Can someone confirm cam lobe order for me?

1FastBrick

Well-known member
Dec 1, 2016
2,602
1,117
113
Junkyard
My Stuff is at the machine shop right now. Does one know the Arrangements of the intake and Exhaust lobes on the Duramax camshafts???

Is the first lobe an Intake or an Exhaust lobe? Not concerned with the firing order.
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,735
804
113
Texas!!!
That looks correct to me. What info did you find out on your cam doctor?
 

1FastBrick

Well-known member
Dec 1, 2016
2,602
1,117
113
Junkyard
I found out I need some one smarter to operate it and give the correct info... lol

I had an LBZ cam checked to confirm specs. Then a stage 1 wagler cam checked.
 
  • Haha
Reactions: JoshH

1FastBrick

Well-known member
Dec 1, 2016
2,602
1,117
113
Junkyard
The lobes were not labeled correctly on the report. But what I don't know is if there is an option to put the rocker ratio value in for the lift at the valve measurement. I had the LBZ cam re-measured and while the lobe lift is withen less than .001 from the previous time, the lift at valve spec is different. Almost like it had a 1.5 ratio the first time and a 1.6 ratio this last time.
And that's the same for the intake and exhaust if you take the lobe lift and put it at that ratio Vs. The real ratios on a Dmax.
 
Last edited:

1FastBrick

Well-known member
Dec 1, 2016
2,602
1,117
113
Junkyard
So I think this software can use the rocker ratio like yours However i think they just left it at 1.5 for both lobes.

The top lobe should be the intake lobe.
 

Harshman

Member
Apr 20, 2021
57
19
8
harshmanauto.com
Lift looks the same. Little different in duration @ .050 and separation.
I checked an LML but some how it didn't get saved. I might have the print out.
Top lobe in your picture should be exhaust.
 
  • Like
Reactions: 1FastBrick

1FastBrick

Well-known member
Dec 1, 2016
2,602
1,117
113
Junkyard
Thanks! For some reason I thought we had it backwards.

Would the Numbers at .050 be affected by the rocker ratio value?

Where are you located?
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,517
501
113
Central OH
Yes and no. Solid roller type stuff depends on lash too, but increased rocker ratio will add a touch of duration after the initial ramp. I don't have any experience with this cam profile equipment, this is from measuring at the valve stem