440 blown intake valley pan cause?

[505Coronet]

So this isnt a B-body. Its actually not even a car....



I have a warmed over 440 with some edelbrock heads and a .550ish hydraulic tappet cam in this. 530hp/550 ft lbs on the dyno.

I swapped in a 8hp75 out of a 19 ram and was doing, lets call them "test passes" on the street nailing down some WOT shift patterns and sprung an oil leak, came to find out it was the intake valley pan. I had the stock sheet metal one in there, looks like someone shot a soda can with a .22 just popped it right in the center, so i ordered the nice stainless one from Hughes, but is it just excessive crank case pressure?

I have a PVC system routed to the intake on this, i don't want to throw a stronger valley pan at this and then have the pressure release somewhere less fun....

 

[493 Mike]

How about a picture? A crankcase explosion would have bulged everywhere not a single hole such as you have. Did something break and cause said hole?
Mike

 

[pnora]

Sounds like you had a crankcase internal explosion.

 

[Darter6]

Only happened once at high rpm didn't blow thru but humped up in the middle.
My guess was stuck PCV valve.Replaced both the valve and valley pan. Never happened again.

 

[505Coronet]

Blew in the reward cylinder area. admittedly i mangled the pan a bit getting it off

Valley itself looks fine, no carnage, no noise, under low RPM there was not even any oil spillage, just when she was spinning north of 5k

I'm thinking the stuck PCV valve is the culprit, i ordered new ones from mancini at the same time. Just was curious if anyone else did the same thing

 

[Grabbergreendream]

I've seen this happen when there's a hole in the piston. Hope the issue is easily solved.

 

[WileE]

I'd do a compression check, and drain the oil before anything else.

 

[pnora]

Only happened once at high rpm didn't blow thru but humped up in the middle.
My guess was stuck PCV valve.Replaced both the valve and valley pan. Never happened again.

Even with a stuck PCV valve this should not happen. A properly sealed engine ring wise should not create enough pressure that a vent cant handle. Only way I have seen them pop up is extreme crankcase pressure due to a hut engine or an internal explosion. Those usually caused by gas in the fuel creating an extremely ignitable vapor that rises to the upper parts of an engine. Anyone that has done oil pan welding repairs can testify to that. Valve covers by design are stouter and do not yield to the external pressure where a valley pan is more flexible and succumbs to the pressure.

 

[pnora]

Blew in the reward cylinder area. admittedly i mangled the pan a bit getting it off

View attachment 1463744

Valley itself looks fine, no carnage, no noise, under low RPM there was not even any oil spillage, just when she was spinning north of 5k

View attachment 1463745


I'm thinking the stuck PCV valve is the culprit, i ordered new ones from mancini at the same time. Just was curious if anyone else did the same thing

{{{{{I have a warmed over 440 with some edelbrock heads and a .550ish hydraulic roller cam in this. 530hp/550 ft lbs on the dyno.}}}}} That sure does not look like a roller cam.

 

[505Coronet]

{{{{{I have a warmed over 440 with some edelbrock heads and a .550ish hydraulic roller cam in this. 530hp/550 ft lbs on the dyno.}}}}} That sure does not look like a roller cam.

That would be because its a hydraulic flat tappet. Apparently i was typing my wishes not my realities lol.

It has and still did run fantastic, a dead hole would be fairly obvious. I drove the truck into the shop and drove it around after i noticed the initial oil leak. Nothing seemed "off" besides the oil being in the valley

 

[Budnicks]

I've seen it happen
but not really under the conditions you describe

#1
carb messed up dumping tonnes of unburnt fuel
excessive fuel, washing your rings/cylinders down with excessive fuel
going by the rings, sort of filling the crankcase with fuel & vapors,
getting past the rings & somehow ignited in the internals of the engine,
boom, blew the valley pan
or
#2
a hole in a piston
or
#3
N2O solenoid stuck & created a problem etc./kaboom

all were serious pressurization of the crankcase
those thing are pretty tough

IMO it'd have to be some serious blow-by
even, for a stuck PCV valve to cause that

did you hear it pop or a boom ?

good luck hope it's nothing major

 

[Will-Fonkjam]

Have you looked at the bottom of the intake for clues?

