Alum Valley Cover

Johnnydidd

Well-known member
I have a 56 Merc with 312, with a 4 barrel original manifold with adapter to fit a holly 4 barrel carb Just purchased an aluminum valley cover with PCV opening, also got a PCV valve from Concourse. Question, will I be able to change or check the PCV valve without pulling the intake manifold
 
It depends if the PCV valve is located under the manifold or not on the aluminum valley cover.

Sal
 
I have one of Mummerts aluminum valley covers with the PCV thing and the hole is situated in back of the intake manifold so access is easy.

A friend of mine has the same unit and there is access.

One thing about Mummert's aluminum valley cover. In the two cases I have run across (mine and the above mentioned friend) we had to notch the front of the cover on the top so the thermostat housing clears.

I have no idea why he makes them this way, and there is no warning with the cover about this.
 
Along the same lines, I had to notch my valley pan cover under the manifold ports. It's not one of John's, its way older. Best to fit everything up first before you set the gaskets.
 
Along the same lines, I had to notch my valley pan cover under the manifold ports. It's not one of John's, its way older. Best to fit everything up first before you set the gaskets.
I'm using an ECZ-B intake and had to shorten the height of the grommet for the front bolt of the valley pan, under the thermostat, so the manifold would sit all the way down. Test fitting things first is a very good idea.
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I have a 56 Merc with 312, with a 4 barrel original manifold with adapter to fit a holly 4 barrel carb Just purchased an aluminum valley cover with PCV opening, also got a PCV valve from Concourse. Question, will I be able to change or check the PCV valve without pulling the intake manifold
It depends on the size of the PCV fitting you got and the location of the PCV opening on the new valley cover.
On an oem valley cover the front edge of the opening is 2 inches from the rear lip of the valley cover and offset to the driver's side.
The rear of the intake manif is about 3/8+ inch forward and about 1.25 inch above the oem vent hole opening.
Since you probably have the ECZ-A intake manif without the cast-on vacuum fitting at the left rear, you'll have more room above the vent opening IF the cast aluminum valley pan has the opening in the same spot.
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if I understand correctly I need to remove enough metal for clearance of thermostat housing, will measure the difference between the two should get me close.
 
if I understand correctly I need to remove enough metal for clearance of thermostat housing, will measure the difference between the two should get me close.
If you're asking me... I didn't remove any metal. The front bolt & grommet for the valley cover was a tiny bit too tall when first installed. The grommet had a metal washer on top which I removed, then shaved down the top surface of the grommet about 1/8 inch, placed the washer back on top of the grommet and installed it.
If yours fits ok the first time that works too.

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I just installed my al valley cover, the clearance between the thermostat housing and the al valley looks to be zero. I bolted the thermostat housing on after removing casting marks, the housing bolted up fine, the bolts lined good no problem starting bolts, I think it may be ok. I will find out after I put liquid in. I will let you know. I need to pull the radiator and install 6 blade, I plan add air condition.
 
In case I caused any confusion...
the bolt that was sitting too high, and I shortened the grommet... is the front valley pan bolt behind the thermostat housing. It was keeping the front of the intake manifold from sitting down on the heads.
Your thicker cast valley cover and grommet on that bolt may or may not cause a similar problem.
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Started the engine let run, had a small leak on the thermostat housing, tightened it up leak stopped. all is well drove about 20 miles, no engine smell from blow bye, very good product, John needs to notch the alum valley cover under the thermostat, real close fit
 
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