AFR LS3 Head Thoughts...
You would want to run roller rockers....spending this kind of money on heads and going with stock rockers is ludicrous IMO. They are the wrong tool for the job. They work of course but you shorten the service life of the heads dramatically. I worked with Yella Terra on designing a rocker for my TFS casting LS3 product.....the same part number will fit the AFR heads. They are half the cost of Jesels so price shouldn't really be an issue. I posted this on the Vette forum recently in regards to stock rockers on LS7 heads.....most of what I typed is applicable to this situation also
"Fixed heads" only reset the clock of the failure and problems associated with ported OEM castings and stock rockers....the problems and issues are going to resurface again.....you have to change some of the players (valvetrain components) if you expect to have different end results.
It's just one of the reasons I always advocate getting away from stock rockers. I don't know why so many people are intent on running them. They were designed to operate with half the spring pressure (seat and open pressure) most of us run, SOFT gentle OEM cam lobes/ramps, and .100 or more less lift. That's the application they were designed for....they are out of their element on most of the aftermarket builds and will take out the guides of your heads due to all the side loading imparted on the stem of the valve and the guide as the flat arced pad of the rocker scrubs and see-saws across the tip of your valve. You end up with an hour glassed shape valve guide and oil consumption issues once you have achieved that shape which is vastly accelerated with aftermarket cams and alot more spring pressure....not to mention a loss of performance from your valves not properly sealing when your guides are worn.
ALL the engines I build and spec are equipped with Yella Terra Ultralites built specifically for the castings Im using but you can buy them for stock heads also....much more affordable than the other big names in the rocker arm business and more importantly they are better designed for an HR system most of us are running (they are lightweight which is crucial to valve control).
I don't understand the love affair with OEM rockers when your upgrading all the other areas pertinent to building a real performance engine, not to mention some guys investing more money in them with trunion upgrades etc.....its silly because you still haven't addressed their major design flaw regarding not having the proper geometry for much more lift and not having a roller wheel which reduces contact patch by a large margin and reduces side loading dramatically as well. Also a roller will offer reduced friction and that will free up a small bit of power also....a nice perk from the upgrade to a roller.
I stock this stuff guys so if you would like to discuss in more detail feel free to contact me. Not a single engine I build (or help spec for a customer by providing them with all the parts) includes OEM rockers. You leave them to collect dust on the shelf with all the other OEM parts you removed when you decided to upgrade and mod your engine in search of more power. The engine is a tuned system.....when you upgrade the valvetrain in other areas (springs, camshaft lift and profile, etc.) you have to also upgrade the rockers as well to better compliment the other changes....this gives you a more reliable piece and a harder running one as well
We should get on the phone at some point to discuss the project in more detail. When you're ready to really dig into this PM or email me and let's do that. Plan ahead though.....with AFR's lead time and my lead time it's easily a 7-8 week wait to get them.
Regards,
Tony
"Fixed heads" only reset the clock of the failure and problems associated with ported OEM castings and stock rockers....the problems and issues are going to resurface again.....you have to change some of the players (valvetrain components) if you expect to have different end results.
It's just one of the reasons I always advocate getting away from stock rockers. I don't know why so many people are intent on running them. They were designed to operate with half the spring pressure (seat and open pressure) most of us run, SOFT gentle OEM cam lobes/ramps, and .100 or more less lift. That's the application they were designed for....they are out of their element on most of the aftermarket builds and will take out the guides of your heads due to all the side loading imparted on the stem of the valve and the guide as the flat arced pad of the rocker scrubs and see-saws across the tip of your valve. You end up with an hour glassed shape valve guide and oil consumption issues once you have achieved that shape which is vastly accelerated with aftermarket cams and alot more spring pressure....not to mention a loss of performance from your valves not properly sealing when your guides are worn.
