Ive looked everywhere on the pan an it looks like its not leaking, but behind the manifold an valve covers its just got some bad leaks. This will be the 3rd time I've tried fighting this leak within a few months span. I know it probably won't seal perfect, but I would love to not have oil burning on my exhaust manifolds and pooling up in the spark plug seats. What type of valve covers do you guys have? I've got these dinky aluminum chrome Edlebrok covers.

 

I cannot emphasize enough how deceptive that intake manifold leak can be. I have fixed more FE oil leaks than I have fingers and toes, and every one was described as a valve cover, pan gasket and most often as a rear main oil seal. None started out as an intake leak - and that is what they all were, intake leaks. A true FE valve cover leak will drip all along the bottom. Large leaks will drip everywhere, a small one may limit itself to dripping off the rear bottom, as the engine slants downwards. You will be able to feel the oily smear all along the bottom of the valve cover, though. The most common valve cover leak cause is overtightened bolts that have deformed the gasket mating surface. Straighten them with a ball peen hammer. The second cause of valve cover leaks is missing oil drip guides. These are a stamped steel plate that sits under the rocker stands. It has drip channels formed in it to collect the oil from the rockers and direct it to the drain holes in the head. Oil will other wise build up in pockets under the valve cover along the gasket where crankcase pressures have a tendency to push it out. However, using silicone and gaskets on clean metal will almost guarantee a perfect seal. I have never failed to seal an intake leak, with one exception, and that was because I was in a hurry at midnight while trying to fix it under pressure to leave the next morning.

 

I was going to ask last night if you are running aftermarket valve covers. I would double check the fit and gasket surface. I tend to stick with stock FE stuff for fitment purposes. If you want valve covers and intake to seal properly; use the sealant called "The Right Stuff." I believe Permatex makes it. I use cork gaskets.

 

Thanks guys! I think your right about going with stock FE covers, I may however get some cast covers so I dont do what Confederate Diesel said by bending the cover by over tightening. I guess Im going to be pulling the manifold off again. BTW, do you guys thing I should use the rubber or cork gaskets with silicon, or should I just use the gaskets or just the silicon?

 

I think you hit the nail on the head!

 

Here is a foolproof method to seal that intake: Remove it and clean the surfaces, and dry fit the gaskets to the block and heads. Install the head-to-intake gaskets, but use no sealant on them. Apply a thin layer of RTV to the block where the intake will mate and then affix the intake-to-block gaskets. I prefer the blue, but that's just a preference. Let cure overnight, or at least for 8 hours. Apply a thicker layer of RTV to the top of the intake-to-block gaskets. Apply a larger blob of sealant to the 4 corners. Install the intake and torque to specs.

 

Make darned sure that the heads, and the intake align with each other on the gasket mating surface. I actually had to have the heads milled just a bit as they sat about .020 higher than the manifold. I have the edelbrock performer 390 intake, and edelbrock says not to use the front and rear block seals for the mainfold, just a 1/4 in. or larger bead of Hight temp RTV. Well my intake doesn't leak but the valve covers have a slight leak. It turns out one valve cover has a slight bend in it, so I am going to replace them with a new set. I prefer the stamped steel, as they do bend, where as if you bend the cast aluminum, (aka; over tighten them) they just break! I have gone through a few valve covers on my drag boat learning that lesson. Oops!

 

Another update...next one should be it running. It was missing some parts, but we got everything, went to start it and that old Holley Fuel pump was dead Got a nice shiney new Carter on the way from Summit though.

 

Cool keep us updated, I figured you were too busy laying down matching rubber ribbons in your neighborhood to update us

 

This is the info I've been lookin for for a while! Thank you!

 

How are you set up with breather, PCV, oil cap etc... Could be your problem if pressure is excessive. I run the cork gaskets using the black permatex, more oil resistant, been running for several years now w/o trouble.

 

If the pressure is excessive, that is a very strong sign of bearings that are very worn, or that there is excessive cylinder blow by, either case warrants an overhaul! Mine did that to the point that it was pumping oil through the pcv system into the air filter, and carb, causing it to run rough. it also pumped oil out of the dipstick tube. I pulled the engine apart to find that the number 1 and 7 cylinders had cracked rings causing blow by! I also had the rear main bearing failing ie; the upper was almost completely gone, but the engine had 349 k on it If you have excessive pressure check your cylinder compression and leak down ie; worn or cracked rings. Make sure your oil pressure is still good, if it is low that is a pretty good sign that your bearings are excessively worn.

 

Do u still have the carburetor?

 

Holy cow a necro thread...

 

Although mine is not a Ford Truck it is however a 1964 Ford Meteor with a (current) 352cid 2 barrel. I am looking to replace my current factory exhaust with dual pipes and headers since I have major exhaust leaks (at the manifolds) but given in try to remove bolts they'll just snap off and with no room to drill them out and re-tap em. So I am looking to pulling apart the top end of the engine so I can drill and re-tap on the ground, while doing so I might as well replace intake from 2 barrel to 4 with a 'Holley' 4 barrel carb. I would strongly suggest to you to go with (A MANUAL CHOKE system) since you will have greater control on fuel/air mixture. I replaced my factory 2 barrel carb. with a 'Holley' 2 barrel carb but changed it from automatic choke to manual choke and found car much EASIER to start when cold. So in doing my top-end I will replace it with a 4 barrel 'Holley' carb with manual choke but (suggest to you as I will do the same) get a 700 or 750CFM rather then a 600CFM as this will provide more power, you may regret installing a 600CFM once in and you see how it runs. I installed a 750CFM on a '69 GTO' way back and then found it was kinda weak, so my strong advice to you is either a 700 or 750CFM with a manual choke. Good luck Brother.