Howdy,

Reassembling the '66 327 NOM in our '62 after having the heads pressure tested. I'm following one of the "rebuild your small block chevy" books, and at the point where I'm about to do the valve adjustment.

First question: Do I have solid or hydraulic lifters? After reading the book and forums, I don't know the answer.

One test: pushing on the rocker arm - hydraulic should yield slightly. I notice no movement when I do that.

Another test: look for a circlip in the lifter body, if it's there, it's hydraulic. It is there.

Photo here, any input appreciated.



Or here: https://picasaweb.google.com/1113834...71191391612610

Thanks!

 

Tighten the rocker with pushrod in place by hand until you reach zero clearance. Then, very slowly turn the handle and see if the plunger starts to depress. If it doesnt, dont force it, because you most likely have mechanical lifters. You arent going to bend the pushrod if you only turn it a small portion past zero clearance and you end up having mechanical lifters.

 

I've not seen a pushrod seat in a lifter like your picture shows with the holes around the seat. May be common on the aftermarket. Don't know.

The OEM '66 issue solid lifters had no snap ring over the push rod seat to hold it in place. The hydraulic lifters did.

Aftermarket solid and hydraulic lifters all use the snap ring. At least some of them do so you can't ID them that way.

If the engine is altogether and you're ready to fire it up, I'd adjust the valves with a little clearance and fire it up.

Once running, you can start to turn the adjustment nuts down and if you hear/feel that cylinder misfiring after the lifter has had time to adjust, then you can bet you have a solid lifter.

What do you do then? Well, I have no idea as you still don't know what soid cam is in the engine or what the valve gap specs are.

 

You won't bend the pushrod anyway. All you'll do is push the valve open and have no compression.

 

My advise is: Set them as if they are solid unless you are sure they are hydraulic.

Don't repeat my mistake. I thought I had hydraulic.. Adjusted accordingly... Turned over the motor.. Rocker stud was pushed out of it's seat.

 

I would be mightily curious how you think this could happen unless you cranked them down 3/4 to 1 1/2 turns and rammed a piston/valve together because you had no relief notches in your pistons.

Adjusting to "a little" clearance won't cause your problem.

 

Did as 65silververt suggested, and I don't see any movement on the plunger, so I assume they are solid/mechanical.

There is a mark on the lifter body - C-37. But I don't find any hits on that.

So I guess the next question is what do you do if you don't know what cam is in there? Is there a ballpark setting that won't do damage?

Thanks again for the input!

 

Yes, I clearly had piston/valve contact to do this.
Zero lash plus 1/2 turn did it.

My motor is an LT-1

 

That's quite unusual - 1/2-turn is .025", or .037" at the valve.

 

Don't want to hijack this thread (OP is looking for lash values)...

I can only relay what happened with my own hands and eyes.
The lift on a LT-1 cam is 435/455 (with 1.5:1 rocker).. Pistons are domed. Must be enough to get into trouble.....

 

Lt-1 has screw in studs. No? How did you lift a screw in stud?

 

See post #3.

 

LT-1 short block. Original heads (283)

 

If he has a cast iron intake you can almost bet the farm its a hydraulic cammed engine....

therefore no lash

 

When the car was running before this work, did it sound like a symphony of sewing machines from the lifters (SOLID LIFTERS) or was it pretty quiet (HYDRAULIC LIFTERS)?

 

how about this:
take apart 1 lifter and see what is inside.
Might have to soak it in parts cleaner. Many old H lifters are froze solid due to varnish that builds up.
Anytime lifters are re-used be sure to put them back in the same hole they came out of, after being cleaned, of course.

 

I believe c37 to be old Crane hydraulic lifters, the holes around the outside of the plunger also ring a bell, phone their tech line and ask if you still need the info.



Paul

 

Good call, I called Crane and they told me C-37 is an old hydraulic lifter. So I'm good to go.

Learned a lot on this thread, thanks everyone.

 

Solid lifters do not have a spring. At least in 20 years working in the Engine Supply business I did not see Solids with a retainer spring. The spring keeps the Hydraulic components in the lifter. Pulled hundreds of those apart looking for the reason one would be noisy.
If the OP is new to adjusting Hydraulics he needs to be aware. The adjustment mentioned above works quite well but is a one time shot. When you tighten a hydraulic lifter it will adjust and at the same time release a little of the oil under the piston in the lifter. 5 seconds after you adjust it will feel loose again. Do not adjust again. Walk away and leave it. If you keep adjusting you will push the lifter piston all the way to the bottom and bottom it out. At this point a running adjustment will be necessary to pump it back up. Memory says the lifter piston has about .120 movement area and you want to try and adjust so it is in the middle of that range. This allows the lifter to have adjustment range to keep your engine running good with quiet lifters.
If you adjust running you back off the rocker arm nut till the lifter starts tapping, then turn it down very slowly till you get quiet, stop exactly where it gets quiet, at this point tighten 1/2 to 3/4 turn more and move on to the next rocker arm. It is very messy to do a running adjustment but if you make shields you can catch most of the squirting oil.
Some use a cut out old valve cover for this, some use things as simple as cardboard to deflect the oil back inside the engine.

 

Those might be anti-pump up lifters. If they are, they'll likely be noisy.

Maybe someone here knows?