Yella Terra Roller Rockers

[mid life]

A friend of mine from northern NSW was told about a product from Yella Terra which replaces the original rocker arms and adds about 10kw to a stock LS1. Has anybody here heard of this, or has anymore info I can pass on?

Cheers
Jeff

[MNR-0]

They are the "accelerated lift" rockers that feature a diffferent rocker geometry to generate increased lift off the seat. They are part of the "gold race" family.

See it here ==> http://www.cranecams.com/?show=promo&id=34&PHPSESSID=cf73765476379873fb24c13b1aeeed34

Taken from their US website:
=======
QUICK-LIFT ALUMINUM ROLLER ROCKER ARMS

An easy bolt-on that’s good for 15-20 horsepower gain in LS1/LS6 engines. These highly efficient Crane rockers employ Crane’s unique new “Quick-Lift” design technology that accelerates valve events for more flow and improved performance. By relocating the pushrod seat down and in, Crane engineers have created a “variable ratio” rocker arm that begins with a ratio of about 1.78:1 and converges to a standard 1.7:1 ratio as the valve reaches a lift point of .250-.300”. This produces a significant improvement in bottom-end and mid-range power. These rockers are great when used with stock LS1 cams, and even more power can be had when they are used with a Crane “Quick-Lift” Z Cam profile. The “Quick-Lift” feature allows use of a milder profile to produce the same or more power than a considerably more radical cam and valve train. With Z Cams and Crane “Quick-Lift” aluminum rockers you maintain engine vacuum, have no effect on the factory ECU and enjoy great street driveability. When you stand on it. . . it’s all there! These rockers are also engineered to be the quietest operating needle-bearing trunion supported rockers available. They run quietly, without the valve train noise that is known to trip factory “Knock Sensors”, which retard spark advance timing and rob up to 20 HP from the rear wheels! Another feature is these rockers is that they fit under stock factory rocker covers. With Crane rockers there’s no need to buy expensive, “tall” aftermarket LS1 rocker covers! These rockers are part of Cranes “Gold-Race” rocker family, precision CNC machined from extruded billet aluminum bar stock. They are available as a complete kit or individually. The kit includes pushrod guideplates, rocker studs, pushrod guideplates, heat-treated chromemoly pushrods, and lock-nut style rocker adjusting nuts.

[Smitty]

They are the "accelerated lift" rockers that feature a diffferent rocker geometry to generate increased lift off the seat. They are part of the "gold race" family.

See it here ==> http://www.cranecams.com/?show=promo&id=34&PHPSESSID=cf73765476379873fb24c13b1aeeed34
....snip

oops thought he asked about Yella Terra ones.... :lol:
so can I direct you to-
http://www.yellaterra.com.au/stealth.php
where the question is answered...

cheer

[MNR-0]

:rolleyes:

Damned if I aint blind today. Sorry bloke. I don't work for them - honest. Watch out Melbourne - moronic blind man behind wheel of Monaro coming your way.

[seldo]

But...do they work..?? I seem to recall someone did a back to back on high ratio rockers a while a go and there was less than the difference between 2 normal dyno runs..

[VooDoo]

Worked for me. about 10rwkw

[seldo]

Worked for me. about 10rwkw
What brand and ratio Stew?

[VooDoo]

Yella terra 1.8's :)

a PT special :)

[all4ford]

Worked for me. about 10rwkw
Is it just me or is that a massive increase to come from just a rocker upgrade?

[MIC33R]

Is it just me or is that a massive increase to come from just a rocker upgrade?

Not really. You are adjusting the amount of valve lift and even a fraction of a mm will greatly increase the breathing ability of the cylinders (there are 8 of them remember). 10kW is a very small percentage, so it'd be quite achievable.