First cam cam was regrinded and lifters were used stock, no wonder why two lobes went bad especially when car didnt start for ages.
Second was schneider cam with comp cams lifters and after proper brake in, fifth cylinder started to pop.
I opened valve cover and lash cap was dropped and so was pushrod.
Exhaust lobe were 2mm down.

Like my garage neighbour said: Maybe there are reason why Y-Block enthusiasts are so rare.


Hyvinkää, FI

Camshaft failures with flat tappet camshaft are occurring at an increasing rate for all makes and models of engines.  While the blame for these failures tends to get thrown towards the oil not having enough zinc/phosphorus (ZDDP), there are other items taking place that must also be taken into account.  Here’s the list of items published in the Y-Block Magazine that are contributors to cam and lifter failure.
http://www.eatonbalancing.com/blog/2012/11/06/camshaft-and-lifter-failure-causes-2/
 
I’ll add to that list by also saying to use only those oils that have 30W or higher in their weight classifications.  Oils with less than 30W have reduced shear properties and those shear properties are required for promoting some lifter drag at the cam lobe that helps the lifter to turn.  Lifters that fail to turn simply wear in a hurry.  Synthetic oils and oils with 20W or less in their classifications have reduced shear amounts and are accordingly inappropriate for flat tappet camshafts.
 
Diesel rated oils should also be avoided as they are too high in detergent for gasoline engines and have a propensity for causing pitting on the cam lobe flanks.  Doesn’t happen overnight but happens at a rate fast enough to be seen in some real world mileage testing.
 
Anyone installing a new flat tappet camshaft would be prudent to measure each lobe and insure that there is sufficient rake angle ground on those.  It only takes one lobe with insufficient rake angle to make for a cam failure.  Camshafts with less than 0.001” of rake angle should be returned to the manufacturer.  My own preference is 0.0015-0.002” of rake angle as a minimum.
 
If you’re dealing with a stroker Y engine, make sure the connecting rods are clearing the camshaft lobes by at least 0.050”.  This seems to be a reoccurring problem for many of the home brewed Y strokers.

Lorena, Texas (South of Waco)

Not a stroker. Only 292ci+0.70"/3.3".
Oil was 20w50 mineral with lot of zinc.
Next time I have to check pushrod rotation if those rotate with lifters? Last time I was too hurry to fix oil, water and gas leaks and keeping engine running during brake in.
Too much pipes and hoses in engine bay.

Is there any change to check old lifter if those can be used with new cam?
Engine and lifters ran only couple of hours and other 15 lifters might be good.
American iron is bloody expensive out here thanks to lousy exchange rate of Euro.


Hyvinkää, FI

in adition to what ted had to say i always cover the new cam lobes with crane molley past ,or equivalent,i would not re use lifters unless they are resurfaced to correct angle.. i leave the oil in for at least 500 miles as i think the money past  mixed in the oil is helpful also i block off the rocker spill tubes as poor rocker oil can't help the new cam to live. with no pressure in the rocker shafts all rockers and valve train do not get ther share of oil .my take on cutting the risk. have yet to have cam failure on ys so far, my number of rebuilds are not in the high numbers like ted 

The lifter face must be convex to help with lifter rotation along with the rake angle on the lobes.  Most solid lifter flat tappet lifters are ground with a 50-52 inch radius and while the exact radius cannot be determined without some specific instruments, the radius can be observed by placing a straight edge across the face of the lifter and observing that the center is slightly higher than the outside edges.  If lifters are found to be flat and/or concave (lower in the middle than on the outside edges), then those lifters needs to be discarded.  As long as new lifters are available, I’m not an advocate of regrinding the lifters.
 
If the lifters pass the initial ‘looks okay’ test and you want to try reusing them, then try to make sure they are still rotating the same direction as they were before.  Putting them back in the same lifter holes will help with this.  When the lifters were initially broken in, they did so rotating in a specific direction.  Reversing this rotation can lead to another cam/lifter failure.

Lorena, Texas (South of Waco)

Here’s another thought.  You didn’t mention what pushrods you were running.  The 3/8” diameter pushrods are problematic in rubbing in the pushrod holes in the heads which in turn stops the lifter from turning and creating another cam failure.  Even the smaller diameter pushrods must be checked for interference fit issues but these are not as problematic in this regard as the 3/8” diameter pushrods.

