Welcome to the Corvette Forums at the Corvette Action Center!

Adjusting Hydraulic Lifters The Correct Way

Joined
Mar 9, 2009
Messages
1,026
Location
Yemen
A whole 60 years have passed since the 265" engines arrived on the scene with their hydraulic lifters. In those early years they used the discontinued "piddle valve" lifters that required 1-1/2 turns down from zero lash to center the lifter's plunger and ensure correct valve train geometry. In the early 1960's the ball bearing check valve style replaced the troublesome piddle valve lifters and they only required one turn down from zero lash. The lifters are supposed to be adjusted cold at the time of the engine's assembly but over the years some people got the crazy idea adjusting them "hot and running" provided a more accurate adjustment. But one turn down is one turn down whether the engine is hot, cold, running, or not running because it is just a height adjustment.

The ball bearing check valve lifters have .150" of available plunger travel and one turn down pushes the plunger down approximately .070" or slightly less than half of the available travel. It is NOT a critical adjustment as anywhere from 3/4 turn to 1-1/4 turns is fine. It takes about 2 to 2-1/4 turns to bottom the plunger and hold the valve off it's seat so you have plenty of leeway. Now days a lot of people are adjusting their lifters to only 1-4 to 1/2 turn down which really screws up the geometry and causes excessive valve guide and valve stem wear so I recommend adjusting your lifters to what the specs call for............ONE TURN DOWN FROM ZERO LASH.

New dampers are marked every 90 degrees for adjusting valve lash at the TDC of each cylinder. By adjusting the valves at TDC all 16 can be adjusted in two turns of the crankshaft and it only takes about 30 minutes if you have a remote starter button with 4 foot leads like Snap on sells. I back off the adjustment nut until I can easily wiggle the rocker arm then slowly tighten the nut down until the wiggle stops at zero lash. Then I turn the nut down ONE TURN then go on to the other valve. And to make the procedure really easy I have a 12 gauge wire running from the "S" terminal of my starter solenoid up to the firewall to an insulated bolt so I can connect my remote starter button to the alternator's HOT post and the bolt. Push the button and BINGO............the engine cranks! And by quickly tapping the button I can bump it over a few degrees at a time.
 

dougelam

Well-known member
Joined
Jul 19, 2011
Messages
453
Location
Michigan
Corvette
2002 Roadster
Are you serious?

Sent from my SM-T530NU using Tapatalk
 
Joined
Mar 9, 2009
Messages
1,026
Location
Yemen
Why Do Novices Do It?

I can't imagine why anyone would even want to adjust their lifters with the engine running. The factories never did it, the dealers never did it, professional engine builders never do it, so why on earth do novices do it? All it does is make a big mess and doesn't result in an adjustment that is in any way more accurate. One turn down is one turn down regardless if the engine is hot, cold, running, or not running. It's a one time height adjustment that positions the lifter's plunger in the middle of the .150" available travel. And.................it takes one turn down to position the plunger .070" deep and maintain the correct valve train geometry.
 

dougelam

Well-known member
Joined
Jul 19, 2011
Messages
453
Location
Michigan
Corvette
2002 Roadster
No, nothing wrong
It's just decades later then he talks to us like we never opened up a hood!

THEN he doesn't know why someone would change the number of turns

He then criticises someone's method and precedes to tell us his and never once referred to the factory service manual. His wiggle method is no better or any more accurate than the running one!

Sent from my SM-N920P using Tapatalk
 

Mac

Well-known member
Administrator
Joined
Feb 13, 2003
Messages
5,475
Location
Ottawa, Canuckistan
Corvette
1973 coupe L82 (gone as casualty of divorce)
No, nothing wrong
It's just decades later then he talks to us like we never opened up a hood!

THEN he doesn't know why someone would change the number of turns

He then criticises someone's method and precedes to tell us his and never once referred to the factory service manual. His wiggle method is no better or any more accurate than the running one!

Sent from my SM-N920P using Tapatalk
I've read carefully through the posts on this thread. The only person who seems to be taking offence to the OP's comments is yourself and I'm not sure why. From my perspective, nothing toobroketoretire wrote appears as condescending or provocative as your responses.

If you don't like what toobroketoretire says when he posts, perhaps you should forego reading those posts. The CAC's software allows members to "ignore" others who they find objectionable. If you don't wish to "ignore" then I'm going to suggest you regulate your replies with a bit more consideration.

