serious valve train and/or oiling issue, probable causes?

[BerniniCaCO3]

3 months ago I rebuilt an engine for my car in class. I then took another 2-3 weeks putting on an exhaust and buttoning down other loose bits.
It ran poorly, I'd really no idea what/why, just that it sounded wrong, little loud, little rough, uneven idle too, oil light on at idle and off when revved.

Finals for regular college came, then a new job, so I haven't had serious time for a while.
I changed out injectors, did some hoses that were aging, rechecked vacuum lines and redid the upper intake gasket. Did a heater core: needed it, and it was a way to avoid dealing with the engine issue ;-) Added some gauges.

Towed it to a shop and started it up again for the first time yesterday.
Actually, it does seem to idle more smoothly. Possible vacuum leak fixed? New injectors? Dunno.

Some other insight. Unless it got bumped to "4" or "6" cylinder mode in installation, the tachometer says it's idling at nearly 2000 rpm. Sound about right for these cars? Or might it think I've got a 6 cylinder? (which would register, expecting 3 pulses/revolution instead of 4, as 33% higher revving). Like I said, I set it to 8 cylinders, but not out of the question that it could have been switched fumbling to install it. But otherwise: figure 1800/2000rpms is correct.
Put on a new oil switch, and a sender. Switch behaves as before, on at idle, off when revved. Sender registers about 10psi at idle. Forgot to check it when revved.
Vacuum is right, at about 18psi.

But still sounds too loud, and not just exhaust loud.

[BerniniCaCO3]

When I started it today, I had a much more experienced coworker with me to look at it (I did my first oil change only a year ago... I'm smart, but experience I have not) As the first bonefied mechanic to hear it, he pronounced that it sounds like top end noise.

[BerniniCaCO3]

Now here are my possibilities/questions.

IF it's in the heads:
-I had new valve seats installed in the heads. I trusted my machinist to have set the correct valve height as he said he did. Never double checked it... I did grind the valves too btw, but very, very little... like .002" little.
When I bolted down the rockers, to spec (25 lb-feet iirc), they did press down on the lifters, not just hanging out loose.
I trust the hydraulic lifters take care of any and all lash, or could valve stem height be a cause? As stated, bolted down, the rockers do all make contact with the valve stems.
-I did by the way change out the lifters, with new chinese ones, if bad lifters could be failing to take up slack??

IF it's an oiling issue:
Indeed, no oil making it to the top end in the first place... would make for noisy rockers!!
-I checked my main and rod bearing clearances. They were *perfect*. No pressure should be lost there. Friend/mechanic coworker also says it doesn't sound like a bottom end issue anyway.
-because I left out the driveshaft, I did at one point have to go back, jack up the engine, drop the pan, and in the 4-5" I made for myself, pull the pump to put the driveshaft in. Thought I bolted it all down, snug as it were, probably 20 lb-ft if I had to guess. But if I did neglect this, just sayin', after ruling other things out it could be losing pressure at the pump.

-I've heard that the front oil galley plugs, which are hammered in brass plugs, have popped out in the past. I did indeed hammer them in flush (I replaced them), and put on white plumber's thread sealant to boot. Seems unlikely, but...

-Or could something in the top end, even, lose oil pressure? Like, leaky CAT chinese lifters? hahaha.

[BerniniCaCO3]

Tomorrow after work I'll have time to pull the driver's side valve cover, the easy one that doesn't necessitate removing the intake if I recall correctly, and see if oil's making it there in the first place.
What should I look for? And where should I go from there?

Is my assumption that all valve stem clearances are handled by the hydraulic lifters a false one? If so, that could be it! Like I said, just trusted the machinist.

Should I rev the engine and see again what the oil gauge I added says? If it remains at 10psi even revved, that means serious pressure loss, and probably that the top end isn't getting oil (which would explain top end noise).
Btw... IF the top end wasn't getting oil, and unoiled rockers and pushrods was my problem... would they have been destroyed by 5-10minutes of running (literally, no longer than that)?

[BerniniCaCO3]

Hah, btw, I'm not sure if I SHOULD trust the other sunpro gauges anyway, regarding rpms, oil pressure, or vacuum... after all, my voltmeter reads 10V, and I know for a fact it's 14.1V at the battery (sigh)
...though I actually haven't checked the hot that feeds the voltmeter...

