Intake Leaking Oil

[bobscuda67]

Perhaps a brief history of the engine will help.
2003 the stock 340 block was was milled to square it up. New magnum heads were milled to a 57cc chamber. Head's intake surface was milled to compensate.
The Mopar M1 was bought new and bolted on in it's stock form. It worked well with no leaks at all.
2012 it started having a small oil leak I noticed on the garage floor. It looked like it was coming from the head gasket.
2013 removed the heads and had them cleaned up and checked the valve springs, no cutting on them.
I wanted to use a Cometic head gasket but the block's deck surface was to rough. I removed the short block and had it gone thru and the deck's were milled .015 to smooth them out.
2014 I started having intake sealing problems and after 4 tear down's it was still leaking. I took the intake in to the same machine shop and was told taking .015 off the block shouldn't make the intake leak. But he cut the intake .015 anyway. That was in August and it still leaked.

It is so close to sealing it isn't even funny. I can drive it for 100 miles before it starts burning oil. All the sealers seam to last until that hot oil loosens the glue bond.

 

[AJ/FormS]

Re post25
Or the intake is down so far that the bolts are trying to stretch the intake from side to side, which of course they cant do.
You know what? Maybe too much has been machined off the sides of either the heads or the intake.That came out wrong.Of course too much was taken off. Its plain to see. Anyway,I wonder if two thick gaskets per side would restore the relationship. The manifold would have to be very carefully torqued down in the proper sequence and in very small steps, so that it would actually draw down. Thats down vertically.
Ive never tried a stacked gasket there, but I think it would work. Still cheaper than a new manifold. Might require periodic retorques though.
- Whaddaya say Bobs. Stick some shims in there to simulate 2 thick gaskets and see how the bolt holes work.That would jack up the end rails too.I know it sounds hokey,but.......
FWIW, I have reused the same intake gaskets, several times,and with no extra sealers.I was broke and thought it was worth a shot. Headgaskets too. You never know until you try.

 

[Bad Sport]

I took the intake in to the same machine shop and was told taking .015 off the block shouldn't make the intake leak. But he cut the intake .015 anyway. That was in August and it still leaked.

Hello, there's your problem, he cut the intake an equal amount, and probably on the flange side only, I bet he didn't touch the ends. That isn't correct, that's why it's resting on the china wall.


Look at the chart here under 340-360

http://www.crankshaftcoalition.com/wiki/Milling_cylinder_heads

 

[Bad Sport]

Re post25
Or the intake is down so far that the bolts are trying to stretch the intake from side to side, which of course they cant do

I bet that's ^^^ exactly what's happening.



You know what? maybe too much has been machined off the sides of either the heads or the intake. I wonder if two thick gaskets per side would restore the relationship. the manifold would have to be very carefully torqued down in the proper sequence and in very small steps, so that it would actually draw down. Thats down vertically.
Ive never tried a stacked gasket there, but I think it would work. Still cheaper than a new manifold. Might require periodic retorques though.

If the flange sides were milled, and the intake ends weren't, that's a problem.

 

[bobscuda67]

Ok seams like I need the intake milled on the bottom as I only have .024 clearance between the wall and intake with .060 intake gaskets.
But I found some Cometic gaskets that are .188 thick, part # C-5566-188. Instead of stacking gaskets and it would raise the intake further away from the china wall.
On my Magnum heads the intake bolt holes go all the way thru, no bottom.
My head gaskets are .040 Cometics.

 

[Bad Sport]

Ok seams like I need the intake milled on the bottom as I only have .024 clearance between the wall and intake with .060 intake gaskets.

I would venture a guess that's the problem, it's hitting the wall before it can apply enough pressure to seal. There is a mathematical equation to do that, look at the link I posted.



But I found some Cometic gaskets that are .188 thick, part # C-5566-188. Instead of stacking gaskets and it would raise the intake further away from the china wall.
On my Magnum heads the intake bolt holes go all the way thru, no bottom.
My head gaskets are .040 Cometics.

Every hole? If so that's good. I checked my LA heads this morning, some do some don't.

 

[Marcohotrod]

use the .188" gaskets and ask cometic what they like for adhesive. maybe some new intake bolts, and what diameter are they and what torque ? and this was a problem before u had the intake cut. on my 340 I cut the block .015" and the heads .015" and did not cut the intake side of the heads and did not cut the intake. the Ed. LD340 intake sits high with felpro perf. 1213 gaskets, and I retighten/check the intake bolts a few times.

 

[AJ/FormS]

Bobs
re post 30, My stacked gasket suggestion was not to get the intake off the wall(although it will do that). The suggestion was to restore the port and the bolt alignments.
So now knowing that .188s are available, you could mock your engine up with the required shims, and check those.

 

[bobscuda67]

I doubled up two pieces of gasket stock and they measure .110 and glued them on the heads.
With the intake snugged down, I didn't torque it, I have .075 between the head and intake on all four corners. From top to bottom of the intake it's the same .075.
I also measured the china wall to intake and it's .095 front and rear.
The bolts were a little harder to screw in by hand though.
Yes I have new intake bolts, at least they were before all this. I think I torqued them 30#.
And I was having sealing problems before I had the intake milled.