ALL the engines I build and spec are equipped with Yella Terra Ultralites built specifically for the castings Im using but you can buy them for stock heads also....much more affordable than the other big names in the rocker arm business and more importantly they are better designed for an HR system most of us are running (they are lightweight which is crucial to valve control).
I don't understand the love affair with OEM rockers when your upgrading all the other areas pertinent to building a real performance engine, not to mention some guys investing more money in them with trunion upgrades etc.....its silly because you still haven't addressed their major design flaw regarding not having the proper geometry for much more lift and not having a roller wheel which reduces contact patch by a large margin and reduces side loading dramatically as well. Also a roller will offer reduced friction and that will free up a small bit of power also....a nice perk from the upgrade to a roller.
I stock this stuff guys so if you would like to discuss in more detail feel free to contact me. Not a single engine I build (or help spec for a customer by providing them with all the parts) includes OEM rockers. You leave them to collect dust on the shelf with all the other OEM parts you removed when you decided to upgrade and mod your engine in search of more power. The engine is a tuned system.....when you upgrade the valvetrain in other areas (springs, camshaft lift and profile, etc.) you have to also upgrade the rockers as well to better compliment the other changes....this gives you a more reliable piece and a harder running one as well
We should get on the phone at some point to discuss the project in more detail. When you're ready to really dig into this PM or email me and let's do that. Plan ahead though.....with AFR's lead time and my lead time it's easily a 7-8 week wait to get them.
Regards,
Tony
TECH Fanatic
Joined: Aug 2009
Posts: 1,845
Likes: 255
From: Coast of San Mateo County Between Pacifica & HMB
Crower makes a Steel Rocker for LS3 Heads with a Bushing, (needle bearing less)
Option for the needle bearing paranoid as well (I resemble that remark!).
LOL
64 Post is using the Crower RR in his 416" AFR LS3, W/ LLSR,
& Hi Ram, E85 Build underway.
Option for the needle bearing paranoid as well (I resemble that remark!).
LOL
64 Post is using the Crower RR in his 416" AFR LS3, W/ LLSR,
& Hi Ram, E85 Build underway.
Maybe I'm tempting fate but two years and 20k on this build. Running YT gen 3
Edit - in case anyone connects this with the clutch thread, I added the clutch six months later
Edit - in case anyone connects this with the clutch thread, I added the clutch six months later
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I think it's worth discussing here guys, the aftermarket rocker failure issue. Exactly what rockers besides the early YT's, (which were redesigned and as far as I know, the breakage issues have been resolved,) were people having problems with? Anybody have first hand experience here?
The T&D's are great, as are the Crowers. I've ran both in the past in circle track stuff with success. The rpm we ran, along with springs required me to spend the coin on my rocker setups. BUT...most guys here never race their stuff...ever.
Tony Mamo puts his name on YT these days. I have just received a rocker set from him, and it says Mamo right beside the part number. It's what Tony speced for the top end package I've got from him. I've never ran YT's before, so I'm entering new territory here, hence why I feel this discussion should take place.
So besides YT's, what other rocker failures have taken place? Surely there's a way to run a roller tipped rocker, and not spend $2k doing it...
The T&D's are great, as are the Crowers. I've ran both in the past in circle track stuff with success. The rpm we ran, along with springs required me to spend the coin on my rocker setups. BUT...most guys here never race their stuff...ever.
Tony Mamo puts his name on YT these days. I have just received a rocker set from him, and it says Mamo right beside the part number. It's what Tony speced for the top end package I've got from him. I've never ran YT's before, so I'm entering new territory here, hence why I feel this discussion should take place.
So besides YT's, what other rocker failures have taken place? Surely there's a way to run a roller tipped rocker, and not spend $2k doing it...
Thread Starter
Joined: Apr 2009
Posts: 6,717
Likes: 24
From: Lafayette, LA
Like YT, Scorpion had their fair share of issues. However, just like YT, they fixed their issues. I'd not hesitate to run their new stuff for a mild build. It's all USA made as well.
