If the leads get crossed, the result is the ignition will try to fire when the paddles on
Warm It Up
Good race engines are built with tight tolerances to maximize the ability to use thinner oil, which sucks up less horsepower to pump throughout the engine. But as you know, oil changes viscosity as its temperature changes. And those tight tolerances are designed for motor oil at operating temp-180 degrees or more.
Most racers are aware that they need to properly warm up the oil before heading out on the track and nailing the throttle to the floor. If you don't, you could wind up with a spun bearing, a stuck valve or worse, because the oil pump can't move the thicker cold oil fast enough.
But Ken Troutman of KT Engine Development says he still often sees engines that are damaged by running at wide-open-throttle with oil that hasn't yet gotten to temperature. One of the problems, he says, is some teams mistakenly believe that if the water temperature gauge has reached the normal operating level, then the rest of the engine is properly warmed up.
That actually isn't the case, especially if you are running a separate oil cooler (one that's not built into the bottom of the radiator). If you have a heat exchanger that's built into the radiator, then oil temp will more closely follow water temp, but if you don't have one on your car, the water and oil can be at completely different temperatures. Running the engine at 2,500 rpm for 10 or 15 minutes will often warm the water while leaving the oil much cooler. The only reliable method is to make sure you have an oil temp gauge installed and then only make full-speed laps on the racetrack after the gauge reads that the oil has reached 180 degrees Fahrenheit or more.
This is an example of a crank journal that has been damaged from something that happened t
Losing Oil Pressure
Both Dorton and Troutman mentioned phantom drops in oil pressure when we were collecting information for this story, so you can bet it's a problem many teams have encountered. The problem we are talking about here is when a race car will often show normal oil pressure levels at idle but then won't increase to racing oil pressure when the rpm levels are up. As a general rule, you will see 15 to 20 pounds of oil pressure at idle and then that will increase to at least 50 pounds at racing rpm.
If your driver doesn't see the oil pressure gauge jump up the expected level once the car hits the track, the natural reaction is to blame the engine as faulty, but it can often be something completely different. One of the most common problems is the plumbing.
First, check to make sure you don't have any crimped oil lines, either as part of a dry-sump system or lines running to a remote oil filter. When several people are working on a car, it is often all too easy to crimp or pinch a line when installing a race engine. You should also check the quality of the oil lines, especially if you have any running near the headers.
Suction lines that are too close to the headers can have the rubber liner come loose from the wire braid. Then the rubber liner can suck closed on the racetrack without leaving a visual clue because the wire braid still looks good. If you spot this, replace and re-route the hose immediately away from the heat source. If you can't find a different way to route the hose, try adding a hose insulator to protect it from the heat. Also, make sure all of your fittings are made for high-performance engines.
Both engine builders mentioned that too often they see race engines fitted with plumbing fittings from the local hardware store. These are cheaper, but they just can't flow as much fluid through them. They will act fine when the engine is at idle but choke the motor of precious lubricant at racing rpms.
Finally, a drop in oil pressure for any reason is a quick way to blow up an expensive race engine. Yes, an oil pressure gauge will show you changes in oil pressure, but a race driver needs to keep his attention on the track, not watching his gauges. A good idea for a race team is to install an idiot light that will light up on the dash to warn the driver if the oil pressure drops too far. This will alert him in time so he can shut down the engine quickly and avoid an expensive repair.