and I'm determined to pull 18-20InHg. This engine is in just too good a shape to live with only 16 InHg of vacuum as compression is 198/199 straight across the board and leak-down shows engine to be within 3% of brand new. There's no reason on earth I shouldn't pull 20 inches of vacuum!!

But this time I'm going to cut all my own gaskets out of .063" thick pressed cellulose nitrile composite as that's what I've used when racing and it's so much more forgiving and long lasting... TOTALLY bullet-proof stuff! Also capable of sealing better than OEM gaskets and at "absorbing" any small warpage or distortions that may or may not be present in the IM-to-head intake runner flanges. Being 50% thicker gasket material than 1mm thick stock gaskets doesnt hurt either. Doesn't have a metal sandwich layer like OEM but since I'm normally aspirated I'm not in the least concerned about a "blow-out" between IM and heads. Having no metal will also go a long way in reducing heat migration between the heads and IM. Being thicker will also help in increasing velocity between IM and intake valves... not a lot but I'll take ANY/EVERY velocity increase I can get!

Also, this time out I'm going to double-gasket the area between the upper/lower manifold halves. Again, primarily for velocity reasons in the high RPM runners but also to have a little more gasket compliance to absorb any possible/potential warpage/distortion between the two halves as well as increase the volume of the IM's internal reservoir... the more air I can store in there the better! Only thing this will affect is length between fuel rail, injector ports and IM injector bungs but I have 2 adjustment slots for length on the RCE injectors so I'm fine with up to 6 gasket layers between upper/lower manifold halves.

Of course I'll be measuring all mating surfaces for flatness as well as looking over EVERY square inch of the inside/outside IM surfaces for any hairline cracks in the IM casting under bright LED lighting and 40x magnification. It would be a nightmare to make all the various jigs/fixtures and clamping plates to pressure test this manifold. And this time upper/lower halves get torqued "with" Loctite Gel... I ain't havin any more "magic attacks" of some bolts inexplicably loosening while others don't budge.

If it leaks this time there's no choice but to have a "Spotcheck" or "Zyglo" treatment done to the IM to check for hidden cracks or stress risers too small to see. Ya just don't throw fully ported/polished/CC'd IM's in the dumpster without know "why" they've failed... or you're doomed to repeat it. If it happens again I'll put IM #1 back on and take my time having IM #2 thoroughly tested for cracks.

This has NOT been a fun-filled adventure and I'm NOT into "settling" on something I know is not as good as it can be! I'd rather eat a baby than go into this again less than a week after buttoning it up... but go in there again I WILL!

besides, I wasn't looking for any problems when I installed it last week. This time I'll be dissecting the stew out of it! If I find something I can't fix then #1 will replace it. Otherwise, if it checks out I've GOT to give it at least a 2nd chance if for no other reason than to know it's IM-specific and not some gasket issue. Just because an IM doesn't seal perfectly is no indication the IM is bad or faulty in any way... could just be a gasket. Take last weeks smoke test and EGR gasket for instance. No reason a brand new EGR gasket should not seal but it happened!

My biggest fear in all this is akin to the events of last week's screw loosening episode, ie; finding NOTHING at all wrong with it then reinstalling it and have it do the same thing. At that point there's but 2 options... undetectable IM casting crack/fracture, stress riser or magic and I've had enough "magic" for '08.

but much better at filling in the gaps between threads and doesn't run or drip like the liquid.

I'm also going to be lapping the IM's upper/lower gasket sealing surfaces with 320 grit sandpaper to insure I have totally "flat" mating surfaces for the "sandwiched" gasket between upper/lower IM halves. I'll also lap the IM runner flanges where they bolt to the heads and a hard sanding block with 320 grit on the cylinder head gasket flanges. Important to note ALL locating pin bushings in IM and heads must be removed to do any lapping then reinstalled afterwards.

With as much time as was put into these IM's via the workshop I can't believe I didn't spend another 30 minutes lapping all the IM gasket surfaces similar to how I recommended people do with their valley pan cover's gasket surface. Had I done that I "might" not be faced with having to R&R my IM again today.

I'll post up some pics later this afternoon of how to "blueprint & prep" IM gasket mating surfaces. It's only fair I guess that I get to be the first one snake-bit by this little over-sight. My biggest mistake in all this was presuming that any/all IM's are perfectly flat & true on all gasket-mating surfaces after 100k+ miles, a gazillion heat cycles and owners or unprofessional shops re-tightening things over the years without a torque wrench and just WHALING on the fasteners. It was a lazy/complacent presumption on my part! Even if it turns out everything is flat & true it was still presumptuous & stupid to not confirm it! It wouldn't prevent me from pulling the IM again today but at least I would "know empirically" that the reason I'm pulling it again is likely due to a crack in the IM and not some stupid gasket-sealing issue.

When I worked with overhead bridge cranes they would require it on high level govt contracts to test welds and the beam for stress cracks, etc.... It may turn something up that your other methods have not.

Another option would be to have somone scan the intake with an electronic Coordinate Measurement Machine (CMM)and plot the data points into a Computer Aided Design program. You would then be able to see exactly how straight / warped all mating surfaces are.

Granted these are extremes but they're just a couple of thoughts.....