I have been losing oil through the intake manifold since my engine build. The block was decked .05, the heads milled .010 (vortecs), running a .015 shim head gasket. I have been running a .120 intake gasket which has leaked in all the intake ports. I tested the spacing by putting a .060 intake gasket set on, putting a .120 piece of solder next to the port showing a .003ish reverse taper (tighter on the top of the port). My machine shop can't fit the stealth ram in their milling machine. (was going to take off .010 off the sides and .050 off the bottom)

I am going to try to run a .060 gasket, but am thinking about running RTV around all the intake ports and on the top of the gasket hoping that will seal everything up.

I know the right thing to do is to pull the heads and have the intake side milled, but I don't really want to go through all of that because I am building a 496.

Any thoughts on this?

 

Oh I was also going to run a sanding block with some 80 grit along the china rail surface of the intake. It is too tight in this area (.08)

 

Sounds like the deck wasn't squared and the china wall wasn't accounted for in the machine work to the deck.

You might consider talking to the machinist about this oversight. There is actual math involved in lowering the china wall to account for decking the block. And usually there is a fairly wide tolerance since the china wall often has a pretty sizable gap that needs to be filled. Thus the usual 1/4" bead of RTV in that location.

GD

 

They did actually did machine the china wall too, but my theory is the heads may have not had the intake surface machined since i didnt take off too much, also i think I had them milled15 years ago when i first bought them, and with the thinner gaskets it got me down too far into the china wall.

I read ideal is "over .050" for the china wall. I think with the .120 gaskets there is that much clearance, but running the .060 gaskets gets the intake to lay down too far.