Technical Y Block Lifter Noise - Lash Adjustment

Ouch!


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I never “think” mine are quiet enough or there is enough oil present when I remove the valve covers. A few weeks ago I took them off one at a time covered the exhaust manifold with clean dry rags and started the engine. We know these are not SBC’s, after a short time there was oil coming out of the overflow tube at the front of the passenger side rocker assembly just like it should. Same for the driver rear. All was ok just hard for me to get use too. They don’t need massive amounts of oil. The rags only got burned; a minuscule amount of oil was even on them or splashed unless I reved it up.
My old 1298cc 65 Sprite had no oiling to rocker shaft just oil vapor from inside the engine.
Guessing I’m a little paranoid.

 

I'm back, thanks for your patience! I got my speedometer rebuilt, back in the car and was then able to do some recon work. Thank you to Rusty in Colorado Springs for fixing the broken speed cup, cleaning it up and even repainting the faded gauge needles.

I adjusted the valves to .015 using the method in the hotrod y-block youtube video in this thread. This adjustment was done with the engine stone cold. I've attached some pictures and videos showing what I believe to be a well-lubricated system. Also included is a video with the noise persisting after adjusting to .015. I didn't take a video of the noise prior to this latest adjustment, but I can tell you it is much quieter than before, however I still think it is noisier than it should be. I did a 5-mile test loop, got everything up to temp and noticed no changes. Is there any damage with experimenting and adjusting down to .012 as mentioned by jaracer above.

 

Greetings Edsel1!...I certainly don't claim to be a Y block expert, or an expert anything for that matter but I can say solid roller lifter racing cams often have a recommended lash of 10-12 thousands these days as opposed to 20 and more thousandths 30 years ago..12 thousandths would not scare me...

 

Looks like some gunk on the rockers and shafts,
What are you using for oil?


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For a fresh rebuild those rockers and shafts sure look old and nasty. Did your buddy or the machine shop not take them apart and clean them before they installed them ?

 

From just a looksee my best guess would be that all but the rockers and rockershafts has been rebuilt. Maybe both have a bit of wear which y-blocks are famous for. I have a 312 and would be scared if it was as noisy as yours...

 

Those look to be high mileage rocker assemblies, could be wrong. Doesn't look like they are oiling properly to me. Everything should generally be wet with oil. Looks pretty parched. Not a good sign.

"Rebuild" means different things to different people, though for my money the valvetrain needs to be serviceable. Doesn't appear they replaced the rocker shafts and rockers? I mentioned this before. But here goes again.

Loosen up a pushrod all the way, and slide the rocker over out of the way. Can't see the rocker bores without removal, but will be able to see the underside of the rocker shafts. Use your inspection mirror. This is where the wear occurs, that's where the loading is. My guess, though only a guess, is they will be severely galled and scored due to lack of lubrication. They will need to be replaced, along with the rocker arms.

With high wear and galling the lash will never stay consistent or measure the same twice. All the clearance or "slop" has to be taken up before anything starts to move.

A rough plan: remove rocker assemblies as a unit. Loosen everything gradually incrementally, so as not to prang anything.

With the spark plugs removed crank over the starter for a few seconds and observe oil flow from each head. Or run a 1/2" drive drill with a 1/4" socket on the oil pump drive rod and observe oil flow.

They replaced the oil pump too, right? Hm.

I can say it is totally possible to replace valve springs and seals with the heads installed but it is a pain. It will run much smoother when they are shimmed up correctly, and both oil pressure and flow will improve. Newrocker shafts are available, the originals are likely filled with sludge. Rocker arms are trickier, they have gotten spendy. If money is no object they are about $25 per. I managed to acquire a complete N.O.S. set in onesies and twosies for an average of $5 ea. but it took a while. Check for straightness of push rods or other damage.

Some "rebuild" eh?

 

^^^^^^^^^^^Were the rocker arms resurfaced at the contact point of the valve? Y blocks are prone to wear there also and you will never be able to adjust them correctly with a feeler gauge. As dirty as your rocker arms are I wonder if this was done.

 

Most valve grinders have an attachment to resurface the rockers if the machinest knows what it is for. Or this tool will work with worn rockers. Which is a buy they were over $100 in the day no it is not my listing. https://www.ebay.com/itm/P-G-P-G-Valve-Gapper-Tool-in-Case-Y-Block-Flathead-V8-Rocker-Arm-Gap-Lash-312/264587989380?hash=item3d9aac5184:g:v3IAAOSw0Thd1TkD&LH_ItemCondition=4

 

Next time you've got the v/covers off you might try taking .002" to .003" clearance out of the intakes only. Then see if it sounds any quieter after the engine is at full operating temperature. If that's too tight you might hear an occasional "pop" back thru the intake.

If that improves things you might do the same procedure on the exhaust valves. And again, at operating temperature listen for any backfiring thru the exhaust system.

 

Thing is, if the rockers & arms are serviceable in good shape, there isn't really that much noise (stock camshaft) even when the lash is set at .020".

It should not be necessary to set the lash up tight, and tight lash risks burning exhaust valves I expect. Neither too loose or too tight is any good.

Fwiw, the shop manual (in bold letters no less) says that resurfacing the rocker tips is not allowed and to replace them if there is excessive wear. Not sure why that would be, maybe the surface hardening isn't very deep. I don't expect it's a huge problem, but.

