HYDRAULIC CAM DYNO TESTS
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The first test of the JGR oil was in a flat tappet hydraulic cammed 5.0 Ford engine. The cam was a moderate 274 degrees of off-the-seat duration but was a fairly aggressive profile. The dyno was UNC Charlotte motor sports department’s Superflow 901. The engine was already fully broken in and had been run on Mobil 1 since break-in. Although the Mobil 1 in the pan had only some two hours running it, along with the filter, was changed for a fresh sump full of Mobil 1 of the same viscosity as the JGR oil.
The plan here as the amount of change in power was expected to be small was to do 10 carefully controlled runs on each oil and then throw out the best and worst run of each. After that the average of the remaining 8 were used to see what changes were effected. The result was an average of 5.86 hp in favor of the JGR oil. That was a result I was far from happy with as it simply looked way too much. Inspection of the numbers did show a marked upward trend and the variation, one run to another, was a lot less than the 5.86 hp average increase. No matter which way these numbers were considered they always appeared to be too big to be accounted for solely from a reduction in friction and viscous losses. A possible answer was that the flat hydraulic lifters sealed up a little better on the Gibbs oil. That would account for the magnitude of the result. I reasoned that because the leak down rate of hydraulic lifters is such a variable in itself another test like this could well produce a lesser increase.
SOLID LIFTER DYNO TESTS
 Fig 1 In this test, using an engine that might be typical of a Saturday night racer, the Gibbs oil showed a 3.1 hp average increase. |
 This solid lifter dirt motor was a low budget deal built to run within very confined rules. Even so it topped out at a highly competitive 366 hp |
The next test of the JGR oil was in a solid flat tappet lifter dirt car engine. This was exactly the type of engine the oil was intended for. After the engine was given a lengthy 2 hour plus break-in on a quality mineral oil the change to Mobil 1 was made. From here on some 150 pulls were made testing various tweaks and components to see what the engine liked.
 The DTS dyno cell used for the solid flat tappet oil tests was well equipped. Corrections were minimal and numbers held consistent due in part to the conditioned air fed to both the engine (red duct in background) and dyno cell independently. |
Once this was all done an oil change to a fresh fill of Mobil 1 was made and the engine, which was by now very repeatable, was re-baselined. The same procedure involving 10 runs to determine an average was done as before. These results looked a lot nearer what might be expected of one top notch oil versus one that might be slightly better. Even so the average (Fig 1) was still, at 3.1 hp, an increase in favor of the JGR oil, and still a little better than anticipated.
