1993 5.7 suspected lifter tick after flat tap cam swap

[Strages]

New here gentlemen, fixed alot of issues because of this site over the past.

1994 350 sbc, with a lunati rv equivalent flat tappet cam. Tbi equipped. Auto tranny, 1993 pcm. [Non self aligning rockers without guideplates, I know this was/is sacrilege, swapping back to stamped steels, until I provision properly]

So I was pretty sure I wiped my camshaft because of user error [me]. Overly excessive cranking before break in. And developed a tap above around 1200 rpm and climbs. This is after 20 minutes of otherwise smooth break in, I figured it would've been likely.
Calculated risk. And I thought I'd struck out and didn't pursue further investigation. Save, for more damage otherwise.

However.
Upon removal of all 16 tappets, I found no unusual wear and all seemed to have survived the break in. But had pretty crudy looking oil compared anywhere else in whole motor I've seen, that may have caused the hyd lifters to stick. Seems relegated to a single cylinder I think in my case.

I've yet to pull the cam to inspect for damage, ie. Flat spot or other surprises.

So I ask
Is the camshaft worth investigating if the tappets survived?
Are the nsa rockers responsible for altering valvetrain geometry to produce the tap even if the rockers didnt walk off the Valvestems, or bend the pushrods?
Or did engine gunk clog and collapse a lifter?
What should I look for?

It's a doozy, and ask away if need I fill in the blanks.

 

[df2x4]

I don't think the site allows direct video uploads, sorry.

If you have a YouTube account you can upload the video there and embed it here by clicking the "Media" button and pasting the link in the box.

 

[Schurkey]

You shouldn't have to "pull the cam to inspect for damage". I'd think excess wear would be visible through the lifter bores.

A dial-indicator would determine if you've lost lift due to lobe wear. A dial indicator and a degree wheel would determine if you've lost lift and duration due to lobe wear.

Did you keep the lifters in order, so they can go back onto the same cam lobe they were broken-in on? If so, pull them apart ONE AT A TIME for cleaning and inspection.

 

[Strages]

Yes I was fortunate that in the back of my mind, I may have this set of circumstances, and kept them all in order.

I do wish I had assistance turning over the motor to check through the bores, but I may do just that anyway. I'm new to the hobby, relatively, and wish I'd just kept the stock one in, but losing lifter order on the stock cam had me get a cheap aftermarket for a little more money. So unfortunately dial bore indicators and other niche tools aren't at my disposal. (Yet)

Though I have to say it didn't seem like all the rockers were moving evenly sort of, some of that I ascribe too unguided nsa rockers, oops. I may have gotten crud and collapsed a lifter too.

Which with a high volume oil pump, is interesting, 45 hot psi, can't recall if while in gear but I think so, 50 out of gear, think I was rocking 20-50 for break in and I think 10-30 after break in, still with a lifter tap but I again cut it short before reaching operating temperature for fear of doing damage.

So maybe I hear the relief valve of that giving hell at low throttle. Wish I went high pressure if my bearing tolerances were better than I expected them to be. Haven't done the distributor bearing mod, so I'll need to address that.

Pondering a roller cam conversion, 202 208 .412 .427 116, I think the tbi will play nice. If 116 is lsa, fairly sure it is.

I may have to post it on youtube, I wasn't sure if this site nukes from orbit for external links, cool.

 

[Strages]

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Here you go gentlemen, the temp gauge isn't accurate I find. But this was probably a throttle punch just to 1500 rpm or so in this case. Idled around 1000 I think immediately after starting. Apologies that phone had a cracked lense at the time.

 

[SlowZ71]

Do you have the bosses in the lifter valley for the roller cam spider?

