Hydraulic lifter issue

[Jeremy MacDonald]

Hi all. I have a small issue here: I replaced the cylinder heads on my 440. I did it with the engine still in the car. The replacements are a later version of the head (from the tnt version, but I'm not trying to increase the power - just run new heads, coz there were cracks in th eold ones above some intake valves, although good compression (~165lbs) and I replaced all the exhaust valves and installed new valve springs. I didn't touch anything else - didn't pull out the lifters because I wasn't having any lifter noise before this job. Well, after replacing several of the rocker arms, I then installed the pushrods and tightened down the rocker shaft. As I did so, I noticed that it was pushing down slightly all the vale stems - even those for closed valves. How far down? Not far - I'd say about 1/16" but I can see the valve stems moving down that distance as I tighten the rocker arm shaft bolts. I decided to do a compression test to find out if the valves were all closing and sure enough I only get about 125lbs right across all cylinders.

So I need the lifters to bleed down, I wouldn't have had any issue if I'd thought to pull out each lifter and collapse it before re-assembling then engine.

So here's my question: will the lifters bleed down by themselves to the correct level once I get the engine going and the oil warms up?... or do I have to pull them all out and manually collapse them in order for them to pump back up the the correct zero-lash position?

Many thanks!

 

[Yatzee]

Hi all. I have a small issue here: I replaced the cylinder heads on my 440. I did it with the engine still in the car. The replacements are a later version of the head (from the tnt version, but I'm not trying to increase the power - just run new heads, coz there were cracks in th eold ones above some intake valves, although good compression (~165lbs) and I replaced all the exhaust valves and installed new valve springs. I didn't touch anything else - didn't pull out the lifters because I wasn't having any lifter noise before this job. Well, after replacing several of the rocker arms, I then installed the pushrods and tightened down the rocker shaft. As I did so, I noticed that it was pushing down slightly all the vale stems - even those for closed valves. How far down? Not far - I'd say about 1/16" but I can see the valve stems moving down that distance as I tighten the rocker arm shaft bolts. I decided to do a compression test to find out if the valves were all closing and sure enough I only get about 125lbs right across all cylinders.

So I need the lifters to bleed down, I wouldn't have had any issue if I'd thought to pull out each lifter and collapse it before re-assembling then engine.

So here's my question: will the lifters bleed down by themselves to the correct level once I get the engine going and the oil warms up?... or do I have to pull them all out and manually collapse them in order for them to pump back up the the correct zero-lash position?

Many thanks!

Anytime you change heads from original to aftermarket, you'd best have a rod length checker to find out if the original rods are the correct length for the new heads. There are no guarantees that rods will work properly across brands of heads or head gasket thickness's. A 1/16 of an inch is huge compare to rod lengths measured in thousands. I visualize impending doom and destruction in your methods. Get that rod length checker, OK! You don't need to bleed down the lifters, you need to make sure their not bottoming out. Valve springs and rockers do eventually collapse the lifter to a point that pretty much centers the lifter plunger in it's bore so I suspect you have the wrong length of rods.

 

[Jeremy MacDonald]

If this was with the lifters flathen then perhaps but nah! the lifters are just still pumped right up and I'll just wait to see if anyone knows if the lifters will bleed down on their own. If not then I'll pull them today and collapse them - and take the max lash readings. The hyd lifters have a wide range of lash take-up - and these heads aren't hot-rodded or even shaved.

 

[Jeremy MacDonald]

I'll button it up this morning and then run at idle it until the oil is good and warm - and then I'll pull some plugs and take new compression readings - and I'll post them here, in case anyone else comes across this situation again. If the compression comes back up to 165 across all cylinders then I'm good to go - but I'm going to pull and bleed down a couple of lifters anyway and take the valve lash reading just for good measure.
Many thx for your time

 

[69Bee]

If you replaced the exhaust valve without doing a valve job, you are shooting yourself in the foot, and this is your biggest reason for the lower cylinder pressures.

 

[oldbee]

Lifters should bleed down in a couple hrs. at the most. Likewise-you need a valve job done whenever replacing a valve.

 

[Jeremy MacDonald]

Lifters should bleed down in a couple hrs. at the most. Likewise-you need a valve job done whenever replacing a valve.

 

[oldbee]

Jeremy- new valves aren't "seated in" to the existing valve seat in the head. And, they won't do it by running the engine.

 

[Jeremy MacDonald]

This is my 66th car and I always do my own work, so I have a lot of tools, like, for example, a Sunnen cylinder honing machine. I have all the equipt here to re-cut valve seats - single, dual and triple angle. I replaced all the exhaust valves - re-cut the valve seats just enough to get the precise contact ring - down about 2 thou - in other words, did way beyond the 'valve job' that back yard car mechanics refer to. I hate using valve grinding paste because it simply ruins the angled face of the valve in order to clean up the seat.
Nope - the valves and heads are spot on. The lifters usually have a wide range - probably the lash range is 30 to 110 thou but I don't know the exact numbers for this engine. All that I noticed is that, since I didn't bleed down the lifters before installing the heads, they're all pumped up to the level they were when the heads came off.

Gonna run it in another hour or so and then with luck the lifters will adjust down once the oil gets warm. That's what I was asking - whether anyone knows if they adjust down, as well as up from being flat.
After the run I'll check the compression again and will pull a couple of lifters, bleed them down and check the clearance. If I need to, I'll pick up push rods that make the tappets sit halfway through their range. I'll be sure to report back.

 

[Jeremy MacDonald]

By the ay, the reason for going with these heads is that Chrysler made some important improvements to reduce the tendency for the 440 heads to crack if there's a coolant leak that goes unnoticed. They're a straight bolt-on fit.

Here's the comparison:
my old heads were 906's:
2843906-1 440 year: 1968-70 int valve:2.08 exh valve:1.74
They were leaking water into a few cylinders, due to cracks above some intake valves.

the replacements are 452's (used on the 440 tnt)
4006452 400/440 1976-78 int valve:2.08 exh valve:1.74
They have hardened valve seats and they also have two more water passageways, on the , which required that I made matching holes on the head gaskets.
Also the intake ports are cleaned up and polished by the factory.

 

[Jeremy MacDonald]

Here's a photo...

 

[Rick Carson]

If the valve seat has been ground before, and you replaced the valves, did you check to see if the valves are even after instalation withe a straight edge? You didn't mention if you trimmed the valve stems to compensate.

 

[Jeremy MacDonald]

If the valve seat has been ground before, and you replaced the valves, did you check to see if the valves are even after instalation withe a straight edge? You didn't mention if you trimmed the valve stems to compensate.

Yes I did and they were within a few thou of each other. By the way, good luck trimming those stems - they're tipped with a super-hard crystal called Stellite !
OK - I have run the car for 45 mins and all is now fine - compressions right up again.

I was initially worried because, after setting the timing and then adjusting the mixture (I now have a tan color inside of the tailpipes) I was getting some slight oil-smelling smoke drifting across the garden. All it took was connecting the breather pipe at the oil filler to the air filter housing and all gone.
Tomorrow I'll pull a lifter and see what the current lash is with the lifter flat.

I hope all the foregoing will help someone else out there.

FInally - want to see what your exhaust valve tips look like? 14 of the 16 exhaust valves I had ( in the old heads and in the replacement heads were seriously damaged) The Stelite smashes away, looking like broken crystal, likely due to valve float/weak valve springs. See the attached pics.

Many thanks to those who took time to reply today.
Best,
Jeremy M.

 

[bm02tj]

I understand the Stellite is on the head of the valve not the tip of the stem
and when you do a valve grind they need to be cut to length