Oil leak found, but why?

[sean68charger]

I have found out why my valley pan on my 440 is always covered in oil, I took the inlet manifold (eldebrock ch4b) off tonight and there are several big cracks/splits in the middle of the valley pan. It was new two years ago and has done less than 1500 miles, any ideas on what would cause it?
also, is it worth blanking off the exhaust cross over in the inlet manifold?

[tan top]

    never heard of that ...   just guessing ..   massive PCV valve / or  breather  failure ,.........  flooded motor  , lots of fuel vapour in side the motor ..  back fire through the carburettor  ignited it  ............

[John_Kunkel]

A cracked valley pan is usually the result of too much crankcase pressure. Even with a functioning pcv valve, if the blowby is severe enough the pcv won't be able to handle it.

[sean68charger]

no crankcase pressure and the cracks are inward noy outwards

[sean68charger]

the craks are going inward in like a spider pattern, as if something has been pushing on it. i have no crancase pressure at all in the motor and it runs under constant vacuum to the intake (no pcv valve)

[aifilaw]

I had this problem on my car back in the day.

two causes,
A. crank-case vacuum pressure
B. tightened it down too much, and cooling and expansion of the block caused a crack to form in the center

[John_Kunkel]

Even though the cracks appear to be inward they are most likely caused by pressure from the interior.

How do you know there is no excessive crankcase pressure? Have you taken manometer readings?

[sean68charger]

Even though the cracks appear to be inward they are most likely caused by pressure from the interior.

How do you know there is no excessive crankcase pressure? Have you taken manometer readings?

no, just there is no blow by in the engine at it is all well with good compression, no oil consumption