HEMI: Intake to Heads Oil Leak

Hi guys!

This is the 3rd time Im having to remove my intake because it keeps sucking oil from the Valley area into the intake ports and then into the chambers, fouling the plugs with oil after a few minutes of running time....

I have checked proper alignment, bolt interference with the intake bolt holes, etc....face of intake is parallel with heads....so its not that the faces are crooked and not sealing right one against the other, they are nice and parallel whenI shim them and then I check them with a gauge on all 4 corners.

I have glued the head side of the gasket to the head with silicone, and I have left the intake side of the gasket with NO silicone, just some grease....but its still sucking oil.

Im sick of this so Im just gonna silicone both side of the gasket to assure a tight leakproof seal.

Now, my other concern is the torque Im applying to the intake bolts.

Richard Nedball's book asks for 25 ft-lbs torque on these bolts....but it sure looks like a lot to me. Its just 1/4" bolts threading into ALUMINUM cylinder heads.

I have just tightened them with a small socket wrench till I felt they were were tight enough, didnt want to overtighten them and risk stripping threads on my brand new ALUMINUM heads!!

Should I just go ahead and torque them at 25 lbs-ft??? Is it safe to do so on aluminum heads? Still it sound like a lot for such a small fastener threading into aluminum.

I would go back and re-read that part in book, it should be inch lbs not 25 lbs. Thanks / Gary

Ditto, re-read that. It's 72 in lbs on some and I think 48 in lbs on the others. Thats 4 ft lbs and 6 ft lbs!!! The proper intake torque and sequence is in the Mopar Hemi engine manual which should be on top of your work bench.

Yes, I do have the MOPAR HEMI ENGINES Bible and it states the tq figures in in-libs and it states to use different torque figures on the center bolts than on the outers.....

There is a majour mistake there on Richard Nedball's book. And I was right about it, its waaaay too much torque!!! I see some people will strip their threads following the suggestions on that book.

Also, it states someplace else to torque the valley head bolts to the same torque as the rest of the head bolts....which will probably cause the intake valve seats to distort and not seal right....

I love Rich and his book is the best but it is wrong on this. Use the torque values and sequence in the Mopar Hemi engine book. That is the only way to do it right. The bolts will loosen up after you run it several times. Retorque every month until it settles in. If possible I prefer to use studs on aluminum heads. I get mine from ARP.

I read somewhere that because the bolts are verticle, if you over-tork the intake bolts, it can wedge the heads apart and crack the block!

domingo make sure it is not the cylinder head studs in the intake ports sucking oil up and through, also if the heads are ported do they have brass tubes for the push rod holes?sometimes those leak.

if those two parts are ok i would only use mr gasket intake gaskets, glue them to the cylinder heads and let the glue "set up", silicone the face of the gasket and the bottom of the intake ports, the silicone will allow the intake to slide down on the gasket as you tighten it down with out pulling the gasket with it.

is this a mp cross ram? or single 4 bbl? if it is a cross ram use lots of silicone down the bolt holes to keep them sealed as well.

Its a stage V dual carb intake. Known as the RAT BUSTER.

I redid this once more. I put silicone both sides.

I torqued it down per the Mopar HEMI BIBLE and we'll see if this time around it seals.

The oil is seeping through from the intake to head joint. When I take out the carbs this intake is big enough to let me see that there is oil right at the seam between the intake and heads. every time is the same. Its the first time im using silicone on both sides of the gasket....lets see how it holds up this time....

I also put some goo on the outside bottom of the intake port so it seals up with the intake when torqued down, I hope it helps sealing...

i had this same problem on my motor. stage v heads and mopar performance x-ram(has very bad port alignment on bottom of runners) I glued the gaskets to the heads with 3m weatherstrip adhesive and ran a thin bead of silicone around each port. 6 years and no leaks. I have seen over tightening of the intake cause the heads to leak water out of the corners, retorqued and it was fine

Sorry guys. Definitely a typo there. I have been seeing a lot more of this problem lately. On the last few engine I did these steps:
* I glued the Mr. G 303G gaskets to the heads using Gasgacince.
* Bolted on the manifold for an hour to press the gasket to the head.
* Removed the manifold and trimmed the gasket to the port using an Exacto.
* On the manifold side I used "The Right Stuff" around each port, spread very thin with my finger.
* Bolted on the manifold using the torque sequence.
* Went over all the bolts several times until there was no more movement.

Not a leak since...

Another thing to check is intake fit. Let's say the block was decked alot. Now the holes in the intake don't line up with the threads in the heads. The intake bolts end up hitting the sides of the intake. You can be tightening the intake and it feels snug but you are really just jamming the bolts. To check this, put intake manifold studs in the heads, (best without the intake gaskets on), and see if the intake manifold will slide all the way down to the head. If not you will have to get a rat tail file and elongate the holes in the intake manifold until it will slide down to the head without wedgeing into the studs.

Be very careful on which type silicone you use on intake gaskets, I like and use "adhesive" silicone only on any gasket that is exposed to oil Make sure the label says Adhesive silicone, not gasket maker or any other label Let it dry 24 hrs or more

I have pretty good luck with the Permatex gray..

I didn't read any comments for checking gasket thickness. If you have too thin a gasket, it could appear to be clamping down enough but isn't.

Had my intake off last week.Used the Mr G 303G and "The Right Stuff to glue everything back together

Thanks again Rich

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Another thing to check is intake fit. Let's say the block was decked alot. Now the holes in the intake don't line up with the threads in the heads. The intake bolts end up hitting the sides of the intake. You can be tightening the intake and it feels snug but you are really just jamming the bolts. To check this, put intake manifold studs in the heads, (best without the intake gaskets on), and see if the intake manifold will slide all the way down to the head. If not you will have to get a rat tail file and elongate the holes in the intake manifold until it will slide down to the head without wedgeing into the studs.

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I caught this the first time around and elongated the manifold holes....still after doing this im still sucking oil into the intake ports.....