The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Engine & Drivetrain

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 09-03-2023, 02:13 AM   #1
paintinx
Registered User
 
paintinx's Avatar
 
Join Date: Jul 2016
Location: Erfurt
Posts: 51
Adjusting valve clearance on a 454 V8.

Good morning to you all.

I have a 1979 Chevrolet suburban and would like to check or properly adjust the valve clearance.
I hope I am expressing myself correctly. Please excuse my bad English.
The problem is that I hear a slight clacking sound on the left bench and I know it is coming from the valves.

Can you please tell me what steps I need to take to get the valve clearance right?

I only have found this

https://brianbradburn.tripod.com/chevy454.htm

I assume I have mechanic valve lifters.

I read, that I need to turn the engine while adjusting. If I had a manual transmission, I would just put it in gear, lift the car to one side, and then turn the other wheel. But how do I do that with an automatic?

Thanks in advance and have a nice Sunday
__________________
2 kids, 2 cars
Sub2k - 5.3 ltr vortec
Sub79 - 7.4 ltr big block
Das Schiff ist im Hafen sicher,
aber dafuer nicht gebaut.
paintinx is offline   Reply With Quote
Old 09-03-2023, 02:21 AM   #2
paintinx
Registered User
 
paintinx's Avatar
 
Join Date: Jul 2016
Location: Erfurt
Posts: 51
Re: Adjusting valve clearance on a 454 V8.

These are the tec specs of my car

Suburban 1979, 7.4 Ltr VIN: TCS269F528860 T - GMC C - Serie S - 7,4 Liter - 4BBL Carburator - 2 - 3/4 ton 6 - Suburban 9 - last digit of model year (1979) F - PlantCode (Chevrolet Flint) 528860 - Production Sequence Number CARBURATOR: 17059520 / 1449 CCP





And maybe it is better to use this link

https://youtu.be/5EGlb_VpTAw?si=fuzntC7Wnu-v9Z2-
__________________
2 kids, 2 cars
Sub2k - 5.3 ltr vortec
Sub79 - 7.4 ltr big block
Das Schiff ist im Hafen sicher,
aber dafuer nicht gebaut.
paintinx is offline   Reply With Quote
Old 09-04-2023, 12:17 PM   #3
kwmech
Senior Member
 
Join Date: Mar 2003
Location: Colfax-California
Posts: 8,343
Re: Adjusting valve clearance on a 454 V8.

I always adjust them with the engine warmed up and running. Back off till clacking then slowly tighten until the noise goes away then another 1/2 turn. It can be messy but it works for me
kwmech is offline   Reply With Quote
Old 09-04-2023, 12:40 PM   #4
geezer#99
Registered User
 
geezer#99's Avatar
 
Join Date: Aug 2009
Location: Bowser
Posts: 13,486
Re: Adjusting valve clearance on a 454 V8.

You don’t need to adjust all the valves, just find the one that’s making the noise and fix it.
Pull the valve cover off and check all the rockers are moving the same amount. If you find one, let us know and we’ll help diagnose it.

Ignore that YouTube vid. Lots of bad info there.
geezer#99 is offline   Reply With Quote
Old 09-10-2023, 02:00 PM   #5
AussieinNC
Moderator
 
AussieinNC's Avatar
 
Join Date: Jun 2017
Location: Cherryville, NC
Posts: 2,150
Re: Adjusting valve clearance on a 454 V8.

Dont be surprised if you find a lifter and cam lobe has failed, especially if you use Synthetic oil in the engine.

Flat tappet cams and lifters need an oil that has ZDDP additive in the oil...(zinc) to protect the flat running surfaces.

You can use an additive or buy an oil with zinc included in the mix. You need between 1200 to 2400 ppm of zinc to protect fully.

__________________
Family and country before all others...

2006 Chevy Silverado (Daily Driver)
2012 Chevy Equinox

AussieinNC is offline   Reply With Quote
Old 09-10-2023, 04:14 PM   #6
RustyPile
Registered User
 
RustyPile's Avatar
 
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,503
Re: Adjusting valve clearance on a 454 V8.

Quote:
Originally Posted by paintinx View Post
Good morning to you all.

I have a 1979 Chevrolet suburban and would like to check or properly adjust the valve clearance.
I hope I am expressing myself correctly. Please excuse my bad English.
The problem is that I hear a slight clacking sound on the left bench and I know it is coming from the valves.

Can you please tell me what steps I need to take to get the valve clearance right?

I only have found this

https://brianbradburn.tripod.com/chevy454.htm

I assume I have mechanic valve lifters.

I read, that I need to turn the engine while adjusting. If I had a manual transmission, I would just put it in gear, lift the car to one side, and then turn the other wheel. But how do I do that with an automatic?

Thanks in advance and have a nice Sunday
It is highly unlikely you have mechanical (solid) lifters unless the engine is a high performance race engine.. Adjust the valve lash with the engine idling, transmission in park, and follow the directions given by kwmech..
RustyPile is offline   Reply With Quote
Old 09-18-2023, 06:26 AM   #7
Ironangel
Senior Member
 
Ironangel's Avatar
 
Join Date: Feb 2010
Location: Falls City, Nebraska "100 Miles From Nowhere"
Posts: 2,219
Re: Adjusting valve clearance on a 454 V8.

Quote:
Originally Posted by paintinx View Post
These are the tec specs of my car

Suburban 1979, 7.4 Ltr VIN: TCS269F528860 T - GMC C - Serie S - 7,4 Liter - 4BBL Carburator - 2 - 3/4 ton 6 - Suburban 9 - last digit of model year (1979) F - PlantCode (Chevrolet Flint) 528860 - Production Sequence Number CARBURATOR: 17059520 / And maybe it is better to use this link

https://youtu.be/5EGlb_VpTAw?si=fuzntC7Wnu-v9Z2-
That video is of no use to anyone but the mechanic in a shop with the motor on a stand and the intake out of the way. Your 7.4L (454) is a Hydraulic Flat Tappet motor unless someone has stuck a roller cam and lifters in it. I have to agree with Rusty and KWmech and Geezer too. Pull that valve cover and find the noise maker. Use KWmech's method and be spared all the confusing details of finding TDC and using the EOIC method. One last thing, I cant count the number of times, myself included, that an exhaust leak is mistaken for a noisy lifter or loose rocker. Check those manifolds for leaks...
__________________
Michael of the clan Hill,
"Two Seventy Two's"
71 1-ton Dually 350 4-Speed
71 C/50 Grain Truck, 350 Split-Axle 4-Speed
02 3/4 ton Express
14 Indian Chief Vintage
1952 Ford 8N, "Only Ford Allowed On The Property"
"Be American, Buy American"
Ironangel is offline   Reply With Quote
Old 09-18-2023, 12:48 PM   #8
truckster
Senior Member
 
truckster's Avatar
 
Join Date: Jan 2001
Location: Orem, Utah
Posts: 7,750
Re: Adjusting valve clearance on a 454 V8.

Quote:
Originally Posted by Ironangel View Post
Check those manifolds for leaks...
Both at the flange (the block side) and the donut (where it connects to the exhaust tubing).

Here's a trick that might help. Use a piece of tubing - it doesn't really matter too much what type or size) and hold it up to one ear. Move the other end of the tubing around the noisy side of the engine until you zero in on the noise.

If it's a mechanical noise inside the engine, you can use a screwdriver with a long handle. Press it against your ear and touch it to the surfaces of the engine. As the noise grows louder, you're getting closer to the source.
__________________
I have sworn upon the altar of God, eternal hostility against every form of tyranny over the mind of man. - Thomas Jefferson
truckster is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 03:17 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com