Improper Cam Break In - Zinc Additives?

flatchat(Chris)

Supporter
Thinking that nothing could go wrong with a mild W302 sbf rebuild -- hydraulic flat tappet "Crow Cams and lifters" (POS) then after about 30 mins of run time this:-
 

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Dave Bilyk

Dave Bilyk
Supporter
Re: They don't make cams like they used to--it seeems

Chris,
does POS stand for Pile of s**** then?
What oil was used and did it contain the requisite amount of ZDDP?
Motor Oil Additives
or am I on the wrong track, maybe this is a different issue.

Dave
 

Randy V

Moderator-Admin
Staff member
Admin
Lifetime Supporter
Re: They don't make cams like they used to--it seeems

Yep - probably not the cam or lifter manufacturers fault on this one... The oil manufacturers have been forced to remove almost all of the Zinc from the oil to meet some emissions specifications.. You can, however, add the zinc back in by using STP or other ZDDP lubricants. Also, there are special oils like Joe Gibbs oil that have SUPER high quantities of zinc just to prevent this from happening.

Proper break-in is the key however... 20 minutes of constant running at a minimum of 2000 RPM.. Also, if your valve springs carry more than 115# on the seat, you should switch to lighter springs for the initial run-in of the engine...

Make sure that you flush that engine very well to remove all the shrapnel from it. I also pull the oil pump and cooler and manually clean / inspect.. If your oil cooler is after the filter, then the cooler should be fine - but would still advise flushing. To flush, I use Kerosine / Diesel fuel..

==edit==

You can still find some Truck use oils such as Rotella that still have ZDDP in them - but as I understand it, even they are being impacted by the emissions requirements and will soon have all but bare traces of zinc removed..
 
Re: They don't make cams like they used to--it seeems

Most filters bypass. I just dispose of coolers after such incidents.

Tim.
 

Rick Muck- Mark IV

GT40s Sponsor
Supporter
Re: They don't make cams like they used to--it seeems

You can still find some Truck use oils such as Rotella that still have ZDDP in them - but as I understand it, even they are being impacted by the emissions requirements and will soon have all but bare traces of zinc removed..

Rotella and other diesel oils do still have Zinc/ZDDP but if you are revving your engine over 5000 RPM they can be problematic. Diesel oils are designed for engines that have a max RPM of 2600 or so and do not have high levels of anti-foam additives and therefor may allow the oil to froth and foam at high RPMs causing pump cavitation and other issues.
 
Re: They don't make cams like they used to--it seeems

Some thoughts:

Wrong oil is my bet.
Old Rotella had good ZDDP, Shell has dropped the percentage. Check your supply before you modify a cam!!!! (rumor - check w/ Shell)
I've never noticed foaming with Rotella - maybe I shouldn't drive my Pantera like a diesel!

Please update us on your oil in that motor.
 

flatchat(Chris)

Supporter
Re: They don't make cams like they used to--it seeems

I think you're right about the oil -- used Penzzoil 20/50 for years in the old motor --can't get that any more, so used what I thought was the equivalent in Lucas 20/50 -- we'll be a bit wiser next time --we have the ZDDP additive and will research suitable oils -- what a PITA !:stunned:
 
Re: They don't make cams like they used to--it seeems

Proper break-in is the key however... 20 minutes of constant running at a minimum of 2000 RPM..

At least. While my expertise is largely in bike engines and I have zero experience with push-rod engines, low rpm is hell on cams, far better to have it running far higher rpms.

In the case of the bikes probably 4k+. Indeed HRC recommend warming up the NC35 at 5-6k, but then that revs to 14.5k! :)
 

Kevin Box

Supporter
Re: They don't make cams like they used to--it seeems

Chris

Check out the Mobil 1 range.
From memory there is one of them that still has good levels of ZDDP.
I know it is not the normal over the counter one.
I will try to find the info for you.

I think it was 5-50 which is a race type oil.

Other option you may consider now is changing to roller cam followers.
If you head down this track I can give you some pointers on pros and cons.


regards Kevin B
 
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Terry Oxandale

Skinny Man
Re: They don't make cams like they used to--it seeems

I've done the taboo thing of running new cams with used lifters, and have never had a problem with the usual (Castrol) oil if the break-in process is followed. I feel the key to the success I've had with any break-in is the 2500 rpm run for 20 to 30 minutes. Keeping that oil spashing around onto the cam lobes is critical.
 

