Solid lifters Or Hydraulic?

[71VERT]

How can you tell if you have solid lifters or hydraulic. My car has the original engine which would suggest hydraulic since its a 350/270 1971. However someone before me put on a aluminum intake from a LT-1 & The head casting numbers seem to be the same for an LT-1 and a 350small block. The LT-1 had solid lifters correct?

The reason I am asking is I have problems with the car starting and idling properly if I preload the rockers the 1/2 turn I am suppposed to. Once I set them to zero lash the car starts fine and idles good but the rockers seem a little loose. If I preload them it runs worse.

Regards

Jerry

 

[vigman]

Bump the engine so a valve is in the UP ( closed)

position..loosen it to zero lash.. now press down on the pushrod using the rocker as a lever.. Do this slowly, did it move down a tad.. and spring back up??


If it did you have hydraulic lifters

If it didnt...you have solid.


Vig~

 

[71VERT]

Thanks Vigman I will give it try today. I dont think they spring back up. Since I just changed the valve stem seals and took the pushrods out and put them back in I do not remember feeling any spring action in the pushrods.

Regards,

Jerry

 

[vigman]

The spring action..

Is in the lifters... which are connected to the TOP of the pushrods.


Vig~

 

[corvgreg]

The sound of the lifters when the engine is running should help. If you here a distinctive tapping sound then you probably have solids. Some hydraulic lifters are noisy, though.

Also. when adjusting lifters, tight to zero lash. If you can continue tightening the adjusting nut, then the lifter plunger is moving down. If it won't tighten any further than zero lash, you have a solid lifter.

 

[Stallion]

lash:
[1] The amount of free motion between two components

When you guys talk about zero lash and just using lash in the valve train, what are you referring to?

 

[page62]

When a valve is closed and the rocker arm is in the "up" position, any potential gap between the end of the valve and the rocker tip is referred to as lash. With solid lifters (like my old Volkswagen), valve lash was adjusted to .006" -- or else!

Found a GM shop manual yet, TR? I just got one for my '79 for 25 bucks on ebay. Dirty cover (who cares?) but otherwise excellent!

 

[71VERT]

They have to be solid lifters, I do not feel any spring in the lifters when I push down on the pushrod. Also when I continue to tighten past zero lash the valve spring begins to compress.
I adjusted them to .020 lash and fired up the car, wow what a differrence. They were diffently overtight. Car Idles better and when you push down on the gas It wants to scream now.
Does any know what a typical solid lifter should be adjusted to or do I need to know the cam in there?
Is there a safer adjustment if I do not know the Cam?

Regards,

Jerry

 

[Stallion]

When a valve is closed and the rocker arm is in the "up" position, any potential gap between the end of the valve and the rocker tip is referred to as lash. With solid lifters (like my old Volkswagen), valve lash was adjusted to .006" -- or else!

Found a GM shop manual yet, TR? I just got one for my '79 for 25 bucks on ebay. Dirty cover (who cares?) but otherwise excellent!

$25!? I was looking at helminc.com and found a '78 Corvette Service Manual (with a couple other goodies) for $99.99!! Which, I figured, the Shop = Service, so this is what I want. But if you got if for $25, I should start looking there. Tell me, what/how did you search and find that? I am really struggling with the searching of it so I can't show for anything. I just found that "new" Service Manual over at helminc.com. Any ideas?

So if you don't have zero lash, what are the consequences? More friction and energy maybe? Quicker wear? What are the problems with varying lash?

Thanks!

 

[vigman]

Hmmmm odd for 73 there is no spec

BUT.. for 64...
.030 HOT clearance for both Intake & exhaust

Will dig some more!

but this WILL work

Ahhhhh
1971 small block 330hp HOT
Intake
.024 ( damn I was .006 off!)
Exhaust
.030

set em
drive the car for a week
check em.


Vig~

 

[71VERT]

Thanks Vigman, I guessed at .020 I will reset them today and try it.

