Do you guys adjust your valves differently from stock when running big cams?

[Brandon Sinclair]

I have always adjusted my valves just like a stock engine with TDC on #1 no matter what cam I ran.

I was reading a post somewhere indicating if you are running a large cam with lots of duration then it is better to adjust the valve lash when you know you are on the base circle of the cam.  Do this by either making sure the valve opposite the one you are adjusting is at full lift so you know you are on the base circle or the old V8 way where you adjust the intake valve when the correspoinding ex valve just begins to open, and then adjust the ex valve when then corresponding intake valve is almost closed.

I think the theory behind this was that in some cases with lots of overlap you could be adjusting the valve when it is starting up the lobe or may not be on the true bottom/base.

I thought the most important part was that you needed to make sure that both valves were closed at TDC on the compression stroke.

Just interested on how you guys go about doing it.

[Jim Ratto]

Every "big cam" I've run, except Clay Smith 320, I adjust lash @ TDC/BDC like stock. The Clay Smith needed to be indexed in order for it to quiet down. When I asked why lash was greater @ TDC/BDC than 20 degrees before/behind, I was told it was designed that way into the ramps. That cam didn't work for me on the street so it came out anyway.

Hope you're doing good