Roller rocker for BigBlock ??

Roller rocker for BigBlock ?? - 04/13/12 04:42 PM

What do you think about them for 0.710 lift??

http://www.kmjent.com/cart/product.php?productid=367&cat=7951831&page=1

Attached picture 7163311-HemiDart.jpg

Posted By: StealthWedge67

Re: Roller rocker for BigBlock ?? - 04/13/12 04:54 PM

Thats a lot of cam for budget rockers. If they were bushed steel units, I'd think you would be okay. But those needle bearing aluminum ones leave a lot of margin for error.... error that could cost you a motor? I'm a guy that normally does NOT subscribe to the "more expensive means its better" mindset, but I'm hesitant with these in your situation.

Posted By: 66er

Re: Roller rocker for BigBlock ?? - 04/13/12 05:32 PM

Junk. I wouldn't buy anything less than Harland Sharps if I were you. I've broke a set of Cranes with my .650 roller. I now run a RAS stainless set.

Posted By: Dart of Denmark

Re: Roller rocker for BigBlock ?? - 04/13/12 06:46 PM

Thanks! That confirm my thought's about them!

My heads are indy sr if I go with Harlans Sharp is S70015k best options for me? I want 1.5 ratio.

Attached picture 7163468-HemiDart.jpg

Posted By: 1968RR

Re: Roller rocker for BigBlock ?? - 04/13/12 07:45 PM

Quote:

Thanks! That confirm my thought's about them!

My heads are indy sr if I go with Harlans Sharp is S70015k best options for me? I want 1.5 ratio.

The S70015k rockers are what I run with my SRs. They fit really well and no shimming was necessary. Be sure to look the Harland Sharp rockers over very carefully for metal shavings before you install them.

Posted By: steeldust

Re: Roller rocker for BigBlock ?? - 04/14/12 03:01 AM

T&D

Posted By: polyspheric

Re: Roller rocker for BigBlock ?? - 04/14/12 05:36 AM

That big photograph tells you exactly where they're going to break.

Posted By: rickraw

Re: Roller rocker for BigBlock ?? - 04/14/12 05:40 AM

x2. haven't had any problems with mine.

Posted By: gregsdart

Re: Roller rocker for BigBlock ?? - 04/14/12 10:59 AM

Definitely spend the money here. I would also be looking for steel body's if anybody like T& D makes them. After what I have spent on repairing Jesel stuff, I want to go to the best.
My total lift is .775.

Posted By: Dean_Kuzluzski

Re: Roller rocker for BigBlock ?? - 04/14/12 02:15 PM

Quote:

That big photograph tells you exactly where they're going to break.

Could you elaborate on that......just curious.

To me, the needlebearings look too narrow to support any real valvespring pressure for long.

Posted By: MR_P_BODY

Re: Roller rocker for BigBlock ?? - 04/14/12 03:24 PM

Quote:

Quote:

That big photograph tells you exactly where they're going to break.

Could you elaborate on that......just curious.

To me, the needlebearings look too narrow to support any real valvespring pressure for long.

Smaller needles gives you more rollers in the loading
area

Posted By: jamesc

Re: Roller rocker for BigBlock ?? - 04/14/12 05:00 PM

Quote:

Could you elaborate on that......just curious.

my guess would be where it's relieved for spring clearance

Posted By: JohnRR

Re: Roller rocker for BigBlock ?? - 04/14/12 05:24 PM

Quote:

Quote:

Quote:

That big photograph tells you exactly where they're going to break.

Could you elaborate on that......just curious.

To me, the needlebearings look too narrow to support any real valvespring pressure for long.

Smaller needles gives you more rollers in the loading
area

Not in the case of those junk rockers , did you check the link ?

Posted By: polyspheric

Re: Roller rocker for BigBlock ?? - 04/14/12 06:57 PM

Yup - the notch where they needed room, top and bottom. All bending stress focuses on changes in shape or direction.
I have to believe that perhaps 50% of the people who make this stuff have no engineering background at all - they just copy someone else's work.

If you need more room, since the strength is already fixed at the cross-section where clearance is needed, the proper method is to remove even more material, and leave the largest possible radius at the transition.
If those were mine, I'd be buzzing away at the cuts with my tiny Dremel, just blending the cuts into the parent casting.

Yes, small needles are better because you get more. Does that seem counter-intuitive? Each needle (assuming equal length) makes only line contact on the shaft and in the rocker, so more = better.
The smaller needles also have lower moment of inertia, so when they stop and change direction (every cycle) they begin rolling properly rather than skate for a millisecond.
The smaller needle also allows the rocker to have more material around the shaft, or a bigger shaft, since the needles are obviously smaller OD by 2 � the difference in needle thickness. It's small but it's in the right direction. Replace 1/8" needles with 1/16", you get 1/8" free room to bulk up another component (or don't, and save weight).

