Cam swap, Should I ditch the Yella Terra's???
07-11-2013, 07:17 PM
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Cam swap, Should I ditch the Yella Terra's??? Ok, I've got a new cam coming from EPS 234/242 .629 lift. Im going to be freshing up the top end with new springs and 11/32 push rods. I'm torn between running the Yella Terras or changing back to stock with a trunion upgrade.
For the roller rockers I should run the BTR max pressure springs but I guess the Yella Terras aren't designed for that much pressure. I'm thinking about getting the platinum springs and TI retainers and run the Yella Terra's?? Is anyone having valve float issues with this setup??
Im hoping for 500 rwhp maybe a few more with this setup probably on a SD tune.
For the roller rockers I should run the BTR max pressure springs but I guess the Yella Terras aren't designed for that much pressure. I'm thinking about getting the platinum springs and TI retainers and run the Yella Terra's?? Is anyone having valve float issues with this setup??
Im hoping for 500 rwhp maybe a few more with this setup probably on a SD tune.
Last edited by Pharcyde50; 07-11-2013 at 07:28 PM.
07-11-2013, 08:08 PM
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After some of the breakages I thought the were only good to around 420? If they are good till 500 I'll go with the max pressure.
Jesels ain't in the budget. I still have to get the tranny rebuilt and a new driveshaft to be ready when the weather cools off to hit the track.
Jesels ain't in the budget. I still have to get the tranny rebuilt and a new driveshaft to be ready when the weather cools off to hit the track.
Last edited by Pharcyde50; 07-11-2013 at 08:14 PM.
07-11-2013, 08:30 PM
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I think these are revision 1 I bought them I think in 06 or 07. I have about 5k on them with prc gold springs. Just actually got the car to the track and ran it this past winter I think it was floating them in the upper rpms. Long story on the car (busy job , kids and i ilke to do my own work even if its only 2 hrs a month) my wife calls it my 30k paper weight cause it just sits in the garage
07-11-2013, 08:32 PM
#7
The Gold's definitely don't have enough pressure to keep them from going bananas on you. I don't know what was changed from Revision 1 to whatever revision.
The BTR Platinums have more seat pressure than the Patriot Golds and a bit more open pressure. They might work. If they don't, you can always swap out some stock rockers and you wouldn't have to swap the valvesprings.
The BTR Platinums have more seat pressure than the Patriot Golds and a bit more open pressure. They might work. If they don't, you can always swap out some stock rockers and you wouldn't have to swap the valvesprings.
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07-11-2013, 09:05 PM
#8
I use BTR Platinums with my EPS 234/242 .600 .615 117+2 cam and Yella Terra Ultralight rockers & 5/16 Comp pushrods. EPS recommended the Platinum springs for my set up.
I had the Yella Terra's on since 2009 when I installed the TFS 215 heads. The TFS springs had 450 open pressure.
Russ Kemp
I had the Yella Terra's on since 2009 when I installed the TFS 215 heads. The TFS springs had 450 open pressure.
Russ Kemp
07-12-2013, 01:42 AM
#10
Were it me I would probably switch to a newer rev YT. You surely have the first version. They also have a set that are designed for higher spring pressures than the ultralights. I know Tony sells them. I have also heard some rumblings of new rockers becoming available in the near future. . .just rumblings, but supposedly from a reputable company.
As for Jesels, hasnt it been established on here, years ago, that they were never designed for 550+ lift? I cant remember the number and am too lazy to look, but they supposedly dont like the newer higher lift cams. In addition, I believe I have read on here that it can be difficult to impossible to get a decent wipe pattern with any of the single shaft rocker sets.
I personally would not run stock anything if I could afford better, especially valvetrain, but lots of folks seem to do OK with trunion upgraded stockers,
As for Jesels, hasnt it been established on here, years ago, that they were never designed for 550+ lift? I cant remember the number and am too lazy to look, but they supposedly dont like the newer higher lift cams. In addition, I believe I have read on here that it can be difficult to impossible to get a decent wipe pattern with any of the single shaft rocker sets.
I personally would not run stock anything if I could afford better, especially valvetrain, but lots of folks seem to do OK with trunion upgraded stockers,
07-12-2013, 08:32 AM
#11
OP - the new ultralites are good up to 500 lbs, but they recommend running YT platinums at anything above 450. At the very least I'd upgrade your set to the Rev 3 design - I wouldn't expect there to be any problems on a mild lobe like eps uses assuming the rest of your valvetrain is under control and your geometry is correct. Along those lines 11/32 rods would also be a very good idea.
07-12-2013, 08:43 AM
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I've decided I'm going to do the BTR platinums and 11/32 push rods. If it floats I'm gonna go back to stock rockers with upgraded trunions. Will YT upgrade them for free? I thought they had a lifetime warranty , when I first bought them they were supposed to be the best thing you could buy. Obviously they have issues if they are on revision 6.
07-12-2013, 09:02 AM
#13
There are 3 revisions.
-The first had a small batch of arms pass through q/c with an improperly machined pushrod cup - the pushrod would basically break through the arm. It was found that improper tooling was used on the machines that perform that particular operation....the tooling was replaced and that issue went away.
-The second revision saw some failures with guys running aggressive cams - the rocker would split in half right at the trunion. Without knowing details of every setup that failed, it's hard to say truly whether it was design of the arms or improper component matching / selection. Perhaps a bit of both. Either way - the rev 2 arms were not designed to handle the lifts and pressures the hobby started throwing at it. At the point in time the rev 2's were introduced, 400+ lb open pressures, cams with .6xx+ lift, and aggressive lobes like X-ER's were not that common.
