Tech Articles

  1. Know your SFI Hardness Expiry Dates!

    Know your SFI Hardness Expiry Dates!



    Anything using an SFI certified racing harness that runs under 200mph the rule is stated as:

    Valid for 5 years beyond the marked expiry date.

    In addition to the above, IHRA also give an extra year on top of the expiry date, taking into consideration the transit time etc. for harness to reach Australia and so on. This info has been handed down from Tim Nielsen – the head of IHRA tech.

    The maximum time a car under 200mph can use a set of belts in prefect circumstances is up to 8 years.


    Sedans, Dragsters, Altereds or Funny Cars with known performance of more than 200mph the rule is stated as:

    Valid ONLY until the marked expiry date.

    The maximum time a car over 200mph can use a set of belts in perfect circumstances is 2 years.

    The above a

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  2. Connect The Rods: I-Beam and H-Beam Connecting Rods Explained

    Connect The Rods: I-Beam and H-Beam Connecting Rods Explained

    Connecting rods are probably one of the easiest parts to understand in an engine - they have to make sure the pistons are moving up and down when the crankshaft tells them to. Where things start to get complicated is in examining the design of a connecting rod and determining the best option for your uses. There are two main choices when it comes to connecting rods: I-beam and H-beam, and in this article, we’re going to look at the difference between the two, along with the ideal engine application for each.

    I-beam and H-beam connecting rods are the most common types of rods you’ll find in high-performance applications because they are so versatile. Every engine is going to be different, so having the option to use a connecting rod that best matches what its intended goals are is very important. When you drill down further and look at each rod type, you'll see there are different design elements put into each that help optimize them for the build they’re used in.


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  3. Tips and Tricks For Filing Piston Rings

    Tips and Tricks For Filing Piston Rings

    The ring gap allows the expansion of the piston rings in the bore – due to engine heat – without butting the ends up against each other. If there isn't enough gap and the ring butts up against itself, it will distort the ring's shape, causing a leak path against the cylinder wall. If the ring gap is too large, it will allow an excess amount of blow-by through the gap, hurting that cylinder's performance.

    In fact, getting the correct ring gap is so crucial and the tolerances so precise, that end gap is measured in each ring's respective bore, to ensure the most accurate fit possible". Ring gap is one of the few things in the assembly process you have complete control over. The rest of the stuff that's done at the machine shop, you have to trust that they followed their procedures correctly. But if you're filing the rings, it's totally up to you to get them right," says Jay Meagher of Real Street Performance.

    Meagher has extensive experience in the automotive performance wor

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  4. Max-Lift BSR Shaft Rocker System from COMP Cams

    Max-Lift BSR Shaft Rocker System from COMP Cams

    The LS engine has been around for over 20 years now, and one thing that makes this engine such a popular choice with enthusiasts is its durability of the engine. It’s not uncommon to see these engines in stock form go well north of 200,000 miles on the odometer with regular maintenance before needing a rebuild. However, this can be a sticky situation if you’re pushing parts at stress levels that they were not designed to handle. It’s even worse if you are asking fatigued, worn out components to perform under these types of extreme conditions.

    One part on the LS series engine that is ill-famed for this type of problem is the rocker arm assembly. Overall the rockers are a fantastic design in their stock configuration, meaning on a stock engine these units are flawless. The problem is when they become worn the part has a problem with parts failure. It’s not the rocker arm itself that’s the problem, but the bearings in the rocker.

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  5. Let's Talk Engine Balancing With SCAT Crankshafts

    Let's Talk Engine Balancing With SCAT Crankshafts

    Crankshaft balancing is just that, a balancing act. When an engine is running, there are many different forces working against each other that need to work in harmony. Unfortunately, the balancing process is something that many enthusiasts rarely give a second thought. After all, that's why you spent extra for better parts and used an experienced engine builder instead of doing it yourself. But, the fact-of-the-matter is, if you're building an engine, having a properly balanced rotating assembly should be one of the most important things on your build list.

    You may be asking yourself why balancing a crankshaft is so important, or saying, of course balancing a crank is important. While it may be an obvious necessity, you might not understand the logic behind it, or know much about the balancing process itself. That's why we sat down with Tom Lieb, owner of SCAT Enterprises to get some insight about crankshaft balancing.

