WARNING LS3 Recall about to happen

[Immortality]

I actually resent that I pay to get this crock of crap show as part of my Motor Trend video subscription, after a few drinks can't help but LOL at the backyard bullshit spewing forth from most of them. As a matter of course I speak to engine masters (not these tosspots but pro LS engineers and race scrutineers at the top of their game) on a regular basis and this fluff is... sensationalist at best.
Anyways, only trying to help with some real world experience over six years of reasonably constant research and development, but of course if you find a serial nutbag video segment which on the face of it says stick with the stock stuff then hells yeah, cheap way forward aye! BTW these guys also proved that the size and shape of header design doesn't matter at all either.

Really? That's not what I got from that at all. My take is that if your on a budget running stock ratio rockers than there is no benefit in going to a stock ratio roller tip rocker. They do agree that roller rockers are of benefit on high rpm/high lift combinations to improve reliability and clearly suggest that if you can afford to run the higher ratio rockers (and your engine combo can make use of the extra lift) then they are of value.

 

[monstar]

Yep, that test kinda debunks the myths about roller rockers been more efficient because they reduce friction. The only reason the extra power was made was because the ratio increase.

It really was interesting to see the stock ratio roller rocker loose power at the top end compared to the standard pressed steel rocker.

I have no doubt that full roller rockers improve longevity of parts and it's very interesting to see that GM have gone with a roller bearing in the trunnion put maintained the standard friction tip, you have to wonder if this was done to keep the rocker tip weight to a minimum? Then there is also the argument of how a roller tip Vs friction tip and how each effects lift. This was debated quiet vigorously around the MACE high ratio roller rockers and what constitutes a roller rocker....

Efficiency vs horsepower... I think the proper coefficient to measure friction would be one that measured energy consumed not energy output? In other words you can always get an engine with poor BSFC to output a given peak HP, but the measure of friction at low rpm (particularly on that old hunk of iron) would best be measured by brake standard output vs fuel consumption. Not just output.
This show's segments are typically smoke and mirror results stunning dumb cnuts into parroting off myths and half-truths to workmates.

 

[Immortality]

You have to remember that that show is aimed primarily at the low buck American car enthusiast just like the majority of their shows are. The results are relevant in terms of performance gains in the target market. I also don't think most Americans give a rats ass about fuel consumption, fuel is relatively cheap in the US.

Yes other tests may prove other benefits of fitting roller rockers, an engine acceleration test would be most interesting.

Something else I would like to see is side to side comparison on valve guide wear between the 2 styles of rockers.

 

[426Cuda]

This is what I settled on, there are other combos for sure.
Rockers
Yella Terra (Whipple) ~$950
Sold overseas under many brand arrangements, Aussie Yella Terra is at the top of its game.

Stock rocker ratio geometry 1.7:1 is what most cams up to Gen IV (except the LS7) have used. Yella Terra PN YT6667.
LS7, Gen V and later engines use 1.8:1 to eliminate the inevitable cam face / lifter roller wear of LS builds, an alternative to achieve >0.550" lift with control and lower friction vs previously small base circle and aggressive cam lobe ramp. Yella Terra PN YT6668.
I kept AFM with revised lifters from the Gen V, so the base circle of the AFM cam is larger than most Gen IV, meaning lobe lift is just 0.300". So with AFM cams the standard 1.7:1 rockers (0.300" x 1.7) give 0.510" lift at valve, OK from an old school standpoint but not ideal for performance. 1.8 gives 0.540", and 1.85:1 (actually 1.865) gives 0.556" lift (bit more than LS3) with the later AFM cams. Yella Terra PN 6685.
There is a bit to explain the other main benefit - being increased cam size - per the time/area duration of the valve opening. Suffice it to say the start and end points of the opening (time) are of course the same duration but increased acceleration and extent of the valve opening (area) is increased which affects the effective time/area duration like an extra one degree duration per 0.5 increase in ratio.
So with 1.8rr Stock LS3 cam spec effectively becomes 206/213 117.5-2.5 LSA 0.583"/0.556" lift. Which is bloody great.

Springs
Peterson American Corporation (PAC Racing Springs) ~$400 with locks and retainers
The shortlist is PAC 1211x, 1511x, 1219, 1519 and Comp Cams 26915. The PAC 12xx series is a cheaper less treated version of the 15xx series. this is my worksheet:
View media item 436I also have Ferrea hollow stainless valves and so I chose PAC 1511x shot peened nitrided race springs with hardened steel valve locks / collets & Manley chromoly retainers.
View media item 250

Pushrods
Manley LS Chromoly ~$200
It's advisable to check pushrod length and replace with hardened lighter rods with less diameter. My geometry is different in order to get a raised compression and stuff so I went with above after getting sized properly.
View media item 437
Then the labour charge for (less than) five hours, ranges $500 to $900.

