Big block intake pan gasket

Big block intake pan gasket - 10/21/08 03:58 AM

Has anybody ever had the valley pan on a big block "balloon" if the fiberglassish material pad isn't installed- plugged PCV or?
I've seen quite a few back in the day, I just wonder if it was excess blowby, a plugged PCV, or? Was it common, or did I just see a few more than most...?

Posted By: 67Charger

Re: Big block intake pan gasket - 10/21/08 04:56 AM

I had that happen when I had a clogged breather...

Posted By: cjskotni

Re: Big block intake pan gasket - 10/21/08 10:13 AM

Quote:

Has anybody ever had the valley pan on a big block "balloon" if the fiberglassish material pad isn't installed- plugged PCV or?
I've seen quite a few back in the day, I just wonder if it was excess blowby, a plugged PCV, or? Was it common, or did I just see a few more than most...?

It has nothing to do with the pad under the intake. The valley van will ballon if you don't have some type of breather/PCV valve.

I had this happen the first day I broke my engine in. In my excitement, I forgot to install a PCV, and with all the blowby of a newly-rebuilt motor, it popped that valley pan like a piece of popcorn!

When, it happened, I'd thought I thrown a pushrod or something

...sounded like a gunshot!

Posted By: dOoC

Re: Big block intake pan gasket - 10/21/08 01:09 PM

Quote:

Has anybody ever had the valley pan on a big block "balloon" if the fiberglassish material pad isn't installed- plugged PCV or?
I've seen quite a few back in the day, I just wonder if it was excess blowby, a plugged PCV, or? Was it common, or did I just see a few more than most...?

To BALLOON up a valley pan ..... is way WAY more than just a plugged-up PCV ..... there are MAJOR piston or piston ring probs going on. The last one I saw was a MH 440 that a guy had gotten out of a JY. The VP was almost "molded" to the bottom of the intake. There was a hole in one of the pistons the size of a quarter !

A plugged-up PCV ? ... you CrAzY CaNaDiAnS !

Posted By: stumpy

Re: Big block intake pan gasket - 10/21/08 02:28 PM

A nonfunctioning PCV system will cause the valley pan to bow up. There is always pressure in the crankcase because pistons are cupped underneath. When they move up and down this causes the air to be cupped in them and forced down which builds pressure. That is one of the reasons there are breathers and tubes on older cars and a breather and PCV in newer cars.

Posted By: R/T1968R/T

Re: Big block intake pan gasket - 10/21/08 04:48 PM

If enough gas gets into the oil pan and you try and start it, then that will happen. had it happen twice. Once from a stuck float in the carb and the other time there was a hole in the piston from detonation!! How are the valve covers?

Posted By: therocks

Re: Big block intake pan gasket - 10/21/08 08:14 PM

I dont know we run no PCVs on 3 motors 1 SB and 2 BBs.My 12.5 440 has 2 breathers and is new under 5K miles but is street and strip.The kids almost 50 year old 413 ses tons of satreet miles and has never been apart.2 breathers on it too.He runs the snot out of it and has for 9 years.If you balloon a valley pan you need a rebuild period.If its a new motor and does it you have problems.Rocky

Posted By: 1970440RT

Re: Big block intake pan gasket - 10/21/08 08:54 PM

My motor did it when new. I forgot the pcv and breather when breaking it in. Not only ballooned valley, also leaking gaskets. I replaced the pan and added a breather. 6 years later the same motor is still running strong.

Posted By: dOoC

Re: Big block intake pan gasket - 10/21/08 09:56 PM

Quote:

My motor did it when new. I forgot the pcv and breather when breaking it in. Not only ballooned valley, also leaking gaskets. I replaced the pan and added a breather. 6 years later the same motor is still running strong.

Well - how you define "running strong" is way diff than mine. If you have enough pressure to "inflate" the VP gasket ..... your motor is a leaker- big-time. And piston-ring-seal is probably the most important factor of a good running internal combustion engine.

To the guy who had the stuck-floats and the oil was diluted with gas .... you probably hurt the rings badly. It is a well-known-fact that you can damage the rings with an excessively rich A/F mixture. What happens is that rich-mixture "washes" the oil off the rings and cyl walls. NOT good.