-third revision and where we are now - beefed up around trunion area and more balanced. there have yet to have been any failures that i'm aware of.
Unless you had an arm break on you I doubt that they will give you a free set. Definitely wouldn't hurt to try though..
-The first had a small batch of arms pass through q/c with an improperly machined pushrod cup - the pushrod would basically break through the arm. It was found that improper tooling was used on the machines that perform that particular operation....the tooling was replaced and that issue went away.
-The second revision saw some failures with guys running aggressive cams - the rocker would split in half right at the trunion. Without knowing details of every setup that failed, it's hard to say truly whether it was design of the arms or improper component matching / selection. Perhaps a bit of both. Either way - the rev 2 arms were not designed to handle the lifts and pressures the hobby started throwing at it. At the point in time the rev 2's were introduced, 400+ lb open pressures, cams with .6xx+ lift, and aggressive lobes like X-ER's were not that common.
-third revision and where we are now - beefed up around trunion area and more balanced. there have yet to have been any failures that i'm aware of.
Unless you had an arm break on you I doubt that they will give you a free set. Definitely wouldn't hurt to try though..
Last edited by ckpitt55; 07-12-2013 at 09:16 AM.
07-12-2013, 09:10 AM
#14
If their engineers truly have no idea, then you certainly don't either.
OP - the new ultralites are good up to 500 lbs, but they recommend running YT platinums at anything above 450. At the very least I'd upgrade your set to the Rev 3 design - I wouldn't expect there to be any problems on a mild lobe like eps uses assuming the rest of your valvetrain is under control and your geometry is correct. Along those lines 11/32 rods would also be a very good idea.
OP - the new ultralites are good up to 500 lbs, but they recommend running YT platinums at anything above 450. At the very least I'd upgrade your set to the Rev 3 design - I wouldn't expect there to be any problems on a mild lobe like eps uses assuming the rest of your valvetrain is under control and your geometry is correct. Along those lines 11/32 rods would also be a very good idea.
Look, I thought long and hard about YTs for my build. The thought of having a part that has a history didn't sit well with me. And when I really researched it carefully, I saw a lot of smoke. In fact, I tried to find some information on the so-called benefits, because the marketing behind it sounded great.
In the end, I found no evidence of the benefits to them - just potentially more life out of bronze guides. The idea that you're side loading the valve or scrubbing the valve tip doesn't actually result in documented power loss. If it does, show me a test where an OEM rocker is down on power to a YT. I've never seen it.
I'm not above saying I'm wrong, but the information does not readily exist, and you would think it would if it were true. And 10HP out of roller rockers would be worth any potential trade offs...
07-12-2013, 09:32 AM
#15
Let's say you have a car that will do 200 mph - do you think it would last longer before breaking if you were to drive 200 mph all the time, or if you went at some reduced percentage of that? Just because you can, doesn't mean you should..
See my post above Jake - that's how I understand the revisions to the best of what I was able to find.
Let's put dyno numbers aside for a second - the advantage of using rollers is the ability to adjust and optimize your valvetrain geometry to control the manner of valve tip / roller contact, reduce friction and minimize wear at the tip and in the guides...which would result in an increase in longevity whether you're running bronze guides or not. Obviously becomes more important with bronze guides but it certainly wouldn't hurt you with PM. That alone was enough for me to warrant using them, once I understood the history of their revisions and failures. Theoretically you also have a much more consistent lift ratio since you're able to obtain a much narrower contact patch. These are the benefits as governed by math and geometry.
If you're using dyno numbers to try and validate any potential benefits, as you say, results are probably not going to be all that numerous because - and let's be real here - not many people are going to hit the rollers just to A/B a rocker arm swap without changing something else like a cam / springs / pushrods / heads. I'd certainly be interested in the comparison - but in my mind the hp gains are secondary to having the ability to optimize the geometry.
See my post above Jake - that's how I understand the revisions to the best of what I was able to find.
Let's put dyno numbers aside for a second - the advantage of using rollers is the ability to adjust and optimize your valvetrain geometry to control the manner of valve tip / roller contact, reduce friction and minimize wear at the tip and in the guides...which would result in an increase in longevity whether you're running bronze guides or not. Obviously becomes more important with bronze guides but it certainly wouldn't hurt you with PM. That alone was enough for me to warrant using them, once I understood the history of their revisions and failures. Theoretically you also have a much more consistent lift ratio since you're able to obtain a much narrower contact patch. These are the benefits as governed by math and geometry.
If you're using dyno numbers to try and validate any potential benefits, as you say, results are probably not going to be all that numerous because - and let's be real here - not many people are going to hit the rollers just to A/B a rocker arm swap without changing something else like a cam / springs / pushrods / heads. I'd certainly be interested in the comparison - but in my mind the hp gains are secondary to having the ability to optimize the geometry.
Last edited by ckpitt55; 07-12-2013 at 09:47 AM.
07-14-2013, 08:04 AM
#20
Funny thing is, you haven't heard of a single Scorpion failure either since their last revision... And they're made right here in the USA, but the bad taste remains and folks still **** on them constantly.
I'd love to see a tip weight comparison between the two.
I'd love to see a tip weight comparison between the two.