Attached picture 7164647-440rockers2a.JPG

Attached picture 7164647-440rockers2a.JPG

Posted By: polyspheric

Re: Roller rocker for BigBlock ?? - 04/14/12 07:03 PM

BTW: those cute 90� angles are proof that this is not an FEA design, and that the "designer" chose the easiest possible solid geometric shapes (like building something using nothing but bricks).
A huge amount of weight can be pared off that rocker with complete safety. Some of it could be done on a mill by mounting all rockers on a shaft and cutting them all at once, then re-position, etc.
I don't think extra RPM is always a goal, but more control with the same springs always is.

Posted By: MR_P_BODY

Re: Roller rocker for BigBlock ?? - 04/14/12 07:04 PM

Quote:

Quote:

Quote:

Quote:

That big photograph tells you exactly where they're going to break.

Could you elaborate on that......just curious.

To me, the needlebearings look too narrow to support any real valvespring pressure for long.

Smaller needles gives you more rollers in the loading
area

Not in the case of those junk rockers , did you check the link ?

Nope didnt look
EDIT
I just looked.... I meant dia not those short needles

Posted By: JohnRR

Re: Roller rocker for BigBlock ?? - 04/14/12 07:32 PM

Quote:

Quote:

Quote:

Quote:

Could you elaborate on that......just curious.

To me, the needlebearings look too narrow to support any real valvespring pressure for long.

Smaller needles gives you more rollers in the loading
area

Not in the case of those junk rockers , did you check the link ?

Nope didnt look
EDIT
I just looked.... I meant dia not those short needles

I had a feeling you didn't look , those bearings are scarey , along with the CCJ rockers and their brittle roller shafts breaking ...

The last place to skimp in on rockers .

Posted By: Dean_Kuzluzski

Re: Roller rocker for BigBlock ?? - 04/14/12 10:08 PM

Quote:

Quote:

Quote:

Quote:

Quote:

Could you elaborate on that......just curious.

To me, the needlebearings look too narrow to support any real valvespring pressure for long.

Smaller needles gives you more rollers in the loading
area

Not in the case of those junk rockers , did you check the link ?

Nope didnt look
EDIT
I just looked.... I meant dia not those short needles

I had a feeling you didn't look , those bearings are scarey , along with the CCJ rockers and their brittle roller shafts breaking ...

The last place to skimp in on rockers .

Yeah, I meant the width of the needle bearings, side-to-side, NOT diameter.

Posted By: polyspheric

Re: Roller rocker for BigBlock ?? - 04/15/12 04:15 AM

The mfg. has decided to avoid the mistake made by almost all rocker mfg. (using full complement Torringtons) and instead is using caged bearings.

Positive: it allows him to use softer shafts by running the inner race directly on the shaft (a full complement uses the shaft as a journal surface and it must be like Rockwell 53-33).
The rollers never sweep past their neighbors turning the other way (as do all full complement). This hasn't been a problem TIKO, since the rocker body does not actually rotate, but only oscillates a few degrees, and despite their small diameter the needles don't rotate much either.

Negative: huge reduction in total bearing area.

Posted By: JohnRR

Re: Roller rocker for BigBlock ?? - 04/15/12 02:18 PM

Quote:

The mfg. has decided to avoid the mistake made by almost all rocker mfg. (using full complement Torringtons) and instead is using caged bearings.

Positive: it allows him to use softer shafts by running the inner race directly on the shaft (a full complement uses the shaft as a journal surface and it must be like Rockwell 53-33).
The rollers never sweep past their neighbors turning the other way (as do all full complement). This hasn't been a problem TIKO, since the rocker body does not actually rotate, but only oscillates a few degrees, and despite their small diameter the needles don't rotate much either.

Negative: huge reduction in total bearing area.

So now I'm lost , the CCJ rocker actually built something RIGHT ??? I figured that bearing was cheaper than a full caged needle bearing ?

Posted By: polyspheric

Re: Roller rocker for BigBlock ?? - 04/15/12 03:01 PM

Sorry, should have used the <sarcasm> tag.
Th caged roller is easier to manufacture but IMHO inferior to the full complement. They eliminate a major cause of failure - shaft hardness - by using the shaft only as a support, not a bearing surface.
Cages for roller separation become important when the speed of rotation gets above perhaps 3,000 RPM at this size. Harley used full complement on cam bearings since 1958 (1/2 engine speed) but caged rollers throughout the engine.

Posted By: JohnRR

Re: Roller rocker for BigBlock ?? - 04/15/12 03:50 PM

Got it ... thanks