Life is too short for the drama, dude…

Mac
 
Joined
Mar 9, 2009
Messages
1,026
Location
Yemen
How The Myth Of "Hot And Running" Got Started

Some time after the 265" engine came out some dimwit got the bright idea to adjust his lifters with his engine RUNNING! Then he told a buddy what he did so the buddy started doing it and passed his newly-found "knowledge" on to other dimwits and that's how the silly myth of adjusting lifters "hot and running" got started. Yes, they can be adjusted that way but it accomplishes nothing other than making a great big mess.
 

Mac

Well-known member
Administrator
Joined
Feb 13, 2003
Messages
5,475
Location
Ottawa, Canuckistan
Corvette
1973 coupe L82 (gone as casualty of divorce)
Yes, they can be adjusted that way but it accomplishes nothing other than making a great big mess.

But they get the satisfaction of creating that great big mess... and some guys aren't happy unless everything is messy!!
:chuckle

Mac
 

navy2kcoupe

Well-known member
Joined
Dec 16, 2006
Messages
799
Location
West Central FL and SE Mass.
Corvette
2000 Navy Blue Coupe A4 Z51
Some time after the 265" engine came out some dimwit got the bright idea to adjust his lifters with his engine RUNNING! Then he told a buddy what he did so the buddy started doing it and passed his newly-found "knowledge" on to other dimwits and that's how the silly myth of adjusting lifters "hot and running" got started. Yes, they can be adjusted that way but it accomplishes nothing other than making a great big mess.

It also mashes the hell out of otherwise perfectly good feeler gauges. Tried that once on my SS396 Chevelle, and never did it again.
Andy :w
 

navy2kcoupe

Well-known member
Joined
Dec 16, 2006
Messages
799
Location
West Central FL and SE Mass.
Corvette
2000 Navy Blue Coupe A4 Z51
YEP! It was a solid lifter L78.
Andy :w
 

LLC5

Well-known member
Joined
Sep 28, 2004
Messages
2,299
Location
Wa.
Corvette
98 black 6spd convert.

Tom Bryant

Well-known member
Administrator
Joined
Nov 9, 2000
Messages
7,279
Location
Edgerton, Ohio, United States
Corvette
1959 black 270hp (9/2/69) 1981 Beige L81(10/20/80)
Did I read this right, you adjusted a solid engine with feller gauges with the engine running?

Yes. That used to be the way most did it. You would warm up the engine, remove the valve cover, install the rocker oil clips to keep the oil from flying everywhere (or else just live with the mess and smoke) use angled feeler gauges and have at it. Then start the engine, loosen a rocker, insert the feeler gauge, then tighten down while moving the feeler in and out until it felt right then pull out the feeler and go to the next one. Over tightening could damage a feeler. Do one side at a time then go to the quarter car wash to clean up the engine afterwards.

The benefit was that you didn't have to be concerned with getting each lifter on the base circle to set the clearance and it was a lot faster to do the job. We used neoprene gaskets available at NAPA so you could use them over and over without damage or leaks. This was usually an almost every Saturday morning ritual for us that were looking forward to friendly competition later in the day and evening and could be knocked out in about 15 minutes.

Tom
 

GTR1999

Well-known member
Joined
Sep 4, 2003
Messages
1,146
Location
New Haven CT
Corvette
1969,1972,1975
I have adjusted them both ways, eng on or off. Both will work if each procedure is followed correctly. When building my engines I dry set them and that usually is it. When I have adjusted them running I used an old steel valve cover I cut out the top out and made a wall of thin cardboard. It kept the oil clean and allowed me to adjust the rockers.

There are many ways to do things with equal amounts of opinions for each. For example, I build posi's without the plates or springs and every rebuilder I speak to will tell me it's not going to work but if the proper procedures are followed it will work better then with the springs. Keep in mind rebuilders gauge jobs by the dollar, car owners by the quality of the work since it's their own car.
 

Mac

Well-known member
Administrator
Joined
Feb 13, 2003
Messages
5,475
Location
Ottawa, Canuckistan
Corvette
1973 coupe L82 (gone as casualty of divorce)
Keep in mind rebuilders gauge jobs by the dollar, car owners by the quality of the work since it's their own car.
And that contrast is why folks often end up disillusioned with dealerships, rebuilders and garages where they use "ProDemand" or other software to estimate the cost of repairs.

