Bigwebb

I've picked up a set of trick 255 ls3 heads, and am in the process of getting everything else together for the project here. It will consist of a little milling of the heads and a thinner gasket to bump the compression 3/4 of a point or so, along with a ported intake (RCR) and throttle body.

I'm waffling on whether or not to let the stock rockers ride, or upgrade to something like YT's. The cam I'm going to go with is going to be moderate for sure. Probably something like the katech torquer(224 / 236 @ .050, .581 / .601 lift, 113 LSA). I may choose something with a touch more intake duration and lift, but not much more.

I'm a little ignorant and still learning about valve train geometry etc. So the question is, what benefit what I get from this setup, if I added rockers? Any horsepower/tq? If so, where in the powerband? I'd love to keep the characteristics of the torquer cam, and extend the power band a couple hundred rpm up top. Is there any durability/reliability gains to be had by adding these to the setup? The consensus seems to be that I can get by without them, just wondering what benefit they would provide if I went that route.

BLKTA

I run those heads on my setup with the stock rockers and a baby cam. No issues, just make sure you torque the rockers following the factory procedure and spec.

Navy Blue 210

I would suggest either the Cam Motion
Titan 2 LS3 222/230 .595"/.587" 113+3 or
Titan 3 LS3 227/237 .621"/.604" 113.5+3
Either of those will perform better with the
TFS LS3 Heads VS the torquer.
I would choose the Titan 3

If you use stock Rockers I suggest the Bushing Trunion Upgrade
Either the CHE,TSP, or Straub. .630" is the limit recommended
With factory Rockers.
Good Luck

farmington

If I remember correctly, the type of rockers you use are dependent on the valve guide material. If they're PM, you use factory rockers, if they're bronze guides you need to use aftermarket roller type rockers

Bigwebb

Thanks for that. I don't believe they are bronze with the TF's. Can anyone confirm?


Daniel

Bigwebb

The 227/237 looks good. At 5 degrees of overlap, this should be getting towards the edge of good street manners, right? I'm trying to get my balance right here. I'd love to make 500whp with the heads and milling plus cam, intake and tb (mayyyybe 10% UDP), but I'm not willing to sacrifice drivability or a ton of my 2500 rpm power. Ideally I'd like power to be very close to stock (remember bumped compression) at 2000-2200 rpm and then see the graphs start to diverge around 2500.

Do you feel like this cam would accomplish those things? The specs tell me it would likely come in around 495 with heads, 11.5 compression, rick crawford intake and throttle body. It will be running stainless works catted headers to bnb 2.5" exhaust as well.

timd38

I used these Comp Cam trunions with my new heads. https://www.summitracing.com/parts/c...hoCTWcQAvD_BwE

Bigwebb

Thanks! How are you liking your setup? any regrets or things you would change?


Daniel

timd38

did it about 6 years ago. No complaints.

z06scentair

Navy hit the nail on the head camshaft wise, my opinion is to replace stock rockers with either HS or YT. Once you hit .630" lift it becomes more critical as the rotational movement on the stock rocker can cause premature valve tip wear.

To answer your question about the guides they are most likely bronze as that is TFS standard option. PM guides are an upgrade and become less important if you buy a full roller rocker to begin with.

Bigwebb

very helpful. What ratio should I go with on the YT's? Someone mentioned something to me about modifying or shimming the springs if I went with the YT's. Any truth to that? One last question, would the YT's combined with a .02-.03 mill and a thinner headgasket, put me at stock push rod length?



Daniel

xBoostx

I have milled .030 off ls3 heads and used same stock push rods.

KW Baraka

Aftermarket.

Comp Cams Ultra Pro-Magnums.....Chromoly Steel.....1.8 Ratio

IMHO, of course.

KW

Bigwebb

old motorhead

It won't affect the ratio. The 1.8's will increase valve lift though. The .621 lift cam's lift becomes .658 by using these rockers. By milling and using a thinner head gasket, you're locating the valves closer to the pistons. You'll definitely need to check PTV clearance. Guessing what length pushrod you'll need is pointless with all of the changes you're contemplating. You'll need to check that too.

KW Baraka

First off.....if you have a LS3 engine with a stock rotating assembly, you don't want a .030" gasket. The pistons of a LS3 comes out of the hole....so a .030" gasket is too thin for a street car. The very thinnest you want to go would be .035".....and .040" would be best from the standpoint of optimal quench AND 'engine safety'.

The biggest issue you'll face is with the 1.8 ratio installed with the milled heads and thinner gasket is that you'll almost certainly need a different length pushrod.

But then, you should count that as being a likely outcome of a cam swap.

As for PTV clearance, depending on your cam, it shouldn't be an issue. PTV clearance is influenced but the valve opening and closing events WAAAAAAY more than whether you heads and milled, the thinness of head gaskets or cam lobe lift.

Point of reference.....until recently, on my LS3 I had ported OEM heads, .040" heads gaskets (thinner than stock) and lift at .667" with CC-Ultra Pro-magnums with a stock rotating assembly. WITH NO PTV ISSUES!!!

KW

old motorhead

If he starts with a narrow LSA high lift n/a cam, adds higher ratio rocker arms, then mills the heads, then mixes in thinner head gasket.....he'd be nuts not to check PTV clearance. He might get away with it. It could also be a very expensive mistake not to check it.

KW Baraka

If the valve events are wrong, he can have a low-lift cam with thick gaskets and un-milled heads and he can destroy the valves and pistons.

95% of any PTV clearance issues can be traced SOLELY to the valve opening and closing events.

KW

Bigwebb

With cam I'm starting to realize I'm going to be landing near 227/237 or 227/239. CMC-30 or the cam motion titan cam. I really liked the katech torquer, but I think I'll look back after a few months and wish I'd don'e a litttle more on the cam end. The theme of that cam is still more or less what I'm after though. A 10.X/130 mph car, that is best suited on a road course or twisty back roads. I want a broad power band, while retaining good low end punch at 2400 rpm, that can make power all the way up to 6500-6800 rpm. Throttle response out of corners is important to me as well. Not looking to gain much down low, just looking to preserve what I have and start to make more power around 2400.

Bigwebb