Technical Y Block Lifter Noise - Lash Adjustment

This summer I had my 292 Y-block rebuilt with 75,000 original miles. Before the rebuild, the engine ran quietly with minimal "ticking" of the solid lifters. After the rebuild, it sounds like a noisy sewing machine and is very loud at idle and highway speeds.

Valve lash was set at .18 (cold engine) per the manual using feeler gauges. After putting some miles on the car I checked the lash again and it was still at .18. I decided to readjust to .20 and the noise changed slightly, but it still doesn't sound like it did pre-rebuild! I have put approximately 500 miles on the car since the rebuild, most of which was a road-trip at 70 mph. The lifters were noisy like this the entire trip but I didn't break down. I don't know what the lash was before the rebuild, the valve covers hadn't been taken off in my 17 years of ownership. I have listened to other Y-blocks at idle at car shows and they were all relatively quiet (like my engine pre-rebuild).

How can I get my engine quiet again? My first thought is to change the valve lash one way or the other, but I wanted to check here before damaging my engine! Since the lash was set correctly, is there something else I need to adjust?

 

I wonder if you could record a video of the engine running, with the hood open, slowly looking around at different places on the engine...then post the video to youtube, and link to it here. Then we could get a better idea of exactly what it sounds like.

And, did you ask whoever rebuilt the engine, about the noise? Seems to me that if they did the work on it, they should make it right.

 

I'd think increasing clearance would make more noise.

Sent from my LG-TP450 using The H.A.M.B. mobile app

 

I had the rebuild done at a machine shop, then an old hot-rodder friend helped me put it back together. I won't be able to post a video of the engine running for a few weeks. I've got the car tilted up on jack stands awaiting a newly rebuilt speedometer & cable. Come to think of it, I've never posted a video to Youtube before!

 

Did you reuse the original cam or go with a new aftermarket cam?
If it’s a replacement, the ramps may be ground to increase seating velocity and valve lift acceleration, both of which will increase noise.

 

I overhauled,not rebuilt, my 292 in 2001 and have been driving it ever since with no valve adjustment, no noise

 

I like to set them at .015", makes them nice and quiet. Be sure you set the lash on the back (heal) side of the lobe. Do it one cylinder at a time, not one of those methods where you have the crank in one position and you do intake on one and exhaust on another yada yada yada. Never liked that way.
This is the way I recommend.

 

Were the heads milled during the rework? If so, have you confirmed that you have good oiling to the upper end? Reason I ask is that milling Y-block heads can restrict the oil flow if too much is taken off. The little offset passage cast into the head gets smaller with milling.

 

I agree make sure it's oiling well on both sides of the aisle. Pull the valve covers (you'll have to, to set or check valve lash anyway) and see that there is generally oil everywhere. Dry is not your friend here.

If the engine has been rebuilt it's not a bad plan to at least check headbolt torque and the rocker arm shaft stand bolts. The latter are 12-15 ft/lbs.

If the rocker arms and shafts weren't replaced you'll never get the same lash measurement twice. This "should" have been done as part of any competent rebuild.

Just so we're on the same page the measurement is .018" say, not .18", in this case decimals matter. I know you know this, but I'm not the one complaining about noisy valve lash either. Even .020" with good rocker arms and shafts should not be noisy.

@Old wolf should be along shortly with his recommendations.

 

I like my Y-block valves at .015 In/.016 Ex.{ if old rocker tips have wear in the tips,then you must adjust with a feeler gauge that is only as wide as end of valve stem tip,so feeler dose not just jump/cover the wear slot in rocker tip=a bad reading an a much bigger gap then you think you set .
As noted by KenC,if heads are milled much( like .060 off),with out also grinding a little tiny bit deeper the oil slot,it is a good idea to at least smooth out the inside of slot in head.

 

@Old wolf should be along shortly with his recommendations.[/QUOTE]

yup

 

I'm sure it was just an error in typing...but did you lash the valves to .18"...or .018"? Could certainly account for noise.

 

I have not played with a y block in a minute but shouldn't the valve lash be .018 and not .180? you are setting your lash at 180 thousandths not 18 thousandths. That is unless the numbers you are putting up is a typo.

This is just an observation not a slam.

 

It's been a long time but when I rebuilt mine and installed a Clay Smith cam the instructions gave different clearances for intake and exhaust. The machinist resurfaced the rocker arm faces (I recall a fixture for the Sioux valve grinder) so I could get a feeler gauge to slide in and out smoothly. I set up the engine with a cold adjustment by rotating the crank as per the Motor's manual and then when the engine warmed up I did the final adjustment.

 

Don’t remember if it’s the Y block or not, but isn’t one rocker stand bolt on each bank different to allow oiling? If the bolts aren’t in the right holes, the upper end won’t oil and the valve train will be noisy, to say nothing of wear fast.

 

It is pretty easy to install the rocker shaft assemblies "backwards" or I guess the shafts upside down, if not paying attention. No oil whatsoever will make it up top to feed the shafts or rockers that way.

 

I believe you are correct, an oiler sticks out of one or two on each bank as I recall.

 

The first thing that needs to happen is for @edsel1 to reply and answer this basic question.
After that refer to Tim’s recommendation and video.

 

GET A MID '50s MOTOR'S MANUAL& READ THE Y-BLOCK SECTION, THEN FOLLOW THE RE-ASSEMBLY STEPS FOR THE VALVE TRAIN & ROCKER ARMS! The noise you describe SHOULD NOT BE THERE!

 

He ain't been back since.

 

Typical, ask a question and then don't bother to look for the help asked for.

He probably wrecked his new engine.

 

he is too busy searching for video on valve cover removal without getting your hands dirty.

 

I'm back, thanks for so many replies! I was not expecting the volume nor the promptness of your replies. I will try to improve my response time!
I was busy getting my hands dirty working on my daily driver.

