Cat cams 421 new profile ?

[mi16chris]

Got my cams a few days ago and the spec on the cat cams site is different to the spec sheet I got , have they change the profile abit ?

On the site duration is 276 intake 268 exhaust lift 11.25 intake 10.25 exhaust

My spec sheet says 279 intake 269 exhaust lift 11.30 intake 10.25 exhaust

 

[Chip-mk1]

That is a hell of a small change, cant see you noticing it.

 

[mi16chris]

That is a hell of a small change, cant see you noticing it.

Just thought it was odd that's all, looking foreword to getting them hoping there a good job

 

[Fred@BTM]

i wonder what that's like compared to a 438..............

 

[mi16chris]

i wonder what that's like compared to a 438..............

I take it no one has a spec sheet for the 438s ? Found it


Part no Duration Duration Max Valve Lift Description
@ 0.1 mm+cl @ 1.0 mm+cl
5502438 276 / 268 240 / 231 11.25 / 10.25 mm Fast Road

Take it there's just a timing difference

 

[Chip-mk1]

From an old post:

http://www.cliosport.net/forum/showthread.php?617769-Cat-438-Camshafts

The "new" cams have lobes which (assuming ktec arent lieing on their website) are:
Same lift as 421
same duration at 1mm as 421
same differential between lift at .1mm and 1mm

If they are the same total lift, the same duration from 1mm onwards and the shape of the ramp is the same (as implied by the two different duration figures at different lift both still being the same) then they must just be exactly the same or incedibally similar lobes but with a different timing centreline.
So if they are different in anyway other than LCA, it must be a bloody small difference!