Rocker Arm Oil Pressure

[Earlie A]

Or 1/3 of the way through the shaft.

Wouldn't there be noise and lash issues before that much shaft is gone?

 

[Newbomb Turk]

Yes, the needle would have to get through the steel end seal/cage and through the steel shim to escape. If the shim were not supported by the pedestal then the shim could be pushed out of the way I suppose.

I'm just trying to understand/find the real facts. If a properly hardened and ground shaft is used and if a good needle bearing is used (like INA, USA made) and if the rocker manufacturer is using the highest quality aluminum or steel for the rocker body, do the needle bearings fail?

One failure by Brand X's needle bearing could ruin the reputation of the needle bearing rocker for all companies on a forum like this. Or what if a needle bearing is used on a non-hardened shaft like a factory Mopar shaft or a Chinese shaft. That might result in a failure, especially if an inferior shaft is subjected to high spring pressures and high rocker ratios. A needle bearing is not going to like a flexing shaft.

Kind of surprising that the best names in the rocker industry are using needle bearings if they are so prone to failure.

In their catalog, T&D does mention that bushings are available as an option for situations where contamination is the norm, like dirt racing.

If we are talking high load applications bushings are better IF you can get oil to them.

As PRH said above, needs will run with near zero oil and they certainly don’t need pressurized oil.

Bushings do. If you can’t get oil to the bushings they will grab the shafts.

Some guys don’t like all that oil in the valve covers that bushings require. So they pushrod oil.

If you have OE Chrysler oiling and you oil through the pushrods you add the leaks at the lifters.

Bushed rockers and even lifters have their issues. The two things that kill needle bearings in the situation we are talking about are not enough spring load and bad geometry.

You want to kill a needle bearing lifter? Let the spring load get low.

I have a friend who just killed his rockers last weekend. I know the geometry is wrong and when it gets here I’m betting his spring loads are in the low 200’s.

It’s going to cost a **** ton of money to fix it because he listened to the simple minded idiots who think it’s 1980.

 

[PRH]

Sometimes…….bad things happen to good parts ;)

The example I use is……..When you see an engine failure in the NASCAR cup series from a major team…….do you really think it’s because they didn’t use the best parts available?
It’s because “**** happens”.

 

[TT5.9mag]

Wouldn't there be noise and lash issues before that much shaft is gone?

I definitely think so. But race cars with race parts are loud and I’m betting not everyone lashes their stuff often enough when using solids.

 

[TT5.9mag]

You want to kill a needle bearing lifter? Let the spring load get low.

The LS we killed one in had a good pac spring on it that was 860lb over the nose. Engine had 1200 street miles and at least 30 passes on it, when one lifter **** the bed. We never did figure out why.

 

[PRH]

If one were talking to say, Jesel or T&D about what they suggested for rockers for an LS drag n drive combo running 860lb open force, what would the recommendation be?

That combo is out of my wheelhouse, but my approach would just be more conservative.
A milder/tamer set of cam lobes that could live with springs around 700lbs(or maybe even less).

 

[Newbomb Turk]

The LS we killed one in had a good pac spring on it that was 860lb over the nose. Engine had 1200 street miles and at least 30 passes on it, when one lifter **** the bed. We never did figure out why.

That’s one of those deals like PRH mentioned. Parts fail.

I almost went to work for a guy back in 1997. I was going to crew chief two cars for him and drive the semi to the races.

He had a pretty big budget and his goal was in 3-5 years start a TAD program.

Anyway, he had a brand new timing set fail. He wanted whoever made it to pay for the damages and they laughed at him.

He paid a destructive testing company to test the failed cam gear and they found not only was the heat treating wrong for the materiel (I forget what steel they were using now) but they used the wrong material. The funny thing is, this guys business was working with all kinds of steel and heat treating. He was smart enough to not use the company he used to test his stuff.

Anyway, he sent the information to his lawyers and in six weeks he had a check to repair the damage and then some.

Sometimes if you have the money and other resources you can determine the failure. Most of us can’t do that.

Sadly, he had a widowmaker the Saturday before Indy 1997. I went to his funeral and it was sad.

Exactly a year later I went to the funeral of my friend who hooked us up.

I’m still sick about both of them. One made it 60. The other was 62. What a shame.

 

[Inertia]

Lotta " what if " theories.
That's where actual testing is very important.
Results being the only proof .
What works for some, maybe not another .

Imagine having to design, then test, then improve on failure.
That's how it was done in the old days, not computer theory .

 

[TT5.9mag]

If one were talking to say, Jesel or T&D about what they suggested for rockers for an LS drag n drive combo running 860lb open force, what would the recommendation be?

That combo is out of my wheelhouse, but my approach would just be more conservative.
A milder/tamer set of cam lobes that could live with springs around 700lbs(or maybe even less).

We were using stock rockers with a trunion upgrade. Very common in the LS world for that to be a solid package.

 

[TT5.9mag]

That’s one of those deals like PRH mentioned. Parts fail.

Agree. Unfortunately it took out the whole bottom end.

 

[AZBoneFish]

I run bushed rockers and bushed solid roller lifters from now on. One of the engines I put together for a drag week type deal ate a needle bearing solid roller lifter and the damage to the engine was “all encompassing” to say the least. Never again. On my personal W2 headed magnum I run bushed crane gold rockers with full time oiling to the shafts with .030 (if I remember correctly) restrictors in each line, as well as pushrod oiling from the hydraulic roller lifter. The pushrod oiling deadheads at the adjuster cup. I measured pressure at the shafts and on a drill with cold oil I had 80psi at the gauge and 80psi in the shaft. Never measured it hot or with the engine running.

On my HS rockers, the oil doesn't stop at the adjuster cup. There's an orifice that leads to the center of the rocker, in the space between the two needle bearings. Blew air through it just to verify. So essentially, it would be oiling the bearings from both the shaft and pushrod. Am I understanding you correctly on that subject? Trying to learn as much as I can on the matter.

 

[Newbomb Turk]

Lotta " what if " theories.
That's where actual testing is very important.
Results being the only proof .
What works for some, maybe not another .

Imagine having to design, then test, then improve on failure.
That's how it was done in the old days, not computer theory .

Yup

 

[TT5.9mag]

On my HS rockers, the oil doesn't stop at the adjuster cup. There's an orifice that leads to the center of the rocker, in the space between the two needle bearings. Blew air through it just to verify. So essentially, it would be oiling the bearings from both the shaft and pushrod. Am I understanding you correctly on that subject? Trying to learn as much as I can on the matter.

Yes, the Harland sharps designed for pushrod oiling, have passages that oil the shaft through the adjuster and rocker body. My cranes are NOT drilled like that. They are designed for normal LA oiling. But I use them on a magnum block and I use the pressure port for full time oiling to the shafts instead of timed oiling through the cam. That leaves no pressurized oil to the adjuster, just splash oil. With big spring pressure that can be a problem. So since I had pushrod oiling as an option with the magnum roller cam and lifters, I use it for the adjuster. But I dead head it there so as not to have too much oil up stairs.

 

[Ironmike]

I personally dislike needle bearing rockers, but that's one guys opinion only.

Yeah, me too brutha. And any motor I build will be pushrod oiled !