Intake Manifold Fit - Experience Requested

[rockhouse66]

My first aluminum intake installation.  I am mocking up the fit.  I have snugged the end bolts of the intake until I get zero clearance at the top of the manifold.  It didn't take much "snugging" to get there.  I then have around .020" at the bottom.  I am using the Reinz/Carquest MS15166X intake gasket and am pretty committed to using these because the intake is port matched using them.  See photo below.

So, is it reasonable to expect this to all pull up and seal OK or must I do some angle machining on the intake?  BTW, bolt hole alignment is good.

[Nightmist66]

How is the other side? Have you tried dry fitting without gaskets? IMO, I would not run it like that, asking for a leak for sure... I ran into the same thing on my last build when I was blueprinting. At some point the manifold I chose(used), was off on the angle on one side. Each intake face should be 45° to the China rail.

[rockhouse66]

There is about .015" difference between the fit top to bottom, without any bolts.  Just resting on the gasket.  The manifold is nicely aligned with the valve cover gasket surface and the bolts will go in so I am thinking it is maybe not that bad?

I haven't tried it without any gasket but will.

[Nightmist66]

I prefer checking without gaskets just because it's easier to "see" how bad it is or not and better for an accurate measurement. With no gaskets, do not install bolts or snug, just let the manifold sit on top. Also, very important to make sure that the bottom of the intake runners are not being held up on top of the head gasket tabs. I make it a habit to just bend them over with a small rubber mallet after the heads are torqued. After I check and/or adjust the intake face angles with no gaskets, then I dry install the gaskets and check for valve cover rail alignment.

Also, during this whole process, make sure the distributor hole is still centered...

[blykins]

Most intakes need cut.  I rarely see one that doesn't.

As mentioned above, I always mock up without a gasket first.  That lets me see if the angles off and how the ports line up.  You can't have any gaps at the top or the bottom. 

I also check all of my intakes with this BHJ fixture just to get an idea of how the angles are.

[rockhouse66]

Nice gadget Brent.

The head gasket tabs were interfering with the intake.  Thanks for the tip Nightmist66.  With the tabs bent down, the gap is pretty much uniform top to bottom at each corner, so that explains the taper I was measuring.  I will get with my machine shop to figure out how to mill the intake to improve the fit.

[blykins]

Good catch on the gasket tabs!

[Nightmist66]

Glad it was simple...


Brent, is that fixture readily available? I've been wanting one for a while.

[blykins]

Yes sir, I can get one for you. 

It works with FE's and SBF's. 

[Nightmist66]

Good to know, thank you.