Best Rocker Arm Geometry

Category: rocker arm geometry 👁 245 👍 10 ★★★★☆4.3

Photograph of the failed rocker arm shaft. One of the major causes of component failure is faulty manufacturing. This includes all effects that increase brittleness or those inducing cracks and or stress raisers in the component.

Anyway, do rocker arms add horsepower?

For engine applications that demand a step up, replacing the stock stamped or cast steel rockers with aluminum roller rockers will typically produce a gain of 10 to 15 hp with the same lift ratio, and even more of a power gain with a higher lift ratio.

However, how do I choose my rocker arm ratio? The ratio of a rocker arm is determined by the distance between the centerline of the pivot point to the centerline of the roller tip (or area of contact with the valve stem), divided by the centerline of the pushrod to the centerline of the pivot point (X).

On another note, how do I know if my push rods are too short?

If the witness mark is too close to the intake side of the valve-stem tip, the pushrod is too short. If the witness mark is in the middle or toward the exhaust side of the valve-stem tip, then the pushrod is too long.

What is the purpose of rocker arm?

A rocker arm (in the context of an internal combustion engine of automotive, marine, motorcycle and reciprocating aviation types) is an oscillating lever that conveys radial movement from the cam lobe into linear movement at the poppet valve to open it.

BESTSELLER NO. 1 in 2021

Ford Racing M6529A302 Rocker Arm Shim Kit

Ford Racing M6529A302 Rocker Arm Shim Kit
  • Use with bolt-on roller rocker arms
  • Package Dimensions: 20.7 H x 5.1 L x 6.2 W (centimetres)
  • Package Weight: 0.053 kilograms
  • Country of Origin : China
BESTSELLER NO. 2 in 2021

COMP Cams Trunnion Upgrade Kit w/Installation Tool for GM LS1/LS2/LS3/LS6 Rocker Arms

COMP Cams Trunnion Upgrade Kit w/Installation Tool for GM LS1/LS2/LS3/LS6 Rocker Arms
  • Trunnion install tool compatible with all stock LS rocker geometry
  • Can be used with an arbour press, bench vies and c-clamp
  • Trunnion upgrade in less than 30 minutes
  • Part number: 13702TL-KIT
BESTSELLER NO. 3 in 2021

Harland Sharp S70016KE BBM Rocker Arm Shaft (1.6Ratiowith Edelbrock RPM Hd)

Harland Sharp S70016KE BBM Rocker Arm Shaft (1.6Ratiowith Edelbrock RPM Hd)
  • Shaft Mount
  • Aluminum
  • Sold as a kit
BESTSELLER NO. 4 in 2021

MID-LIFT Advanced Rocker Arm Tech, by Jim Miller: Shattering the Myths of Rocker Arm Geometry, Cam Selection & Cylinder Head Integration

MID-LIFT Advanced Rocker Arm Tech, by Jim Miller: Shattering the Myths of Rocker Arm Geometry, Cam Selection & Cylinder Head Integration
BESTSELLER NO. 5 in 2021

Elgin Rocker Arm Kits compatible with 1974-1979 AMC 304 360. 16 Rockers Pivots & 8 Stands

Elgin Rocker Arm Kits compatible with 1974-1979 AMC 304 360. 16 Rockers Pivots & 8 Stands
  • compatible replacements for AMC 1974-79 304 & 1974-78 360.
  • 16 Rocker Arms Pivots and bridges
BESTSELLER NO. 6 in 2021

New Rocker Arm Set compatible with 1955-1986 Chevy sb 400 350 327 307 305 302 283 267 265 262 (Rockers, Nuts and Balls)

New Rocker Arm Set compatible with 1955-1986 Chevy sb 400 350 327 307 305 302 283 267 265 262 (Rockers, Nuts and Balls)
  • Rocker Arms, Nuts and Balls
  • Fits 1955-1986 Chevy sb 400 350 327 307 305 302 283 267 265 262 V-8's.
  • Ratio: Stock 1.5 Stud Size: Stock 3/8"
BESTSELLER NO. 7 in 2021

Elgin TEK460 Rocker Arm Kit

Elgin TEK460 Rocker Arm Kit
BESTSELLER NO. 8 in 2021

Elgin Industries Rocker Arm & Pushrod Set compatible with 1955-1986 sb Chevy 400 350 327 307 305 302 283 265

Elgin Industries Rocker Arm & Pushrod Set compatible with 1955-1986 sb Chevy 400 350 327 307 305 302 283 265
  • compatible replacements for small block Chevy 400 350 327 307 305 302 283 265
  • Rocker Arms, Balls & Pivots
  • (16) Stock Push rods
BESTSELLER NO. 9 in 2021

Elgin Industries Rocker Arm studs compatible with Cheverolet GM LS-1 Engines.Performance upgrade for Roller Rockers

Elgin Industries Rocker Arm studs compatible with Cheverolet GM LS-1 Engines.Performance upgrade for Roller Rockers
  • 8mm x 3/8"
  • For use with upgraded roller rocker arms with 3/8" bottoms
BESTSELLER NO. 10 in 2021

TR5358 TRA5358 raxxas Revo Progressive 2 Rocker Arm Set

TR5358 TRA5358 raxxas Revo Progressive 2 Rocker Arm Set

6 More Questions Answered

How do you test a valve train in geometry?

How To Verify Valvetrain Geometry
  • The first step is to install a solid lifter and an adjustable pushrod. Mark the tip of the valve with a marker.
  • Install your rocker arm and set it up with zero lash. Rotate the crankshaft clockwise several times. Remove the rocker arm. ...
  • Rotate the crankshaft clockwise several times. Remove the rocker arm.
  • How do you find the correct rocker arm in geometry?

    What's the difference between 1.5 and 1.6 rocker arms?

    1.5 rockers lift the valve 1.5 times the lobe lift of the cam, 1.6 lift the valve 1.6 times lobe lift. Generally, 1.6 rockers are used to improve the lift of a camshaft that has low lift. They can also be used to get the valve lift into a specific head flow range.

    How much lift does 1.7 Rockers add?

    According to This Article from Hot Rod magazine, a . 1 increase in rocker arm ratio (such as 1.6 to 1.7) will increase lift by about . 030, which would put me right back at the . 542 lift of the X-303, while maintaining the extra duration of the F-303.

    Can you drive with a bad rocker arm?

    With broken or loose rocker arms, the exhaust valves and intake valves can't function correctly and the cylinder associated with the faulty rocker arm will be disabled. This will ultimately limit the performance of your engine and your ability to drive the car smoothly and safely.

    Do overhead cam engines have rocker arms?

    Single Overhead Cam The cam actuates rocker arms that press down on the valves, opening them. ... These springs have to be very strong because at high engine speeds, the valves are pushed down very quickly, and it is the springs that keep the valves in contact with the rocker arms.