Competition cylinder heads: How would you know if air-fuel movement is good or bad?

By Ben Mozart: The race engine requires a precise mixture of air and fuel, approximately 13.0:1 by weight ratio.   But the power it makes depends upon how well the mixture is emulsified and atomized. How well it is delivered through the intake manifold runners and cylinder head ports. And it’s ability to negotiate the intake valves and to swirl in the combustion chambers, which are an extension of the ports, and to occupy the cylinders.   For most of us, arranging and controlling the movements of the gases in the cylinder head ports are beyond our imaginings. Is the air-fuel mixture moving efficiently in the intake tracts or clinging, vexingly, to its sides? If so, how could it be reintroduced into the air stream? And further downstream, how is it negotiating the short turn, the five valve-angles in the throat, and does it demonstrate swirl as it moves into the combustion chamber? Read... read more

Restoring vintage engine blocks in five steps

By Freddie Heaney: Rare casting repairs: Five-step process in restoring vintage blocks to race-ready condition Each winter frozen coolant causes severe damage to hundreds of racing engine blocks in the northern hemisphere. Though troubling, its effects are usually even more concerning when frost damage strikes a rare, historic racing block. However conscientious you are the misfortune can happen, but if it does don’t be too dismayed for the problem is not insoluble. In Chatham, Virginia, there is a well-established engineering firm, Virkler & Bartlett, who possesses a knack for returning severely damaged engine blocks, often considered unserviceable, to race-ready condition. Their most common candidates are vintage blocks like this Maserati example damaged by frozen coolant. Here is their five-step repair process: 1. Inspect to determine mechanical and dimensional condition.  This includes examining deck angles, deck squareness to main bore centerline, main bore alignment and other critical dimensions. 2. Find crack locations using Magnaflux or dye penetrants and determine repair strategy.  Welding repairs work well in some applications, but V&B prefer steel or aluminum pins with special barbed threads that pull cracks together for most castings.  Pin repairs have the advantage of not distorting the casting. As a result, ridged fixtures are unnecessary and re-machine work is kept to a minimum.  Pins are installed with anaerobic sealants to lock them in place and prevent leaks.  Sometimes it is necessary to machine away a portion of the damaged metal and replace it with an insert that is pinned in place.  Pins are stronger than the casting and V&B has successfully pinned cracked main bore housings on highly stressed race engines. 3.... read more

How to make a Street Stock racing clutch survive

By Freddie Heaney, Photos by Moore Good Ink: Racers frequently face the inconvenient fact that some clutch-flywheel assemblies are so light they fail prematurely, often during the taxing process of getting the car into the trailer. Curiously, most professional clutch makers agree that you quickly reach a point where the ultra light clutch unit has no advantage at all and instead its arch attribute, lightness, undermines the process bringing decreased durability. A stroke of marketing brilliance some might say! Racer purchases ultra light clutch, racer quickly destroys ultra light clutch, racer purchases successive ultra light clutch. You may think racers would resent these dubious practices, but there is no evidence to suggest they do. In all likelihood if you added a little strength to the unit you would probably gain 50 percent greater clutch longevity without any perceptible loss in power. In either case, to reduce these often unnecessary costs here are a few tips intended to prolong the life of the racing clutch. Persistent clutch killer Probably the most persistent clutch killer strikes when the racer is on his own. Without crew members or a winch to assist, he is often obliged to load the car by himself. So he slips his thin, thin lightweight clutch a couple of times and as it colors dark blue its end is nigh. To minimize clutch damage during loading and unloading without crew members it pays to use a winch. Of course, the amount of wear on all racing clutches is largely determined by how much the slippage is provoked during takeoff.  Excessive slippage will cause premature warping, especially in lighter... read more