 

[AJ/FormS]

The following is maybe going to sound mean.But its not meant to be.I dont know how to write in a gentle way.
You put the shims in all the wrong places. Of course you have the same measurements. How could it be any different?The way youve done it, proves nothing.You have forced the manifold to do whatever the heads are doing.
Think three legged stool. A three legged stool does not wobble.You need to set your intake down as a three legged stool.
You cant use a compressible shim, like paper.
You need to place the non-compressible shims in three places, as detailed earlier, so that the ends of one side are free to float.That means front and rear on one side and center on otherside.I would ransack the washer supply for three, fairly thick( in the neighbordood of .100), identical, FLAT washers;or equivalent.Put these shims; on,or very near to, the end bolts on the one side, and on or near to the center of the otherside.Torque the two-shim side down first, to around 12#.Then the remaining one to a lot less, maybe 5to8# Then measure the end-gaps on the one-shim side.
Then repeat the whole procedure,on the other side,swapping the shims side-for-side.
If your manifold is twisted, or the heads are running uphill/downhill, this will be proven by varying end-gap measurements.If everything is straight,true and not twisted, then that will also be proven; by equal measurements everywhere.

 

[Marcohotrod]

I think the first intake gasket picture u posted looked like the stock replacement blue teflon coated steel fel pro ms9---- , not the hot set up for an aluminum intake. I think your measurements are good, bolt it down tight with a .120"-.185" gasket and any recommended sealant, the right amount of silicone only front + rear, let it dry overnight, retighten 3 times after running

 

[bobscuda67]

Ah, it's a little clearer now.
I shimmed the intake with .120 plastic shims as was suggested.
My results are;
Left front has a .081 gap at the top and a .63 at the bottom.
Left rear has a .120 gap at the top and a .100 at the bottom.
Right front has no gap at the top or bottom.
Right rear has no gap at the top or bottom.

Now what?

 

[Marcohotrod]

anyone make a .120" magnum gasket

 

[70aarcuda]

look at pn 169106

http://scegaskets.com/product/sce-gaskets-part-number-169106/

169106 is mag

169107 is LA

 

[AJ/FormS]

Swap the shims to the other side and repeat
Then we will analyze the results.
Bobs, please dont tell me you put 4 plastic shims on one side and 1 card board shim on the other!
If you did, Im outta here.

 

[bobscuda67]

Swap the shims to the other side and repeat
Then we will analyze the results.
Bobs, please dont tell me you put 4 plastic shims on one side and 1 card board shim on the other!
If you did, Im outta here.

Ha! No. Thats just when I took the picture, I was in the process of taking them off.
I did switch the shims from side to side, look close in the pictures. I posted the results in my last post. I just didn't take a picture of it. Thanks.

 

[AJ/FormS]

Phew. You had me worried Bobs
So to recap;
All the shims are the same thickness,right?
And the multi-shim side has just 2 shims, and they are on the ends,right?
And on the one-shim side its at, or near to, the center,Right?
There should be 4 pairs of numbers; one pair from each corner. Im only seeing 2 pairs of numbers.
All measurement come from the one-shim side, be it left or right . Right?
---------------------------
Left front has a .081 gap at the top and a .63 at the bottom. =.018 large top
Left rear has a .120 gap at the top and a .100 at the bottom. =.020 large top
The numbers from post#37 show that each left corner seems to be tapered about .019 +/- .001 from top to bottom.The numbers also show a trend of about .038 from end to end.
Is a picture coalescing yet in your mind?
Now lets see what the other side is doing.

 

[bobscuda67]

I found a mock up on the Hughes Engine site showing how to check manifold clearance.
I made two intake gaskets and punched four holes in each one. I cut eight little pieces of .123 rosin core solder and Scotch taped them in the holes. Torque down the intake in small increments to a total of 20 ft. lbs.
If you can make out my chicken scratch on the photo you can see that the numbers are not ideal but not bad, well within the gasket crush range.
I did measure the gap at the china wall and the front was .024 right and .012 left. The rear was .024 right and .004 on the left. Way to close.
I know that the machinist cut .015 off the block and never cut the end wall portion of the intake.

 

[Marcohotrod]

use the thickest gasket u can and u will not need to cut the intake front and rear. use a soft gasket, not like the steel one in your first picture. retorque bolts

 

[AJ/FormS]

So you abandoned me.
And you forced the intake to conform.Again.
And the china wall numbers you are ignoring! They are telling you a story, but its falling on deaf ears.

 

[Marcohotrod]

I think we are making this too complicated. bolting the intake down to 20 ft/lbs is not much forced to conform. see post #44

 

[bobscuda67]

So you abandoned me.
And you forced the intake to conform.Again.
And the china wall numbers you are ignoring! They are telling you a story, but its falling on deaf ears.

No! I am listening. I now have .120 between the intake and the end wall front and rear.with .060 gaskets installed.

 

[bobscuda67]

I think we are making this too complicated. bolting the intake down to 20 ft/lbs is not much forced to conform. see post #44

That's right, I didn't think 20 ft/lbs would force the intake out of shape. My last mock up was showing that the intake to head angle is very close.

 

[Marcohotrod]

with the side gaps around .040" , and the issues u have had , I would use gaskets thicker than .060". thicker to the bolts going in

 

[AJ/FormS]

Well lets see if I remember this right.
5 times it leaked with .030 gaskets, and
1 time it leaked with .060 gaskets, lasting just 200 miles.
Today you want to put it back together with .060s and go for #7.
What, did you do/are you doing, different?
Did you re-machine something?