I am in the market for a set of roller rockers. I am aware that the factory rockers (Which I ran for about 30,000 miles) are supposedly a "light at the valve" design. But, due to some excessive wear on my AFR's valve guides, I feel that a roller tip could be beneficial as to the guide wearing issues. I know that if money was no object, I would get some Jesel's. But....money IS an object, at least for me. And, I am not building an all-out race car. So, it seems that the Yella Terra's have been highly regarded here for some time. How much do they cost and where is a good place to buy 'em? Have any of you had any experience with the Scorpion brand, or maybe the Curtisbuilt's? I know that the Harland Sharp's have been out for awhile, but I don't see a lot of guys running them compared to others, like the Yella Terra's. Would like to go with a shaft mount of some kind. I am hoping to hear from some of you guys that have tried these and can base your opinion on actual experiences and installations- good OR bad. I want to stay with the stock 1.7:1 ratio. Maybe the 1.75:1 ratio of the Comp Pro Magnum's, which the Curtisbuilt's come with. I am running the "Cadillac" hydraulic roller lifters, a Comp cam with around .610 lift and 238/242 duration@.050 lift, and AFR proprietary springs.Thanks, guys.

 

Help me out guys! Thanks.

 

I'm going to be going with the Comp Pro Magnums. They're the only reasonably priced steel rockers I can find. From what I've seen and what my machinist has said, they're lighter at the tip than an aluminum rocker and they have an infinite service life compared to aluminum rockers. ALL aluminum rockers will FAIL at some point, that's one of the bad sides about aluminum. It will always happen at the bottom of the fulcrum at the center of pressure unless geometry blows *****.

 

I think you really cant go wrong with any mainstream set, whether its harlands, scorpions, or yella terras. in any case, just make sure the geometry is correct and i dont think youll go wrong with any of those. FWIW, I was pleasantly surprised at the scorpions; I bolted them on to check geometry, and right out of the box it was perfect. no shimming or screwing with it whatsoever. they clear under stock valve covers, although i did grind on the oil baffle in the stock cover just to give myself a little extra room in one spot. they look well built and sturdy enough. id reccomend them again.

 

Thanks to all who posted. I was really thinking hard about the Cutisbuilts, but evidently they are not thinking about customer service nearly as hard as I was about their products. I could not reach a person in three tries, and I left a message each time I called, after their machine said to do so, and they would return my call. I am still waiting!!!! As I said in another posting on GENIII internal engine threads, I DON'T have time for this B.S.! PERIOD!!! And I won't beg ANYONE to take my money. Shouldn't, and DON'T, have to. There are plenty of choices when it comes to quality roller rockers-And no matter how good Curtis is, if at all, they are NOT a part of my future plans on
ANY project I may have lined up. Apparently, they don't need my money, or have never heard of customer service!!! And I don't have time to find out in which department they have dropped the ball.

 

I think I am prolly going YT Ultralites here very soon unless I learn something to change my mind. I read the new design fixed earlier flaws (Valve float) and is light on the tip. I know I am not going to expose my bronze valve guides to stockers.

 

I understand the frustration, it's a shame there are many nice parts out there with poor customer service behind them. If it's difficult to do business with a company in the first place, imagine what issue's you would have if there was a problem. There are many other quality rockers on the market and it looks like you made the right decision to move along.

 

Here is the contrary view.

Unless the AFR valve/rocker mounting geometry is different from stock, for your engine with moderate lift, duration and spring loads, the stock rockers are the best deal. Why is that, you may ask. If you don't ask, skip the rest of this post.

The stock LS rockers are one of the best strength/weight designs I have ever seen (with the possible exception of some very exotic steel LS7 rockers you probably have never seen). Their weak point is the cheap trunnion bearings, but there are folks selling replacement bearings, or stock rockers with the better bearings installed. If you re-bearing your stockers, AND SET THE GEOMETRY CORRECTLY BY CHOOSING THE CORRECT LENGTH PUSHROD, you have a very lightweight, extremely stiff rocker. It's better than any aluminum roller and lighter than ANY replacement roller I've seen.

The main reason for roller tips on aftermarket rockers is to get something hard enough to not wear on the valve tip. Roller tipped rockers, esecially aluminum ones, are less stiff than one-piece steel rockers and most of the roller is dead weight which doesn't carry loads, but adds a bunch to the mass that the springs need to control. Those are big negatives. In many cases the roller barely "rolls". It slides or skids.

With re-bearinged stock LS rockers properly set up with the correct push rod length, you can use less spring and run higher rpm which the Caddy lifters are designed for. Not that you would need to turn 7500+ but that's doable. I am not a valvetrain guy (but I did sleep in a Holiday Inn Express recently) but I deal with one who has 7500 rpm HR LS engines running. The spring choice as well as the mass of the other parts and pushrod stiffness is important, of course, but the stuff to make it work is out there. It's not in "here" (LS1Tech).

If it were my engine, which would be using T4P heads, BTW, I would use LS rockers with better "bearings", a single spring, with >14 gm steel retainers, very stiff pushrods and probably the Cadillac lifters. I probably march to a different drummer however.

My $.02


Jon

 

He is so right the stock rockers are very strong. I know a guy who is running 9.06 with stock rockers with no problems. Also he is really about to put them threw the test and get in the mid8's with stock rockers.

 

Are there any applications where you think Jesels would be better than the stock rockers?

 

Sure, on a endurance race engine or one that runs to 7K daily, or if I needed to use very aggressive lobes in a lift-limit class and even higher revs. Of course if you aren't worried about money, $4500 or so will get you a really nice steel rocker arm system that is much stiffer than Jesel stuff, much lighter, lower moment of inertia, and lower friction. It's not off the shelf, however. $4500 rocker arm systems rarely are.

This kind of stuff was developed for LS engines which need to spin to 8+ with aggressive lobes. Pushrods can be 1/2 to 7/16 tapered to keep flex to a minumum. Each application is special. That's a part of the cost, but the parts and treatment of them are also very costly to produce.

I'd really like to see a super trunnion/"bearing" kit with modified stock rockers for a price somewhere between the "belly button" aluminum roller replacements now available and the Jesel shafts. Rumor has it one is in the works somewhere. I haven't seen it however.

Jon