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  6. Edelbrock’s AVS2 Carburettor: Improving Response and Modulation

    Edelbrock’s AVS2 Carburettor: Improving Response and Modulation

    Finding a good compromise between having the response and throttle modulation of EFI with the price and versatility of a proper carburettor is challenging. Many want to keep their classic car authentic and avoid too much retrofitting of parts, so the appeal of the classic carburettor is usually the way to go. However, the prevalence of fuel-injected cars and the usability they offer, have some drivers - even those who are true to their past - wondering how to get the best of both worlds.

    Aware of this dilemma, the folks at Edelbrock asked, "How can we make an older car perform better, or even on-par with, a modern, fuel-injected car?" By modifying its tried-and-true Thunder Series carburettor with an intriguing piece of technology and retaining a simple and effective design, they've managed to produce a unique carburettor that provides remarkable drivability at an enviable price point. The new AVS2 carburettor nearly gives classic cars the kind of response available by EFI.

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  7. Checking and Setting Lifter Preload On the LS Engine

    Checking and Setting Lifter Preload On the LS Engine

    The LS is officially 20 years old now, yet it seems something new comes along almost daily with regard to performance-building these engines. On the traditional small-block Chevy, everyone learned at a tender age about setting lash, whether it was clearance on a solid lifter cam or preloading the lifters for a hydraulic cam. One of the “advantages” of the LS engine was that this process of setting lash became unnecessary. All LS engines were designed around the net lash system. But that turns out to have both positive and negative ramifications.

    Here’s how it works. As we all know, assembling the valvetrain for an LS engine is downright simple. With the cam and lifters in place, you slide in the pushrods, install the rockers and just bolt everything down. GM calls this the net lash system and when all the parts are stock, this system works very well. With a stock camshaft, lifter, and pushrod, the system is designed to depress the piston inside the lifter by roughly 0.050-inch. The t

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  8. Multi-Layer Steel Head gaskets

    Multi-Layer Steel Head gaskets

    Back when the automobile was in its infancy, things were very basic. You could rebuild your Model T with a flathead screwdriver, a couple wrenches, and a hammer. Today, technology has advanced to well beyond using simple tools and techniques to build our modern-day high-performance engines. And so it goes with head gaskets.

    High-winding small-blocks have been around for decades, and folks have been rebuilding them with the help of hand-held hones and scrapers from the beginning. When boosted street applications and nitrous began to creep into the performance world, it became obvious that as cylinder pressures went up, so did the need for better sealing of the cylinder head. This was achieved through better machining practices, improved fastener technology, and head gasket construction advancements.

    WHY MLS?

    Unlike the conventional, composite head gasket that uses a compressible substrate, MLS head gaskets are comprised of layers of embossed steel. Most MLS gaskets

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  9. Bearing Down

    Bearing Down

    Engine connecting rod and main bearing clearances have tightened in recent years for many racing applications, but there are caveats to this trend that engine builders need to acknowledge before bending traditional guidelines, especially when adapting those practices to street engines.

    "There are specific classes that really go towards the tighter oil clearance and thinner oil," says John Himley, engine builder at CNC Motorsports. "NASCAR and obviously Pro Stock, those guys nit-pick every tiny bit of horsepower they can out of that engine. That's where you see the tighter oil clearances being used." As with any high-end racing innovation, there's always the temptation to leverage that technology into sportsman classes and even to street vehicles.

    Plastigage, which has been available
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  10. Straight VS. Curved Fan Blades - Dispelling The Myth!

    Straight VS. Curved Fan Blades - Dispelling The Myth!

    As a result of the extensive research program, Davies Craig were able to ascertain that curved blades generated less noise, however, this was achieved at the expense of a significant loss in performance. The loss in performance is caused by the fact that curved blades stall at a lower static pressure than straight blades. If a fan moves less air, then simply, you can expect less noise. As shown in the performance curves below, Davies Craig Thermatic Fan outperforms a competitor’s curved blade product across the full pressure range:


    Noise Control: Most fan noise is generated from a blade passing a shroud strut. The noise level is higher when the whole length of a blade overlaps/passes a shroud strut and if all the blades pass all the struts of a shroud at the same time, noise is at its worst. Some m

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