Hey guys, never had this happen before. My valley pan somehow looks like someone pounded it up from in the lifter valley. As if an explosion happened in the block. As far as I know it never backfired or anything. It was fine say a week and a half ago during some races we had but now it is pounded up so much it's touching the bottom of my TM-7 intake. I pushed it back down for now and there are no real leaks anywhere on the engine that I can see.
Car drives fine with no missing or popping, starts fine, idles fine, everything. I was shifting it at 62-6300 but I always do. My vented cap on the valvecover is nice and clean and the dipstick has never pushed itself out. I'm stumped. Might there be something going on for this to happen?

Don.

I've seen that happen on cars that the distributor was either stabbed 180* out or wired backwards (ala clockwise instead of counter on the cap)

Engine has been in the car for 2 years and nothing ever changed. just noticed this morning when taking water out and adding antifreeze.It's just that I figured that if there was enough pressure to balloon the valley pan like that you'd think there would be gaskets or seals somewhere else that would be damaged.

There was some "chat" on just this topic about a week or so ago. Some people say that THIS is normal.

I do not agree. It takes some SEVERE pressure to blow-up a VP like that.

Again .. the last time I saw one of these VP's that did this .... there was a hole in the piston almost the size of a quarter.

something is causing pressure in the crankcase....

Clogged PCV valve usually results in the dipstick blowing out....along with copius amounts of oil! DAMHIK!

I've had it happen a couple times, personally I'm wondering if felpro is sneaking a couple thou here and there of metal off them and they've gotten weaker over time.....

You had a little back fire just didn't notice/hear it when it happened. I'd say you're good.

I had this happen twice on the same engine. All was good in life, I installed a Moroso evac kit and the valley pan balloned, changed the pan and it happened again. I removed the moroso kit and installed a dirt cheap Mr.Gasket evac kit and have not had any problems sence.

What do you mean by an EVAC kit? A PCV system?

It might be time to do compression and leakdown tests on the engine. Then you'll know. Excessive pressure in the crankcase will push out a valley pan.

It may have just been an un-heard backfire, but would be a good idea to check compression to be sure.

May not be a problem if the engine is running fine.

P.S.: A "Pan-Evac" is a Crankcase Evacuation System. Basically, a 1/2-inch pipe, cut at a 45-degree angle, inserted/welded into your header-collector.

A check-valve is screwed onto the threaded-end of the pipe, and hose connects check-valve to closed-type crankcase breathers.




The pipe, placed in the exhaust stream, draws air from the crankcase, causing a partial vacuum, reducing crankcase pressure, removing blow-by, improving windage. Sort of a poor-mans crankcase vacuum pump. Pan Evac Kit

I've seen a bad fuel pump cause this. Gas gets pumped into the crankcase, ignites, ballooning the valley pan, valves covers and even the oil pan. It you're running a mechanical fuel pump you may want to take a look at it. Does your oil smell like gas?

DC !!! Do you need some sort of breather in the system also or just the two shown. I would think that if there was another breather in the sytem it would just vent the valvecover area.

Actually, it is supposed to be a closed-system. The breathers included in the kit are used (or similar if you want something else.)

The kit also includes grommets to seal the breathers to the valve covers.

Serious race engines (some street engines too) use crankcase vacuum pumps (if legal per the controlling sanctioning body) to remove the air and extraneous combustion gasses, etc, from the crankcase.

This provides better ring seal, but in addition, removing the air improves horsepower, as the back sides of the pistons do not need to move air around inside the crankcase.

You think about the air above the piston (air/fuel mixture) but there is also air inside the crankcase below each piston that has to be displaced/moved around, energy being expended in the process. Also, there is less wind resistance for the crank to spin around as well.

A Pan Evac provides some of these same benefits to a much lesser degree, but still helps.

I use both the Pan Evac and PCV on the 440 in my '71 Charger and even the AMC 304 V8 in my CJ-5 Jeep.

Id say you have blowby in the motor.My 440 and the kids original 62 413 run just 2 breathers.His gets tons of miles daily.Never had one pop up.Rocky

Did it happen cruising around town? or on a wide open pass?

If it happen just cruising around town. I would say you might have some fuel in your oil that did back fire. With no mech. fuel pump, is your choke set too rich? also do you do a lot of short trip that does not let the oil heat up? does the oil smell like fuel?

If it happen after a wide open pass you most likely have a pcv problem. This would happen from time to time on my old jet boat. Make sure your pcv is working well.