You’ve got questions. We’ve got answers. We work with the Summit Racing tech department to tackle your automotive-related conundrums. This week, we’re talking about aluminum vs. steel roller rockers and rocker ratio in daily-driven, high-mileage fleet vehicles. Q: I have some questions concerning the use of aluminum roller rockers on a street engine with a stock-type
Q: Last year, I rebuilt my Ford 300 cubic-inch straight-six engine. The head was shaved .010”, the valve seats were reground, and the crank resized. The block was bored and cleaned also. The cam is a Competition Cams 260H grind with matched lifter, pushrods, and rocker arms. I also installed a new oil pump. The problem
Stamped steel rocker arms are common on budget crate engines, and many race classes require the use of stamped steel rockers. Because they do not feature a roller bearing pivot, stamped steel rocker arms generate more friction than performance-oriented roller rockers. That’s why proper break-in of stamped steel rockers is a must to maximize the lifespan
I race a Corvette in the vintage road race classes and I have had a rash of broken rocker arms. The rules prevent me from converting to roller rockers. Is there any way to prevent these rockers from breaking? The failures usually occur right in the middle of the rocker arm but the pushrod also
You’ve got questions. We’ve got the answers—the Summit Racing tech department tackles your automotive-related conundrums. This week, we’re examining how changing rocker arm ratio can help performance. T.Y. Thornton, IL Q: I am in the market for roller rockers. I own a 1966 SS Chevelle with a 396. The engine is bored .030 over, has 10.25:1
[portfolio_slideshow id=33751] When Chevy’s small block debuted in 1955, it didn’t take long for it to be regarded as a marvel of performance engineering, particularly when it came to its innovative valvetrain. Its lightweight, ball and stud, stamped rocker arm configuration allowed it to turn unheard of (for that era) engine speeds. It wasn’t long
Which rocker arm mounting system is best for your application? You’ll find out by watching this five-minute Summit Racing Quick Flicks video. In it, the Summit Racing crew will explain the difference between pedestal-mount rocker arms versus stud-mount rocker arms versus shaft-mount rocker arm systems. Click play and learn the difference!
Rocker arms are among the most stressed components in your engine—and the most important, too. They’re essentially tasked with transferring movement from the camshaft lobes to the valves, making them a key cog in your engine’s power production. So are you getting optimum performance from your rocker arms? According to the valvetrain experts at COMP Cams,
Good news motorsports competitors: Scorpion Racing Products offers shaft mount rocker arms. Shaft mount rockers are ideal for high-rpm applications, including circle track, dirt track, and drag racing engines, because they increase the rigidity and stability of the entire valvetrain, allowing more efficient power transfer from the camshaft to the valve. That makes them an effective way
Got questions? We’ve got the answers—the Summit Racing tech department tackles your automotive-related conundrums. This week, we’re covering rocker arm ratio and how it affects performance. S.B. • Atlanta, GA Q: I want to purchase a set of COMP Cams rocker arms for my 327-powered 1966 Chevy Nova. What is the difference between 1.5- and
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