View Full Version : classic 18 and aluminim intake. water in oil.

08-19-2013, 04:35 PM
A couple weeks ago I bought a new edelbrock performer intake and 1409 carb. Swapped them out, rtv around water ports and front/back. Ran it in the driveway to warm it up and retorqued the bolts.

Took it out and it was sucking water in pretty good. So thinking it was my work, I'm no mechanic, I took it to a shop and had them swap it again. Thicker gasket this time around as the machine shop said one side was warped .015". Same result, water in the oil. Swapped back to original intake and all is well again. Ideas? I'd like to stick with the performer and 1409 carb as it runs way better.


Edit. This is an 85 merc 260hp 350.

08-19-2013, 11:02 PM
Is the original intake cast iron or aluminum? Where is the aluminum intake warped, one end, both ends, middle,???
A few things I would check, an do... check the mating surfaces of the new intake against the gasket to make sure it matches up correctly, when you use silicone on the water passages be sure not to over do it, I put a bead the size of the "grooved" ring around the port on both sides. At the front and rear of the intake to block I put a decent bead. I let both beads "skin" for about 5 minutes before mounting the intake to the block. I tighten the bolts starting at the center bolts and working my way out to the ends. I go over this 3 times, then run the engine to operating temp and check it again.

08-20-2013, 09:02 AM
I'm having the same issues with the same intake. I wonder if it's warped or what. I might just ry to find a used Merc intake manifold and regasket the thing. Either way, the water issue really sucks.