Air Gap Machining

[FJ5]

Ok, here goes. Trying to put the Air Gap intake on my magnum small block
408 build. Intake has huge gaps and slides side to side with all gaskets in place. Called Dave at hughes engines he said to remove the china wall gaskets and use silicone there. Then he had me measure the gap between the gasket surfaces (between intake and head) .003" at the top and .007 at the bottom. Dave says to have .016 shaved off of the top down to .000" at the bottom. This is to allow a wider gap at the top so when it is torqued down it will lay flat. My question is... is this really necessary or do you guys just simply bolt them on?

 

[805moparkid]

would you use a head as is with a warp knowing it wouldn't seal?

 

[RustyRatRod]

Ed, you're startin to sound like me. Smart elleck. lol

 

[805moparkid]

Ed, you're startin to sound like me. Smart elleck. lol

well he called hughes and they told him the deal, so i gave him another example

 

[FJ5]

:banghead:

 

[aengineguy]

FJ5,

I would take Dave's advice. I had to do some similar things to mine, even though the magnum eddy gap sits on magnum heads on an LA block. I even had to slot the holes slightly. You don't want to start cranking down on the bolts with too great of differences in your measured gaps, or you will more than likely hear a "tink" (intake cracking) and then you will be procuring a new intake. I like the silicone on the china walls. Zippo leaks.

 

[mopar66]

dumb question > what are the 'china' walls ? ? .. the front and back edges of intake ?

 

[FJ5]

Front an rear of the engine block where the intake gaskets sit. Timing cover bolts to the front china wall

 

[FJ5]

The machine shop near me quoted $200.00 to mill one side of the intake. Doesn't that sound kinda pricy?