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Hi All, just about to use this Comp Cam Louis tool to elongate the pushrod opening holes on a set of iron heads. Lots of conflicting info on the internet, and further confusing pics as well. No instructions come with or seems available for the tool.
My thinking is you need to elongate the pushrod hole inwards going TOWARDS the rocker stud. So the flat part of the tool faces inwards when used on the head. This makes sense to me if I understand pushrod geometry correctly. But I want to make sure before drilling. Info I'm seeing shows the tool being used both ways. Also, the flat side of the tool seems to want to ride up against the valve cover ridge of the head - opposite to the way I think it should be used. So looking for reassuring input.
Two pics from Summit webpage. The upper pic is also used in an old Comp Cam catalog. Nothing on current Comp website.
This is how I think the orientation should be. You can see from top you would be cutting towards the rocker stud View from side
Orienting the tool the opposite way cuts outwards, but the flat part of the tool wants you to think it's there as a guide up against the valve cover ridge. You can see here it almost naturally wants to sit this way, and the valve cover ridge steadies the tool as well so it doesn't move as much
Yes....drill closer to the rocker studs. The 1.6 rocker is closer from pushrod center to fulcrum pivot than a 1.5. I have done this procedure on a mill......neat tool.....about a million years too late LOL!
Louis Tool - Orientation
