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Slipstream - October 2017

The monthly newsletter of the Maverick Region of the Porsche Club of America

Lube for Thought:

Lube for Thought: Lubrication, Part 1 By Mike Mahoney, Region Concours Chair Photos courtesy of the Author his is the first in a series T of articles on lubrication and how important it is to you and your car. We all know we need engine oil. But do you know its various functions? Do you know what types of additives are needed in engine oil and why? Do you know why you need to change your engine oil? What’s the difference between engine oil and gear oil? Grease, what is it? We will tackle these questions and more. I’ll begin with the basics of engine oil and then move on to gear oil and grease. You’ve probably heard the phrase “oil is the life blood of your engine.” While that happens to be true, it’s especially true in Porsches. One reason is the high-revving engines. And in air-cooled engines, it’s the high heat. In an air-cooled engine, about 8% of the heat generated by the engine finds its way into the oil. As all of us air-cooled nuts know, those engines get pretty hot! And I know 8% may not seem like a lot, but every degree in temperature equates to increased oxidation of the oil or thickening of the oil. For every 10-degree increase of the oil, the rate of oxidation doubles. 18 October Dirt is another enemy of oil. Oil deteriorates from the various contaminants that find their way in to the crankcase. Dirt from dirty air filters, cracks in the air system, as well as from limitations in air filter design and from crankcase ventilation systems. The oil also picks up metal particles from normal wear of engine parts, and if not removed, can cause premature wear as well. There are various additives in engine oil. Additives for neutralizing acids, anti-wear additives, dispersants, etc. Over time, the oils additives are depleted and are unable to do their job of neutralizing, suspending, dispersing, and solubilizing contaminants. Oxidation of the oil itself happens over time for the same reasons, and is accelerated by heat. In addition, the combustion process is dirty business, as a result of the thousands of explosions going on inside the combustion chamber in each of the cylinders. One of the byproducts of combustion is water. Most of the water that comes from the combustion process is in the form of steam or water vapor and goes out the exhaust. But at low temperatures and short trips, the water condenses and sticks to cylinder walls, ultimately making its way into the crankcase and the oil. This can lead to the formation of sludge and corrosion of metal parts. There are also acidic gases produced by the combustion process. They too adhere to the cylinder walls at low temperatures and end up in the oil. They combine with the water and become corrosive. Additives assist in in preventing damage from these factors but you have to regularly change your oil. It’s the only way to get rid of the contaminants and acids that are suspended in the oil. The filter will not remove everything, and with the additives being depleted, it won’t be able to continue to do its job. Well, as you can see, your oil is working hard for you. So do your part. If your engine oil could talk, it would be doing its best Jerry Maguire: “help me help you!” That covers the basics of engine oil. Next time we will talk about viscosity, synthetics, and gear oil. Did you know that viscosity is the single most important factor when selecting any lubricant? So what is viscosity? See you next time. Mike Mahoney spent over 35 years with ExxonMobil where he worked in lubricant manufacturing and sales. He retired 2 years ago and is a 1 year PCA Maverick Region member.

Porsche 968: End of the Transaxle Era By Rob Adams Photos courtesy of the Author t the end of the successful run of the A 924/944 series, the marketing types at Porsche needed something to stimulate sales until development of their newest entry level offering, the 986 Boxster, was ready for production. Porsche redesigned the 944 S2 to such an extent that marketing decided to brand the new design the 968. Porsche’s 968 production was moved to Zuffenhausen, where it was manufactured alongside the 911. Styling cues (courtesy of Harm Lagaay) were borrowed from the 928, 959, and the 993 (1994 and later) but to most, they were still rooted in the 944. However, the 968 brought significant innovation in the Porsche evolution: the first Porsche to use VarioCam timing and the first Porsche 6-speed manual. The naturally aspirated 3.0 liter inline, 16-valve four was the third largest production engine of its type at the time and incorporated twin balance shafts to counteract the vibration created by relatively large cylinders (4.09 in. bore x 3.46 in. stroke) and a compression ratio of 11.0 to 1. The engine was rated at 236 horsepower at 6200 rpm, and 225 lb-ft of torque. The 968, with its near 50/50 weight distribution resulting from the front engine/rear transaxle layout, is a delight to drive. It is very nimble and can be tail-happy with a little coaxing, yet forgiving and easily brought back under control. Gathering 60 mph takes about six seconds for the manual, and top speed is around 156 mph. Owners had the option of upgrading the suspension to the M030 sport version as well as a limited slip differential. The 968 shown here has the standard suspension, but the rare option of the lsd. The interior was clearly a carryover from the 944, but during the 968 years, Porsche offered a high level of options allowing consumers to custom design their car. The 968 shown is an example of the “deviated carpet color” option resulting in a striking two-tone interior. Unfortunately, the 968 came at a difficult time for Porsche financially and Japan was quickly catching up with similar offerings at a much lower price. Porsche countered with variants including the Club Sport and Sport, which offered the same power but lighter, stripped-down platforms. There were a few exotic and ultra-rare 968 production cars, the Turbo S and Turbo RS, which are now highly collectible. Over the 968’s production run of five years, a total of 12,776 were produced worldwide, with only 2,234 coupes and 2,008 cabriolets making it to the US. These cars are quickly gaining value and are considered a very collectible Porsche for the future. 19

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