pushrod and hydraulic lifters
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Results 1 to 8 of 8
5.0 and 5.7 Discussion, pushrod and hydraulic lifters in Cadillac Engine Technical Discussion; What does it mean that we have "hydraulic lifters" in the LT1. I thought it was a pushrod engine......
  1. #1
    Hammondsix's Avatar
    Hammondsix is offline Cadillac Owners Fanatic
    Automobile(s): Cadillac Fleetwood 94
    Join Date
    Oct 2006
    Posts
    121

    pushrod and hydraulic lifters

    What does it mean that we have "hydraulic lifters" in the LT1. I thought it was a pushrod engine...

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    N0DIH's Avatar
    N0DIH is offline Cadillac Owners Master
    Automobile(s): 94 Fleetwood Brougham
    Join Date
    Aug 2004
    Location
    Rockford, IL
    Age
    47
    Posts
    7,498

    Re: pushrod and hydraulic lifters

    All pushrod engines have hydraulic lifters. You can replace with with Mechanical lifters, but hydraulic lifters are more tame. The lifter rides on the camshaft that transmits the camshaft motion into lift that pushes the pushrod up and opens the valves. There are also hydraulic lifters with a higher bleeddown (See Rhoades) that make larger cams seem smaller by bleeding off duration at lower oil pressures.

    OHC cam engines don't have lifters, they have followers.

  4. #3
    joe_padavano is offline Cadillac Owners Member
    Automobile(s): 93 Allante
    Join Date
    Mar 2006
    Location
    Northern Virginia
    Posts
    78

    Re: pushrod and hydraulic lifters

    Quote Originally Posted by N0DIH View Post
    All pushrod engines have hydraulic lifters. You can replace with with Mechanical lifters, but hydraulic lifters are more tame. The lifter rides on the camshaft that transmits the camshaft motion into lift that pushes the pushrod up and opens the valves. There are also hydraulic lifters with a higher bleeddown (See Rhoades) that make larger cams seem smaller by bleeding off duration at lower oil pressures.

    OHC cam engines don't have lifters, they have followers.
    Are you refering to just Caddy engines or all engines, since there were lots of pushrod engines built with mechanical lifters, including a whole bunch high performance small block and big block Chebby motors.

    Note that some OHC engines DO have hydraulic "lifters" (OK, that's probably a bad term). Some OHC engines have rocker arms with a hydraulicly adjustable pivot point to self adjust the valve lash, the same way a hydraulic lifter works in a pushrod motor. These are distinct from the followers that ride on the cam.

  5. #4
    N0DIH's Avatar
    N0DIH is offline Cadillac Owners Master
    Automobile(s): 94 Fleetwood Brougham
    Join Date
    Aug 2004
    Location
    Rockford, IL
    Age
    47
    Posts
    7,498

    Re: pushrod and hydraulic lifters

    Primarily GM engines seen in Cadillacs. No way to define every engine out there.

  6. #5
    Hammondsix's Avatar
    Hammondsix is offline Cadillac Owners Fanatic
    Automobile(s): Cadillac Fleetwood 94
    Join Date
    Oct 2006
    Posts
    121

    Re: pushrod and hydraulic lifters

    what is a hydraulic lifter?

  7. #6
    N0DIH's Avatar
    N0DIH is offline Cadillac Owners Master
    Automobile(s): 94 Fleetwood Brougham
    Join Date
    Aug 2004
    Location
    Rockford, IL
    Age
    47
    Posts
    7,498

    Re: pushrod and hydraulic lifters

    The lifter is the small cylinder like piece that connects the camshaft to the pushrod. Engines with roller lifters have roller balls under them, older style do not

  8. #7
    joe_padavano is offline Cadillac Owners Member
    Automobile(s): 93 Allante
    Join Date
    Mar 2006
    Location
    Northern Virginia
    Posts
    78

    Re: pushrod and hydraulic lifters

    Quote Originally Posted by Hammondsix View Post
    what is a hydraulic lifter?
    Let me try a little more basic explanation. The valves are opened and closed by a camshaft, which has a series of "bumps" on it. The lifter is a cylindrical part that rides on these bumps and (through a series of other parts) translates this motion into opening and closing the valves. Early engines simply used a solid metal cylinder to ride on the camshaft, however normal wear would eventually result in excess clearance in the valve system and a ticking or clattering noise that may owners found objectionable. The valves would need to be adjusted regularly to eliminate this noise.

    Hydraulic lifters use a small piston and spring system inside the cylindrical lifter with oil pressure to automatically make up for this wear and tear. That eliminates the need for regular valve adjustments. Sometimes the mechanism inside the hydraulic lifter will get gummed up, resulting in the clattering noise and an expensive replacement repair.

    Finally, newer engines have incorporated rollers on the end of the lifter instead of the metal-to-metal contact where the lifter rides on the camshaft. Racing motors have done this for years to allow more radical camshafts to be used for increased power. On street cars (like the late 1980s 307 motor) this was done to reduce internal friction in the motor and provide a small increase in efficiency and economy.

  9. #8
    Hammondsix's Avatar
    Hammondsix is offline Cadillac Owners Fanatic
    Automobile(s): Cadillac Fleetwood 94
    Join Date
    Oct 2006
    Posts
    121

    Re: pushrod and hydraulic lifters

    thank you!

    so does the LT1 use rollers? i guess not....

    Right!?!

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting