Servicing Mass Airflow Sensors

Servicing Mass Airflow Sensors

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 introduce brief, informative features which apply to both farm and automotive equipment. Most modern fuel injection systems employ a mass air flow sensor (MAF) that is located between the air filter assembly and the throttle-body. The MAF measures the air flow into the engine. This data is mainly used by the engine controller (ECU) to determine fuel injector pulse width. The MAF output is also combined in an algorithm with the outputs from the crankshaft and throttle position sensors to determine engine load. This influences both fuel and ignition timing. The MAF output will skew when coated with air-borne contaminants. This is how to easily restore its accuracy. Watch the...
Helpful tips you need to know about racing oils

Helpful tips you need to know about racing oils

Meet specialist Len Groom. By Freddie Heaney: Between a crankshaft journal and a rod bearing a film of oil resides in a space approximately the thickness of a human hair. In last year’s Pro Stock 500cu in V8 racing engines, crankshafts were spinning near 11,500rpm. In 2006 the V8 Cosworth F1 racing engine reached an astonishing 20,000rpm. Oil film operating in passages the thickness of a piece of paper prevented their parts from touching—as it is in most racing engines. Oil film, which is also referred to as an oil wedge, can be better understood if you consider a piston ring moving down a cylinder. When in motion, the oil begins to accumulate before the ring and forms a wedge-like shape. If severe, the ring can hop on top of the oil wedge, which breaches the seal between the ring and cylinder wall, causing blow-by of combustion gases. Though more difficult to visualize, the wedge effect is also present in the lubrication space between the crankshaft journal and the rod bearing. Its depth measures approximately 0.003in. Recently, at the annual MPMC conference where 100 racing parts manufacturers met the media, AMSOIL’s Len Groom was on hand, as intelligent a man as ever discussed synthetic racing oils. High quality racing oils, he explains, demand attention in several key areas in order to provide protection. Two of the most important areas lie within their film strength and resistance to viscosity loss under high pressure. “In fact,” says Groom, “when racers using our 15w-50 tell me they are running oil temperatures of 260F, I don’t get too concerned so long as the...
Gibtec Pistons: Guide to top ring placement from Pro Stock to Street

Gibtec Pistons: Guide to top ring placement from Pro Stock to Street

By Sam Logan: Denver, Colorado: Though piston maker Gibtec was established a mere two and a half years ago, the individuals behind it have specialized in Pro Stock billet piston development since 2003. Notably, during this period their skills contributed to approximately 80 percent of the championship-winning Pro Stock engines. Recently, Tom Prock, the general manager of Venolia Pistons for thirty years said, “Currently, Gibtec is making some of the best Pro Stock pistons I’ve seen.” On the subject of top ring placement, Gibtec Pistons’ head, Rob Giebas explains, “On forced induction and on nitrous applications, which encounter extreme shock loads, we move the top ring down from the piston crown to around 0.300in. However, the top ring could be moved down by as much as 0.450in, depending upon valve size and configuration, as well as the positioning of the valve pockets, the radial width of the top ring and the piston pin height, “Often it’s the intake valve pocket, which is always bigger than the exhaust that determines the position of the top ring. Compact rings and therefore small ring grooves provide more potential for variation in ring placement than larger ring grooves. For example, a naturally aspirated engine with a top ring of 0.6mm (0.0236in) axial depth and 0.110in radial width, which requires a ring groove width of 0.115in, offers more pocket clearance than the top ring spec of a nitrous engine, which might measure 0.043in axial depth and 0.173in radial width. “But on most small-block applications with a standard in-line valve pattern and a power adder, lowering the top ring to around 0.300in protects it and...
2015 Mustang Clutch Upgrade:

2015 Mustang Clutch Upgrade:

The Trouble with Supercharging. Adrian Gomez, an industrious 27-year old who manages Mak Performance, a Miami specialty shop established in 1995, bought a 2015 Mustang 5.0 and with fewer than 7,000 miles on the clock installed a ProCharger centrifugal supercharger. Power instantly jumped from 376 rwhp to 600 rwhp, an impressive sixty-percent improvement for the mathematicians out there. Doubtless it was tempting to ascertain just how long the original factory clutch might support the additional horsepower, which didn’t take long to find out. Read the full story of Gomez’s entrant in NMRA’s True Street Class 2015 season opener in Bradenton, FL, as published in Fastest Street Cars, November 2015...
FIRE and the poignant story of endurance road racer Stephen Cox

FIRE and the poignant story of endurance road racer Stephen Cox

He begins: It was the same sound you hear when you pour too much lighter fluid on the charcoal as you’re preparing a Fourth of July barbecue. A giant “whoosh” followed by a flash of flame. Except it was a thousand times louder. And it wasn’t charcoal that was on fire. It was me. Read the full article...