2nd craked valley pan,need help

[Lamont AKA Big dummy]

Ok yall,I took a 383 bb and stroked it to 496ci. Got the blue printed kit from 440 source. Trick flow 240 heads,big cam,edelbrock rpm intake,went the whole way. The engine is a monster,only issue is its cracking valley pans from internal pressure. On the fist 1 I figured I needed more venting from valve covers so I installed a free flow catch can 1 tube off each valve cover. I am abusive to this car,68 Barracuda 4 speed. I do burnouts and wind this thing up as often as I can. Came home today another cracked valley pan. I see trick flow makes a valley plate for their 270 heads but cant find anything for the 240s. Or should I go the rout of an internal vacume to redice the internalpressure? Car is 10.5-1 compression pump gas.

 

[68HemiRR]

Ok yall,I took a 383 bb and stroked it to 496ci. Got the blue printed kit from 440 source. Trick flow 240 heads,big cam,edelbrock rpm intake,went the whole way. The engine is a monster,only issue is its cracking valley pans from internal pressure. On the fist 1 I figured I needed more venting from valve covers so I installed a free flow catch can 1 tube off each valve cover. I am abusive to this car,68 Barracuda 4 speed. I do burnouts and wind this thing up as often as I can. Came home today another cracked valley pan. I see trick flow makes a valley plate for their 270 heads but cant find anything for the 240s. Or should I go the rout of an internal vacume to redice the internalpressure? Car is 10.5-1 compression pump gas.

I may be off base here but if memory serves me right back in the early 60's Mopar was having trouble with valley pans cracking from vibration on the big blocks. They started putting aluminum foil wrapped foam between the intake and valley pan to put a slight amount of pressure on the pan to keep it from vibrating. It seemed to have solved the cracking problem.

 

[Lamont AKA Big dummy]

I've never heard of this going to look it up

 

[Dana67Dart]

I saw that on my 66 383 I assumed it was a heat blocking insert.

Post some photos of your crack (keep it clean)

 

[Fast340cuda]

Is it cracking under the heat cross over? I recall an interference fit with the RPM intake heat cross over and the valley pan on a friends low deck build a few years back. We ended up cutting part of the cross over off for clearance. Might be worth a look.

 

[fishmens67]

The engine is a monster,only issue is its cracking valley pans from internal pressure.

You have other issues if the engine is producing enough internal pressure to rupture the valley pan.
Are you running a PCV system, if not you should.

 

[fishmens67]

I assumed it was a heat blocking insert.

That's what it was intended for.

 

[Lamont AKA Big dummy]

I have caps on the valve covers with hoses running to a catch can

 

[Bewy]

My guess is you are getting blow-by past the rings. Poor ring sealing, made worse by the longer stroke. The dip stick getting pushed out is another symptom.

 

[RustyRatRod]

I have caps on the valve covers with hoses running to a catch can

You need a proper PCV system.

 

[Bewy]

If my diagnosis is correct, PCV is not going to fix the problem.

 

[fishmens67]

PCV is not going to fix the problem

PCV system helps ring seal

 

[toolmanmike]

I may be off base here but if memory serves me right back in the early 60's Mopar was having trouble with valley pans cracking from vibration on the big blocks. They started putting aluminum foil wrapped foam between the intake and valley pan to put a slight amount of pressure on the pan to keep it from vibrating. It seemed to have solved the cracking problem.

I always thought that was insulation for heat.

 

[Newbomb Turk]

You have a ring seal issue. You are probably beating the rings out with detonation. You can put a PCV valve on it and you should.

But I’d figure out why the crankcase pressure is so high it’s killing the valley pan first.

 

[Oldmanmopar]

Put an Evac system on it. an aspirator valve on each header. to evac the pressure.

 

[rbkt65]

I agree with above. pan o vac should fix problem. we run them on all our cars, including street cars.

 

[fishmens67]

I always thought that was insulation for heat.

It is. lol

 

[Dicer]

Maybe stainless-steel valley pan...

 

[RustyRatRod]

Put an Evac system on it. an aspirator valve on each header. to evac the pressure.

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I agree like a million percent, BUT...doesn't that work mainly at high RPM? If he sees street duty a lot, wouldn't he see benefit from a pcv valve too?

 

[RustyRatRod]

Maybe stainless-steel valley pan...

I'm having a hard time with why he hacked that intake all to hell. It couldn't have been making contact with that valley pan. I didn't hear him give a reason.

 

[Dicer]

Rusty, the new stainless valley pan is flat, not concaved like most of the pans we can purchase. lol

 

[RustyRatRod]

Rusty, the new stainless valley pan is flat, not concaved like most of the pans we can purchase. lol

I did notice that, but it appears it has room for the intake. Maybe it didn't. If Hughes makes them so they interfere with the intake manifold, that's just stupid.

 

[Dicer]

"Flat won't clear intakes with heat crossover" mentioned on web site.

 

[Newbomb Turk]

I agree like a million percent, BUT...doesn't that work mainly at high RPM? If he sees street duty a lot, wouldn't he see benefit from a pcv valve too?

That’s why I run both.

When I get my junk back on the pump I’ll take some pictures of what I do. It’s simple.

 

[CRUZE 418]

I seem to be learning something here. First, was told that I could not use a header evacuate on a car with mufflers. Second, run a PCV valve too? I mean, both at the same time?