Engine Forensics — Inside A SBF After Completing The Baja 1000

After 45 hours of continuous torture, we were still in the running to finish the prestigious SCORE Baja 1000. Other than during pit stops, our 410-cubic-inch small-block Ford Windsor had not shut off. We were 55 miles from the finish line of the 1,135-mile race. With three hours left before timing out, it was just a matter of not doing something dumb.

At about 9:00 am, just outside of the small village of Comondu in southern Baja, running slightly uphill at a strong pace, we heard a single backfire… then silence. The race car drifted to a stop on the side of the course. Repeated cranking, but no fire. Fuel pressure? Check! Air? Check! Spark? Negative! We got to work replacing the coil with no luck.

We swapped in our second MSD ignition box, still no luck. Checking the cap and rotor, no issue. That is, until we tried turning the engine over with the cap removed. Our test confirmed something failed between the camshaft and the rotor. Out came the distributor assembly; lo and behold we found our problem — a worn-out distributor gear. It also happened to be one of the few spare parts we didn’t have on board.

This is the original bronze gear consumed by the engine.

Some satellite-phone calls were made, and our support team located a spare distributor (and gear) and were en route. By the time they arrived we’d stripped the engine of accessories so it was only a matter of finding TDC in the number-one hole and installing the new parts. However, the decision loomed whether to push on to the finish line and risk further damaging a $30,000 race engine, or limp her to the nearest road and find the trailer.

We hadn’t come this far to save money — it was all-or-nothing in our minds. Before leaving the scene we were told “go easy for about three miles. If there are no issues, go for it.” That plan lasted about 30 seconds before all hell broke loose and we were streaking towards the finish line. Long story short, we finished with nine minutes to spare. This is the point at which the story of our engine begins.

Well Doc, How Bad Is It?

With over 1,135 miles of high-RPM wear and tear, it was time to find out just how much punishment we inflicted on this endurance engine. It was evident that the engine already had plenty of bronze (from the distributor gear) find its way through oil passages until the oil filter could capture it. But what about other contaminants such as sand and fuel-borne contributors?

To handle the forensics, the engine was delivered to SouthWest Racing Engines (SWRE) in Covina, California. Having built this engine and many others involved in desert racing, its team was ready to dig in. To kick things off, the engine received a light external air bath to reduce the chance of introducing external contaminants while the tear-down took place.

Evidence of contaminants in the cylinder head’s oil drain-back hole.

Next, a 3-ounce oil sample was taken from the engine and shipped off to SPEEDiagnostix for analysis, along with a 3-ounce sample of fresh oil reserved from the original case of oil used in this engine. The idea is to match physical findings with chemical analysis for confirmation as well as to examine chemical properties which may not be so visually obvious.

While not absolutely required, sending new and used oil samples will provide a more comprehensive view of what has been introduced to the oil throughout the useful life. SPEEDiagnostix maintains a well-stocked analysis library of commonly available lubricants. While taking oil samples, the magnetic oil drain plug was inspected for debris. To the delight of the team, minimal ferrous debris found its way onto the drain plug.