LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

cam measurements

Thread Tools
 
Search this Thread
 
Old Sep 19, 2011 | 12:42 PM
  #1  
jerry2004's Avatar
Thread Starter
Registered User
 
Joined: Feb 2011
Posts: 9
From: avery tx
cam measurements

Hey all just had a random question. I was wondering if there was a way to get the lift measurements without tearin down the whole motor because the kid i bought my car from lost the card that came with it.
Old Sep 19, 2011 | 12:52 PM
  #2  
RamAir95TA's Avatar
Registered User
 
Joined: Sep 2001
Posts: 4,152
From: Woodstown, NJ
Re: cam measurements

An accurate way? Not really.
Old Sep 19, 2011 | 12:57 PM
  #3  
jerry2004's Avatar
Thread Starter
Registered User
 
Joined: Feb 2011
Posts: 9
From: avery tx
Re: cam measurements

im just lookin to get a rough estimate now until i get a chance to tear this thing down and change the rings bearings and all the fun stuff that i should have done right after buying the car but didnt take the time to do
Old Sep 19, 2011 | 03:51 PM
  #4  
lt1-xjs's Avatar
Registered User
 
Joined: Dec 2005
Posts: 426
From: Dayton, Ohio
Re: cam measurements

For just a lift measurement put a dial indicator on the retainer and measure its total travel. For the lobe lift divide by your rocker ratio.
Old Sep 19, 2011 | 08:24 PM
  #5  
1963SS's Avatar
Registered User
 
Joined: Jan 2008
Posts: 30
Re: cam measurements

Yep, like stated above. Use a dial indicator and set it to zero on the lowest part of the cam. Rotate the engine until max lift is shown. Multiply that figure by 1.5 or 1.6 to get your valve lift. I use 1.6 shaft mount rockers. In the example below....my dial indicator shows .408 lobe lift. If I multiply that by 1.6 I get .653 lift at the valve.

Name:  intake006.jpg
Views: 34
Size:  45.1 KB
Old Sep 20, 2011 | 03:45 AM
  #6  
jerry2004's Avatar
Thread Starter
Registered User
 
Joined: Feb 2011
Posts: 9
From: avery tx
Re: cam measurements

thank you guys very much i will have to get this done as soon as i get home just so i can ease my mind because i know it has a healthy cam in it just not sure of size. Here is a video just because

[autostream]http://autostream.com/camaroz28/?page_type=firebirdplayerthumbnail&framepage=1760& transactionid=1316508331-626886234&posted_by=jerry2004_www.camaroz28.com&yo utube_video_id=b1Rqc2sFTZI[/autostream]

and if you expand the more info on the video there is alot of what the car had done and of course this video was done by the previous owner.

Last edited by jerry2004; Sep 20, 2011 at 03:48 AM. Reason: more info
Old Sep 20, 2011 | 08:33 AM
  #7  
lt1-xjs's Avatar
Registered User
 
Joined: Dec 2005
Posts: 426
From: Dayton, Ohio
Re: cam measurements

Sounds like the cc 503 to me.
Old Sep 20, 2011 | 01:54 PM
  #8  
TGGodfrey's Avatar
Registered User
 
Joined: Aug 2011
Posts: 72
Re: cam measurements

You should never take the lift and duration measurements at the retainer. Hydraulic lifters will give you erroneous measurements everytime. Just like degreeing a cam you MUST take the measurement at the lifter with no preload or pressure on it. Meaning the pushrod must be removed.

The method above using the pushrod with no rocker is a way around taking the intake off but be very careful how you setup the dial indicator becuase if it isnt set in a manner that maintains proper geometry then your going to get another bad measurement.

Terry

Last edited by TGGodfrey; Sep 20, 2011 at 01:56 PM.
Old Sep 20, 2011 | 08:55 PM
  #9  
MachinistOne's Avatar
Registered User
 
Joined: May 2004
Posts: 2,001
From: Bay Area, CA
Re: cam measurements

Originally Posted by TGGodfrey
You should never take the lift and duration measurements at the retainer. Hydraulic lifters will give you erroneous measurements everytime. Just like degreeing a cam you MUST take the measurement at the lifter with no preload or pressure on it. Meaning the pushrod must be removed.

The method above using the pushrod with no rocker is a way around taking the intake off but be very careful how you setup the dial indicator becuase if it isnt set in a manner that maintains proper geometry then your going to get another bad measurement.

Terry
Yep.

The dial indicator in the picture posted is obviously not parallel to the push rod and that induces a cosine error, lobe lift is actually more than is being shown on the gauge.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
rideordie
LS1 Based Engine Tech
9
Nov 5, 2019 04:52 PM
Speeds8erM-1
Drag Racing Technique
4
Aug 20, 2002 09:12 PM
Speeds8erM-1
Drag Racing Technique
3
Aug 13, 2002 10:24 PM
dansam
Midwest
8
Jul 20, 2002 01:10 PM




All times are GMT -5. The time now is 12:46 PM.