 

Rebuilt rocker assembly’s are resurfaced, the rocket arm can wear in the middle and not give a true lash setting, check the rocker arms if they were not rebuilt. They made a tool years ago to adjust the lash based on movement not a feeler gauge

 

On the subject of getting the cam on the base circle for each cylinder; Sun made a gauge that did that for you while using their cylinder leakage tester. It was a disc marked in 90 degree increments and 120 degrees (8 cylinder and 6 cylinder). You removed your distributor cap and put this in place of the rotor. You then lined one of the marks up with a convenient landmark like a vacuum advance. To get to the next cylinder in the firing order you turned the crank until the next mark lined up with your landmark. I thought I had one, but I must have put it somewhere safe. I've always watched valve movement on both the cylinder I'm adjusting and it's running mate.

Also, many years ago I came upon a P&G valve gapper. A very handy device for setting valve lash, no "feel" involved. I actually had two. The first was part of a package deal on a valve grinder setup. The second I found at a swap meet for $15.00. Sold it to a buddy.

 

Have to inspect to be certain, but just from seeing the varnish & dryness from here they are almost certainly completely trashed, the bores especially.

 

I can see in the first video at least one rocker is more than .020; the rocker below the red video start when the video ends. In the second video it sounds terrible, as in way too loud! As a reference a fellow stopped by years ago long after I had been messing with solids wanting me to adjust the lifters in his old police car; a Ford with 390 v8..They didn't sound too loud to me and guaranteed nothing except my effort..I set them all at .020 and threw the covers back on..He started it up I was surprised how quiet they were, I would guess looking back if he had cast alum valve covers they wouldn't be heard at all..

 

I use 5w-30 synthetic oil. The oil pump is new. I adjusted the lash this time to .012 and have noticed a change in the noise, but it still persists. I forgot to experiment with adjusting only the intake valves. For reference I will upload the .012 idle along with the original .018 idle for comparison. That first video I uploaded last week was when the car hadn't been started in 6 weeks. When I popped the valve covers off today, I thought everything was much "wetter", though I do agree about the rocker arms. The rocker arms are original and were not resurfaced. One thing I keep going back to is that, before all this work was done, I didn't have any of this noise except for a small ticking sound. If the rocker arms are bad/don't stay adjusted, then you would think I would have had this noise long before the rebuild. After comparing the videos now, to me, it sounds better at .018, even though it is still noisier than I think it should be.

Original idle at .018


idle at .012

 

You did a very good job on the pics,,,,and an excellent job on the videos.
I agree with some others here,,,,,way more noise than is normal.
As long as you don’t mind,,,it will be okay.
The only problem I really see is the oil,,,,or lack there of .
There should be more oil on there than that.
Also,,,,,,more lube will make it somewhat quieter.

I still like your setup though,,,,,,keep up the good work.

Tommy

 

Sure its not an exhaust leak!?! That has fooled me several times (but I have 'old-ear' syndrome)
6sally6

 

Thanks! I know some of y'all are probably pulling your hair out at the sight of my incompetence/lack of knowledge but I really appreciate the comments on here. I grew up in the age of throttle-body k-cars, so much of this is all new to me.

I don't think it's an exhaust leak. I'm headed to a local "Coffee & Cars" tomorrow morning with the car and might ask a few old-timers their opinions too.

 

Thanks for staying with this.
It sounds louder than the 292 in my Wagon, but it doesn’t sound like all the rockers are making noise.
Keep at it you’ll find it,
I came from foxbody mustangs to y blocks so I feel your pain!


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Buy an auto stethoscope,,,they are very useful with detecting noise.
Only a few dollars,,,,and they isolate sounds from noise .
You won’t hear exhaust racket,,,,only noise from vibration or movement.
Place it on a header,,,,you hear wind blowing,,,not a cylinder firing.
On an alternator,,you hear bearings whirring .
Water pump,,,,you get what I mean.
Place it on a valve cover,,,you hear rockers clattering.
Move it around the valve cover lip,,and you can isolate the noise to an extent.
Good luck.

Tommy

 

You state that your engine was quieter before the rebuild. How much sludge was in the valve covers before the rebuild? That can insulate the noise and make engines sound much quieter.
I was given a 57 Fairlane that belonged to a friend. It was his wife's car and she went to the grocery store and to church. Never more than 2 miles from home and never more than 30 mph.
I pulled the valve covers and the sludge had formed a perfect coating over everything. You could barely see the valve springs. The oil pan had about two knuckles worth of sludge.
The oil light came on at idle,but went out as soon as you raised the rpm's.

 

No harm there. The main reason I suggested initially adjusting the intakes only is that on many engines the exhaust lash tends to run a few thousandths looser than the intake. Due to the extra heat the exhaust valves see, they need room for just a skosh more thermal expansion. If they're lashed a bit too tight they'll work just fine until they get up to full temperature and you may hear an occasional popping in the exhaust stream.

 

Edsel 1 - You previously stated that you are using SYNTHETIC OIL 5W-30

GET THAT SHIT OUTTA THAT ENGINE !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

In the era that these engines were utilised and due to the fact that these are solid lifter engines , the oil has to have ZINC (ZDDP) in the oil makeup as a lubricant.

This is especially important in any engine using solid lifters.

The use of your chosen oil could in fact ALONE could be the root cause of your excessive noise.

I reccomend 15-40 Rotella Diesel truck oil. Been using Rotella in my Y Blocks for years with no problems. NOT THE SYNTHETIC ROTELLA.

I hope you have not already done damage to your engine by the use of the wrong oil and the tightening of the lash.

Oldmics

 

Tim Mcmaster the builder of my Y block recommends Brad Penn 20-50.
That’s all that will ever be in my engine, it’s high ZZDP.

 

I bought a stethoscope like someone mentioned above and it didn't work worth a crap. I then found a 3-4 foot piece of rubber 5/16" hose works great for identifying where a noise is coming from. I stick it in my ear and if the right size it will stay there. Then I move the other end around checking for noises. Works really great for small exhaust leaks.