I did mean to say .018, my OP had a typo. A new cam was installed, the original was not reused. New springs were put on, not sure if rocker arms were replaced, but I will find that out.

When I've adjusted lash before, I used the hotrod video above as a reference, doing one cylinder at a time, and yes, the guy that helped me reassemble had his 1950s manual out and we followed those measurements/directions.

As for oiling, I will have to check again to see just how coated the valve train is. I've read about the oiling problem and have seen the videos on modifying those little tubes to improve oiling to the top end.

Everything y'all mentioned makes sense and I have not tried adjusting the lash below .018 yet. After Christmas I will get my repaired speedometer back along with a new cable and will then be able to properly test what y'all have mentioned. In the mean time I will seek answers to these questions, the rebuild, etc. Thanks again for all your help!

 

OK, good info.

If you want to take a look takes about two minutes, loosen up the ball adjuster all the way, and slide the rocker over and out of the way. While you can't see the rocker bores without removal, you can see the rocker shafts and should give you an idea.

The shafts will be all galled up and worn, esp. on the underside, where the load is, if they are old/original. The rocker tips also get chewed up after long use and makes accurate adjustment using a flat feeler gauge problematic.

There is a method to adjustment that you might find useful, even if the rockers and rocker shafts are new. Try this technique and see if it helps.

---------

Y Block Valve Lash

Y-Block enthusiast, let’s talk valve lash. As y-blocks have no hydraulic lifters, it is necessary to adjust the tappets quite often. Unfortunately, the use of a feeler gauge is satisfactory only if the rocker faces are in good condition. If the rocker faces have wear pockets, from contacting the valve stem, the use of a feeler gauge will provide results which are little better than calculated guessing, as the gap will always be greater than the thickness of the feeler gauge due to said condition.

About fifty years ago when solid lifters were most common, a tool was developed for adjusting valve lash, utilizing a dial indicator, called a P&G Valve Gapper. These tools were supplied with specific adapters for different makes of engines, including y-block Fords, by P&G manufacturing co. of Portland, Or., but to the best of my knowledge they no longer exist. Can anyone expand on the existence of this company or a source of this tool, or parts thereof? I have found a few at swap meets but not in the last decade. This is the finest tool ever developed for adjusting solid lifter equipped overhead tappets as anyone who owns one would testify.

For those of you without the luxury of such a precision tool, may I suggest a very satisfactory method alternative to feeler gauges anyone can perform without special tools.

The tappet adjust screw is 20 threads per inch thus 1 full turn represents .050” of linear travel. It works just like a micrometer. Multiply 1 turn turn of travel times existing rocker ratio. Example, .050 ” X 1.54 = .077 ”. As you can deduct, one full turn of the adjust screw used in a 1.54 ratio rocker will represent .077” of tappet clearance.

Now divide one turn of tappet clearance i.e, .077” by 60 as in the 60 minutes of a clock face. This number is .001283” = 1 minute of clock face rotation. Thus 15 minutes of rotation will = .0192” Very close to .019” which is the specification for valve tappet clearance on 292 and 312 engines. 15 minutes clock rotation = 90 degrees rotation, an increment most auto enthusiasts can easily estimate quite closely.

Get into the engine, with the lifter all the way down obtain some tappet clearance then carefully rotate the adjust screw clockwise to obtain .000’ valve lash. Just touching, but not depressing the valve. Now rotate the adjust screw counterclockwise 90 degrees. The resulting clearance should be very, very close to .019” regardless of rocker arm face wear.

If adjusting 1.43 ratio rockers rotate the adjust screw 16 min. of rotation ccw. To obtain .01906” clearance. Very, very, very close.

In order to determine the ratio of said rocker, observe the # on the side. 1.54 rockers are marked ECG 6564-B2 or –B1. I am led to believe any rocker with a B1 or B2 suffix will be a 1.54 ratio rocker and all those without suffixes will be 1.43 ratio.

Walt Nuckels 12/31/00

 

When I rebuilt my 312 about 12 years ago, I sourced a new cam, lifters and rebuilt rocker arm assemblies from John Mummert the Y Block guy. It's supposed to be a bit hotter than the stock T-Bird cam. The card that came with the cam specified 0.012 in lash and that's what I have been running them at with very little noise and no problems. FYI, my 57 service manual calls for 0.019 - 0.020 with the original cam.

 

Tapping my toe for Old Wolf...

 

That's a good point, performance camshaft will have a different lash than a stock grind.

The "1/4 turn" method described earlier works really well for factory cams and I've tried a few different ways including P&G valve gapper. If the rocker tips are new or in good condition no special technique is required. A feeler gauge works fine. One thing I've wondered about.

Sometimes you'll hear machinists talk about proper usage of a feeler gauge, "like slicing through butter" or "light drag" etc. OK, Except, if I put a micrometer on a .019" feeler gauge it's "pretty damn tight" if ya ask me.

Just messing around with it, have found a close consistency between every cylinder makes for a really smooth idle. A little loose is better for low end grunt. This is where having baseline measurements of manifold vacuum is useful too - if valve lash is too tight the vacuum will fall off. This can also burn valves. The ex. valves esp. are cooled by contact with valve seat. "A tappy valve is a happy valve" they used to say. I replaced all the valve train stuff and now they stay adjusted fine, and will tend to be quiet and stay quiet. Once everything gets beat to hell it will never quiet down I reckon.

I don't understand why everyone thought they needed "frequent adjustment"? I think the manuals said every 8,000 miles?

 

Were new lifters installed with the new cam?

 

Hoping the grouchy old bastard stays away

A Y Block thread without his opinion ( Which is worth a whole lot less than 2 cents )
would be quite refreshing.

 

tell us how you really feel about him