Posted By: CrAzYMoPaRGuY

Re: Big block intake pan gasket - 10/21/08 10:56 PM

Quote:

Quote:

My motor did it when new. I forgot the pcv and breather when breaking it in. Not only ballooned valley, also leaking gaskets. I replaced the pan and added a breather. 6 years later the same motor is still running strong.

Well - how you define "running strong" is way diff than mine. If you have enough pressure to "inflate" the VP gasket ..... your motor is a leaker- big-time. And piston-ring-seal is probably the most important factor of a good running internal combustion engine.

To the guy who had the stuck-floats and the oil was diluted with gas .... you probably hurt the rings badly. It is a well-known-fact that you can damage the rings with an excessively rich A/F mixture. What happens is that rich-mixture "washes" the oil off the rings and cyl walls. NOT good.

I think you would be surprised how a good running engine WITHOUT a breather or PCV valve can pop a valley pan gasket.
Regular blowby running at highway speeds, I've seen it.

I'm not sure your motorhome could make it up to such speeds, being fiberglass and all.

Mind you- MY motorhome was a STEEL shell, and could SUSTAIN "highway speeds"....

Posted By: CrAzYMoPaRGuY

Re: Big block intake pan gasket - 10/21/08 10:56 PM

Posted By: dOoC

Re: Big block intake pan gasket - 10/22/08 02:36 AM

Quote:

I think you would be surprised how a good running engine WITHOUT a breather or PCV valve can pop a valley pan gasket.
Regular blowby running at highway speeds, I've seen it.

I'm not sure your motorhome could make it up to such speeds, being fiberglass and all.

Mind you- MY motorhome was a STEEL shell, and could SUSTAIN "highway speeds"....

You CrAzY cAnAdIaNs ! ...

BLOWby equals lost power ! ....and fuel econ.

And as far as fiberglass vs steel ? ....with your AERO equal to a barn-door ...and mine same-same to the Space-Shuttle ...we will see who will do what .... at a 100 mph "roll" !

.....

Posted By: stumpy

Re: Big block intake pan gasket - 10/22/08 02:39 AM

It hasn't been proven to be blowby yet. That's just your opinion. There are other equally as valid opinons brought up in this post.

Posted By: dOoC

Re: Big block intake pan gasket - 10/22/08 02:53 AM

Well -- why don't you list here(in your opinion) what the probs might be. Or are you suggesting that this is "normal" ?

IMO ... it is either severe and way-excessive blow-by, a heavy gas mix in the oil that has mildly "exploded" .... OR it is just the way CrAzY cAnAdIaNs build their engines !

Posted By: stumpy

Re: Big block intake pan gasket - 10/22/08 02:56 AM

Please read the above posts and you will find the other opinions on different causes.

Posted By: NITROUSN

Re: Big block intake pan gasket - 10/22/08 02:57 AM

The motor needs to be vented or where else does the pressure go? Seems like the dipstick should lift up. I wonder how much pressure it takes to belly a pan? Maybe some pans are thinner and belly easier.

Posted By: CrAzYMoPaRGuY

Re: Big block intake pan gasket - 10/22/08 02:58 AM

Quote:

Quote:

I think you would be surprised how a good running engine WITHOUT a breather or PCV valve can pop a valley pan gasket.
Regular blowby running at highway speeds, I've seen it.

I'm not sure your motorhome could make it up to such speeds, being fiberglass and all.

Mind you- MY motorhome was a STEEL shell, and could SUSTAIN "highway speeds"....

You CrAzY cAnAdIaNs ! ...

BLOWby equals lost power ! ....and fuel econ.

And as far as fiberglass vs steel ? ....with your AERO equal to a barn-door ...and mine same-same to the Space-Shuttle ...we will see who will do what .... at a 100 mph "roll" !

..... .....

ALL engines have blowby.

Fiberglass vs steel? STEEL WINS!

Here's MY 100 mph "roll on"... let's see yours!