[1980c10]

Well the idle should be around 750-900ish rpm. Stock cam, rockers, and pushrod length I assume? Did you measure the lash on the rockers and set it correctly cold? I can't remeber if the stock setup requires the lash set or if you just tourqe them down and go it's been to long lol the last couple I put together weren't stock. Yes if no oil is making it up there more than likely you valvetrain is ruined.

[86VickyLX]

Torque and go. And a retorque after being run is helpful too. After I did my engine, a couple of the rockers were not at the same torque as I had left them when I assembled the motor in the car. They've been fine ever since.

If the car hadn't been started in over a week, I wouldn't blame it for having some noise, since the hydraulic lifters do bleed down after a while of no oil being pumped through them. As long as the noise goes away...

Got a video?

[P72Ford]

You are supposed to rotate the cylinder to TDC when you are tightening the rockers for each given cylinder.

Did you do that?

[BerniniCaCO3]

Let me check that the tachometer isn't set at 4 cylinders then! That would double the apparent rpms

how long should it take for the lifters to gain oil pressure?
I never ran the engine for more than 5 minutes straight, at any point in time, probably less than 5 minutes. Never got up to temperature either.

I just torqued; no lash adjustment... I don't think there's a lash adjustment, but if there is, I didn't do it.

No, I just torqued them all down at once, didn't rotate to TDC for each cylinder. Would that result in noisy rockers? Is it that important?

[BerniniCaCO3]

if lash adjustment is my only issue... either bolts need to be retorqued, or hydraulic lifters never pumped up, or torquing them at TDC really matters...
Could that possibly explain the oil pressure light being on at idle? Would oil be bleeding out of the pushrods, or out of the lifters, faster?

If there's nothing there that would explain 10psi @idle according to the oil gauge, or <6psi according to the switch,
then I can only conclude that there's something else wrong in the oiling system no matter what may be up with the rockers? Hoping that's not the case, that lash adjustment could explain oil pressure as well as the top engine noise

[P72Ford]

You should start with number 1 at TDC on the compression stroke (before the exhaust valve opens). Rotate the engine 90 degrees, then do 3. Rotate 90 degrees, then do 7. Follow the firing order.

I believe at one time when I was checking for PR length, I just torqued everything down. I found some loose rockers afterwards. I would rather do it the right way, and eliminate the possibility. You get a much more correct torque reading that way. I believe the spec is 18-20 ft*lbs for Crane/ FMS rollers, and the rockers should not be overtorqued.

Are you using stock rockers, or roller rockers? Are the pedestals in good shape? I found a broken one when I had my engine apart, so I changed them all.

Did you check lifter preload? How do the witness marks on the valve stems look?

These are just ideas for the noise. I'm not sure about the low oil pressure. If you plastigauged, and the clearances were in check... did you prime the engine's oil system before starting? Rotating the crank 90 degrees every so often?

I think you have an oil pressure problem, which is causing valvetrain noise at start up, not the other way around.

[1987cp]

- As a starting point, what engine is it that you're working on?

- Bolt-down rockers work fine (even with careless installation, in my experience), provided the pushrod length is OK. You'll need to check that and possibly correct it with different-length pushrods, rocker shims, adjustable rocker swap ... you get the idea.

- Your low oil pressure sounds VERY worrisome! As one point of reference, my rebuilt '96 motor still has 40psi at idle. TOTCG's old motor, with quite a few miles of hard-ish use, had 15-20psi at idle when it developed a lifter tick.

[1990LTD]

plastigage?

[mrltd]

We had a motor that made a lot of topend noisy and ran a little weird. Ended up being the plug in the oil crossover under the intake. Was dumping all the oil in the oil galley for the passenger side IIRC.

[86VickyLX]

My machine shop teacher would kick your ass if he heard you built your engine with plastigage. It's not very accurate.

No I didn't rotate the engine to TDC on every cylinder for the rocker arms. I did for the roller rockers, because that's what the instructions told me. But when I had to switch back to stock because those stupid valve covers wouldn't fit with the intake.