LS2 TFS heads Rocker Arm question Options

[pharmd]

Is the stock rocker with trunion upgrade adequate, or is their a real concern necessitating I run a full roller?

My engine guy says anything over .600 lift and 6000rpm needs full roller (he is a Ford guy). He also is concerned about spring pressures. Additionally he suggests that once preload is set with pushrod length if the valves need to be adjusted in a different spot it would be nearly impossible with the limited travel lifters. He says with aluminum block/heads preload changes a lot when it gets hot.

I have too much money in the setup as is, and really don't want to have to buy yet another set of rockers. The motor will be used for HPDE, autox, and some daily driving.

Anyone know the limits on these stock rockers with the upgrade?

Any help appreciated!

[Rampant]

The issue with the Trick Flows is they use a soft guide, bronze. The side load wears the guides rapidly. The factory heads use a harder guide. I had TFS 245s and used Jesel Mohawks. My current head is a Mast and I am now using LS7s with the trunion upgrade. They have not had the same issues as TFS.

The Trick Flows are a great head for the money. The exhaust ports flow really strong, more than my Mast's.

[pharmd]

The issue with the Trick Flows is they use a soft guide, bronze. The side load wears the guides rapidly. The factory heads use a harder guide. I had TFS 245s and used Jesel Mohawks. My current head is a Mast and I am now using LS7s with the trunion upgrade. They have not had the same issues as TFS.

The Trick Flows are a great head for the money. The exhaust ports flow really strong, more than my Mast's.

Yeah, I am running PM guides to address the wear issue. This is Advanced Inductions TFS heads (not the standard TFS). I really didn't want to have to spend another grand on rockers, although I realize Jesel or T&D would be the ultimate option. My understanding was that the stockers with trunion upgrade were really a nice option for the money. I have run stockers on both motors before, both with lift over 0.600, and rpms over 6500, with no issues.

Im about to pull my hair out, seems like everytime I turn around on this motor there is a big decision to make, and usually its tied to spending more $$

[GlennCMC70]

I ran 6800 on OEM stock rockers. I don't see the need unless you just have to spend money.

[pharmd]

I ran 6800 on OEM stock rockers. I don't see the need unless you just have to spend money.

How big a cam were you running, and how many miles did you put on that setup? I've had 2 motors, both turned up to 7K, both made well over 500fwhp, had cams over 0.600 lift, 1 had 50k miles, the other 20k miles with no issues on stock rockers WITHOUT trunion upgrade.

[GlennCMC70]

.600" lift w/ 232/240 dur on a 112 LSA. XER lobes. Street/track car. 450hp/420tq at the wheels.

[dailydriver]

I've actually heard some engine builders state that the GM stockers, especially with the upgrade, are better than even the top, shaft mounted or otherwise, Jesels or T&Ds, regardless of cost considerations, or upper rev limits. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/dunno.gif)

[pharmd]

I've actually heard some engine builders state that the GM stockers, especially with the upgrade, are better than even the top, shaft mounted or otherwise, Jesels or T&Ds, regardless of cost considerations, or upper rev limits. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/dunno.gif)

Just ordered the Yella Terra Adjustable shaft mounts. So lets see what happens. My engine builder basically said he wouldn't put out this quality of motor with stock rockers on it. So I will have a set of rockers with brand new trunion upgrade up for sale soon!

[1qwikbird]

I've actually heard some engine builders state that the GM stockers, especially with the upgrade, are better than even the top, shaft mounted or otherwise, Jesels or T&Ds, regardless of cost considerations, or upper rev limits. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/dunno.gif)

Just ordered the Yella Terra Adjustable shaft mounts. So lets see what happens. My engine builder basically said he wouldn't put out this quality of motor with stock rockers on it. So I will have a set of rockers with brand new trunion upgrade up for sale soon!

I would hold off on selling the stockers until you get the motor on the dyno and see if you experience any kind of valve train instability in the upper RPMs. Seems like some guys with aftermarket setups have valve float or flutter in the upper RPM, as seen on the dyno sheet, then go back to stock rockers and the problem goes away. Its not universal, but I'd hate to see you sell off stuff only to buy it back later.

FWIW I have a set of TFS heads as well (215's bought directly through Brian Tooley with all the goodies), and I went through exactly what you are going through now. I have Comp Pro Magnums on the motor, but it hasn't been run yet. Fingers crossed and a set of stockers with the trunion upgrade on standby, just in case. I did have a stocker spill its guts, so I've been down that road as well. At one point, TFS recommended a full roller with their heads, but I believe that was tied to the guide wear issue more than valvetrain stability, but looking at their website, they seem to have backed off that stance and if you look at the rockers they sell, they only offer upgraded stockers or a crower shaft system for the LSX crowd, coincidence?


Good Luck either way.

[GlennCMC70]

I've actually heard some engine builders state that the GM stockers, especially with the upgrade, are better than even the top, shaft mounted or otherwise, Jesels or T&Ds, regardless of cost considerations, or upper rev limits. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/dunno.gif)

Just ordered the Yella Terra Adjustable shaft mounts. So lets see what happens. My engine builder basically said he wouldn't put out this quality of motor with stock rockers on it. So I will have a set of rockers with brand new trunion upgrade up for sale soon!

Alot of non-LS motor guys underestimate the LSX platform from crank, rods and pistons. I had nitrous on a can and header only LS1 that put down 670tq to the rear wheels on a 100 shot. GM didn't miss much on this motor.

Also - back in the day when I was doing alot w/ LS motors, Yella Terra was complete crap. I hope they have changed.

[pharmd]

I've actually heard some engine builders state that the GM stockers, especially with the upgrade, are better than even the top, shaft mounted or otherwise, Jesels or T&Ds, regardless of cost considerations, or upper rev limits. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/dunno.gif)

Just ordered the Yella Terra Adjustable shaft mounts. So lets see what happens. My engine builder basically said he wouldn't put out this quality of motor with stock rockers on it. So I will have a set of rockers with brand new trunion upgrade up for sale soon!

Alot of non-LS motor guys underestimate the LSX platform from crank, rods and pistons. I had nitrous on a can and header only LS1 that put down 670tq to the rear wheels on a 100 shot. GM didn't miss much on this motor.

Also - back in the day when I was doing alot w/ LS motors, Yella Terra was complete crap. I hope they have changed.

The Harlan Sharps are truly problematic...the YT's have had some issues, but those were the non-adjustable rollers. Lets face it, in alot of these situations the fault may actually not lie on the rocker, the rocker may have failed because the pushrods were the right length, too much spring pressure etc. I am hoping that I have made the correct choice, the engine builder wasn't giving me a whole lot of options. He is sort of a friend, so I really don't want to end a friendship over this, but its been an adventure.

Well, see, I think within the next 3 weeks it will be in the car. Hoping the "buy quality parts, having knowledgable people work on your car, and sweat the details and you'll have success" plays out for me.

[Rampant]

I am running upgraded LS7s on mine and it has .671 lift on hyd lifters, with a some what agressive ramp rate. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/burnout.gif) They are by far the lightest option. the rollers add a fair bit of weight right on the tip of the valve. We pulled to 6800 on the dyno and will likely go to 7000 on the track.