Seymour Snerd

Lifetime Supporter
Re: They don't make cams like they used to--it seeems

Re: ZDDP etc.

The valvoline racing oil that is "not for street use" has a level of zinc that's probably OK, and the "street use" VR1 is not far behind. See:

Valvoline.com > FAQs > Motor Oil Car FAQs > Racing Oil for a discussion of zinc and flat-tappet issues.

Also you can buy it as an additive, although this is something where too much can be bad as well.

The Mobil One racing oils that address this issue are described here:

http://www.mobiloil.com/USA-English/MotorOil/Oils/Mobil_1_Racing_Oils.aspx
 
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Re: They don't make cams like they used to--it seeems

If that much damage was done in 30 mins of running, I would say its more likely to be no oil rather than the wrong type. Even vegetable oil should have been able to prevent that much damage for 30 mins.

The other thing I would check is the spring loading on those two valves, the others seem fine. So its not a problem affecting the whole valve train. Or are they all like that?
 
Re: They don't make cams like they used to--it seeems

That seems like some bad metallurgy.... So long as the cam lobes were splash lubricated in the normal manner then the cam and follower shouldn't wear like that, even with a low-zinc oil. If either the cam or the follower wasn't properly hardened and treated then I wouldn't be surprised, but that's assumed when you buy new parts from a reputable source. Or at least it should be.
 
Re: They don't make cams like they used to--it seeems

Hi Chris

I agree on with jon and cliff,

I have wrecked my fair share of engines and did the reseach afterwards, and I'd be surprized that lack of zinc could cause this much damage in such short time.

it looks like a severe lubrication problem (ie complete lack of oil let alone zinc), or indeed a wrongly heat treated set of followers although that would be very strange.

also are you sure the combination of followers, rockers, rods, springs, etc etc is OK?

I saw this in the old 1900cc engine of our 40 year old campervan (citroen HY) it had such worn out rockershafts that on 2 valve the full lift coud not be had so the followers were badly pitted. probably from years and years running without adjusting the valves, they looked much the same as the ones in your picture, yet this engine has probably been around the world a dozen times.

regards Thomas
 
Re: They don't make cams like they used to--it seeems

in the aircraft industry, both Lycoming and Continental have an engine oil supplement they recomend for thier engines at each oil change. has all the additives, cost about 8 to11 bucks and is approved by the FAA so its not snake oil. Thire engines cost about 24-40 thousand each.
 

flatchat(Chris)

Supporter
Re: They don't make cams like they used to--it seeems

Great info re oils Tx lads--still digging
I've got a mate who runs and maintains '70s Escorts with BDA 1600 motors that turn 10K + rpm ---had some oil issues --now uses a Motul brand (grade??)
Anyway, had some cam and cup wearing --so we drilled a 2mm dia hole thru to the centre of the cam (oil galley) in the middle of each lobe ramp --a special carbide drill was used (or EDM)--- results are of great success--so far :thumbsup:

Other things to consider :-
To nitride the cam ? (comp cams suggestion)
Groove the lifter bores (for xtra lobe oiling)
Use HSS(High speed steel) or stellite lifter tips
.........
 
Re: They don't make cams like they used to--it seeems

Looks quite normal for a cam that hasn't been run in properly, they can easily go like that in less than 30 mins if you don't take the basic steps.
If you think that's bad you should try running in Chevy cams !
Mike
 

Kevin Box

Supporter
Re: They don't make cams like they used to--it seeems

Chris

If you only want a mild cam I suggest you get a set of 5.0 hydraulic rollers and select a roller cam for your combination. You will probably need pushrods as well to suit. Distributor cam needs to be changed also - use 5.0 cam gear for preference to the bronze options. If you look around there is heaps of 5.0s that have done more than 160,000 kms not many bronze ones that have lived past 5,000 kms
If you head down this track take care to check the lifter height in the block - some are fine but some are a little high and require smaller base circle cam diameter. In this case use a stock 5.0 cam and get a custom re-grind. Phil Duggan at SureCam can do this for you. +61 (02) 6581-5042
Call me to discuss if you like.
You gain two things this way. No more wear issues and better options in cam profile. This also a lot easier than hardening cast camshafts and playing with oiling.

Cheers Kevin B
 
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