How do I know?

[Mike Boell]

So the (new to me) bus is a 1977 with the GD engine.

GD engine by Mike P B, on Flickr
I purchased this as a non runner and brought it home on a flatbed trailer. It has not run in 5 or 6 years and after draining off a 3lb coffee can of water from the tank, changing the fuel filter, and blowing the fuel lines out with air she fired.
From there I drained the oil and changed the filter and went onto a valve adjustment starting with number one. Adding some pressure to the rocker arm in order to slide the feeler gage into place the rocker arm just sank pushing the push rod in towards the case.
The 77 GD engine is suppose to be a solid lifter, correct? I've not dealt with hydraulic so I read up. What I remember reading on Ratwell is that if a hydraulic lifter sits (for like 5 years) it can bleed down and running / driving the engine for 30 minutes should pump them back up, so that is what I did. Yesterday morning I pulled the covers off to once again check / adjust the valves and I can not slide a feeler gage. They are tight, no clickity, nothing. I back off the nut and turn the screw out about 1 1/2 turns before I feel relieve. This all seems to fall in line with hydraulics but how do I know. Here are a few photo's of the heads if that helps.

DSCN0457 by Mike P B, on Flickr

DSCN0458 by Mike P B, on Flickr
Mike

[tristessa]

Steel spacers between the rocker arms == hydraulic lifters. And don't trust the code on the shroud, find the one on the case. I betcha they don't match ...

[Amskeptic]

So the (new to me) bus is a 1977 with the GD engine.
rocker arm just sank pushing the push rod in towards the case.
I back off the nut and turn the screw out about 1 1/2 turns before I feel relieve.
Mike

Then what happened? Do you still feel relieve.

More importantly, did you preload the lifters 1 1/2 turns in from "0" contact?
Colin

[Mike Boell]

Then what happened?
Colin

That is where I left it for the evening.

Tris,
Where might the engine case number to be found?
Mike

[Amskeptic]

Then what happened?
Colin

That is where I left it for the evening.

Tris,
Where might the engine case number to be found?
Mike

It to be found on the engine case just under the breather box, facing you, as you stare into the engine compartment over the fan shroud.
Colin

[Mike Boell]

More mystery.
The number by the breather is different as Tristessa suggested but in the wrong direction. The case is an ED which I believe to be a 1975 solid lifter.
So was this case rebuild as a 2.0 with hydraulics?
Do I adjust the lifters as if they are hydraulic? It has been starting right up the way it was set.
Do I have steel spacers between the rockers? I can pull the cover off my 1975 bus and compare or can you tell by the photos I posted?
Mike

[tristessa]

Solid-lifter engine with springs between the rocker arms:

Hydraulic with steel spacers between the rocker arms:

[Mike Boell]

That's a big spacer... Pretty obvious when you know what to look for.
Thanks guys.
1 1/2 turns in from zero it is.
Mike

[DjEep]

I guarantee you have hydraulics if it ran with 'em 1 1/2 in. Solis woulda hung the valves open and the thing would just freewheel with the stater.

But for future/general reference don't trust the spacers/springs difference. I've seen both on both, though they aren't supposed to be. Almost surefire way to tell is by looking down the pushrod tubes to check for the circlips in hydraulic lifters. I say "almost" because once I saw some weird non-stock solid lifters that had circlips for some strange reason.

[Bleyseng]

Having the spacers isn't a forsure bet either as I run them in my solid lifter Westy. I have a sticker on the fan stating that you adjust the valves to .006.

[Mike Boell]

I felt a little silly posting the hydraulic question but am happy now that I did after reading the many replies.
Again, the first time I checked the valve clearance the rocker arm sank, pushing the push rod into the case. I knew that wasn't correct and read up on hydraulics. Ratwell describing that a hydraulic can leak down, especially after sitting and in my case about 5 years, I followed what I read, changed the oil, and ran the engine for 20 minutes or so. This time I had zero clearance, again confirming hydraulics. As DjEep wrote, solids woulda hung the valves open and the thing would just freewheel with the stater which I totally understand.
Thanks guys.
Mike