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Unread 12-28-2012, 08:19 PM   #16
olliehopnoodle
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Yeah, I am totally confused too.
I won't argue with you about the cross over since my original line of thinking that a threaded plug might be the issue is moot.

The crank case needs to either vent into the atmosphere or, via a PCV system, have the gasses scavanged into the intake to be burned. If you are doing neither, you are building up positive pressure (heat and blow by) and the weakest seal point will fail.

So you have a pcv valve in the intake. It has a hose connected to it that is routed to the base of the carb so that the air in the crankcase can be drawn into the combustion chambers and burned with the normal air/fuel mixture. RIght? In order to allow air flow into the crank case the oil filler cap has a connector that allows air to be drawn in. The connector usually has a hose on it that routes to the air cleaner.

If you don't have this setup, or it is not working correctly, then the crank case might be experiecing positive pressure. The pressure may be forcing itself out the ends of the intake which is probably the weakest sealing point.

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Unread 12-28-2012, 08:24 PM   #17
Eric_B_1984
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Quote:
Originally Posted by olliehopnoodle View Post
Yeah, I am totally confused too.
I won't argue with you about the cross over since my original line of thinking that a threaded plug might be the issue is moot.

The crank case needs to either vent into the atmosphere or, via a PCV system, have the gasses scavanged into the intake to be burned. If you are doing neither, you are building up positive pressure (heat and blow by) and the weakest seal point will fail.

So you have a pcv valve in the intake. It has a hose connected to it that is routed to the base of the carb so that the air in the crankcase can be drawn into the combustion chambers and burned with the normal air/fuel mixture. RIght? In order to allow air flow into the crank case the oil filler cap has a connector that allows air to be drawn in. The connector usually has a hose on it that routes to the air cleaner.

If you don't have this setup, or it is not working correctly, then the crank case might be experiecing positive pressure. The pressure may be forcing itself out the ends of the intake which is probably the weakest sealing point.
I no longer have the factory air cleaner. I just have a 10 inch open air cleaner, I have a vented oil cap on it as well as the pcv ran to the base of the carb.
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Unread 12-29-2012, 06:41 AM   #18
RockRollin
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Then something is plugged, hose, filler cap, PCV valve, or there is a volume of pressure building that is overwhelming both, blow-by, or steam. If oil is pooling in the valley, I would think you would see drop in oil pressure first. I would drain the oil and inspect for coolant, could be cracked water jacket, or leaking seal in the water passage between head and intake
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Unread 12-29-2012, 08:20 AM   #19
olliehopnoodle
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The best part about 'helping' someone is I often learn something more. Here is an interesting wiki about the PCV system.

http://en.wikipedia.org/wiki/Crankca...ilation_system

A couple of things I didn't know (and this first one may be of interest to your issue). At higher load conditions where the intake manifold vacuum is low the PCV valve closes and the crank case pressure actually escapes via the breather. (No wonder my Mustang engine with the breather on the valve cover and no tube to the air cleaner gets oil on it). If your breather system is restricted perhaps the crank case pressure builds and pushes out the gasket? Or like RockRollin indicated, a small coolant leak could create even more pressure as the water is turned to steam and completly overwhelming the system.

At high vacuum the valve restricts the air flow. This keeps it from providing too much air at idle and making the mixture too lean. I did not comprehend this. So the sensitivity depends on the spring and the intake manifold vacuum at idle. If you have a strong spring and lower manifold vacuum (bigger cam for example) the amount of air the PCV is letting slip by may be causing a lean condition at idle (making tuning more difficult). I need to go see what I have in my Mustang. It has a more performance oriented engine in it. If you have high manifold vacuum and a weaker spring than, depeding on the PCV design, it might closing off the air completly. This means pressure buildup in the crank case if the breather side is not working correctly too.
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Unread 12-29-2012, 09:11 PM   #20
Eric_B_1984
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I am like 80% sure I do have a coolant leak in the intake, it is not getting into the oil tho. So I know that the intake has to come off again, what is the best advice for reinstalling it to attempt to resolve this issue.
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Unread 12-29-2012, 11:11 PM   #21
RockRollin
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I would pull the bottom plate of the intake and make sure the PCV baffle is clean. New valley pan, RTV black the water jackets , put a 1/4" tall bead of RTV for end seals, set intake, start all bolts, let sit for 24hrs then torque. Make sure oil fill tube is vented, PCV valve is working, no blockage in PCV line. PCV line should be hooked to back base of carb.
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Unread 12-29-2012, 11:40 PM   #22
dbabicky
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I agree you're building pressure. Something in your PCV system is plugged. Change hoses,PCV valve, breather cap,and reroute PCV valve hose and the oil breather cap hose to the underside of your 10" air cleaner, there should be a "punch-Out" hole just for that. When you pull your intake and reseal, use a valley pan, no gaskets, and I know it's expensive but, go out and buy "The Right Stuff" gasket maker. You can also buy the small gun to dispense it or just use a caulking gun. Use the "Right Stuff" on the front and rear of the intake with no gaskets.
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Unread 12-30-2012, 12:58 AM   #23
Eric_B_1984
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That's one of many things, I believe there is more than 1/4 inch between the intake and the block on both the front and rear. And also I do not recall ever seeing any type of "bottom plate on the intake. I think some time next week I will start pulling the intake off again.
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Unread 12-30-2012, 01:14 AM   #24
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I have a 401 in my Gremlin... When I first had it built It seamed everytime over 5000 rpm it would blow the oil cap off during deceleration... I then changed my pcv hose to a stronger transmission line hose which doesnt collapse when pulling negative... IT helped some but still hasnt totally solved my issue. i most likely am going to have to put breathers on my valve covers and possibly have an exhaust scavenge kinda thing where the exhaust pulls the vapors out..... And those little rubber seals lol hate em... its definately better to use RTV sealant ... however like the instructions say you also need to worry about the gap. if you have machined heads or a manifold that has been machined and your heads havent or your block as been decked you will have different sealant gaps.... Kind of off topic Something that not many people know is the Installation instructions for the Edlebrock Performer have changed... They push using the 7213 gaskets with the valley pan... If you have the instructions prior to 2011 they dont even mention using the 7213 gaskets. I think the gaskets will help the longevity of the the seal and maybe any surface irregularities..


