Intake Oil Leak

-
Green Hornet

Green Hornet

Active Member
Joined
Oct 24, 2008
Messages
42
Reaction score
0
Location
Maryland
I'm looking for some help with a problem on my new 408. The intake refuses to seal along the port face of the heads. When I take the intake off there is oil half way up the ports. I am running Eddy heads and a M1 single plane intake. I had bought the short block and assembled it from there. I know the shop who put together the short block milled the deck some to zero it. I expected to have to mill the intake, but all the bolt holes line up perfect. Also, when I set the intake down on the heads with no gasket there doesn't appear to be a gap at the top or bottom of the port surface when your looking at the intake from the ends. I've use a Mopar and Fel-Pro gasket set with the same result. It really has me puzzled. Any help would certainly be appreciated.

Mopars Rule!
 
mine does this same thing. i was told and may try it if someone dont chime in, to just use some silicone no gaskets. i tried 3 gaskets already one even used a little silicone on it. they all allowed oil to be sucked in the intake ports both sides.
 
I had the same problem with W5's. I use gasgets with silicon (the right stuff seems best) and the leaks have all but cleared up.
 
After pulling the intake back off I put a straight edge down the port surfaces and found a high spot on the front left corner. My machine shop had to remove .012 to correct it. Everything seems sealed now as far as oil leaks. Still fighting a miss though.
 
Was the motor smoking when the intake was leaking?

I used the wrong gaskets on my aluminum intake and it leaked and smoked. I changed to the Felpros and it does not smoke now but was curious how you knew the intake was leaking.
 
Mullinax95- I have been dealing with a miss since putting this motor together. At first I had an oil leak on he base gasket of the intake on the back side. I resealed that and then the front base gasket started leaking so I tore it back apart. Both times I saw where the port side gaskets were oil soaked about half way up the port. From this I suspected there was a vacuum leak from within the cam valley. That is when i discovered the high spot on the intake. I was hoping that would have taken the miss out of the motor, but my old friend is still with me.
 
Pulled the intake off again. Thought maybe a wiped a couple lobes on the cam because plugs 5 and 6 were fouled. Just the same oil leak again sucking in to the ports. Can't quite figure this out. I have used Fel-Pro and Mopar's gasket kit with silicone on the end rails Oil is soaked half way up the gasket on the ports, mainly toward the rear of the engine. I have been anal about following the proper procedure for sealing this thing up. Most mechanics around me think I'm crazy. Picture should be attached.

Dart Intake Manifold 2 005a.jpg
 
was the intake from another motor? wondering if it had been previously milled. the only thing i can think of is that the intake isn't square cross ways. that migh explain the high spot and why it still won't seal since even after maching its just pulling and twisting to the other side when you torque it down. if you have another intake you could torque it down using just some thick paper gasket material and check the contact pattern.
 
This is a brand new M1 intake. I do have the original cast 340 intake sitting here I could try. Are you saying to get an imprint of both intakes and then compare?
 
yeah. that way if you see the same pattern on both then you can rule out the intake as the problem. you have already tried gaskets so the next step should be the intake.
 
Thanks for your assistance. I will try it out when I get a chance. For now it's time to make hay while the sun shines (literally). Then I'm gone for a week with our youth group. I'll let you know how I make out once I try this. Thanks again.
 
You must log in or register to reply here.
-

Back
Top