Rocker problems

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coronet69swede

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Hi. A couple of my roller tip rockers bushings have failed on the axel with big çlearences. Engine 340 is nearly stock with a bit hotter cam and springs. I have NOT done any oiling mods. Oil is coming when the camholes line up and i pump with electrical drill. Should i have done the groove in nr 2 and 4 camjournal? Not a race engine.
Johan.

20180211_103452.jpg


20180211_103444.jpg
 
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What is your definition of failed? Have the bushings in the rocker body worn out resulting in too much play?
Not evident to me from the images...
 
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I kept smoking rocker arms in one of my engines. I took a dremel and cut a small groove in the rocker shaft from the oiling hole to get oil all the way across the rocker bushings. Worked great. Been driving it for years and no more burnt up rockers.
 
Maybe a silly question but are you sure you didn't install the rocker shafts upside down?
 
There in no silly quastions and no.
Cam Style:Hydraulic flat tappet

Basic Operating RPM Range:1,200-5,000

Intake Duration at 050 inch Lift:204

Exhaust Duration at 050 inch Lift:214

Duration at 050 inch Lift:204 int./214 exh.

Advertised Intake Duration:278

Advertised Exhaust Duration:288

Advertised Duration:278 int./288 exh.

Intake Valve Lift with Factory Rocker Arm Ratio:0.421 in.

Exhaust Valve Lift with Factory Rocker Arm Ratio:0.444 in.

Valve Lift with Factory Rocker Arm Ratio:0.421 int./0.444 exh.

Lobe Separation (degrees):112
 
He said the axles in the roller-tips
I know..... he said bushings and then showed us the shafts..... but he said a couple of roller tips,lol, so
Hydraulic lifters? At what preload?
Lotsa ticking going on?
Are your push-rods still all straight?

Kindof sounds like shock damage. I better go check mine,lol.
 
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i have read about bananagrooves


If those rockers have 2 half bushing pressed in from each side, a groove won't do anything.

If I was a betting man, I'd say you have two issues. Number one is you don't have near enough flow and pressure to the rockers. If I don't have 40 pounds at idle hot I fix it. This is why a high volume pump is critical. You get more oil sooner. The rockers are the last to get fed. If you have under 40 pounds of pressure with a standard pump you'll be lucky to have 5 pounds at the shafts. That isn't enough and I've tested it many times over the years. It's not a needle bearing rocker. It has to have oil volume and pressure.

Second, I'd say you also have geometry issues. They show up in many ways. The bushing isn't as forgiving as a needle bearing (I don't use needle bearings on a reciprocating shaft but the engineers will tell you it doesn't matter) when it comes to geometry. You can load the rocker in the wrong direction, or move the load so that direct pressure isn't acting on the rocker at the correct place.

You'll have to fix the rockers with the worn bushings and polish the shafts. Then fix the other issues.
 
Hi Guys.
Read my 1 post. Sorry for the confusion. Of course it is that shaftbushings i mean.
All are worn betwweeen 0,0118-0,0255 inch
Yes some ticking. None at begining of summer.
All push-rod straight. Yes.
Hydraulic at half turn preloade.
As for geomerty i only tested that the rollertip moves in the middle of the valvetip.

Thanks for the tips.

Johan
 
Hi. A couple of my roller tip rockers bushings have failed on the axel with big çlearences. Engine 340 is nearly stock with a bit hotter cam and springs. I have NOT done any oiling mods. Oil is coming when the camholes line up and i pump with electrical drill. Should i have done the groove in nr 2 and 4 camjournal? Not a race engine.
Johan.

View attachment 1715140770

View attachment 1715140771

what brand of rocker is that?
 
I vote for an off the shelf install, soft shaft, heavy grade oil or low pressure.
 
So with those rockers where's the oil going to go? It's going to follow the path of least resistance. And what is that, Thru the shaft, out the oiler hole, between the two bushings, around to the top, and exit the pee hole on the top. The bushings get nothing cause it all exited out the pee hole on top of each rocker. = dry worn bushings. You need more volume of oil to keep up!
 
rockershaft.jpg
Hi.
Thanks for all the input.
The rockershafts on the the old setup is like sandpaper.
my new compcams is like mirrorfinish.
I have melling HV pump.
Is it time to full time rocker oiling?
Put it on the lahte and make a trail all around
or drill new holes for oiling twice per revolution?
 
View attachment 1715154644 Hi.
Thanks for all the input.
The rockershafts on the the old setup is like sandpaper.
my new compcams is like mirrorfinish.
I have melling HV pump.
Is it time to full time rocker oiling?
Put it on the lahte and make a trail all around
or drill new holes for oiling twice per revolution?


If you are running a solid roller you can groove the cam. If it's not you don't need the groove. FWIW unless the shaft is coated I mirror polish them all. I have the same rockers and shafts you do, and mine don't look like that.

I run no less than 50 pounds of oil pressure at hot idle. Especially if it's a plain or bushed rocker. Needles can use a bit less but there are other reasons not to run oil pressure low.
 
That grey looking shaft looks shot blasted.

Is the cam for a magnum and has no oil feed holes?

Something real wrong , viscosity is not an issue, it's lack of flow.
 
If you are running a solid roller you can groove the cam. If it's not you don't need the groove. FWIW unless the shaft is coated I mirror polish them all. I have the same rockers and shafts you do, and mine don't look like that.

I run no less than 50 pounds of oil pressure at hot idle. Especially if it's a plain or bushed rocker. Needles can use a bit less but there are other reasons not to run oil pressure low.

Second, I'd say you also have geometry issues.
how can you se that?
 
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