the bottom plate is an oil baffle... I believe the idea there is it will prevent oil directly getting sucked into the pcv system. You just want vapors ideally.. The edelbrock RPM manifold has its own little baffle.. SO maybe just maybe if you dont have that baffle your pcv is sucking in the oil temporarily clogging it, causing your seals to blow out?


Good luck
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Unread 12-30-2012, 01:56 AM   #25
Eric_B_1984
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Quote:
Originally Posted by jeeppwner View Post
I have a 401 in my Gremlin... When I first had it built It seamed everytime over 5000 rpm it would blow the oil cap off during deceleration... I then changed my pcv hose to a stronger transmission line hose which doesnt collapse when pulling negative... IT helped some but still hasnt totally solved my issue. i most likely am going to have to put breathers on my valve covers and possibly have an exhaust scavenge kinda thing where the exhaust pulls the vapors out..... And those little rubber seals lol hate em... its definately better to use RTV sealant ... however like the instructions say you also need to worry about the gap. if you have machined heads or a manifold that has been machined and your heads havent or your block as been decked you will have different sealant gaps.... Kind of off topic Something that not many people know is the Installation instructions for the Edlebrock Performer have changed... They push using the 7213 gaskets with the valley pan... If you have the instructions prior to 2011 they dont even mention using the 7213 gaskets. I think the gaskets will help the longevity of the the seal and maybe any surface irregularities..


the bottom plate is an oil baffle... I believe the idea there is it will prevent oil directly getting sucked into the pcv system. You just want vapors ideally.. The edelbrock RPM manifold has its own little baffle.. SO maybe just maybe if you dont have that baffle your pcv is sucking in the oil temporarily clogging it, causing your seals to blow out?


Good luck
I was thinking of having my metal guy punch holes in the valve covers for the same breather caps I have on my oil fill tube, funny I thought that could be enough. But When you do use the gaskets and the valley pan, the bolt holes do not line up right. If you use one or the other, they do line up right. I guess when I put it back together I will try a better hose for the pcv as well, it is just standard vacuum hose. I just hate the fact that it keeps coming back to this in my mind, if it doesn't work this time, give trans dapt a call so I can put an engine I understand in it.
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Unread 12-30-2012, 07:31 AM   #26
RockRollin
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. There all the same. Except Ford's. Here is a shot of the PCV tray. The left is rear. I would go with the biggest valve I could get, also check that breather cap
20121230_082909.jpg  
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Unread 12-30-2012, 10:57 AM   #27
Eric_B_1984
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It's been almost a year since I had it off, and I can say mine looks nothing like that underneath
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Unread 12-30-2012, 11:05 AM   #28
RockRollin
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Quote:
Originally Posted by Eric_B_1984 View Post
It's been almost a year since I had it off, and I can say mine looks nothing like that underneath
We may have found the problem. If there is no baffle the PCV is going to get saturated pretty quickly, then only the filler tube breather will be venting. Once that plugs up, icky black goo blowing out of somewhere.
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Unread 12-30-2012, 11:50 AM   #29
olliehopnoodle
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Interesting, I don't remember my edelbrock having the baffel.
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Unread 12-30-2012, 03:17 PM   #30
Eric_B_1984
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Quote:
Originally Posted by olliehopnoodle View Post
Interesting, I don't remember my edelbrock having the baffel.
I've been very up close and personal with it and I don't remember seeing holes on the bottom that I didn't know what to do with
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