C4 (84-96)

Which Rocker Arm Is Right For Me?

Assembling the perfect valve train combination is challenging for even the most seasoned engine builders because there are so many variables involved. One area of the valve train that many people have difficulty with is selecting the perfect rocker arms. With a wide variety of options available, it can be hard to know which rocker is the best choice for your application. “Which rocker is right for me?” is a question that the technicians at COMP Cams® are asked every day.

HighEnergyThe three most important factors in deciding which rocker arm is right for your application are valve spring diameter (pressure), RPM range and valve lift. As these factors increase, you will need a stronger rocker arm because the stability and durability of your valve train depend on perfectly matched components. COMP Cams® Engine Builder Technicians pay close attention to valve lift when deciding which rockers an application requires.

For stock replacement rockers in applications where valve lift has not been increased, COMP Cams® carries High Energy™ Steel Rocker Arms. Although they feature a long slot for higher than stock lift camshafts, these rockers are engineered to handle the demands of only very mildly upgraded valve trains. They are best suited for eliminating the noise and slop associated with worn stock rockers.

HighEnergyDieCastWhen more aggressive upgrades are made to the valve train, COMP® technicians recommend Magnum Rocker Arms. As the ultimate in street performance, these rockers are designed to last longer and help the serious performance enthusiast make even more power in any application with less than 350 pounds of open spring pressure.

ultragoldFor bulletproof reliability in any application using less than .550″ lift, COMP Cams® designed the new High Energy™ Die Cast Aluminum Roller Rocker Arms. Lightweight but durable, they are great for street and moderate race use. Featuring a die cast body constructed of lightweight aluminum, High Energy™ Die Cast Rockers utilize a needle bearing fulcrum and roller tip to decrease friction, thereby improving response and horsepower.

UltraProMagnum

When valve lift is between .550″ and .700″, it’s time to step up to an even more durable option. Ultra-Gold™ Roller Rocker Arms are made from a durable, lightweight aluminum alloy that is perfect for performance street and race engines. Precision-sorted trunion bearings, multiple oil passages and unrivaled ratio accuracy make Ultra-Gold™ rockers a premium aluminum rocker alternative that won’t break the bank.

XDAn even more durable alternative for high performance street and race applications is the Ultra Pro Magnum™ Rocker Arm. With a nearly unbreakable investment cast 8650 chromemoly body, these rockers use an arched, web-like design to increase strength and rigidity while reducing the moment of inertia. Built to handle up to 7,000 RPM, these unique rockers feature hardened roller tips, an oversized trunion and precision-sorted needle bearings that easily stand up to the abuse of the high load valve springs needed to handle increased lift and RPM.

shaftOnce lift goes above .700″, it’s time to step up again. Depending on RPM range, there are two options. If your high lift application stays below 7,500 RPM, the new Ultra Pro Magnum™ XD Rocker Arms are a great option. As the next design evolution in steel stud mount rocker technology, these extreme duty rockers are engineered specifically to handle the abuse of endurance, circle track and drag race applications. Made from ultra-durable 8650 Steel, these rockers use precision-sorted needle bearings and hardened roller tips to better distribute the load and reduce wear.

For applications turning more than 7,500 RPM, shaft mount rockers are the only recommended option. At this point, stud mounted rockers can no longer handle the extreme stress of your engine. COMP Cams® Shaft Mount Rocker Arms are constructed with durable aluminum rocker bodies attached to an ultra-rigid steel shaft. This system is more durable than stud mounted rockers and offers more stability than any other option on the market. Shaft mount rockers are also the most efficient way to transfer the power of the cam to the valve, making them perfect for radically prepared engines used in extreme racing applications.

You will never hurt your setup by using too big (strong) of a rocker. However, if you install a rocker meant to handle .550″ lift and 6,500 RPM in an application with .700″ lift turning 8,500 RPM for example, the rockers will not be able to handle the stress. A broken rocker arm can cause catastrophic engine damage. When in doubt, always go with the more durable option.

Originally Posted on CPG Nation Forum

Leave a Reply

  • (will not be published)

Leave a Reply

  • (will not be published)

Leave a Reply

  • (will not be published)

C4 (84-96)

Corvette Front Suspension Bushing Service

CC C4 Front Suspension Assembly (23) (Large)

By Chris Petris

Petris Enterprises

This is the second installment of a C4 suspension overview series.  To view the first article, click here.