 

[Geoff 2]

V/pan might have been rusty, which weakened it. Excesssive blowby is what causes it to deform/break.

 

[pwDave]

So this isnt a B-body. Its actually not even a car....



I have a warmed over 440 with some edelbrock heads and a .550ish hydraulic tappet cam in this. 530hp/550 ft lbs on the dyno.

I swapped in a 8hp75 out of a 19 ram and was doing, lets call them "test passes" on the street nailing down some WOT shift patterns and sprung an oil leak, came to find out it was the intake valley pan. I had the stock sheet metal one in there, looks like someone shot a soda can with a .22 just popped it right in the center, so i ordered the nice stainless one from Hughes, but is it just excessive crank case pressure?

I have a PVC system routed to the intake on this, i don't want to throw a stronger valley pan at this and then have the pressure release somewhere less fun....

505, I had one in a 64 Bel in 75, did that on a regular basis, mine would spilt the pan right down the middle, bout 6 inches. didn't seem to hurt any thing except for the mess of oil and the trouble of changing the gasket. the only time it happened was when I missed a shift and the rpms went north of 6500, this was not a tight engine. my solution was extra vents on the valve covers, three on each side, worked like a charm. Dave.

 

[kiwigtx]

I cracked a 440 valley pan once from a massive backfire caused by plug wires 5 & 7 being reversed.

I was told there is a lot of internal air pressure built up in a 440 when they are running hard, so any additional problem could lead to the pan going - it would be the weakest link.

 

[505Coronet]

Going to address a few comments at once

The engine has blowby, i wouldn't call it excessive but its definitely present.

The valley pan was new +/- 5 years ago, no rust.

The engine had not seen 5k+ RPMs in some time, probably 3 plus years (the poor 727/stockish convertor trying to turn the 43" tires even with the 5.38s just struggled, hence the 8hp75 swap)

No holes in pistons, scoped it yesterday. No gas in oil.

From what i can tell in the valley, cylinders, and oil this is a healthy 440 that should live for a few more seasons.

This truck spends 60% of its life at idle -2500rpms crawling through trails (Moab/Rubicon/Fordyce), and the other 40% of its life in the 4k+ range bombing through the desert, so its not an easy life, and it is driven hard. I fought a timing issue last year with the MSD Atomic fuel injection randomly locking out timing control and had 20-22 * in at the distributor which was causing some overheating/overfueling issues. Ended up being a bad ground and since then the engine as ran very well.

Pics for anyone who cares

The aforementioned non easy life proof

 

[Geoff 2]

So it has blowby. That is combustion pressure escaping past the rings. As rpms go up, there is less time for the BB to dissipate. It builds up pressure & finds the weakest link to the outside world.....

You are kidding yourself if you think this is a 'healthy' engine....

 

[505Coronet]

So it has blowby. That is combustion pressure escaping past the rings. As rpms go up, there is less time for the BB to dissipate. It builds up pressure & finds the weakest link to the outside world.....

You are kidding yourself if you think this is a 'healthy' engine....

I realize in the world of finely tuned drag cars and pristine show cars that this is not deemed "healthy", I'm sorry if my choice in words was not satisfactory to your opinion, i should have said "Strong enough for my hobby"

It does not smoke at idle, it does not leak oil, it has some slight pressurization at the breather/PCV openings. No enough to push my hand off but enough to feel it.

In other news the Hughes stainless valley pan was a really nice piece, very impressed. Hard to get a good picture with all the tube/accessories in the engine compartment

 

[505Coronet]

No holes in pistons, scoped it yesterday. No gas in oil.

From what i can tell in the valley, cylinders, and oil this is a healthy 440 that should live for a few more seasons.

This truck spends 60% of its life at idle -2500rpms crawling through trails (Moab/Rubicon/Fordyce), and the other 40% of its life in the 4k+ range bombing through the desert, so its not an easy life, and it is driven hard.

This truck probably sees 40-50 hours of drive time a year (under 300 miles), so I'm asking for another 100-150 hours out of this powerplant before I pull it for a refresh/swap. Had the wrong carb gaskets so ill try to get a video of it idling today with the aforementioned blow-by. Have to do some light driving to get a trans log of some different shift scenarios anyways

 

[vance.dykes]

i use this from mancini racing