Who would have thunk this 50 years ago? Most of you who have been around that long know what this writer is talking about. Back in the day – the best you could hope for was those hard to find factory castings – “fuelie” heads, PowerPaks, and a host of other high-performance Bow-Tie heads that were not only hard to come by, but pricy, made of iron and short on potential when you consider what we have now.
And, if you wanted fancy port and bowl work, you’d have to get out your checkbook and wait weeks for results. We’ve come a long way in the past 20 years with a treasure trove of great aftermarket cylinder heads for small- and big-block Chevys alike.
Few companies understand this better than Edelbrock. Edelbrock has been at the leading edge of cylinder head development, design, and manufacturing for the better part of the past two decades offering consumers great bang for the buck in an affordable cylinder head. Cylinder heads are a natural extension of what Edelbrock has been doing since World War II – high-performance induction systems.
E-Street From Edelbrock
Edelbrock’s Performer Series cylinder heads and induction systems have enjoyed great success making it possible for the masses to enjoy high-performance driving at affordable prices. Sounds like a sales pitch doesn’t it? It isn’t. Having been in this business for 30 years, I’ve witnessed the great evolution of aftermarket parts and services first hand.
Never has it been better when it comes to cylinder heads and induction systems. Edelbrock has led the charge for untold thousands of enthusiasts. Some say the pride is back, with jobs coming back to America.
However, at Edelbrock, they never left. Edelbrock’s new E-Street A356 aluminum cylinder heads for Chevrolet small- and big-blocks are developed, cast, and machined right here in the Los Angeles area and roll off delivery trucks worldwide with a message – affordable performance spoken here that’s also made in America. The all-new E-Street head is a completely new approach to Edelbrock deck topper castings because it offers entry level performance in the 300-400-horse arena. It is a great street head that’s good to go for your Bow-Tie project.
First question we had for Edelbrock with E-Street is – how do you make a great street cylinder head even better? Edelbrock responded with E-CNC cylinder heads for small- and big-block Chevy. E-CNC is clean-shaven CNC-machined port and chamber work without the high cost of a custom port job. What this means for you is optimum airflow, horsepower, and torque. The E-CNC head stays with the stock 23-degree valve angle. It also engineered to accept pre-1986 intake manifolds.
Bare, the E-CNC 185 head retails for $738.99 at Summit Racing Equipment. At the other end of the scale at Summit is the complete E-CNC 355 big-block rectangular port head for $1629.95.
Spotlight On Greatness – Rick Roberts
“My design philosophy for heads starts with selection of the intake valve size. I first find the peak air flow at 100% volumetric efficiency (air consumption at peak power rpm). Using this volume flow rate, I calculate the cross-sectional area that will produce an average air velocity of 300 ft/sec during the 180 degrees from TDC to BDC during the intake stroke,” Dr. Rick Roberts, Director of Engineering at Edelbrock briefed us, “From the cross-sectional area I calculate the diameter of a circle that has that area and that’s my intake valve diameter. I will design the port with a throat of about 88% to 90% of the valve diameter and if possible try to keep a constant cross-section area throughout the port. All of that will pretty much dictate the volume of the port for a given engine platform.”
Rick and the engineering staff at Edelbrock has the latest technology available, which allows them to conceive the most effective port design possible. Roberts has his roots in Northeastern Ohio. From there, he attended the Illinois Institute of Technology where he received his degree in Mechanical Engineering.
E-CNC Big-Block Chevy Oval Port
- RH Intake Flow at .600-inch Lift: 332cfm
- LH Intake Flow at .600-inch Lift: 335cfm
- Exhaust Flow at .600-inch Lift: 232cfm
- Chamber Size: 112cc
- RH Intake Runner Volume: 325cc
- LH Intake Runner Volume: 308cc
- Exhaust Runner Volume: 133cc
- Intake Valve Diameter: 2.25-inch
- Exhaust Valve Diameter: 1.88-inch
- Deck Thickness: 9/16-inch
- Valve Spring Diameter: 1.55-inch
- Maximum Valve Spring Lift: 0.700-inch
- Rocker Stud Diameter: 7/16-inch
- Push Rod Diameter: 3/8-inch
- Spark Plug: 14mm with 3/4-inch reach (Champion RC12YC)