Regards,
Jerry

 

[vigman]

Ya know...

Drive it for a day ot 2.. then re do em.. let things re seat a bit... the valves were to tight correct? as in NO free play.


Just a thought


Vig~

 

[Stallion]

Re: Hmmmm odd for 73 there is no spec

BUT.. for 64...
.030 HOT clearance for both Intake & exhaust

Will dig some more!

but this WILL work

Ahhhhh
1971 small block 330hp HOT
Intake
.024 ( damn I was .006 off!)
Exhaust
.030

set em
drive the car for a week
check em.


Vig~

So these numbers are the amount of lash that you want on intake/exaust?

 

[vigman]

Yes on a solid lifter car

this however would be death to a hydraulic lifter car..

The valve has to COMPLETELY seat on the seat in the head.

... Thats why you need clearance ( read free play).. and it needs to be checked HOT because as you know.. heat EXPANDS metal.. so if you set it cold.. that dimension would not be correct when hot.

As the car ages.. metal gets worn from the edge of the valve ( where it contacts the seat) so the valve has less & less clearance to the rocker.. that's why you have to check it every so often..

In a hydraulic. this adjustment is made FOR you automatically.

 

[page62]

TR, your car has hydraulic lifters. Simple and reliable. You don't need to mess with them unless you need to replace valve seals or remove & replace the heads.

For your manual, go to ebay and try some different searches. I used "1979 Corvette Shop Manual". You could try these:
1978 Corvette Shop Manual
1978 Corvette Service Manual
78 Corvette Shop Manual

...you get the idea. By the way, that price included shipping

 

[71VERT]

Vig,
Is there any other way to tell for sure they are solid and not hydraulic other than taking it to a mechanic. The car runs much better with the lash adjusted for solid and I cannot feel any spring action in the lifter. However I do not want to do any damage.

Regards,
Jerry

 

[vigman]

Do you have access to a bore scope?

Or any other imagining device....

Here the trick.. you would have to remove 1 rocker and the pushrod.. stick the bore scope down the hole and look at the top of the lifter... If it has a clip around the inner OD of the lifter.. its hydraulic.. if it's just a machined piece..it's solid...

The other way is to remove the intake.... but that's a pain.

Is it making weird noises... klackity...or loud ticking?

If you cannot push the lifter piston back down( via the procedure you tried before) it HAS to be solid.

Do you have any motor head friends that have lifters laying around.. or a buddy at the auto parts store.. you could get a feel that way...


Vig~

 

[71VERT]

Everything tells me they are solid but I have this feeling they may be hydraulic. I do feel like there is a clip on top of the lifter when I put the pushrod back in, If you play with it it feels like there is a clip attahing itself to the pushrod.
When should I try to push the lifter down ? right after running it, if I try when its cold wouldn't they have already bleed down.
I tried to push those suckers down yesterday and there was no way it was moving.
The car makes some noise but if you tighten down enough on the rockers the noise goes away but then the car does not run right.
I guess I may have to pull the intake or take it in to be 100% sure.

Thanks,
Jerry

 

[71VERT]

Vig,
I ran the car ,pulled the valve cover and put a paint mark on the pushrod, now if they are hydraulic the paint mark should move down correct? I cant get it to move down even if I continue to tighten down past zero lash. When I tighten down the valve starts to move down not the pushrod.

Regards,
Jerry

 

[JohnZ]

hydraulic lifters have an internal preload spring that keeps the plunger/pushrod seat in the "up" position when there's no load on the lifter; pressurized oil fills the cavity under the plunger when the engine is running. If the valve is closed and the lifter is on the cam's base circle (which will be the condition at #1 cylinder for both valves with the engine at #1 TDC), if you loosen the rocker and swivel it out of the way you should be able to push on the end of the pushrod and feel it move about 1/8"-3/16" against the preload spring. If it doesn't move, you have solid lifters. From your previous description (runs poorly when adjusted as hydraulics, runs great with some clearance), it sounds like you've got solids.