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Racing Oil Pans - A Baffling Experience

A New Oil-Pan System Cures Pressure Drop Caused By Deceleration And Hard Braking

By Sky Wallace, Photography by Good Communications

At first glance, it seems a bit of a stretch to link the pouring of concrete with the latest development in oil pan technology, and the involvement of four high-tech-inclined industry powerhouses in a joint effort to help solve a common problem, but stick with us here and we'll run it down for you.

As the namesake of Jeff Johnston's Billet Fabrication, Jeff Johnston has long been pondering a situation that many wet-sump, high-horsepower cars experience. Both after the burnout and at the end of a pass, when the binders are applied, the oil pressure drops as the oil slams toward the front of the pan and away from the pump. Internal pan baffles and their "trap doors" have been an integral part of race-engine oil pans for years, but still the problem has persisted.

Some racers get around the top-end pressure-drop problems by simply shutting off the engine right at the finish line, which causes another segment of the racing fraternity to shudder. John Gianoli, proprietor of Reggie Jackson's Performance Engines (San Bruno, California) is in this group.

"If someone is running an automatic transmission," Gianoli told us, "and it isn't adjusted properly, the trans can easily go into reverse when the racer puts it into neutral. This is obviously bad enough, but another result can be even worse. If the rear is set up with ladder bars, the front rod ends of the bars often break off at this point, and then the car crashes."

And, no matter what one does at the top end, that still leaves the burnout to deal with. Killing the motor at the end of a burnout is obviously not an option. Letting the car drift downtrack for a while after getting off the throttle and slowing very gradually, in hopes of keeping the sloshing oil from getting too upset, can sometimes be marginally effective, but again is far from ideal.

As a builder of aluminum, billet-railed, high-performance oil pans and valve covers, Johnston has long pondered possible cures for this oil-control problem. And he's had many conversations about the subject with Bob Sanders of Titan Speed Engineering (Ojai, California), manufacturers of wet-sump oil pumps for the racing industry. Billet Fabrication builds pans designed to accommodate the large Titan pumps, so Jeff and Bob have many opportunities to chat. They had spent some time brainstorming possible solutions, but hadn't yet come up with any answers.

And so one weekend day, late in the 20th century, Johnston was helping a friend pour some concrete. While idly watching the mixture flow out of the hose from the pumper truck, he became intrigued by the operation of the 4-inch check balls that, simply and efficiently, governed the movement of the ooze from the two-stage pump and kept it going in the intended direction.

The proverbial light bulb lit up over Jeff's head, marking the beginning of some frenzied activity for Billet Fabrication. Phone calls were made, and a few days later, he had some new steel balls to work with.

A bit of time was spent at the computer, and a spew of commands was sent to the in-house CNC machinery. One thing led to another; before long, a seemingly optimal cylindrical device was in his hands. Billet-carved and featuring an interior that sports a cone at either end, it is shaped to accept a caged, 3/4-inch steel ball in one side that stops the flow of oil when the ball is forced forward, while allowing controlled fluid movement at all other times. (The actual dimensions and shapes of the tubes were the result of both mathematical equations and actual testing.)

And this ball slams shut tighter than a woman's purse in New York's Central Park. In other words, this valve arrangement seals really well.

The next steps in the process led to a test pan, with a half-dozen of these check-ball assemblies welded side by side into a baffle, just a bit above the pan floor. A standard trap-door baffle was installed at the other end of the pan, to provide a good look at the difference in the two methods of oil control.

We can attest to the fact that the difference is dramatic. We got to watch a demonstration during the Indianapolis Performance Racing Industry (PRI) Trade Show, and the closed trap doors, while slowing the fluid down, still allowed a lot of it to slip past. This seepage was substantial even with only gravity pulling on it, leading us to wonder what it would look like when the g-forces of deceleration were factored in. The new "Baffle Balls," on the other hand, stop the oil dead in its tracks, holding absolutely all of it in the sump for the pump's use. With the theory seemingly sound, an on-track test of a Baffle-Ball pan was the next thing on the schedule. It's here that the fourth company got involved.Steve Collins is the production supervisor at Chris Alston's Chassisworks, and he has a primered, high-8-second '66 Chevelle that, aside from providing Collins with loads of fun, has also occasionally served as a Chassisworks test bed. Needless to say, traction has never been much of a problem for this car, and with a nitrous-fed, 460-inch big-block from Gianoli at Reggie Jackson's Performance Engines, it has power to match.

However, Collins had noticed the oil-pressure drop mentioned earlier. As soon as the brakes were applied, the pressure in his existing oiling system would go from 60 psi down to around 25 psi. It always recovered once the car was almost stopped, but needless to say, the downward movement of the gauge's needle was causing him great distress. He put in a call to Gianoli to discuss the problem, and Gianoli mentioned the new developments at Billet Fabrication. (Many of the motors built at RJPE feature the products of Titan and Billet Fabrication, so Gianoli had been following the process closely.)

At this point, Collins immediately offered the use of his heavy Chevy as a test mule for the new design. The Titan pump was retained, the existing pan was scrapped, and the first purpose-built Baffle Ball pan was installed.

Aside from the ignition system, this Chevelle lacks any over-the-top electronic devices, so Collins mounted a video camera on the rollcage and aimed it at the dash to keep track of the readings of the oil-pressure gauge. And the following Saturday, Gianoli and his shop rats showed up at the Chassisworks facility to warm the motor and run the valves. Then, with Chris Alston in tow, they all headed out to nearby Sacramento Raceway to proceed with the testing.

As soon as the car pulled into the water box, one of the shop helpers leaned in and activated the video camera. Keeping a close eye on the gauge, Collins then went through his usual pre-run procedure, staged, and cranked out an 8.86 at 155 mph. His grin when he got back to his pit area seemed a bit wider than usual, but it wasn't only because of the results.

"The pressure stayed right at 62 pounds the whole time, and it has never done that before," he said. "But it was weird. I started hearing this clunking sound before the run, and I thought something must have broken. I was going through the possibilities in my mind, wondering if I should shut it off, when I remembered what we were doing out here. I rolled forward and hit the brakes, and sure enough, there it was again. It was the balls doing their job, and I just started cracking up. I've never heard an oil pan working before!"

Collins made a half-dozen runs, and the oil-pressure needle stayed steady the whole time the motor was running, whether on the gas or on the brakes The videotapes of the runs were reviewed, the experiment was declared a success, and Johnston was notified.

The enthusiasm of all those who participated in this test session prompted Johnston to file for legal protection on his new product. With a patent now pending for this application, he then brought the demonstration Baffle Ball pan to the aforementioned Indianapolis PRI Trade Show for its official introduction to the motorsports world. Representatives of other oil-pan manufacturers were among those crowding the Billet Fabrication booth throughout the course of the show. And the sound of the balls slapping back and forth, coming from the hands-on displays, probably drove the other vendors within hearing range of the booth completely nuts by the time the event was over.

The elegant simplicity of the Baffle Ball design caused many folks to mutter, "Now, why didn't I think of that?" According to Johnston, it also led many others to place orders on the spot.

Indeed, the number of Baffle Ball pans that have been ordered since November confirms the widespread nature of the pressure-drop syndrome, and the pent-up demand for a solution. And somehow it's fitting that this seemingly concrete fix for the problem was revealed through a batch of concrete!

SOURCES
Jeff Johnston's Billet Fabrication
Simi Valley, CA
www.billetfab.com
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By Sky Wallace
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