had a customer recently say that they needed to get their head machined for 1/2 studs by the shop doing the block so that they would match. These pictures show why that is not the case. Because in all reality, both shops are going to indicate or set the hole in the perpendicular to the cutter and cut. Same guy can machine both and destroy it or make it work. It's all about what all of us know something about, getting it straight in the hole!


First the hole is indicted in. We use a precision pin that is .002-.003 (2-3 thousandths) smaller then the hole. We use something smaller because you are looking for the pin to slide in and out the hole. If it's off it hits, and won't be center.


Here the match is made. We are center to the hole, and can now lock down the machine to cut in this exact spot with a end mill


Now that we change to the cutter, we make a swipe by hand just turning the cutter making sure that it is center and taking out the same material all around.


And BOOM we are cutting!!

 

Very cool. What kind of added clamping force over standard size are we talking? At what point would you recommend this mod?

 

Honestly we have never recommended it, it's something a few customers have asked for. But all were running 50-65psi without a o'ring if that helps.

 

We do this mod to our top 7 bolt engines. Here is some more information on cylinder bore deformation.

http://www.dsmtuners.com/forums/cyli...formation.html

I ran a 1/2 head stud in my talon, compound turbo, no orings, felpro permatorque,50psi with no issues torqued to 85 ft/lbs. 1/2 8740 head studs have more clamp load than L19s and the entire conversion cost less.

 

and MUCH easier to maintain if you have to mill the head for any reason!

Like the link btw