Software says 5 hours for the job so charge $X... Technicians (there are few real mechanics anymore) push the job through as quickly as possible... for example, the job gets done in 3 hours... The customer gets billed for 5 hours and the tech looks like a hero to the boss. If the quality of repair is lacking, oh well... come back and we'll do better next time (not).

If the 5 hour job takes 6 hours, you can bet the shop finds a way to make you pay for that extra time, even if it is as simple as charging extra due to "pre-existing conditions" or whatever.

Mac
 

GTR1999

Well-known member
Joined
Sep 4, 2003
Messages
1,146
Location
New Haven CT
Corvette
1969,1972,1975
And that contrast is why folks often end up disillusioned with dealerships, rebuilders and garages where they use "ProDemand" or other software to estimate the cost of repairs.

Software says 5 hours for the job so charge $X... Technicians (there are few real mechanics anymore) push the job through as quickly as possible... for example, the job gets done in 3 hours... The customer gets billed for 5 hours and the tech looks like a hero to the boss. If the quality of repair is lacking, oh well... come back and we'll do better next time (not).

If the 5 hour job takes 6 hours, you can bet the shop finds a way to make you pay for that extra time, even if it is as simple as charging extra due to "pre-existing conditions" or whatever.

Mac

You got that right Mac. I could post some interesting pictures of units sent to me to correct, that were supposed to be done correctly by some of the big boys in this business. All were poorly rebuilt, if you can even call it that and all were driven by greed and/or lack of experience.
 
Joined
Mar 9, 2009
Messages
1,026
Location
Yemen
Yes. That used to be the way most did it. You would warm up the engine, remove the valve cover, install the rocker oil clips to keep the oil from flying everywhere (or else just live with the mess and smoke) use angled feeler gauges and have at it. Then start the engine, loosen a rocker, insert the feeler gauge, then tighten down while moving the feeler in and out until it felt right then pull out the feeler and go to the next one. Over tightening could damage a feeler. Do one side at a time then go to the quarter car wash to clean up the engine afterwards.

The benefit was that you didn't have to be concerned with getting each lifter on the base circle to set the clearance and it was a lot faster to do the job. We used neoprene gaskets available at NAPA so you could use them over and over without damage or leaks. This was usually an almost every Saturday morning ritual for us that were looking forward to friendly competition later in the day and evening and could be knocked out in about 15 minutes.

Tom


Back in the "old days" many shade tree mechanics adjusted valves with the engine running because of clearance ramp issues at TDC when using long duration mechanical cams. But all you need to do is set the valves about .003" to .004" tighter at TDC to allow for the clearance ramp. And drag/track racers routinely set their valves tighter or looser to change the engine's torque characteristics (tighter moving the torque curve lower and looser moving the torque curve higher). So the clearance specs of a mechanical cam are only for general purpose street usage and the specs do NOT have to be adhered to. At the track you'll never see the professionals adjusting their valves with the engine running for the same reasons I pointed out earlier; a big mess for no reason. And adjusting mechanical lifters with the engine running destroys feeler gauges quickly; another reason why professionals never do it.
 
Joined
Mar 9, 2009
Messages
1,026
Location
Yemen
C3 Myths

Once these myths get started by well-meaning but ignorant people and get passed on to other well-meaning but ignorant people there's no stopping them. It's like the "need" for drilling holes in thermostats or the "need" to shim distributors (which accomplishes nothing) or the "need" to run figure 8's after a lube oil change (which also accomplishes nothing) or the "need" to run maximum 35 psi pressures in the balloon tires used on the '70's C3's (which destroys the tires in a very short time).
 

navy2kcoupe

Well-known member
Joined
Dec 16, 2006
Messages
799
Location
West Central FL and SE Mass.
Corvette
2000 Navy Blue Coupe A4 Z51
Did I read this right, you adjusted a solid engine with feller gauges with the engine running?
Yes I did, but only once! Made too darn much of a mess, stunk like crazy, trashed the feeler gauges, and got me so oil
spattered that I had to take a shower and change clothes before I could take the Chevelle for a bath. Learned how to do it
with the engine off and did it that way from then on.......
Tom.........NO clips, just took off the valve covers and had at it. LOL
Andy :w
 

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors

Dealers:

MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Parts/Accessories:

Vetteskins

Advertise with the Corvette Action Center!

Double Your Chances!

Partners

Top Bottom