Jump to content

Cam Identify


Recommended Posts

  • Replies 25
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Intake and exhaust springs are the same

 

There are two springs on each valve, inner and outer. 

 

 

Intake and exhaust spring pressure at compressed length. This would be the same as the valve at maximum lift 0.413"

 

Outer.............. 108 lb. @ 1.161"

Inner................. 56 lb. @ 0.965"

 

 

 

Intake and exhaust spring pressure at assembled length. This would be the same as the valve closed

 

Outer..............  47 lb. @ 1.575"

Inner................ 27 lb. @ 1.378"

Link to comment

Is that the open and close lbs

 

 

Well it does involve reading......

 

 

Intake and exhaust springs are the same

 

There are two springs on each valve, inner and outer. 

 

 

Intake and exhaust spring pressure at compressed length. This would be the same as the valve at maximum lift 0.413"

 

Outer.............. 108 lb. @ 1.161"

Inner................. 56 lb. @ 0.965"

 

 

 

Intake and exhaust spring pressure at assembled length. This would be the same as the valve closed

 

Outer..............  47 lb. @ 1.575"

Inner................ 27 lb. @ 1.378"

 

 

 

 

 

Together spring pressure

 

 

Well that would involve adding. Let me get that for you...

 

108 + 56 = 164lb

 

47 + 27 = 74 lb

 

 

The factory service manual (FSM) only lists the separate spring pressures.

 

This is for the stock cam. For higher cam lifts, I have no idea, you'll have to measure those yourself.

 

I believe when the cam lift nears 0.480" ? the spring risks stacking. Avoid this.

Link to comment

since my cam is 460lift ( on this motor) lift I used one stock spring and one Motorsport spring Inner outer or visa versa. I cant remember. Its when nearing 475/480 lift you need to swap the springs as one inner or other gets close to binding. But one can cut the spring seat lower where the spring set on to leesen the pounds if you have a strong aftermarket spring.

 

 

remember when a cam says 460 that with zero lash. Subract the valve las then that whats the real valve lift.  so maybe minus .006 to .012

Link to comment

No spring is 100 open and 200 closed. Other way round?

 

Use Chevron Dello 400 or Shell Rotella T in 15w40. It contains higher levels of ZDDP anti scuff agents in it just like the oil back in the 70s. You should be running this already.

 

 You should be fine

Link to comment

Sorry it says my cam spring pressure is 200-210 open and 100-110 closed will these work for 180-90 or not

 

 

It'll be fine but get that Rotella T!!!!!! The piss they sell today that they call oil is formulated with up to half the anti scuff zinc in it, Why? because all cars made today run roller rockers. We still have 'flat tappet' cams that need protection.   

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.