Attached picture 4765301-launchinsmoke.jpg

Posted By: dOoC

Re: Big block intake pan gasket - 10/22/08 03:02 AM

Quote:

Please read the above posts and you will find the other opinions on different causes.

I was asking YOU your opinion.

Posted By: dOoC

Re: Big block intake pan gasket - 10/22/08 03:14 AM

Quote:

The motor needs to be vented or where else does the pressure go? Seems like the dipstick should lift up. I wonder how much pressure it takes to belly a pan? Maybe some pans are thinner and belly easier.

Good points ..... and all engines have some degree of less than 100% ring-seal.

How much pressure would it take? ...I would think it would be EVERY BIT of the compression and ignition process of one cylinder !!

Posted By: CrAzYMoPaRGuY

Re: Big block intake pan gasket - 10/22/08 03:19 AM

Quote:

Quote:

The motor needs to be vented or where else does the pressure go? Seems like the dipstick should lift up. I wonder how much pressure it takes to belly a pan? Maybe some pans are thinner and belly easier.

Good points ..... and all engines have some degree of less than 100% ring-seal.

How much pressure would it take? ...I would think it would be EVERY BIT of the compression and ignition process of one cylinder !!

I think the accumulation of pressure while running at high rpms with no pressure relief (read- plugged PCV/no breather) would do it.

I am every bit an iron based steel kinda guy though.

Posted By: dOoC

Re: Big block intake pan gasket - 10/22/08 03:26 AM

Quote:

ALL engines have blowby.

Fiberglass vs steel? STEEL WINS!

Here's MY 100 mph "roll on"... let's see yours!

Yes indeed .... blowby is just a fact of life ... but CaNaDiAnS are so much better at it than all-us are ! ...as is shown in that pic of yeerrs! ...or is that your holding-tank afire ?

Steel wins ? ... you are pSyChO - EXIT that MH now ...and get some fresh air !

You have seen the pic of mine ....and I give-up .... YoU wIn - you DO have more blow-by than me !

Posted By: CrAzYMoPaRGuY

Re: Big block intake pan gasket - 10/22/08 04:23 AM

Quote:

or is that your holding-tank afire ?

YOU CAN'T SAY THAT ON THE INTERNET!!!!!!!!!

Posted By: cjskotni

Re: Big block intake pan gasket - 10/22/08 10:25 AM

Quote:

Quote:

Quote:

My motor did it when new. I forgot the pcv and breather when breaking it in. Not only ballooned valley, also leaking gaskets. I replaced the pan and added a breather. 6 years later the same motor is still running strong.

Well - how you define "running strong" is way diff than mine. If you have enough pressure to "inflate" the VP gasket ..... your motor is a leaker- big-time. And piston-ring-seal is probably the most important factor of a good running internal combustion engine.

To the guy who had the stuck-floats and the oil was diluted with gas .... you probably hurt the rings badly. It is a well-known-fact that you can damage the rings with an excessively rich A/F mixture. What happens is that rich-mixture "washes" the oil off the rings and cyl walls. NOT good.

I think you would be surprised how a good running engine WITHOUT a breather or PCV valve can pop a valley pan gasket.
Regular blowby running at highway speeds, I've seen it.

There was nothing wrong with my motor when it ballooned the valley pan. IF you think it would pop up the dipstick think of how much surface area a dipstick has to "push" on as opposed to a valley pan. It makes perfect sense a valley pan would balloon before your dipstick "rocketed" out! Pressure is force/area so since the pressure is about constant per unit area, the total force would be orders of magnitude greater on a valley pan than a dipstick.

There is also something to be said about when an engine is FIRST cranked that it has a break-in period where it will seat the rings. Blow-by is lost horsepower but from what I have gathered, after about 30 minutes of running the engine at 3000 RPM, the problem subsided. To bad within that time, I had NO BREATHER OR PCV and ballooned the pan after about 20 minutes. After adding that, everything has been totally normal. ANY motor with out any type of venting will build up pressure and eventually balloon/blow something. BTW, nothing else was damaged on my motor. Just loosened up the oil cap for a sec to let the gas escape...

I posted exactly what happened in this case up here around a year ago and nobody had anything bad to say about it then...