Oils & Additives

Flat Tappet Oils & Additives

In spite of the wholesale O.E. switch to roller lifters that started a couple of decades ago, if you’ve got a vintage rod chances are it has flat tappets, and maybe you don’t want to go to the trouble and expense to retrofit to rollers. Plus, some racing venues only allow flat tappets. These operate at higher temperature and pressure levels at the lobe/lifter interface than rollers do, so require greater wear protection. The primary anti-wear additive for flat tappet camshafts and lifters is ZDDP (zinc dialkyl dithiophosphate), but that’s been phased out of ordinary motor oils mostly because of fears that it’ll foul the cat. Racing oil and additives provide zinc in adequate quantity to provide the protection you need to prevent catastrophic lobe and lifter wear.

CC Rider, Part 2:  Step-by-Step

CC Rider, Part 2: Step-by-Step

Last time, Greg explained static and dynamic compression, the factors that determine them, and how to calculate what you’re going to get. Now, he gives us the proper procedures for measurement.

CC Rider, Part 1

CC Rider, Part 1

What we’re talking about here is a bunch of “C” words — cubic centimeters, combustion chambers, compression, and calculation.

Starting Line: (What’s) Under The Hood

Starting Line: (What’s) Under The Hood

You may have noticed that HOT ROD Professional has morphed into Performance Technician. What does that mean? Initially, it means a renewed commitment to a wider variety of performance-related topics of interest to you, our tech-savvy readers.

Performance Technician August 2014

Performance Technician August 2014

You may have noticed that HOT ROD Professional has morphed into Performance Technician. It means a renewed commitment to a wider variety of performance-related topics of interest to you, our tech-savvy readers.

Whistling Syclone

Whistling Syclone

GMC came out with the Syclone pickup and we got just one in on allocation.  A local street racer decided to relive his mis-spent youth and stopped in to buy the only one we had (fewer than 3,000 were built in 1991, and only about dozen in 1992.)

We Have Ignition! Or, Do We?

We Have Ignition! Or, Do We?

The job of the ignition system is to provide the spark that initiates combustion, and it’s our job to keep this process going. To do that effectively, we need a firm grasp of how the system works.

Supply & Demand – Volkswagen Fuel Supply

When customers experience drivability problems, it is our job to isolate the cause. With systems changing all the time, we must keep pace. Even something as simple as fuel supply has had updates and changes that we need to be aware of.  The first successful...

CAN We Do This?

CAN We Do This?

The CAN concept has made our lives easier by connecting all the computers in the car in a network we can access with a scan tool. But what do we do when you cannot communicate with one or several of those computers?

Tuning a Carburetor-Equipped Supercharged Engine

Tuning a Carburetor-Equipped Supercharged Engine

Whenever people see a carburetor-equipped supercharged engine in a hot vehicle, they can’t help noticing how impressive it looks, and they wonder how much power it produces. But they also see an engine they think is almost impossible to tune, is not very reliable, and will overheat at the drop of a hat. It doesn’t have to be that way.