Y Block Valve Springs, Rocker Arms &c

[Ole Don]

You have a well thought out plan. When doing this work, I like to restrict the oil flow out the overflow tube, to force more oil to the left side of each shaft. I have cut the tapered tip off the overflow tubes, then tapped the tube and put in a drilled screw. A pinch with a vicegrip may work as well. The exercise is good if at warm idle you have the same oil seepage from under all the rocker arms equally.

[Crankster]

I'd sort of like to compare the flow from both sides, before reinstallation of the rocker assemblies. Seems to me have read it's the passenger side that often has trouble first. All of the oil flows from just a single gallery at each head. I was always a little unclear on how the whole arrangement worked. So the idea of "backflushing" the oil gallery with shop air isn't really a good one?

Just eyeballing the valvetrain in the past, say during a valve lash adjustment, it seemed to have pretty good flow to both sides. Everything wet with oil and no sludge buildup, it's tough to know how at this late date how much of the galling and wear evident on the rocker shaft was from a prior life. Modern detergent oils (and leaded gas) keep things a lot cleaner.

[dmsfrr]

Originally Posted by Crankster

..... I was always a little unclear on how the whole arrangement worked. So the idea of "backflushing" the oil gallery with shop air isn't really a good one? ....

Double checking the oil flow to each head is a very good idea and lots of folks do modify the overflow tube for good reasons.

I'd be concerned that backflushing the oil passages down from the rocker stand surface could force debris into the center cam bearing.

Both heads get their oil from passages off the center cam bearing. Those passages have two 90* turns at the head gasket and are slightly smaller up thru the head. That spot at the head gasket, sludge buildup and the shallow flat oil passage under the head getting clogged may have been the underlying cause of oil starvation to the rocker arms.
If the head gasket under that shallow oil passage swells slightly that doesn't help either.

"modern" motor oils.
With the addition of catalytic converters to newer cars, motor oil had some previously included necessary chemicals removed to avoid contaminating the newly mandated emission equipment.
Having those additives in your oil is highly recommended for pre-emission era engines. See this link...

https://www.ctci.org/gilsgarage/EngineOil.php

.

[Crankster]

I guess I'm not very good at writing clearly sometimes! Well aware oil flow is critical on these.

The problem is I don't really have any baseline to compare it to. Can let it idle warmed up, pull the valve covers and say "Yep, it's getting oil". But then how much is "enough"? For example a mechanical fuel pump has a pretty good shade tree estimate of at least a pint in under 30 seconds. Not scientific but it's in the ballpark.

What I can do at this stage is check to see if both galleries are flowing evenly from the heads, while the rocker assemblies are being rebuilt. A lot of people do this with a drill on the oil pump shaft. I've about had enough of pulling and reinstalling the distributor after recurving, so the plan is to spin the motor with the starter, plugs removed etc.

[Crankster]

Seems to be good news - after about 10 or 15 seconds of cranking I was relieved to see what I would deem to be both strong pressure, and volume, from both rocker pads. In other "Might as well" news, replacing the valve stem seals would seem to be a no brainer too.

Laying a straight edge across the valve stem ends seems to show they are all identical in height, but doing the same across the valve spring retainers shows they are way off. Maybe 1/16 or more, they are all over the place. The way Comp Cams explains it, each valve assembled height is measured and recorded. Then all the other valves are adjusted with shims to the "shortest" spring. To get real fussy, actual spring pressure in pounds of each individual spring is measured at the assembled height on a spring tester. We're just going to get them all the same height. I looked at maybe borrowing a barrel micrometer, but it sounds like a lot of the commonly available types won't work on Y block heads? Maybe something to do with the valve guides getting in the way.

How do the plugs look, btw. Any insight?

[Crankster]

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Will a valve really drop? Starting in replacing the springs. I took a section of soft rubber hose, tied a knot on one end and stuffed all of it in the spark plug hole, and brought that cylinder up to TDC, or near enough. But I got to thinking, with piston at TDC will a valve drop that far where the stem couldn't be retrieved?

Noticed a couple valve stem tips show indication that they haven't been rotating. There's no measurable wear or fretting or anything but the rocker tip has made a line where the color is different. Aren't the two piece retainers + keepers supposed to allow for valve rotation?

[Crankster]

OK, all sixteen (16) (whew!) new valve springs installed and shimmed to spec. Can sort of unrecommend that with the heads installed but it's definitely doable. 1/2" OD rubber hose, tie a knot in it, cut to 14" long works slick to keep valves from dropping. Have an el-cheapo air compressor but the fitting was not the same size as the compression gauge hose.

Old springs free height has definitely sagged and a few checked at random are no longer square. One thing I've read, at least with old springs, it's not so critical to have ZDDP oils. Spring manufacturers also recommend a run-in RPM of 2000-2500 till engine warms, and a cool down. This seems like a good plan considering the ole camshaft and lifters haven't seen normal spring pressure in a while.

[Crankster]

Well got it buttoned up this weekend and ran it in @ 1500 to 2000 till it warmed up pretty good, and test drive, checked for good oiling, set the valve lash hot etc and the rest of it, and would call it a success. Very much noticeably smoother and better power. Crane cams has a .pdf where they outline the importance of valve springs and one of the things they mentioned that even with a stock engine, proper valve spring pressure will result in a "smoother idle and better cold start and cold weather driveability", something that hadn't really occured to me.

So I thought I'd check that this morning, and darned if they aren't exactly right. Started right up with a couple pumps, and just for test purpose was able to take the choke off within seconds and slow idled real nice. It's not super cold right now but this wasn't possible before swapping out those springs. If you're chasing some cold start or other driveability problems like this, maybe give those springs a second look!

[dirtywaterdiver]

Anyone know the correct size or part Number for the wave washers on the Rocker Arm assemblies? Need 'em for my 292

https://www.mcmaster.com/wave-washers

[KULTULZ]

Originally Posted by dirtywaterdiver

Anyone know the correct size or part Number for the wave washers on the Rocker Arm assemblies? Need 'em for my 292

B8A 6598-A

1.18in OD
.86in ID
.008in Thick

[wellcraft17]

Out of curiosity how and what tool did you use to remove the springs?

[dirtywaterdiver]

Originally Posted by wellcraft17

Out of curiosity how and what tool did you use to remove the springs?

Which springs?

[wellcraft17]

Valve springs

[dmsfrr]

Originally Posted by wellcraft17

Out of curiosity how and what tool did you use to remove the springs?

wellcraft17,
go back and look at the difference in dates between comments 28 and 29... Nov '17 and April of '19.
dirtywaterdiver tagged a new/different question onto the end of an older thread about valve springs.

[KULTULZ]

Originally Posted by wellcraft17

Out of curiosity how and what tool did you use to remove the springs?

Originally Posted by wellcraft17

Valve springs

Are the heads on the vehicle or are the heads on the bench?

[wellcraft17]

I’m thinking about replacing the valve seals with the heads still on the block and was thinking how to compress the valve springs. Or maybe it’s easier just to pull the heads?

[KULTULZ]

There is a tool(s) that allow you to do it on the car. You will need a compressor to hold the valves closed with air pressure and another to compress the valve retainers to remove the springs.

[wellcraft17]

Thanks, can you or someone point me in the right direction as to where I can get one of these tools. The adapter for the compressor that screws into the spark plug hole I have, it’s the tool for compressing of the valve spring I need.

[KULTULZ]

There are two styles here- https://www.lislecorp.com/specialty-...ing-compressor

[wellcraft17]

Thanks Kultulz