Three reasons why power steering systems fail

By Archie Bosman, Photography by Moore Good Ink: You might be surprised to learn that one of the three principal reasons for power steering pump failures is forgetfulness. To run a hydraulic power steering pump safely during a dyno run, simply form an oiling loop. Connect the power steering reservoir to the pump’s inlet port and the pump’s outlet port back to the reservoir’s return port. Then fill the reservoir with fluid, about 1in above the return port. “With the best will in the world though,” says Ken Roper, head of KRC Power Steering, “it’s easier to remember to put oil in the engine than it is in the power steering reservoir, and the consequences of the oversight can be severe.” As most power steering pumps rotate at engine speeds, the internals of one without oil will soon turn blue and invariably weld themselves together. The same transgression is common when breaking-in a new camshaft or similar. Although break-in speeds are usually significantly lower, often around 2,500 to 3,000rpm, a dry power-steering pump may survive the torture, though it usually suffers some adverse consequences. The second reason for power steering pump failure occurs when the oil hoses have not been thoroughly cleaned in the aftermath of a previous pump wreckage. Avoid this demoralizing calamity by ensuring all related hydraulic hoses are flushed clean. If not, the new replacement pump will be soon sabotaged by shrapnel from the previous failure. The third condition that causes power steering pump failure is improper bleeding or worse, disregarding the bleeding procedure completely. In common with a dry-sump lubrication system, expelling air bubbles from... read more

Emperor of Engine Masters Challenge: Kaase claims purse

By Ben Mozart, Photography by Moore Good Ink: It takes uncommon pluck to enter an engine performance contest—what happens if you finish 39th? Developing racing engines is a serious business. Your reputation, your record of success and your credentials are constantly on the line. Despite the obvious reservations, however, entering the annual Engine Masters Challenge is generally beneficial for all competitors. Some engine builders bring along unusual or rare engines, knowing the media will fill pages with their editorial in the aftermath of the competition. Others build engines not to compete for the best average power output at all, but instead with peak power in mind, knowing their achievement will also receive recognition. Importantly, most if not all engines will be photographed and featured in the magazine articles during the following twelve months. So even if the event turns out not to be the shining hour you’d hoped, entrants gain much more recognition for their engine shop than by staying at home. For the front runners in the dyno room though, tension is usually high and interestingly the contenders deal with stress in very different ways. Some like Accufab’s John Mihovetz remain quiet; deep in thought he scarcely issues a word. On the other hand, the face of Chris Thomas, Kaase’s right hand man, is profoundly focused. Kaase himself seems to play it like a sport—with a lighthearted gusto, but plays to win. Lima, OH: The 2013 Engine Masters Challenge, the eleventh in a series first started in 2002, was won by Jon Kaase Racing Engines. His fifth victory in the Challenge, he collected a purse just under $70,000. When the reward amounts to more than any Pro Stock race... read more

Power steering: Three common shortcomings, two helpful tips

By Freddie Heaney –   Photography by Moore Good Ink: In the early 1990’s, before power steering became prevalent in F1 racing cars, Michael Schumacher, statistically the greatest driver the sport has seen, remarked, “You have to carefully judge the amount of steering angle required as you turn into a high-speed corner, as it is very difficult to correct if your assessment is wrong.” His comment came as a result of increased steering caster angles, functioning at 9-12 degrees that made the steering heavy. The problem was further exacerbated by increasingly high aerodynamic down forces. Over twenty years later, power steering still has its abiding problems: slow response; unnecessary parasitic losses; and premature pulley failures are three of the most common. But first, commit to memory these two valuable tips. 1) Should a power steering pump fail, ensure the lines are subsequently flushed clean. If not, the new replacement pump will be immediately sabotaged by shrapnel remaining in the system from the original failure. 2) Power steering hoses, in common with all high pressure hoses, are typically made from layers of rubber, steel braiding and cloth. If you use an abrasive cut-off wheel on power steering hoses, it will cause the rubber to melt. To complicate matters further, sand particles from the abrasive wheel together with metal particles from the braided steel will adhere to the melted rubber. Later, when the system is assembled and operating at normal temperature, the globules of rubber with sand and metal particles glued to the inside of the hose will melt. Soon after, they’ll be delivered to the pump, which they’ll destroy, usually in... read more

