[goatman65]

My cam is a SFT. Earlier this summer I found the lash was opening up on some of the CC roller tip rockers. I checked the cam lobes and lifters and all looked fine. I replaced the rockers with HS 1.65 rollers and still have the same problem.
Ihave driven it less than 50 miles and have had to readjust the same 3 rockers 3 times now. This last time I noticed what looks like a moly lube[dark gray] paste on and around these same rockers,which are the intakes on 6 and 8 and the intake on cyl. 5. The tip of the pushrods are also wearing,flaking.

So before I tear into it again, does it sound like the cam/lifters are wearing or maybe an oiling issue? I do have a zinc add. in the oil.

[77 TRASHCAN]

More info needed...
What type kind of rocker nuts, lock nuts, poly locks?
Screw in studs?
Which heads?
Was the rocker arm geometry ever checked?

[goatman65]

I forgot to add that the pastey stuff is magnetic. The Heads are alum KRE with KRE guideplates,screw-in studs. Heads were built by CVMS and only have about 500 miles. The cam and lifters have been in the engine and maybe a couple thou miles. The polylocks are not coming loose but the lash keeps opening up on the same rockers. The pushrods are CC Magnum and the rocker end oil hole on these 3 is flaking and much larger than it was. It also won't idle when the lash needs readjusted. I guess pulling the valley pan will tell for sure.

[Skip Fix]

Zero lash them and compare the total lift on those lobes with a dial indicator.

[goatman65]

I thought to do that before I take it apart.

[72LuxuryLeMansLa.]

I am no expert and as that is the case I refuse to add anything to oil. It has already been designed to do the job. Additives will more likely than not have an adverse effect. Run a quality oil like Mobil1 5w30 or Castrol GTX 5W30. If you prefer a 10W30 try 10W30 Valvoline VR1 Conventional Racing Oil (silver bottle).

[lust4speed]

Are you using stock pushrods? Not unusual for the pressed ends to start disintegrating and slowly grinding apart when used with aftermarket rockers at higher spring pressures. This pretty much fits you only finding metal powder on the pushrods/rockers coming loose. A cam going flat has the particles from the lobes/lifters washed back into the oil pan, picked up by the oil pump, and then distributed evenly throughout the engine. So you should be seeing gray goop on all the assemblies if it is the cam going flat.

Karl, I'd agree with you 10 years ago. The EPA stepped in and mandated a reduction in zinc and phosphorous content. It was pretty well accepted that the levels should be at about 1,600 ppm to protect flat tappet cams. EPA set the limit to about half that, and that's when cams were being lost left and right. Any multi-grade for street use falls under the EPA, and will have low levels. Even my favorite VR1 oil has been reduced to about 1,200 ppm - which is marginal.

[screamingchief]

What Skip said x2.

That's one good reason to run solid lifters,makes it super easy to check the lobe lift and see exactly where the lobes are at.

Just remember that lift @ the valve needs to account for the rocker ratio.

And understand that there will be some degree of loss/variation in a fully assembled valvetrain for various reasons (flex/play/etc).

Best way to check this is by removing the rocker arm & pushrod on the suspect lobe(s) and use a long dial indicator mandrel to take the dial indicator reading directly off the solid lifter itself as then you will see exactly what's up with that lobe.

It's also a good idea to establish a baseline for this too,as it's not unusual for the lobe lift to be just a tic even in a brand new cam.

HTH ~ FWIW

Bret P

[rexs73gto]

I've lost 3 cams in 4 years due to the junk oil we have now & I only use Brad Penn now because of the high zink & phosphate in it . I haven't lost a cam since using it. But it sounds like your looseing the cam as we type. Thats the kind of stuff I found on my rockers & push rods & all the other parts when I took it apart just to check it to.

[70f400]

Originally Posted by lust4speed

Are you using stock pushrods? Not unusual for the pressed ends to start disintegrating and slowly grinding apart when used with aftermarket rockers at higher spring pressures. This pretty much fits you only finding metal powder on the pushrods/rockers coming loose.

