New lightweight cast-iron racing block emerges

New lightweight cast-iron racing block emerges

SBC power up to 750hp. By Bertie S. Brown:   Does a heavier engine block harm the prospects of a race car? If you sought the support of savvy oval track engine builders about a 750hp block that has every admirable feature except one—it weighs 30lbs more than the lightest available—they’d state their position in two words: Too heavy! As a rule, oval track race cars require a greater proportion of their weight at the rear, usually 55 to 60 percent of the car’s total mass. It follows, therefore, that if the front of the car is carrying an additional 30lbs an equal amount or more is required at the rear. This affliction introduces a substantial handling disadvantage, particularly for those cars competing in classes restricted by a minimum weight ruling. Though mindful of the drag racer who wants to build a lightweight small-block Chevrolet, World Product’s new Motown Pro Lightweight was devised principally to meet the needs of the oval track racer. In this regard it marks a new chapter in engine development for both manufacturer and competitor. Significantly, the first tangible insight of its potential struck immediately when WISSOTA star Cory Crapser’s prowess won first time out in a Modified race at Cedar Lake Speedway. The engine was built by Tim Ludwigson of Tim’s Automotive Machine in Bloomer, Wisconsin. Weighing 178lbs, the Motown Pro Lightweight is about 18lbs heavier than GM’s standard 350 Chevrolet block and about 8lbs more than their popular 400 casting. The 350, which is produced in Grade 30 cast iron and giving a yield strength of 32,000psi, uses cylinder walls exposed to 360-degree...
Competition piston rings and what the OEMs taught us

Competition piston rings and what the OEMs taught us

By Sam Logan:   In our racing world we tend to think of ourselves as the elite corps. But in pistons and more particularly piston ring design, it is not our racing brains that are the driving force but those of the Original Equipment Manufacturers. It would be a glum glimpse of the US racing industry if nothing changed. But it has and nothing could be more illustrative of change than ring development. In fact, if we’re not careful our tow vehicles will operate with 1 x 1 x 2mm ring packs before our race cars. And it’s not just skinny rings that’s been pioneered by the OEMs, the enduring cast iron top and second rings have been replaced by stronger and lighter steel types. Furthermore, thermal face coatings are being applied to top rings by high-velocity oxygen-fueled spray guns at supersonic speed. The force of the collision causes the face coating to become embedded in the rings. What are they seeking? Well, with regard to the thermal face coating, they are pursuing bond-integrity. Second, they are also constantly looking for improvements in overall strength and toughness of the top ring. And third they seek to lower the ring’s coefficient of friction; that is the ratio between the force necessary to move one surface over another and the pressure between the two surfaces. The high-velocity oxygen-fuel technique that applies the thermal face coatings allows the OEMs to run high-tech rings in their latest turbo applications. These are subjected to countless detonation incidents. Tod Richards, a ring specialist at MAHLE, a racer and a race engine builder marveled, “The rings...
Tough NMRA classes beg the question: What is a good clutch?

Tough NMRA classes beg the question: What is a good clutch?

By Fergus Ogilvy:   There are several schools of thought on the question of what constitutes a good clutch. But first there are two separate strands to this narrative that need to be addressed: street or track. It’s key to distinguish whether the car will be used mostly for high-performance street-travel or for track use and its purpose needs to be decided. In either case the clutch has to transmit the car’s horsepower and torque and a stock clutch assembly will flounder in thermal shock and abuse, even in a slightly modified car.   Let’s focus our attention for a moment on selecting a good clutch for a high-performance street car that visits the drag strip occasionally. In this pursuit, the first consideration is usually vehicle weight. Accurate information about the vehicle’s poundage not only guides to the proper selection of an adequate clutch but also has relevance in the selection of the most effective flywheel. Another necessary statistic is the amount of power being transmitted through the clutch. And third, let’s not overlook the gearing. Lastly, pay attention to the size and type of tire conveying the rotational energy to the road or track.   Flywheels and a simple gearing formula Lighter flywheels provoke engine speeds to accelerate and decelerate quicker while the opposite is true of heavier flywheels. Heavier street cars usually benefit from a heavier flywheel, which maintains its advantageous momentum—it inhibits engine speeds from descending too quickly. However, shedding 10 to 15lbs of mass from the rotating assembly of a properly geared vehicle has a pronounced effect on its responses. Hence, lightweight, high-revving race cars...
World’s most powerful Y-block

World’s most powerful Y-block

“To the best of my knowledge,” said Jon Kaase, “prior to last year’s Engine Masters Challenge, the most powerful naturally aspirated Ford Y-block engine produced around 600 hp.” This enduring feat, however, was substantially exceeded on January 17, 2016, when Kaase’s efforts raised the peak power record to 709 hp @ 6,300 RPM and 748-lb.ft. of torque at 5,400 RPM. Read the full story compliments of Hemmings Muscle Machine’s July 2016...
Competition Connecting Rods

Competition Connecting Rods

24 things you need to know. By Sam Logan: Nothing undermines the legitimacy of a connecting rod maker more than a deficient batch of rods. They agonize constantly about heat treatments, high revs, heavy pistons, heavy pins, the number of race laps between rebuilds, but probably most of all whether or not nitrous is being sprayed. It’s a complicated business determining minimum weight while yielding maximum strength, enough to withstand the abuse sustained by the average race motor. Read the full story as published in Engine Professional...