Words and Photos by Richard Holdener
If there is a red-headed stepchild of the performance world, it might well be the oiling system. Here is a short quiz; be honest. How many of you do anything more than take an occasional glance at the oil pressure gauge, if you even have one? Truth be told, most of us take it for granted the oiling system is working and our precious motor is receiving sufficient lubrication. That’s a lot to take for granted, even on a bone stock motor, but it’s not something you want to leave to chance on your modified street/strip motor, let alone a dedicated race motor.
Those who have paid some attention to the oiling system seem to fall into the add a high-volume oil pump, or extra capacity oil pan category. While it is important to have sufficient (but not excessive) oil pressure and even capacity, there is much more to a well-designed oiling system than a pump and pan. The right oiling system for your application can actually increase both engine life and outright performance.
What better way to illustrate both the installation procedure and power gains than to cover the installation on a typical performance motor. Milodon makes pans for most popular engine combinations and applications, including most forms of racing (drag, road, and circle track to name a few), but for our install, we chose a 5.0L Ford. Truth be told, the combination actually displaced 347c.i., thanks to a stroker assembly (crank and rods) supplied by Speedmaster and combined with JE pistons. Though we detailed the installation on the smaller 347, we ran a direct test on the effect of the oiling system upgrades on a larger, more powerful stroker combination displacing 427c.i.
The basic installation steps are the same for most motors, and included proper selection of the components and critical measurements for the depth of the oil pump pick-up. Proper selection and installation of the oiling system components will ensure operational success.
Check out the supplied photos for tips on installation of the Milodon oiling system on the smaller 347 stroker. Makes sure to first order the proper matching components for your application (i.e. drag racing, road racing, street/strip etc…), but be prepared to spend a little time making sure everything fits properly. Though the systems are designed to fit specific engine applications, it is up to the end user to ensure things like the pump pick-up depth is accurate and that the windage tray is positioned so that there is no crank or rod interference. A little extra time spent during mock up and assembly will ensure the engine works properly for years to come.
Make sure to remember the little things like a HD oil-pump drive shaft. This is especially critical in colder climates or when running a high-volume oil pump. High-volume oil pumps are also not advised for use with stock (small capacity) oil pans, as they tend to evacuate the pan and can cause oil starvation. Little things go a long way!
Though we performed the installation of a Milodon system on the 347, we also ran a back-to-back test on a larger 427 stroker. We figured the wilder 427 would better illustrate the gains offered by the oiling system upgrades. The 427 featured a Dart block stuffed with forged internals from Speedmaster and Probe. The Probe pistons featured dual valve reliefs that allowed us to run either conventional inline or TFS-R heads. We chose a set of CNC-ported TFS-R heads topped by a Wilson-ported Edelbrock Super Victor intake. Feeding the intake was a Holley Dominator using a 4150-4500 adapter. Rounding out the package was a healthy COMP roller cam, rockers, and hardened pushrods, along with a valve spring package that allowed plenty of engine speed. It is important to note that crank throw speed (at the tip) exceeds 300 mph at 6,000 rpm. Eliminating windage from this maelstrom can result in significant power gains.
The extra capacity of the Milodon drag-race pan was certainly welcome, but the power gains did not come from the extra three quarts of oil. The Milodon pan featured a few tricks, including a full-length, louvered windage tray and kick out. Both were designed to keep oil away from the rotating crankshaft. Spinning at 6,500 rpm, a crank counterweight just six inches from the crank centerline will be traveling at speeds exceeding 116 miles per hour. Add to that equation the weight of the residual oil and there is plenty of resistance. The net result is a drop in the overall power production, to say nothing of the potential loss of oil pressure from aeration. It should be evident from this example that modifications to the oiling system do not increase the power output so much as decrease the losses associated with running the motor. A well-designed oiling system helps eliminate much of the power-robbing windage, and allows the crank to spin in (nearly) oil-free air.
To demonstrate the power potential of a proper oiling system, we ran our 427 stroker first with a 7-quart aftermarket oil pan. As expected, the 427 produced good power, with a peak of 654 hp at 6,500 rpm. The big-inch Windsor also produced 585 lb-ft at 4,900 rpm. To ensure accurate testing, the oil manufacturer, viscosity, and temperatures were kept constant during the test, as were things like water temp, air/fuel, and timing.
After installation of the Milodon pan, we were plenty impressed by the results. The 427 stroker motor responded with both an improved (consistent) oil pressure curve and gains as high as 19 hp. Oddly enough, this did not come at the power peak. But the oiling system did show significant gains from 5,000-6,500 rpm. It just goes to show you that if you are looking for more power, it might be better to start from the bottom and work your way up.
Sources: ARP, Arp-bolts.com; COMP Cams, compcams.com; Holley/Hooker/Weiand/NOS, holley.com; L&R Automotive, lnrengine.com; JE Pistons, jepistons.com; Milodon Inc, www.milodon.com; Speedmaster, Speedmaster79.com; Trick Flow Specialties, trickflow.com