I had a similar problem. Re adjusted a few rockers several times found out that the CC rockers were eating the pushrods ends. Whent to full rollers and heavy wall pushrods no problems since.

[goatman65]

Just came to me. When I built the engine it had Butler 6X heads,screw-in studs,guideplates..etc. I checked the valvetrain using HS 1.5 roller rockers and found I needed longer pushrods. I drove it for awhile like that then bought the KRE alum D ports. I put the heads on along with CC 1.65 roller tip rockers, that's when the problem started.

The lash kept opening up so I bought HS 1.65 rockers. Same lash problem and gray metallic paste.

Here's what I come up with, Could the pushrods now be too long? They were ok with the 1.5 rockers but now with the 1.65 I have .622 lift on the intakes and the intake rockers are the ones that are wearing and not staying lashed.

[goatman65]

best pix I could get. You can see the gray stuff on the underside of the rockers it is also on the studs and pushrods of the same rockers,all intakes.

Pushrod tip is not really worn but the hole is jagged and flaking and bigger than it was.

Last pic is cyl 5. the oil puddle you see is where the metallic paste is, it is also in the same place between cyls 6 and 8. I can also see some wear starting on the valve stem face.

[screamingchief]

KRE-D's typically need longer pushrods as SOP.

And depending on what specific solid lifters you are using,that too could dictate a longer pushrod as well.

If the pushrods were too short with the 6x's,then they're definitely too short with the KRE-D's,it's almost certain they're not too long.

Comp roller tip rockers suck,so it's good that you got rid of them,but it sounds like you did'nt use new pushrods with the swap from 1.5 HS rollers to Comp roller tips and back to 1.65 HS rollers,so a wear problem w/the pushrods could have migrated from one rocker to the next to the next.

Even with the cr@ppy pics it's obvious the pushrods are now FUBAR.

Also,are you sure you dont have any binding in the valvetrain with the HS 1.65's and the KRE-D's?

That too could cause problems...

FWIW

Bret P.

[goatman65]

Sorry I forgot to say that I did install longer pushrods with the 1.5 HS rockers. They are CC magnum 9.500 long. When I swapped them for the CC roller tip 1.65 is when I started having the lash issue. So I swapped them for the HS 1.65 still with the longer pushrod.

Everything looks like it should,no coil bind,roller tip is not over the valve stem edge,rocker slot to stud clearance is good. It seems odd that it is only on the intakes and not the exhaust. It sure seems to be something with 1.65 ratio.

I'm going to change oil/filter and reinstall the HS 1.5 rockers and see what happens.

[steve25]

Also note that the lash opening up on Aluminum heads will always take place as they expand from heat.
I have found that decreasing the lash when set cold by .006" will keep things in the ball park.

[Half-Inch Stud]

Another case of...aluminum camshaft ?

[Skip Fix]

I've found on my motors HS 1.5s and 1.65s end up the same pushrod length.

[goatman65]

Up till now I was only looking at the pushrods/rockers on the vavles that wouldn't stay lashed. So now I pulled the rest and compared them. ALL of the intake pushrods are really bad and all different lengths. The tips are grinding down causing the lash to open up.
The exhaust pushrods show no wear and all are the same length. Now to figure out why they are wearing away. Any only the intakes. Since the 1.65 rocker puts the pushrod closer to the rocker fulcrum would that cause it to wear?
The roller pattern on the valve face is practically dead center so the length should be okay,right?
And should I buy the same pushrods and go back to using the HS rockers?

[68WarDog]

Wouldn't buy anything until I verified everything with a push rod length checker. You are running solid flat tappets correct?

[70f400]

I think the cc magnum push rods are junk. When I had a similar problem I took a file to the end and it cut them like butter. get a good set of push rods once you confirm your length is correct with an adjustable push rod.