Arch rule of carburetor tuning: Ignition first

By Sam Logan. Photographs by Moore Good Ink:  Download text and hi-res images here. The cardinal rule of carburetor tuning is Ignition First. Once the static ignition setting and the ignition advancing mechanism in the distributor is correct, the air-fuel mixture can be tuned for full power and fuel efficiency. High-performance carburetors, intake manifolds, cylinder heads, camshafts, and other tuning components are all dependent upon correct ignition timing; if the spark is not delivered at the proper time to the combustion chamber, the quest for optimum power or economy is impaired. But the distributor has vanished! Tuning contemporary hot rods involves electronics and computer software. Sensors abound. They sense Manifold Absolute Pressure, Mass Air Flow, crankshaft position and so on. They report to an ECU (engine control unit) that constantly ascertains all the variables and tells each spark plug when to fire. Where there was once a distributor, multiple coils now exist, often one on each spark plug. Still, what a joy it is to understand the psychology of the hot rodder who lusts for a carburetor and a distributor. And, ironically, older vehicles can be simpler to tune. They require no fancy equipment or computer knowledge, often just a timing light, a screwdriver and a few wrenches. Brief background on points-and-coil ignition Before sophisticated electronic management systems arrived, we used the points-and-coil ignition system that first appeared on the 1910 Cadillac. A distributor was employed to determine when each spark plug should fire. An engine-driven mechanical cam in the distributor rotating at camshaft speed operated a set of breaker points. The points switched electrical current to the coil which converted it... read more

Kaase’s P-38 cylinder heads: Greatest Windsor news since 1962

By Sam Logan:   The Chevy faithful like to tell us that their small-block engine is cheaper and easier to build than the Ford counterpart—but it’s a myth. First, the cost of aftermarket high-performance and competition parts is similar whether they are Ford or Chevrolet. And with regard to the simpler engine build, the small-block Ford is probably the all-time easiest engine to build. In street form, the head bolts—of which there are only 10—don’t penetrate the water jackets, unlike the SBC, thus their threads don’t need sealer applied. In addition the Ford engines don’t have mirror-image pistons and ports, so they don’t have a right and a left piston—all the pistons are the same. Further, the Ford distributor is clamped directly to the block, unlike the SBC distributor which is located by the intake manifold. Therefore the height of the SBC distributor can alter if the heads or the intake manifold has been milled. Washers are often used to correctly position the Chevrolet’s distributor, allowing its gear to mesh correctly with the camshaft. On the Ford you can remove the intake manifold without touching the distributor. Moreover the Ford distributor is located at the front of the engine, thus more accessible for setting the timing compared with the rear mounted Chevy unit. Lastly, the SBC uses a cam thrust plate—a little bearing that pushes against the timing cover—that prevents the cam moving fore and aft when using roller tappets. When Kaase first conceived the P-38 cylinder heads for Ford’s small-block Windsor engines, they were created with high performance in mind. They were also obliged to be user-friendly. Porting to... read more

Induction: How Keith Wilson made bad air flow good

By Ben Mozart. Pictures by Moore Good Ink: It’s not inconceivable that the induction system of a four-cycle engine just might be its most complicated component. Keith Wilson made a career of manipulating air flow in racing engines. At 17-years old he was employed at a Florida company called Air Speed Engineering. There he spent ten years porting cylinder heads and intake manifolds. Then in 1985 he branched out on his own and formed Wilson Manifolds. Quickly he seized the opportunity to not only rework cast aluminum intake manifolds but also to explore his theories on cylinder filling in conjunction with induction designs constructed of aluminum sheet metal. As you might expect, these are the fundamentals around which Wilson Manifolds has evolved. Recently we sat down with Keith Wilson to hear his thoughts. He began by explaining the most basic: the carburetor spacer. Wilson maintains, “Good spacers are the least expensive form of tuning hardware known to the racer.” A spacer attaches to the intake manifold between the carburetor and the mounting pad, or more precisely the top of the manifold plenum. The charge (the fuel and air mixed together) exits the throttle body or the carburetor and flows through the spacer into the manifold plenum. From there it’s distributed to the individual runners and onward to the ports of the cylinder head. For the best engine performance, the charge distribution in the manifold needs to be even so that each cylinder not only receives the same mixture strength but also uniform volumetric efficiency. If the distribution is uniform but the emulsification of the fuel (the mixing with air) is uneven, performance... read more