 

[CumminsBronco]

This may have nothing to do with your situation but.......I got into diesels and in the process of rebuilding my 5.9 Cummins for converting my 97 Suburban I learned a few new things about engine oils. One, way back in the early 2000's, the EPA mandated that engine oils loose their zinc and a couple other additives. Zinc was the major "high pressure" lube, ie, the lube that prevented cam lobe and lifter wear...on flat tappet cams. Lots of guys switched to diesel engine oils as those oils were allowed to keep their high zinc levels....until about 2015 when the EPA mandated their levels be reduced also. Didnt affect roller tappet cams. I have yet to fire up my completely rebuilt 5.9, and am debating using the old valve springs for the break-in period. I have also purchased some rather expensive "break-in" oil from a diesel engine oil manufacturer. It contains a high level of zinc and other additives that are not in on-road engine oils. Hopefully, these steps will allow my cam, which is higher lift and uses much stiffer valve springs, to survive break-in without undue wear.
As a side note, I am helping a coworker rebuild his Jeep 258 engine. It uses a flat tappet hydraulic cam. The tech sheet that came with the cam listed 3 engine oils that the cam manufacturer suggests for break-in. The 3 are diesel engine oils Shell Rotella T, Mobil Delvac, and Chevron Delo. The tech sheet shows the specs of those oils and the amount of zinc and two other anti-wear additives that each contains as parts per million.

 

[Strages]

The bosses do, to my relief, I thought I recalled them during the rebuild. And confirmed over pulling the intake last night.

In my case with zinc content, I used Lucas break in oil 20w-50 as it has by far the highest levels of zinc at something like 2-3000 ppm compared to the lows of today's shelf oils being in the 100-400 range if I recall, but it's been a long time since I looked into it.

I also added half a bottle of Lucas tb zinc+ In addition to 4.5 quarts of Lucas break in oil. Maybe even having danger high zinc content if I recall reading. And the other half bottle to 10w-30 synthetic blend motor oil after 20 minutes of break in.

 

[Schurkey]

The EPA did demand lower ZDDP levels in motor oil. They did not demand that it be eliminated altogether. Just reduced.

The REAL problem was that the cam companies switched to cheap-shiit Communist Chinese cam cores and lifter bodies, then blamed the resulting carnage on the oil so they didn't have to warranty all the defective junk lifters and cam cores they sold.

Reduced "zinc" (really, ZDDP) is nowhere near the problem the cam companies and hot-rod magazines made it out to be. But since that story made sense, and got published all over creation, oil companies started making "break in oil" at three times the profit margin. Now it's a self-perpetuating deal--and everyone but the consumer is rolling in money because of it.

 

[Strages]

The EPA did demand lower ZDDP levels in motor oil. They did not demand that it be eliminated altogether. Just reduced.

The REAL problem was that the cam companies switched to cheap-shiit Communist Chinese cam cores and lifter bodies, then blamed the resulting carnage on the oil so they didn't have to warranty all the defective junk lifters and cam cores they sold.

Reduced "zinc" (really, ZDDP) is nowhere near the problem the cam companies and hot-rod magazines made it out to be. But since that story made sense, and got published all over creation, oil companies started making "break in oil" at three times the profit margin. Now it's a self-perpetuating deal--and everyone but the consumer is rolling in money because of it.

I do believe that has its merits. An un-abused, maintained small block can last 200-300k miles with modern engine oils before significant internal engine wear, many relatively quiet in the process.
Even with flats
However, these tbi truck motors are somewhat different from older emission bound carbs. Built restricted for for fast intake velocity with these 193 swirls, but with a [modest cam] that lasts a few hundred k miles, that coupled with that big*ss exhaust valve. You would expect more when coming from carb to tbi, but gm needed the gains for emissions and econmy just as much squeezing 30 extra ponies from 86 prior.
Corporate average fuel economy.

But once you stray from the less radical gm factory cams, is where one can run into problems.
Between steep ramps, high lift with high valvespring pressures?
That's where the zinc and other antiwear additives become necessary for the long term, I believe.

But straying off here a little.
Sprayed some penatrating oil into the hyd tappets. See if all will bleed down, again all removed, all in order. Half won't bleed down it seems.
I plan soon today to tilt the pan, remove the timing cover and pull this flat tappet cam out for inspection. And swap this roller cam in its place. Which btw nulls the zinc necessity, another reason I didn't wince at it.