Rocker arm wear, oiling issue?

[Gregs672000]

So I knew I had some pitting on a couple rockers that I figured were simply a bad regrind or metallurgy. However I found that the front 5 rockers were all starting to pit, and I have some minor scratches on the cam (not on the end, but on the ramp) that will polish out. The back 3 were perfect. When I swapped in the Isky cam (with reground rockers) I had a plug or something that stopped oil flow to the front 4 which resulted in pitting fairly quickly. I cleaned out the cam (or so I thought?), got the rockers recut, and off we went. Now a year later, the problem is back or has continued. I pulled all the rockers, pulled the plugs and spun the engine (ignition off of course) and checked oil flow through the cam. Sure enough, the oil starts flowing at the back of the cam and works forward. 20 cranks, no oil. 10 more, oil to the rear 3 or 4. 10 more cranks and oil is flowing through all 8. Oil pressure, granted being measured on the idiot gauge, has always been fine. I also always pre-lube the engine from a cold start by spinning the engine before firing it (usually 15-20 cranks, may do more after the results of my tests). Currently running Castrol 20/50, oil tube in the filter.

I plan to pull the cam, clean it out again, regrind another set of rockers and see what's what. My question to the group is, has anyone else had pitting or oil flow problems with more aggressive (or stock) Cams? My springs are stock and well able to control the valves (non-stock, lighter, 7mm stems) so no additional spring pressures, and the wear on the cam is on the ramps, not the tip. I'm thinking that I've just got some degree of plugging in the cam, but thought I would put it out there. Some engines are known to oil some areas better than others.

[Linda]

Are you using the zinc additive products? Lucas break in oil is used in smaller amounts by some owners, I have read, with every oil change.
Since the stuff is supposed to adhere well it might reduce wear.
Linda

[Toptech360]

I'll catch flack for this cause people are hard set with their oils but 20w50 is too thick! I bet you will see cold oil flow much faster if you switch to a 10w-XX oil.

If oil is eventually flowing to all rockers as you describe its likely not a plugged passage. I would suspect that your oil pump is bypassing because it can't flow the thick oil on startup.

As a side comment, i recently switched to a 0w40 oil (blasphemous i know!!) The engine runs great with it, and i get nearly instant oil pressure on cold starts. I'm pretty ocd when it comes to my engines and even the switch between 10w30 to 0w40 the oil light turns off noticably faster and my aftermarket gauge shows an instant 50 psi once the engine pops off.

Try a 10, 5, or 0 oil and i bet you will see those front rockers get oil much quicker.

[mlwebb]

Most modern oils have eliminated or greatly reduced zddp (zinc compound)- which really helps reduce metal to metal wear. Most pre 75 or so engines should use an oil with high zddp (valvoline VR-1, some rotella, and a few of the fancy brands). IMHO all other oil choice questions (weight, syn or dino, brand, etc) are secondary to the zddp choice. There are probably a few dozen pages of discussion on the subject on the subject here, and another several thousand pages elsewhere (Bob's the Oil guy, etc). Going a little lighter might help too.
Michael

[msampsel]

Is your car driven frequently? Old tales of yore (Thomas Walter) claimed the overhead cam cars needed to prime the oil by turning the pump (remove dizzy, and with a drill and appropriate tool prime the oil pump)

I believe one month without a start was too long per this expert.
I've never done this. I can revisit the article for additional details if there is interest.

[fj20spl311]

An Accusump and 5W or 10W oil

[spyder]

I pull the cover and smear molly grease on the cam after an extended rest.

[fj20spl311]

I pull the cover and smear molly grease on the cam after an extended rest.

Good idea, it could be done a the beginning of an rest.

[Gregs672000]

Thanks for the replies and ideas. I thought I had switched to a lighter oil but 20/50 is written on my filter, so maybe I didn't. I was running Mobil 1 15/45 previously, and have researched various oils and as I recall I did decide on Valvoline racing VR1 (in fact, that may be what is in there... I honestly don't recall now, will start writing it on the filter) as it has a good amount of zinc. It is possible I was not able to get the VR1 last time and just did Castrol 20/50. I did read the various discussions about flow vs weight, so I do appreciate the feedback on different weight oils and how fast they flow in the real world. I think I will switch to a 10/40 or 10/30 and stick with the Valvoline VR1. I did consider an Accusump but unless others have had problems I probably would not go with the expense, though I do know they reduce wear at start up everywhere so maybe it would be worth it. Since I have run many cams and I didn't have chipping problems on my rockers, I am thinking that I'm just not getting enough flow and some kind of plugging may still exist. The back three are perfect and they clearly got the oil flow faster than the others. I also tend to set my lash tighter than stock (4in and 6ex cold, comes to 6 and 8 hot), and I noted the wear on the cam is nearer to the base circle, so maybe the tighter lash contributed? I think I will check valve lash with the tip straight up but also slightly off to one ramp or the other where it should still be the same lash. However, again that would only make a difference if the oil itself is not lubing the rocker well enough after the cam has wiped the rocker... but there has got to be a lot of oil splashing around under that cover, and the pressures on the rocker/cam would be minimal even if the lash is reduced or non-existent, so...
As I recall, oil flows to the cam from the back, but as I look at the cam towers (minus cam) it looks more like the center tower and the cam are different there, with a big groove machined into the cam... is this the source for oil or does it come up all towers or just the back? All of the towers have holes for oil, but I don't know the source of the oil for the inside of the cam and thus the lobes. If oil comes from the center tower, then that does suggest a plugging problem as why would the back three rockers oil up quicker than the others?
The cam and rockers are at my friends shop now and he will inspect them and run them to Delta cam to get their feedback as well