Lorena, Texas (South of Waco)

To add to what Ted has mentioned, it is a good idea when possible to use some worn out or lighter springs during beak in.. This puts less pressure on the cam/lifter interface till the parts have a chance to seat themselves.. There is also less chance of the lobes being destroyed before you check to see the lifters are all rotating.  I also recommend a lifter made by Trend Performance.. They are tool steel  and very durable. The lifter face has a very smooth finish which seems to be easier on the cam lobes.. I have reused this lifter on different cams with no issues  There are rarely any witness marks left on the lifter after use, indicating a total lack of wear on the lifter face.
It seems that successfully breaking in a flat tappet cam is part science and part black magic..

Ted,
Just curious, but what area exactly are you specifically referring to (cam lobe 'flank'), and why would pitting matter if it's not the part of the lobe that contacts the tappet? (likely, because pitting in general can have negative consequences elsewhere?).
Back when the zinc/cam-failure issue first came up, and people were switching to Rotella, I stocked up before they altered the formula. I still have a couple gallons left, and never worried about the excess detergent since my high-mileage motor was initially neglected by the original owner (a lot of 50s era non-detergent sludge). The bearings are worn enough now that I gain 8# of oil pressure when I let off the throttle, so I always throw in a quart of Lucas with every change, AND since I have another motor waiting in the wings I am not overly concerned about this one, BUT, since it goes against the grain to inflict any avoidable damage to a (still) strong-running (and no doubt internally clean by now) engine, maybe it's time to give away the remaining Roella 15w40 and switch to 20w50?

6 VOLTS/POS. GRD. NW INDIANA

The flanks are those areas of the lobe before and after the nose where the valve is either opening or closing.  While the lobe area taking the highest load hit is the nose of the camshaft, the flanks are still taking a beating and especially where the lash is just taken up and the valve starts to lift off of its seat.  Pitting is just one of the effects seen on those flanks where ‘zinc overloading’ or the opposite where the oil itself is not providing adequate pressure lubrication.
 
Over the course of time, I’ve found three topics that will always bring on a spirited discussion; religion, politics, and engine oil.  Here are my thoughts on engine oil in general.
 
While oil with reduced amounts of zinc/phosphorus (ZDDP) can be compensated for by simply changing the oil more frequently, too much ZDDP creates a situation where the zinc can build up in an excessive layer on the lobe/tappets and in turn can force premature wear in that area when those layers are peeled away when those layers get to high for the metal parts to simply slide over them.
 
Diesel engine oil is higher in detergent than gasoline engine oil and part of that is to combat the excess diesel fuel that gets past the rings on a diesel engine.  If the detergent level is too high, then the detergent can strip the zinc away from the metal parts to which they have adhered and especially if the zinc levels are on the high side where it is layering on the metal to metal contact parts.  Even the reduced amount of detergent in an API service rated oil for a production gasoline car engine is likewise too much in a race engine.   That detergent ends up being detrimental in that the detergent can work its way up past the rings and into the combustion chamber thus making for some unwanted detonation.  Many of the race oils are very low in detergent if they have any at all for this reason and subsequently must be changed out more often. 
 
I was part of a two year episode of engine teardowns performed back in the Seventies where diesel oil versus gasoline oil was used in gasoline engines only.  The diesel rated oil resulted in a measurable increase in both cylinder wall wear and bearing wear when looking at engines with 100K miles on them.  Part of that has to do with the brand of oil while another factor is diesel oil having a lower percentage of base stock oil.  Engine oil technology for the flat tappet engines was at its peak in the late Seventies/early Eighties and with the advent of roller tappet camshafts across the board, the oils have become more application specific.
 
As always, this is just food for thought.  Having worked on engines for almost fifty years now, I’ve torn down a multitude of engines run on the various engine oils which has defined what oils I run in my own engines as well as the engines I build for customers.

Lorena, Texas (South of Waco)

I have been using the original Rotella 'T' for 10 years (more zinc than 'T-3'), and changing it often.  I have to wonder if alternating between high detergent Rotella and a high-zinc/low-detergent racing type oil might not be a good idea?  The racing oil would lay down a fresh zinc layer to protect the cam/cylinder walls, and the Rotella would keep it from building up with the resulting layering grief that Ted describes (?).

6 VOLTS/POS. GRD. NW INDIANA