Machining Intake Manifold

[FirstEliminator]

   Hey guys,

    Yesterday, I attempted to install the intake on the 445. I've found the valve cover rails on the intake were about .070 higher than the rail on the heads.  I milled .025 off each port face. Now, I am down to around .045" of a step. So, it sounds like the I need to mill about another .040-.045 to get them level.  I don't always trust what seems to be obvious---especially when removing metal.   Last night I did a bunch of reading around the internet and I mostly found formulas using sin and other equasions on machining intake faces. My head was about to spin.  It seems strait forward. But, I'd hate to miss something then buy an intake.

    Confirmation would be wonderful at this point.

    thanks,
     Mark

   

[jayb]

The amount of the mismatch is the amount you have to cut off the face of the intake.  Here's some pictures that I hope will help - Jay

[FirstEliminator]

      Hey Jay,

     Thank you, that is a terriffic description.
   
     16 years ago when I was in vocational school for precision machining we had to study about cosines, sines, tangents, chords,etc. Perhaps I'd be more on top of angles and such if working at a transmission shop didn't pay more than entry level CNC operator.

    Awesome, that manifold has been mounted on the milling machine since lunch time. Just need to make a 2nd run now.
 
    This was the first pass on a Van Norman model 21 milling machine from 1933.
   http://s52.photobucket.com/user/FirstEliminator/media/MVI_0326_zps5db6d4af.mp4.html
   
   thanks,   
       Mark

[Barry_R]

Don't forget to put a flashlight and an eyeball down the bolt holes when test fitting - misalignment will be pretty clear and pulling it into place will cause all sorts of trouble.

[FirstEliminator]

    Thanks Barry, looking in the manifold bolt holes I noticed the threaded holes in the head were offset a little to the bottom. It wasn't much, I believe they will get centered better after the machining is done.

   thanks,
     Mark

[cjshaker]

And keep an eye on the bottom intake-to-block surface. With 35-40 year old parts, they have most likely been machined at other points and that gap may be close to begin with and close up pretty quick to the point they may touch. As long as they don't touch you should be good. If you just use sealer instead of a gasket, the close gap can be a good thing.