Installed the Yella Terras...

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Jun 10, 2003 | 06:09 AM

#21

WILWAXU

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From: League City, TX

Re: Installed the Yella Terras...

So I guess there is a set of these in my cars future?

Jun 10, 2003 | 09:07 AM

#22

Smoke_ur_5.0

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From: KS

Re: Installed the Yella Terras...

Yeah basically JPR is right on the lift's and durations. The results we gained from on the dyno were from 1.7 ratio rockers. We have the rockers on the RMS formula now and have less valvetrain noise than when we had B1 cam with stock rockers...and the cam we are using now is bigger than the G5X2.

Jun 10, 2003 | 04:34 PM

#23

robertbartsch

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From: Hartsdale, NY

Re: Installed the Yella Terras...

The terra's have a roller tip that reduces friction; this is why the produce more power ove rthe stock rocker that has no roller tip.

JMX claims they only pick up 3 or 4 HP ...not sure where he gets this from, however..

I think the main advantages are strength and quietness...

Jun 10, 2003 | 05:01 PM

#24

Fenris Ulf

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From: Objects in mirror no longer matter.

Re: Installed the Yella Terras...

Quote:

The YT's do not flex anywhere near as much as a stock rocker. A stock rocker might only transfer 95% of the lift to the valve due to flex, the added power comes from the increased efficiency in transferring the lobe lift to the valve.

Jun 11, 2003 | 03:17 AM

#25

Fenris Ulf

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From: Objects in mirror no longer matter.

Re: Installed the Yella Terras...

Hey Joe, have you heard when YT will release their adjustable rocker set? If they price it well they will put T&D and Jessel on the street.

Jun 11, 2003 | 03:43 AM

#26

Tom@SpeedInc

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From: Chicago

Re: Installed the Yella Terras...

I myself am going to get a set of YTs for my HD, but do you people know who yella terra is, as a company. Its actually an australian high performance company, hey the aussies are as big on V8s as we are. I'd imagine they were built to satisfy the local demand for LS1 parts as they have the holden Commodore SS and "monaro" commodore coupe that are LS1 powered and are generally modified by alot of their owners as camaros are here.

Jun 11, 2003 | 04:20 AM

#27

HOWQUICK

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From: Australia.

Re: Installed the Yella Terras...

Quote:

In your opinion (JPR, Mark, etc), is there a certain level (horsepower, rpm, etc) when you'd advise the use of these Yella Terra's?

Hey Big SS,
I don't know if Mark will echo the exact sediments, but in my opinion as I mentioned above, "A proportional duration to .550 lift", ie 224 cam + which would have a direct reflection on what spring rate must be used to run these cam size mentioned and are usually shifted at 6,200 and higher. Not only that, it's just good insurance IMHO. Recently, I installed a set of brand new stock rockers on a 230 cam car, quiet at first, then they began clattering within 1,500 miles if thats anything to go by? I give them my seal of approval and all our new builds will either come with them or be suggested, but we have made due over the years with the stock pieces too but with issues.

The reason for the explanation in my frst post is that they are not exactly "plug N play" you really have to check your valve train geometry well if your extensively modded. For example, I tried to install them on EZSS's car, and we had no preload at all, so at this point, there would be a coulpe different things that could be done, longer pushrods, re-adjust lash cap thickness to ballance out the "strike" area on the valve tip, starting at -0- lash is a tough one though because there is no real reference point besided subtracting out what the stock rocker preload was at so it's kinda hit or miss till the correct geometry and pre-load is acheived.

Joe.

have been using them over here for ovewr a year now with great results. Had one engine with the no preload problem- corrected it by removing some off the bottom of the pedistal-25000km on and all well....

Jun 11, 2003 | 10:15 AM

#28

Ozz

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From: Columbia Mo

Re: Installed the Yella Terras...

My car was one of the ones Mark is talking about and what I noticed was that the dyno graph was MUCH smoother on top. I changed them because I was shelling the stock ones (I

hate needle bearings in my pan) They do help make it quiter but not dead quite (I have double springs). Comp says that we see a HP gain because the stock really are not 1.7 they are more like 1.68, I have no idea if thats true but I do know I have not broke any more and I have 7rwhp gain from what I have.