by admin | Jul 29, 2015 | News, Top Stories |
By Sam Logan Photography by Moore Good Ink & V&B Engines Often Vintage racing engines exhibit excessive spark scatter caused by torsional vibration in the distributor drive system. To correct it Virkler & Bartlett adds a miniature flywheel to the system. They mold a series of rubber couplers with a range of Shore A hardness, which allows them to tune the system. Note rubber coupler glued within steel ring. How to get the best from a Vintage engine ignition system Chatham, Virginia:Vintage racers are often forced to live with points-and-coil ignition. But the most successful know the shortcomings of the ignition system and have it corrected. For the past forty years or so electronic ignition has been the standard, but most Historic race cars produced before the 1970s are equipped with something other. Unfailingly, coil-and-points ignition systems work best when optimized mechanically and electrically. But how is it achieved? Vintage racers seem to run a little faster each year, and as compression ratios and engine speeds creep up, deficiencies in points-and-coil ignition systems can precipitate the perfect storm of performance problems. Background Just over one hundred years ago, the brilliant engineer Charles Kettering invented the ubiquitous battery-powered “points-and-coil” ignition system that first appeared on the 1910 Cadillac. Remarkably, it was used in most cars until the mid-1970s. An engine-driven mechanical cam operated a set of breaker points, switching electrical current to the coil which converted it to high voltage required to fire spark plugs. A rotor within the distributor routed high-voltage impulses to the correct spark plug. The condenser had the dual function of extending the...
by moore1 | Jul 15, 2015 | MGI News Briefs |
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by moore1 | Jul 9, 2015 | News |
By Ben Mozart: Bowling Green, KY: Holley’s new patent-pending HydraMat fuel system is unique. It can deliver the last droplet of fuel in a tank or cell through the introduction of two clever principles: fluid wicking and surface tension. The term surface tension refers to sealing the tiny pores of the HydraMat media with fuel in the same way water clings to the fine mesh of a screen door. This has the rewarding effect of accumulating and sequestering fuel in the reservoir, delaying any vapor intrusion until the fuel supply is exhausted. Wicking symbolizes capillary action, which promotes liquid flow in narrow spaces and small diameter tubes. Capillary action is impressive because the flow is unassisted; it even defies gravity. As a result it invests the HydraMat with the ability to draw fuel from any area that has contact with it. Designed to operate in stock fuel tanks or racing cells, HydraMat’s shapes and sizes vary from a single section to cross sections and from square- to rectangular-shaped mats. Obviously, its attributes are indispensible during low-fuel conditions and on inclines where fuel runs away from the pick-up. But also it is highly effective under hard cornering, acceleration and braking. Some years ago I remember the mood of an indignant racer robbed of a Daytona victory. When the car raced along the 31-degree banking the fuel supply was satisfactory but on the flat section as it approached the last corner on the last lap it died! Source: Holley Performance Products 1-866-464-6553 HydraMat info click...
by moore1 | Jul 7, 2015 | Clutches, News |
Archie Bosman: As you sit quietly reading these lines, a whirl of activity is taking place in the bell housing. Let’s imagine for a moment the clutch assembly could express its greatest anxiety, what might it be? Might it be the use of excessively harsh friction compounds on the clutch discs or inadequate clamping forces causing slippage? Perhaps, extremely sticky tires are the main threat? Enumerating the cardinal sins: Apparently ‘no’, according to Ram Clutches none of these represent its greatest fear…its principal concern would be mass—that is the weight of the car carried into motion by the clutch. A heavier vehicle imposes a greater load on the clutch system than a lighter one. Further perils include poor gearing, improper flywheel mass and, indeed, sticky tires. A high performance car with an inadvisably high rear-gear requires more manipulating of the clutch pedal to prevent it from slipping than one with a lower gear. A higher first gear (lower numerically) is also problematic as it, too, imposes a greater load on takeoff and, furthermore, can be detrimental to the clutch even when it is fully engaged. Linked closely with high first-gear ratio deficiencies is the flywheel. The purpose of the flywheel is to create inertia, which refers to preserving a state of uniform motion that helps to get the car moving. A heavier flywheel generates more inertia and thus makes it easier to accelerate from standstill. It also reduces clutch slipping on takeoff. On the other hand, with a properly geared vehicle, that is one with an appropriately low gear that invites the use of a light flywheel, it will...
by moore1 | Jul 5, 2015 | News |
Ray Bohacz is a journalist in the automotive field and author of CarTech’s book “How to tune and win with Demon Carburetion”. He is also a monthly contributor to Hemming’s Muscle Machines magazine. Additionally, Ray writes short articles for the agriculture industry and is featured in a series of videos as the SF (Successful Farming) Engine Man. His videos are short, informative features which apply to both farm and automotive equipment. Here Ray shows you how to find a vacuum leak in a gasoline...
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