I've been toying with the idea of changing my rocker ratio,but someone told me that when you do this(from 1.5 to 1.6) anyway, you have to machine some of the push rod hole on the head because of the geometry?I would imagine I'd need longer push rods,but could some of you shed some light on this for me.I realy never heard of this.
Thanx as always.

MY VELLE (http://www.prestage.com/Member+Pages/1201.aspx)

The rocker ratio is changed by moving the pushrod cup towards the pivot point. This moves the top of the pushrod away from the intake gasket face of the head. Some pushrod openings are not long enough in that direction, causing the pushrod to bind.

There is a small tool--basically a drill guide--called a Louis Tool, after the guy who invented the first one. Other companies sell 'em now. You could get 'em through Summit, Competition Products, Jegs, or whoever your favorite supplier is. Pop it into the head, drill a hole, move to the next pushrod opening, drill another hole. When you've drilled 16 holes, you're done.

Pushrods are the last part ordered for an engine. Maybe you need different length pushrods. Maybe not. No way to know until you've checked pushrod/rocker geomertry.

You can enlarge the holes on the engine if you exercise extreme caution to keep the chips under control. A fine tooth round file can be used, too. Cast iron cuts pretty fast.

Thanx all

MY VELLE (http://www.prestage.com/Member+Pages/1201.aspx)

The holes's are not a problem with your heads if you still have AFR ;)

I still do have the AFR's on the motor.So I can switch rockers without incedent? Would you know if I need to change push rod length as well with the 1.6's? Thanx again graemlins/thumbsup.gif

MY VELLE (http://www.prestage.com/Member+Pages/1201.aspx)

Probably not but you should always check.
You know, measure once, cut twice or somethin like that :D

I remember somethimg like that.
Thanx again Mike graemlins/thumbsup.gif

MY VELLE (http://www.prestage.com/Member+Pages/1201.aspx)