Speed’s Secrets March 2008
Bullet-Proofing the Cam Case
For the past few issues we’ve been talking about Twin Cam performance engine builds, and last issue we addressed the ins-and-outs of the Speed’s Performance Plus “Specialty Engines.” These are the engines that the guys at Speed’s custom-build from the cases up. Nothing’s spared and absolutely nothing is overlooked with these engines. One of the bulletproof mods they give these engines is the inclusion of their Cam Plate Kit. This is a custom-designed cam plate that’s much thicker than the factory piece, much more stable, allows absolutely no flexing whatsoever, has an improved oil passage system and relief system, and includes bottom venting that allows the engine to vent from both the top and the bottom. That’s quite a list and it’s only the beginning. There are Speed’s Cam Plate Kits for all the Twin Cam engines to fit the original TC88 up through the new 96. That includes motors introduced for the ‘06 Dyna that have since been used throughout the H-D line for 2007 and 2008. The Cam Plate Kit for those engines is of particular importance because it puts back the bearings that Harley left out.
For whatever the design reason, Harley-Davidson has seen fit to eliminate the outer cam bearings in its newest engines. The inner bearings are still in place but the outer camshaft journals, now larger in diameter, run without bearings right in the aluminum of the cam-support plate. “We just believe you’re lots better off running those camshafts in bearings instead of plain aluminum, hardened or not,” Speed’s Wayne Hanson figures. “It would seem there’s a real tendency there for the fit to get pretty sloppy pretty fast.” Speed’s Cam Plate Kit was especially designed to run the camshafts in bearings on both their journals, inner and outer. When used on earlier-model Twin Cam motors—the ones with bearings already in their plates—the Speed’s Cam Plate works seamlessly with any set of gear-driven cams bringing all those strength, venting and oiling benefits listed above into play. But on the newer engines—the ones coming from the factory without bearings for the outer cam journals—Speed’s has its own 615-grind cams which are a great match with Speed’s cylinder heads and the 103-inch upgrade for 96-inch engines. They also offer a 520 bolt-in cam set that works great in a stock-displacement 96-inch engine and nets about a 10-horsepower increase. The reason those special Speed’s cams are required here is the dimension of the camshaft journals. Remember, later-model applications have a larger-diameter outer journal. The journal on the Speed’s cams is reduced in size to allow the use of a bearing—exactly as it was used in the pre-2007 engines.
Now, the addition of those bearings—not to mention all the other benefits the Cam Plate Kit brings—is something certainly welcome on the late-model Harleys. And the earlier-model Twin Cams—those motors already running their cams in bearings—can get an added benefit, too. There are a couple versions of the Cam Plate Kit available; one allows earlier Twin Cam engines to retain the stock oil pump, and another allows for the bolt-in upgrade of a 2007-later Harley-Davidson high-performance oil pump which is vastly improved with larger gears and much better scavenging. This becomes a cost-effective move for someone considering the installation of a high-performance aftermarket oil pump. The price on those older H-D oil pumps—those in the engines before the 2006 Dyna and then 2007 models—has gone up considerably. They can cost more than $300. An aftermarket pump is even more, as much as $400. The improved Harley-Davidson 2007 high-performance oil pump, on the other hand, can be bought for less than $100. Couple that with the affordable cost of the Speed’s Cam Plate Kit and you can have a high-performance oiling system for just a bit more than the cost of an aftermarket pump all by itself. And in the deal you get all the other benefits of the Speed’s Cam Plate.
Another benefit is the gaskets this kit uses. The Cam Plate Kit is gasket-sealed everywhere—between the cam support plate and the engine case and the outer cover. There’s no chance for leaks.
The Speed’s Performance Cam Plate Kit includes the cam plate and the outer cover, along with the necessary hardware to mount it. The camshafts and gear drive, of course, are available separately, as is the H-D high-performance oil pump for the earlier engines. Now, is all of this really necessary? That depends entirely upon just how serious you are about bulletproofing everything. After all, having bearings where there were none before can never be a bad thing.
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