intake manifold leaking oil into cylinders. any ideas?

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Don't waste your time with different sealers. I'll bet you'll have to angle mill your intake .002 to .004 off the high side to get it to seal.
My intake has the same problem leaking oil into the cylinders and I wasted all summer last year trying to seal it. My angles between the heads and intake were about perfect. Talked to Dave Hughes after using lead to check the actual clearance and he said I needed .002 to .003 more crush at the bottom for ideal sealing.
I had it angled milled .003 and I'm picking it up on Monday. Hopefully that fixes it.
 
Have you place a good straight edge along the lower half of the manifold port sot see if there is any warpage in the intake manifold?

Snug down the bolts on one side without gaskets and see if it lifts the other side up at all.
 
bobscuda67 said:
Don't waste your time with different sealers. I'll bet you'll have to angle mill your intake .002 to .004 off the high side to get it to seal.
My intake has the same problem leaking oil into the cylinders and I wasted all summer last year trying to seal it. My angles between the heads and intake were about perfect. Talked to Dave Hughes after using lead to check the actual clearance and he said I needed .002 to .003 more crush at the bottom for ideal sealing.
I had it angled milled .003 and I'm picking it up on Monday. Hopefully that fixes it.
Click to expand...

But shouldn't gaskets make up for that very minor deviation in the fit-up? I thought that's what gaskets were for?
 

Hey bobscuda67
Did you take a bit off each side of the manifold or does itjust need to come off one side? What ft lbs do you torque to? Is yours a magnum intake too?
Hey nm9stheham
I will try the straight edge and clamping one side

Cheers
 
Tried sliding some feeler gauges around it? As I sad earlier, clamp one side and see what it looks like. You may need to put a gasket on that side to raise the manifold so it's not touching the rail.
 
I do have a magnum manifold.
I thought that a gasket would make up any difference between head and intake angles, but it doesn't, at least the .060 thick gaskets I used. And I used eight sets of them last year and this spring.
You really need to do the Hughes lead shot mock up to see the crush thickness. If it needs to be milled you have to give him a number.
I torqued down my intake to 20# in four steps.
My intake will be milled on both sides .003. I called Jerry Friday and he said he had one side done and was setting up to do the other side. I'll have to let you know if it worked.
 
I should have gaskets in the next couple of days so I will get onto it as when I pulled the heads off some water got into the cylinders and into the rings. I blew it out with air and have put oil in etc but every time I turn the engine over tiny drops of water come out from the rings. I don't want them to rust.

I will clamp one side as suggested. What is the lead test. Do you clamp small balls of lead in each end top and bottom and then measure them? Maybe use grease to keep them in place while fitting the manifold
 
well I think I have found it. At least I hope I have
I checked every angle i could and couldn't find anything wrong at all.
Then i decided to go back to basics and check every thing from the start. The shaft on the bolts are too long. They run out of thread just perfectly as they touch the manifold with no gasket.
I screw them in until the run out of thread and with no gasket or washer they sit up above the manifold. If i put on the washer then they bottom out just as the washer touches. So if i ad the gasket they seem fine but its so close that i cant help but think this must be the problem.
 
I take it those are non-stock fasteners? I bought the MP stock replacements when I bolted down my airgap...worked fine, no issues...
 
No I had galv bolts in the manifold when I got the engine.
A few years ago I had it rebuild by a local engine shop and they replaced them as they said my mild steel bolts would not hold torque.
Looks like they may have not checked them properly
 
It's always something isn't it? Hope you got it now. A grade 5 strength (similar to 8.8 metric) should be fine at these torque/tension levels, by the way. (Not counting Chinese grades 5's!)
 
maca said:
No I had galv bolts in the manifold when I got the engine.
A few years ago I had it rebuild by a local engine shop and they replaced them as they said my mild steel bolts would not hold torque.
Looks like they may have not checked them properly
Click to expand...

What a bunch of Whackers!!!!
 
Well I couldn't find any problems with the angles so I sealed it up and slapped it on
wink1.gif

On a closer inspection of the old bolts I found on 3 or 4 bolts that where the thread ends on the shaft where I suspected they may have been bottoming out, there was shiny wear marks. So I am pretty sure they must have been bottoming out.
Ran great tonight with steady vacuum and great idle
I will get some new plugs and give it a run.
 
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