Chevy Nova Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
354 Posts
Discussion Starter #1
I know this subject has many opinions. I using the 1 intake at full lift adjust 6 intake. I know there are many ways to adjust valves.
First question while adjusting the valve and once you feel resistance and tightening the nut 1/2 turn should you be able to turn the push rod or should be tight?
Second while adjusting the valve why do some push rods have some resistance while others bind up with little turn of the wrench?
 

·
Registered
Joined
·
1,002 Posts
I would not try for resistance. Use the up and down movement of the rod. That ensures there is no clearance and resistance is objective. Once the push rod no longer clicks up and down, you are at zero. Now preload the lifter. Then put a white mark on the nut at 12:00 to show that they are all adjusted. That way if you ever have to add or decrease preload you have the mark to reference and don't have to go through the whole process again.
 

·
Registered
Mike - 74 Nova Baltimore, MD
Joined
·
1,448 Posts
I agree with bracketchev70. I also do not like the "spinning the pushrod" method when adjusting hydraulic lifters. Sometimes, you may actually begin to preload the hyd lifter(s) without even knowing it.
I like to carefully move the pushrod "up and down" with my fingers to determine "zero lash" prior to adjusting the preload into the hyd lifter.

I believe that you are noticing a difference in pushrod resistance during the valve adjustment process due to how quick the lifter may bleed down. This is the reason for not spinning the pushrod to determine zero lash and using the method mentioned above.
 
  • Like
Reactions: Magnus

·
Registered
Joined
·
848 Posts
All my life I've been adjusting my valves the same way. When the intake valve starts to move I adjust the exhaust. When the exhaust valve goes down and starts back up I adjust the intake. I usually set on the engine stand with the number one cylinder and go from there. I also don't do poly locks. I put a stud girdle on everything I build. It is easy to go past zero lash on a hydraulic camshaft because of the spring in the lifter. Even if it is a hydraulic roller. If the lifter is dry it doesn't take much pressure to start to compress the lifter.
 

·
Registered
Joined
·
3,807 Posts
All my life I've been adjusting my valves the same way. When the intake valve starts to move I adjust the exhaust. When the exhaust valve goes down and starts back up I adjust the intake. I usually set on the engine stand with the number one cylinder and go from there. I also don't do poly locks. I put a stud girdle on everything I build. It is easy to go past zero lash on a hydraulic camshaft because of the spring in the lifter. Even if it is a hydraulic roller. If the lifter is dry it doesn't take much pressure to start to compress the lifter.
I think it is the other way around. When the intake is opened and then half way closed , you adjust the exhaust, when the exhaust just starts to open you adjust the intake.

.
 

·
Registered
Joined
·
183 Posts
When you do your 1/2 turn preload---you will be able to spin the pushrod . Stop there. All that's happening is the lifter bore is bleeding down because there is no oil pressure ---engine not running. If you want to make a real mess---adjust while running---fire hazard.Start the engine-- get the rocker nuts set so the one you are on is just quiet. Get them all that way---shut off the engine. Wind the nuts down 1/2 turn --one at a time. Your done except for cleaning up the oil. Best way is to warm up the engine so there is no fast idle 1st---pull the covers & then fire it up. I hate a mess so i prefer the not running method---lol
 

·
Registered
Joined
·
848 Posts
I think it is the other way around. When the intake is opened and then half way closed , you adjust the exhaust, when the exhaust just starts to open you adjust the intake.

.

Oops, senior moment even though I'm not quite a senior yet.
 

·
Registered
Joined
·
848 Posts
When you do your 1/2 turn preload---you will be able to spin the pushrod . Stop there. All that's happening is the lifter bore is bleeding down because there is no oil pressure ---engine not running. If you want to make a real mess---adjust while running---fire hazard.Start the engine-- get the rocker nuts set so the one you are on is just quiet. Get them all that way---shut off the engine. Wind the nuts down 1/2 turn --one at a time. Your done except for cleaning up the oil. Best way is to warm up the engine so there is no fast idle 1st---pull the covers & then fire it up. I hate a mess so i prefer the not running method---lol
I've seen guys take a old valve cover and cut a slot out of the top so they could get to the rockers and set the valves while running. It's still messy. After you learn how it's a lot better to set them while the engine is not running as long as you don't get confused and do it backwards like I indicated in my other post.
 

·
Registered
Joined
·
1,002 Posts
I've seen guys take a old valve cover and cut a slot out of the top so they could get to the rockers and set the valves while running. It's still messy. After you learn how it's a lot better to set them while the engine is not running as long as you don't get confused and do it backwards like I indicated in my other post.
I have been adjusting solid lifters for 30 years. I still have it written on a piece of paper on the wall of the garage.
 

·
Registered
Joined
·
376 Posts
The spot guys not familiar with E-O-I-C typically screw it up is the I-C part...

E-O is "exhaust just starting to open" set intake....but I-C is "intake just coming down to fully closed", set exhaust.

Where they typically mess up is exhaust just starts to open, they set intake valve...that's right
Intake just starts to open, they set the exhaust....and that's were it went wrong.....when the intake is just starting to open the exhaust is just closing, it isn't on the base circle and they end up with a ton of loose lash on the exhaust valves.
 

·
Registered
Mike - 74 Nova Baltimore, MD
Joined
·
1,448 Posts
All I can remember is E-I-E-I-O... but I think it has more to do with farming :D
 

·
Registered
Joined
·
848 Posts
I have been adjusting solid lifters for 30 years. I still have it written on a piece of paper on the wall of the garage.
I had a guy help me when I was just a young guy. He told me and I wrote it down on a piece of a parts box. Later I got a pair of scissors and trimmed it into a fairly neat square. I carried it around in my wallet for years. There have been times when I would be at the race track and guys would walk up and ask me if I had my valve adjusting paper. I would give it to them and they would bring it back when they were finished. I'll bet I toted it for twenty five years. I still have it somewhere but I'd have to look it up now and that's been almost thirty five years ago. At the time I had a solid roller so I carried feeler gauges with me. I don't miss those days. Now my car has a hydraulic roller. I haven't been in a race car in probably 15 years.
 

·
Premium Member
Joined
·
2,477 Posts
Why all the fuss. Do it the easy way. Do it the way Chevrolet has said in there manuals for 40 years. I have done it this way for that long and NEVER had a problem.
Adjusting Valves
Small Block Chevy

Get #1 to Top Dead Center

Exh.- 1 3 4 -8
Int.- 1- 2 5 - 7


Get #6 to Top Dead Center

Exh.- 2 5 6 7
Int.- 3 4- 6 - 8

Adjust until pushrod will not spin between fingers and then add ¼ turn and tighten poly lock.

You will only turn the engine 2 times. TDC #1 and TDC #6
1
 

·
Registered
Joined
·
376 Posts
Why all the fuss. Do it the easy way. Do it the way Chevrolet has said in there manuals for 40 years. I have done it this way for that long and NEVER had a problem.

1
That method can get you into trouble with long duration aftermarket cams....it is really only applicable to mild factory stuff.
 
1 - 15 of 15 Posts
Top