[Gregs672000]

Talked to Steve after he checked things out. Got some wear on the lobe tips too but not bad, should easily grind out. He's thinking oiling problem as well. Lash etc of no issue. We're gonna get things cleaned, recut etc and assembled, then we're gonna put some oil pressure to the system via the sending unit fitting and see how the oil is flowing to the cam. Will probably fit an external pressure gauge on a T-fitting at the block just to see what it's really doing vs the idiot gauge to make sure my pump is good.
Regarding flow, he said there is not much difference between 10 weight and 20 weight, and mostly proper oil weight is determined by the tolerances the engine was designed to (and outside temps). Someone told me a long time ago to run 20/50 for "better pressure" but I do believe stock weight was 10/40. He suggests I run stock weight. I expect to get things back sometime next week, will report results.

[Toptech360]

I also ran a t fitting to have both idiot light and actual gauge reading. Added comfort being able to see a gauge!

I think running a 10w40 is a good choice. The end goal is getting oil to all points as fast as possible. Once warm the 10 or 5 or 0 doesnt matter. But cold (even at 80 degrees f) is where "thicker" oil won't flow as quickly. I chose to try the 0w mobil1 oil because it had really good technical specs both hot and cold and since my engine was refreshed with new bearings and rings all the tolerances are (barely!) within specification. sounds like your engine is also healthy and a 40 weight oil is what the engineers called for 50 years ago, it should still apply today! Hope you get it sorted out quickly and back on the road.

[JT68]

I'll be surprised if you actually find an physical oiling problem although sometimes the cams get some crap in them when reground. The only way to clear it is to remove the plugs on the ends and flush. I think if you had any major restriction it might have failed in a much worse manner.

This sounds like oil/metallurgy to me...

I don't trust the castrol at all for this cam/lifter design. Even back in the day it was not as good as some other oils and my bet is that like most oils, the castrol formula now is inferior to that of 20 years ago. Just a lot of marketing banter.

Mobil 1 is very good, but again I'm not certain about it either with this lifter cam design for long time use.

Kendall green oil was exceptionally good for these high surface loading parts. The closest to that these days is Brad Penn which has a lot of ZDDP (more than Mobil 1). I've had no wear issues with Brad Penn to date, but it is hard to find/mail order.

Redline also makes some amazing products - incredibly lubricious. Nice folks, they will talk to you about specific wear issues/weight and help you out. Redline is the only oil I've ever met that may actually increase your idle rpm (noticeably) simply due to friction reduction-- no joke, it is real slippery stuff.

Sounds like a U20 oil test is in order....

You do need to polish (preferably parkerize) the cam, grind the rockers (or new) and use break in lube again. BradPenn and redline make great cam/assembly lubes too. Hope this helps. j

[Gregs672000]

Thanks JT, pretty much the Plan! I know there was a plug in the cam before, as I had already wiped out 4 rockers in the same way. I cleaned it out myself, but did not remove the ends, so I think my cleaning job may be somewhat suspect. It will be done right this time! We'll test flow after its all back together via the pressure sending unit in the block and a pump. If that's good, then we'll break in the cam and get an actual pump pressure and make sure it's decent. Then an oil change (VR1) and off we go to see how it does.

BTW, do you know where the cam gets its supply of oil to the lobes?

[JT68]

Yes, going from memory, it is supplied by the 1,3 and 5 camstands. (I can double check). There is only one oil galley supplying the head at the rear. Everything feeds off that through the center galley that ends at the upper tensioner.

valvoline? Probably not too bad, but Since you are having this issue, I'd strongly recommend Bradpenn or Redline to try to rule out the actual oil-especially during break in. J

[Toptech360]

Very very long blog, but lots of good information on all things motor oil. I'm sure much of it is debatable for arguments sake, but overall its interesting in an overwhelmingly repetitive way. Lol.

https://www.google.com/amp/s/540ratblog ... nking/amp/