pinning the heads....101
 

just wondering if anyone has had a problem with the boss cracking to do up force on the roll pins.....im scared to get on the gas after i pinned the studs.

i drilled the hole about an inch down from the top...i would have gone more but i couldnt really do that much witout a hard angle like --> / <--- that and i figured that wouldntevenly distribute the upforce on the boss delivered by the pin.

so any ideas...anyone...anyone....

ST,

What diameter pins did you install?

1/8 ...i figured any smaller and they wouldnt be much good, and any larger posed more of a threat to potential cracking....also, you can also go bigger, if needed, just not smaller....

Most factory heads only have the studs pressed in about 1-1/8", so you may be right on the edge of the studs. You shouldn't have stud boss cracking problems, but you might not have good retention, either.

i drilled about one inch, maybe 3/4 of and in down from the top of the boss.....dead center through the stud.....

it seems to be hlding up, then again i havent passed 500 rpm ...so who knows....in any event if they do crack...416 castings are easy to find, so ill jut port, polish, and pin....and deal with it...cussing the whole time

The roll pins I used to pin my heads and all the others are .095" thick.
The drill bit used is .092".

Has stood to numberous 7000rpm+ blasts and .550" lift.

I would not use a pin any thicker than .125" (1/8")

That would weaken the stud boss.

yea i didnt want to go above 1/8...i prolly shoulda went smaller than that but i was just trying to insure the pins not bending ......is it bad that i used 1/8?

I think you'll be fine at 1/8" :)

note to self, use smaller pins next time..heh

don't worry dude they will be ok for one thing if you keep the geometry of the rocker correct. it takes a lot of spring pressure and vavle to to start moving or flexing the studs around to cause damage.....pins are fine for street set ups use them alot, but if your planning on some serious racing mll down the stud boss and tapp for screw in studs

yeah, this is a pure street car....at least for now, and as for these heads, no matter what i do to them they are still gm cast iron hyeads and are never going to be as good as aftermarket.

you are pretty close to me, im in columbia

with a pure street car.......i do't really see the need in piningor adding screw in studs to stock type heads .........just my opinion as stated you don't have enough vavle spring pressure when vavles are close to pull studs out of boss

well actually im in lamar right off I-20 at 131 exit

well....two of my studs got pulled, thats why i pinned them....its only a .450 lift cam too...weird huh....who knows......yeah Technically im in irmo....but oh well lol