Street Performance Valvetrains
Street performance requires everyday driveability and reliability. A good street performance engine should have a broad torque curve, plenty of low end power and a reasonable amount of intake vacuum at idle, especially if the engine is backed with an automatic transmission. A street engine also has to be capable of lasting tens of thousands
What’s New with Oil Pumps, Pickups and Pans
The two greatest concerns from a lubrication standpoint are dry starts and loss of oil pressure while the engine is running. Dry starts are more of a worry in engines that have front-mounted oil pumps with relatively long pickup tubes, which includes such popular engines as the GM 3800 V6, Chrysler 3.5L V6, etc. as
A Closer Look at Today
The location of the wrist pins must match the stroke of the crankshaft, the length of the connecting rods and the deck height of the block. The compression ratio needs to be right for the application, and the configuration of the piston dome and valve reliefs have to be compatible with the combustion chambers in
Checking Fuel Pressure
Fuel pressure can be checked by attaching a gauge to the Schrader valvefitting on the fuel injector rail, or by teeing the gauge into the fuelsupply line if the fuel system lacks a test fitting. The operating pressure of the fuel system must be within the rangespecified by the vehicle manufacturer. The numbers will typically
Advanced Machine Tooling
The key to boosting productivity is to remove more metal in less time. However, faster cutting speeds and feeds require tooling inserts that can take the heat and abuse without dulling. To achieve these goals, tooling suppliers have come up with various cutter shapes, edge geometries and surface coatings that significantly improve tool performance and
Performance Valve Springs and Retainers
Old school thinking on these matters has usually been to increase spring pressure as much as possible by using the stiffest dual or triple springs that can be installed in the engine. But that kind of thinking is changing, thanks to improvements in spring technology. Stiffer springs are obviously needed if you are building a
Crankshafts and Bearings for Street Performance and Racing
Most engine builders have strong opinions and brand preferences when it comes to choosing a crankshaft and bearing combination for a performance engine application. Their preferences (and prejudices) are usually based on years of experience, both good and bad. Many subscribe to the philosophy that “if it isn’t broke, don’t fix it!” Consequently, if they
Performance Rocker Arm & Shaft Systems – Time-Tested Technology Provides Proven Performance
The SB Chevy ball and stud stamped steel rocker arms were a revolutionary departure from the shaft mounted rocker arm systems of that era because they allowed it to outrev its competitors. More revs means more airflow and more power. It wasn’t until 1962 that Ford finally dumped their old Y-block 312 rocker shaft engine
Uncovering the Culprits That Cause Head Gaskets to Fail
Most installers should know the first symptoms of a head gasket that is failing are usually a slowloss of coolant with no visible leaks, engine overheating and/or aCheck Engine light with cylinder misfire codes. The Onboard DiagnosticII (OBD II) system should detect any misfires that occur due to a lossof compression or spark plugs fouled
Gaskets, Seals, Sealants and Fasteners
The factors that typically cause a gasket to fail include age, heat, thermal expansion, abrasion, pressure, vibration, corrosion, material breakdown or poor design. Some gaskets go the distance and others do not. With head gaskets, problems like detonation and engine overheating can damage the gasket very quickly, causing an otherwise good gasket to crack or
Manifold Makeover – Increasing Engine Power
An intake manifold is more than the plumbing that connects thecarburetor or throttle body to the ports in the cylinder head. It is anintegral part of the induction system that has to match the airflowcharacteristics of the cylinder head and camshaft, as well as thedisplacement and rpm range of the engine. A well-designed manifold that
Chevy LT1 Engine and Reverse-Flow Technology
The Chevrolet LT1 5.7L V8 engine that was produced from 1992 to 1997 has some significant differences compared to the previous small block Chevy it replaced, and the third generation LS1 small block that later replaced it. The most obvious difference that distinguishes the LT1 from these other engines is the front-mounted Opti-Spark ignition system.