Indy RHS head failure

rmchrgr said
Where/how do you come up with that number? Just curious. Is it a percentage or is that number some sort of standard? If it is too wide it's not by much. I initially thought it was too narrow. There can't be that much wasted motion here if any.

It is a mathematical equation that takes into account the radial sweep of the rocker when the fulcrum point is at the proper location.

rmchrgr said
That is true because when I did shim it, the pattern moved toward the exhaust side. I used an adjustable pushrod and dial indicator set up on the valve retainer to check for max. lift with the valve all the way open. I know got it right, I spent a lot of time with it.

If you set up for max lift you will most definitely be at the wrong place. Contrary to popular belief, proper geometry will actually lose a few thou at full lift.

rmchrgr said
So what to do? To get it perfect you'll be doing custom machining on every single part. If I wanted to get into that level of perfection, no way I would be running RHS heads, I'd be looking into much higher cost aluminum stuff. Sure, I could machine the rocker stands and make some offset blocks but that's where I draw the line, these are 'budget' heads and doing that sort of stuff throws budget out the window. I think it will run pretty good and won't be leaving much on the table with what I have.

Hey, if you're happy with it, run it. BTW, it doesn't take custom maching on every part to get it right.