Once all the original bushings are pushed out and the parts cleaned up bushing installation can begin.

There are a couple of things to be aware of before the first bushing is installed. The bushing bore must be clean and free of any snags of metal that may have been raised during the bushing removal process. Powder-coat or paint may also be in the bushing bore and should be removed to ease bushing installation. A raised area, whether it be paint, powder-coat or gnarled metal, causes the bushings inner sleeve to drag on the urethane, preventing smooth suspension movement. Unlike rubber bushings, urethane bushings should rotate smoothly throughout their suspension range of motion (one of the major reasons for the change to urethane). Too much clean-up of the bores is also a concern: the bushing should require effort to push in. You should be able to squeeze your hand and force the bushings in. Read more on “Corvette Front Suspension Bushing Service” »

Leave a Reply

  • (will not be published)

Body & Paint

C1 Corvette Windshield Post Problems and Fixes

Fix 2

Many of our 1956 to 1962 Corvette customers report a noticeable vibration or rocking at the base of their windshield.  More frequently than not,  the windshield mounting posts are snapped off.  Over the years, many of these posts have been subjected to questionable repair work, with shims, metal strips and welding being employed to varying degrees of success.  In the mid-1980′s, Corvette Central developed a permanent fix for this issue by designing a machining operation which allows the installation of steel tabs that are much more resilient than the originals.  Follow along as we describe the post variations, breaks, and solutions to windshield posts.

 

There are two variations of  windshield frame posts.  The 1956-58 version has a square notch relief for the door post with the upper window stop (Corvette Central part number 281009).  The 1959-62 version has an angled notch to allow for the later style door weatherstrip, which features a built-in stop and continues over the door post (Corvette Central part number 631010). Read more on “C1 Corvette Windshield Post Problems and Fixes” »

Leave a Reply

  • (will not be published)

C5 (97-04)

C5 Easy Z06 Front Grille Installation

 lead-in

Article & Photos courtesy of

www.AllAboutVettes.com magazine

 

If you want to really dress up the nose of your stock C5, then adding Z06-style front grilles is an easy and inexpensive way to do it. Corvette Central offers these after-market grilles for less than $100 a pair and installing them really couldn’t be easier. In fact, you don’t even need any tools, and the whole installation takes well under a half-hour, even if you’re a novice wrench. Here’s how to do it! Read more on “C5 Easy Z06 Front Grille Installation” »

Leave a Reply

  • (will not be published)

C4 (84-96)

C4 Suspension Overview

Suspension Lead Shot (1)

 

By Chris Petris

The fourth generation Corvette was a radical departure from General Motors early Corvette engineering.  It eliminated a perimeter frame to support the suspension and driveline.  Two front frame rails integrated into the first ever Corvette uni-body construction.  This made for an interesting driveline mounting installation.  The front suspension subframe was bolted to the frame rails while providing engine mounting points. The lack of a transmission crossmember added another twist, with a torque arm supporting the transmission and connecting it directly to the differential. The differential was mounted with two large bushings at the outer uni-body rear frame area. Rear vehicle weight was supported by a transverse spring that bolted directly to the differential rear cover. Read more on “C4 Suspension Overview” »

Leave a Reply

  • (will not be published)

C1-C6 (53-13)

Corvette Central Exhaust Systems Overview, Part I

011 (Medium)By Chris Petris

Exhaust systems have improved immensely from the early years when we would replace rear exhaust, mufflers and tail-pipes almost yearly on dual exhaust vehicles. Corvettes were no exception.  If they were driven infrequently with rich running engines, it destroyed the carbon steel exhaust tubing quickly. The rear of the exhaust system was most prone to damage as the moisture was blown backward and, in many cases, rarely dried up.  Most of us complained loudly when engine temperatures exceeded 180 degrees, saying that our engines would not last under the intense temperature pressure. That rise in temperature along with aluminized tubing just about put specialty exhaust shops out of business. Now we come to expect that an exhaust system will last the life of the vehicle, and in many cases, it will. Read more on “Corvette Central Exhaust Systems Overview, Part I” »

Leave a Reply

  • (will not be published)