Roller rockers

[Chuck R.]

Is there any advantage to installing roller rockers in the valve train if everything else is bone stock i.e. valves, springs, keepers etc.?

Chuck

[Joe L.]

Re: Roller rockers

Chuck-----

Personally, I think that there is. If nothing else, the engine oil temperature should run a little cooler due to the elimination of the rocker ball frictional heating. There may be other machanical advantages, too. As far as increasing HP or performance goes, I would expect the change to roller rockers would produce negligible benefit.

[Duke W.]

Re: Roller rockers

For a street engine that runs at relatively low average revs, there is no meaningful reduction in friction or oil temperature.

For a racing engine - slightly less friction might result in a percent or two more top end power. This applies primarily to FULL roller rockers, not the "roller tip" variety. Overall, there are a lot of better ways to spend money on a street engine - like pocket porting the heads and installing bullet-proof connection rods, especially on mechanical lifter 327s, whose rods are inherently weak for their rev range.

Duke

[Chuck R.]

Re: Thanks Joe & Duke

These ARE roller tip rockers that I've had on the shelf for years.

Not that I was looking for gobs of HP, I was just wondering if they would be of benefit valve train friction wise.

As always, I appreciate your help.

Chuck

[Terry F.]

Aligning vs non-aligning rockers?

Can you explain non-aligning vs self aligning rockers and when they are applicable? Thanks, Terry

[Duke W.]

Re: Aligning vs non-aligning rockers?

Self-aligning rockers arms have a shallow "slot" at the valve stem contact point that keeps the rocker arm centered on the valve stem. For this reason they are only suitable for mechanisms where constant contact is the norm i.e. hydraulic lifters.

As you can probably imagine they are not suitable for mechanical lifters.

Duke

[Terry F.]

Re: Aligning vs non-aligning rockers?

I am wondering what happens when you use roler tip rockers? Do they require a special guide? Or, are they engineered to self-align? I suspect they need a special guide or something. Just wondering, Terry

[Joe L.]

Re: Aligning vs non-aligning rockers?

Terry-------

I don't know of any roller-tipped ONLY rockers (i.e. the type with a roller tip and a ball fulcrum pivot) that are of the self-aligning type. However, there are many needle gearing pivot, roller tipped rockers which are self aligning. These in manufactured in a variety of ways to achieve self-aligning function. In some cases, the roller is a bit smaller and the rocker body forms the "Guide". In other cases, the roller tip is manufactured with a "groove" which forms the sides.

The rocker arms used on the 1996 LT4 were the first self-guided, roller rocker arms used in PRODUCTION that I am aware of. Aftermarket self-guided roller rockers were available prior to that, though.

Self-guided rocker arms, of whatever type, do not require the use of guide plates and guide plates should NOT be used when self-guided rocker arms are installed.

[Terry F.]

Re: Aligning vs non-aligning rockers?

Most of the big block heads that I have seen use guides. I wonder if they are sufficient for use on non-aligning roler tip rockers. I supose I could call crane cams and ask. Just wondering,
Terry

[Craig S.]

Re: Aligning vs non-aligning rockers?

Terry - using guide plateson the heads with ball fulcrum and roller tip (non-aligning) rockers is just fine.....Craig

[Terry F.]

Thanks for the info! Terry *NM*

[Jim V.]

Noisey...roller tips...

Had to remove some roller tip rockers on my SHP SB due to excessive sewing maching racket!.. Factory rep admitted that was a common issue. Any yes I repeatedly and accurately set the valve lash. Cam was a hydraulic as well. My 2c...dont waste your money on a motor that will rarely run at redline.

[Joe L.]

Re: Aligning vs non-aligning rockers?

Terry------

I don't think that self-aligning type rocker arms are made for big blocks. If they are, I've never heard of them. So, all big blocks use guide plates regardless of what type of rocker arms are used.

[Barry Chappell]

Re: Roller rockers

Correct me if I'm wrong on this.
I believe that Duke has stated that the stock stamped rockers are listed as having a ratio of 1.5:1, and that when measured, actually vary from that specification.
Something like 1.4?:1.

Can one assume that roller rockers, or roller tipped rockers are a "better" machined product and actually have a ratio of 1.5:1 ?

If so, then you would think that the engine should actually perform better.

Any comments ?

Thanks
Barry

[Joe L.]

Re: Roller rockers

Barry-----

Yes, that is another advantage of most roller rocker arms. The rocker ratio is usually much closer to the specified ratio than stock-type, "stamped steel" rocker arms. So, that will result in some performance benefit.