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rocker arm geometry from T&D

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wyrmrider

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The B3 kit is $200. You take some measurements, send them the info and they machine the offset spacers and hold downs. I don't think the geometry can be 100% corrected without building in an offset such as the B3 kit incorporates. Valve height is just part of the equation.
 
Exactly
T&D evidently changes the stands
just using shims would not center the valve without throwing sweep off -and vice versa
I think they have one adjustment backwards- I have to re-read
 
threewood said:
The B3 kit is $200. You take some measurements, send them the info and they machine the offset spacers and hold downs. I don't think the geometry can be 100% corrected without building in an offset such as the B3 kit incorporates. Valve height is just part of the equation.
Click to expand...
Agree. The offset is as critical as the distance from the head. Once you can visualize the valve-train in action you can see where the rocker arm needs to go to do the job properly.

Imagine if one of aftermarket cyl head producers would just incorporate the almost necessary change that 95% of it's purchasers will require. It seems about every build can benefit from marginal move in the rocker shaft position up and to the center of the engine. Certainly can't be any worse than the factory position.
 
For the longest dang time I've been going to throw my Ebrock heads up on the Bridgeport and cut the stands off and then get or machine the correct size stock and bore the shaft holes so you can basically put the rockers where they need to be and if you change the cam you could just shim. sounds awful easy to me. Might take a little R&D to get in the groove but if they are bolted/studded and pinned it would work. I rounded up eight different major brands of rocker arms years ago and put them on a shaft on V-blocks, huge difference in all as well as the adj.placement and angle. WOW
 
Crypl ever use the heads with the aluminum stands- much easier to work with
saw this in a hot rod article
https://www.hotrod.com/articles/rescue-random-chrysler-rocker-failures-really-arent/
from Hughes
"There are several theories on proper geometry, basically boiling down to whether you want max performance or better durability.
For ultimate performance on periodically torn-down race motors, Hughes sets up the geometry to obtain full cam lift.
Provided it doesn’t actually roll off the tip edge, the amount the roller tip is off-center as it wanders back and forth across the valve-stem tip as the cam cycles is less important than achieving max lift."

Totally wrong Hughes
no cam grinder does his masters to work with that geometry
basically it involves moving the fulcrum down towards where the line through fulcurm center to roller is tangent at max lift
Geometry dictates that you get the most ratio multiplication at tangent.
problem is the area under the curve takes a beating
and stiffer springs are required as the rocker is trying to fling the valve as the cam goes over the nose
the master/ grind is trying to slow down the valve and the rocker is trying to speed it up
valve float
others say you are increasing ratio multiplication when the springs are near max
comments?
 
I read up on the TD and they will alter there system to correctly fit without shims or the help of a B3 kit. Though the b3 kit would easier and faster IMO.

Ether way.... ownwers choice.
 
BS with Hughes
Proper geometry is getting the valve to move the way the camgrinder wants it to move
not crutching for "more lift"
which causes more problems than benefits
been there- done that
you want more lift get a different master or rocker ratio that the camgrinder supports
 
just plain wrong
https://www.hotrod.com/articles/rescue-random-chrysler-rocker-failures-really-arent/

". To laterally center the roller tip as viewed from the side, adjust the rocker shaft vertical height. Shim the pedestal (bottom, A) to move the rocker toward the intake side of the valve stem tip (B); subtract shims to move it toward the exhaust side. If all shims have been removed and the contact point is still biased toward the intake side, mill the pedestal."
HRM article - you have to move the shaft toward Intake side (most of the time) to center the valve on the stem as well as up and down for geometry
"On street Mopars, Brandes sets valvetrain geometry to keep the rocker-to-valve contact travel point within the center third of the valve-stem tip throughout the opening and closing cycle. If the pattern’s biased toward the exhaust side, get a shorter pushrod; if toward the intake, get a longer one." also wrong you move the shaft changing the pushrod changes the geometry


"On shaft-mount rocker systems, both the rocker shaft height, rocker position on the shaft, and the pushrod length affect geometry. With Brandes’ method, at rest (valve closed, pushrod not lashed), the tip is centered over the valve-stem tip both longitudinally (edge-on) and laterally (side-on). Shim the shaft spacers and shaft pedestals as needed to get there. Using an adjustable checking pushrod and light checking springs, set the preliminary valve lash to zero, and adjust pushrod length to achieve minimum motion off-center through the cam cycle.'
 
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