02Reaper

iTrader: (2)

Every since I installed my milled heads on my 02 silverado, I have had a lifter ticking. Just recently I had my cam changed for the second time. Here is the post. https://ls1tech.com/forums/generation-iii-internal-engine/245874-cause-collapsed-lifters.html . I think my problem may have been caused by too much load on the lifters. Here is why.

Stock cam base circle
1.551"
Old comp cam base circle
1.53"
stock pushrods
7.380
Thunder hardened pushrods
7.40"
Ported heads
Milled .030

Ok, Now I did some figuring (aftermarket cam base circle - stock cam base circle /2) this gets me to how much load on the lifters above or below stock. In this case I have -.001". Now add the .020 thousandths for the hardened pushrods and I have +.0095". Everything was fine there. No lifter noise. Then I added the heads milled .030". This brings it to +.0395 over stock. This is where the lifters start dragging and one or more is making noise. Now on the new cam The base Circle is 1.465" So now by my formula I have +.007 above stock. Is this too much load on the lifters? It seems to me like you should be trying to get back as close to the stock settings as possible.