Mate that is epic! Thanks so much. I appreciate your effort here!
I'm definately going for a cam, so GenTech will need to check clearances across the entire valve train obviously.
Yella Terra look good.
I used higher ratio rockers on my 360 La Mopar, with a custom ground high lift solid cam. It went like the clappers in the light VJ Charger, but I had to set the valve lash quite frequently. Loved the free revving and clackity clack of the solids though

 

[426Cuda]

I actually resent that I pay to get this crock of crap show as part of my Motor Trend video subscription, cheap LOLs after a few drinks watching the half-arsed backyard bullshit spewing forth from most of them.
The engine is thirty years old, the results are always shocking, never as up-to-date as using LS-specific components, stuck at the back of the class mired in Old Skool.
As a matter of course I speak to engine masters (not these tosspots but pro LS engineers and race scrutineers at the top of their game) on a regular basis and this fluff is... sensationalist at best.
Anyways, only trying to help with some real world experience over seven years and 200k miles of reasonably constant research and development, but of course if you find a serial nutbag video segment which on the face of it says stick with the stock stuff then hells yeah, cheap way forward aye!
PS these guys also proved that the size and shape of header design doesn't matter at all either.

Lol. Yeah it is a bit amateur hour.

 

[monstar]

I also highly doubt a stock rocker is just 8.2grams. That's ~ 122 rockers : kg! It's an importa t point, because weight of roller rockers is a big downside compared to stock. Can you check your source on this one?

This is one of the inputs in Engine Analyzer Pro, so I've been looking for this info for a long time also (> 10 years). Same as you've reported, no luck from anyone other than what I've been able to measure myself.

I have taken the tip weight measurement you identify here. I have a medical scale that's accurate to a tenth of a gram. I have a calibration weight that I test accuracy with to ensure weight measurements are correct. Here's what I came up with:

Test condition: The rocker arm trunnion supported and the tip of the rocker on the scale. Scale zeroed prior to measurement.

Stock rocker: 8.2 grams
Crane 1.8 roller rocker: 22.8 grams
Harland Sharp non-adjustable 1.7 roller rocker: 22.5 grams

Here is the link.

 

[monty_vfssv]

I'm gonna leave this here

Interesting video.. so there is no horse power benifit from reduced friction using the roller rockers..
Looks like the only added horse power came from the ratio increase.. which could be achieved with more lift in the cam and leaving the stock rocker ratio??
Whats the fail rate of the stock rockers are they a common part to fail?
Im thinking of just doing the trunion bearing upgrade or am i missing something and should be considering roller rockers?

 

[monstar]

Interesting video.. so there is no horse power benifit from reduced friction using the roller rockers..
Looks like the only added horse power came from the ratio increase.. which could be achieved with more lift in the cam and leaving the stock rocker ratio??
Whats the fail rate of the stock rockers are they a common part to fail?
Im thinking of just doing the trunion bearing upgrade or am i missing something and should be considering roller rockers?

Stock rockers are cheap cast numbers that barely fit the engineering bill in performance terms. Same as the springs (they are at the operational limit even with the hollow intake). Question marks hang over long term reliability of stock spring / valve / rocker combo, particularly under heavy duty or upgraded operational range / output.
Yes, fully encased bearings and shaft mounts are superior to the weak cageless dangerous stock rockers, and the reduced friction at various loads (power and economy) is measurably better with the more advanced geometry.
Consider the benefit of more volumetric flow upgrading to 1.8rr modifying your effective cam timing without spending a few thousand. Any prospective new cam beyond that can utilise the 1.8rr geometry per LS7 and Gen V and mine to result in less cam face / lifter roller wear.
On the other hand there is zero advantage in sticking with 1.7rr apart from fitting three bolt older cam designs; no advantage sticking with springs at their limit, and lighter stronger pushrods help to deliver more control, particularly over stock peak (5700). I definitely would not be revving an LS3 with stock upper valve train near the factory rev limiter!

 

[426Cuda]

Here is the link.

Ah ok thanks. So the arm including trunion bearing I assume, is 82 grams. But the theoretical calculated weight of the rocker arm "tip" is 8.2 grams, or 10% of the total weight. Sounds plausible enough.

 

[07GTS]

i have done the trinion upgrade to my stock rockers would highly recommend it or spend another 400 and get the YTRR, the stock rockers have play side to side alot and also up/dn when they are unloaded and the trinion bushes remove all of that so run much better, just make sure ur rockers ratio suit your cam/engine i had valve touching piston with just cam 0.597 lift and stock rockers had to space heads up a smidge...