Dr_Whigham, maybe you were gone for a while? There's been a couple of threads regarding the AFR 260, with Tony Mamo, the design and development guy himself leaving some nuggets of info on them. Not a bad looking LS3 head, real good line of sight through the ports and AFR quality, you could compare it to the TFS 255's. Buy it bare and build it the using Tony's light valve option.
Last edited by 64post; Aug 7, 2017 at 09:29 AM.
Thread Starter
Joined: Apr 2009
Posts: 6,717
Likes: 24
From: Lafayette, LA
Dr_Whigham, maybe you were gone for a while? There's been a couple of threads regarding the AFR 260, with Tony Mamo, the design and development guy himself leaving some nuggets of info on them. Not a bad looking LS3 head, real good line of sight through the ports and AFR quality, you could compare it to the TFS 255's. Buy it bare and build it the using Tony's light valve option.
Haven't really seen anyone talking about them..I'm strongly considering these for a high lift hydraulic build.
http://www.autopressreleases.com/_up...%20Engines.pdf
http://www.autopressreleases.com/_up...%20Engines.pdf
Last edited by spanks13; Aug 7, 2017 at 06:05 PM.
I don't know, but their math is all effed up....
Reduces valve sweep by 400%? Really? So, instead of valve sweep of X, its -3X? I'm sure they mean it reduces it by 75% or the regular GM rockers have 400% more sweep.
and three times less MOI over the valve tip? You mean 1/3 the mass?
I've never seen them reviewed, and they might actually be a great product, but at that price point, you're in YT ultralite territory.
Reduces valve sweep by 400%? Really? So, instead of valve sweep of X, its -3X? I'm sure they mean it reduces it by 75% or the regular GM rockers have 400% more sweep.
and three times less MOI over the valve tip? You mean 1/3 the mass?
I've never seen them reviewed, and they might actually be a great product, but at that price point, you're in YT ultralite territory.
The first bit is just using the most marketable statistic to say the same thing. 400% less sweep meaning the tip of the rocker moves across a contact patch 4x smaller than stock (which is the issue with high lift cams and stock rocker arms).
1/3 the moment of inertia and 1/3 the mass is not the same. Mass moment of inertia is a property that is influenced by total mass, location of the center of mass, and as such the geometry of the part.
The moment of intertia is what actually matters in the dynamics and control of the assembly.
These won SEMA's best new product at SEMA 2016. I'm also curious why they haven't really shown any builds yet.
1/3 the moment of inertia and 1/3 the mass is not the same. Mass moment of inertia is a property that is influenced by total mass, location of the center of mass, and as such the geometry of the part.
The moment of intertia is what actually matters in the dynamics and control of the assembly.
These won SEMA's best new product at SEMA 2016. I'm also curious why they haven't really shown any builds yet.
Originally Posted by spanks13
The first bit is just using the most marketable statistic to say the same thing. 400% less sweep meaning the tip of the rocker moves across a contact patch 4x smaller than stock (which is the issue with high lift cams and stock rocker arms).
1/3 the moment of inertia and 1/3 the mass is not the same. Mass moment of inertia is a property that is influenced by total mass, location of the center of mass, and as such the geometry of the part.
The moment of intertia is what actually matters in the dynamics and control of the assembly.
These won SEMA's best new product at SEMA 2016. I'm also curious why they haven't really shown any builds yet.
1/3 the moment of inertia and 1/3 the mass is not the same. Mass moment of inertia is a property that is influenced by total mass, location of the center of mass, and as such the geometry of the part.
The moment of intertia is what actually matters in the dynamics and control of the assembly.
These won SEMA's best new product at SEMA 2016. I'm also curious why they haven't really shown any builds yet.
In all truth it looks like a great concept. But I wonder if the price point is too close to yellaterra so people just get the YT?
The 'engineers' give the advertising agency the product information and the agency 'massages' the wording for maximum effect.
KW