Blown Head Gasket

[HT32BSX115]

Re: Blown Head Gasket

Yeah, It probably is.....


I usually go back to basics when I think about heat transfer characteristics of different materials.

We know that copper and aluminum are VERY efficient heat transfer mediums.

Stainless steel is not so good at conducting heat.

If you take a look at the following list of some common materials. The thermal conductivity of each is indicated.

http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

Notice that silver copper and aluminum have VERY high thermal conductivity.

Stainless steel is actually quite low..... about 1/3 the conductivity of regular carbon steel.


Water has a conductivity that is approx 4 times better than SAE 50 oil.


Oil is a coolant. It does collect heat from hot surfaces, but it does not (and cannot) collect nearly as much heat from those surfaces as water does.

All the excess heat generated by that engine either goes out the exhaust, exits as hot water, or is radiated by the block .

AND this engine doesn't have an oil cooler. But if it did, that little bit of heat from the oil would be dumped into the cooling water before it went thru the engine.....

My 454 DOES have an oil cooler. The (water) discharge from the oil cooler goes directly into the main heat exchanger before dumping into both risers and ultimately overboard.

The small amount of heat dumped into the cooling water from the "hot" oil is insignificant.


This stuff is really not at all relevant to the original discussion..... It's pretty clear that the engine was damaged by water in the oil.

Whether it overheated from all that might be..... Ultimately the insurance company or mechanic will decide who will pay, how much they'll pay and whether labor will be fully covered or not.....


Next time don't leave the "Bung" out!

Or get a bung-hole like this one.....It's what I have in mine.......

 

[JustJason]

Re: Blown Head Gasket

On a classic GM 350 (low pressure oil pump version) as used in hundreds of thousands of cars and pickups in the last 30-40 odd years, there's only a fraction of a liter of oil per minute pumped up through the lifters, through the tiny holes in the push rods, and dribbled onto the rocker arm. Then it drips off the rocker onto the head and drains back to the pan.

I don't know about you but on just about every engine i've ever worked on, when you run the motor without the valvecover, it certainly sprays and makes a mess. That's the reason they sell the little plastic clips for when your adjusting the valves, to control the spray.

you sure that was a storm?
maybe someone was trying to spare you the humility....

Dude..... this is for you and everybody else that needs a vocabulary lesson.

From Merriamwebster.com (the dictionary)

Main Entry: 1pri?ma?ry
Pronunciation: \ˈprī-ˌmer-ē, ˈprī-mə-rē, ˈprīm-rē\
Function: adjective
Etymology: Middle English, from Late Latin primarius basic, primary, from Latin, principal, from primus
Date: 15th century
1 : first in order of time or development : primitive <the primary stage of civilization> <the primary lesion of a disease>
2 a : of first rank, importance, or value : principal <the primary purpose> b : basic, fundamental <security is a primary need>
3 a : direct, firsthand <primary sources of information> b : preparatory to something else in a continuing process <primary instruction> c : belonging to the first group or order in successive divisions, combinations, or ramifications <primary nerves>

http://www.merriam-webster.com/dictionary/primary

I did edit out parts of the definition that were non-relavent.

So now that you know the definition to the word primary, lets see how your definition of water being the primary coolant in engine works.

1 : first in order of time or development : primitive <the primary stage of civilization> <the primary lesion of a disease>

Okay first in order of time.... Water does not start to cool an engine first, Oil does.

2 a : of first rank, importance, or value : principal <the primary purpose> b : basic, fundamental <security is a primary need>

The cooling properties of oil (not including the other 3) are much more important to an engine than water is. We run waterless engines but we never run oiless engines.
Remember, if oil did not have any cooling properties, we could not have such tight tolerances that we do today because it the insides would expand and sieze. If you run a motor without water for a few minutes at idle, it's not going to hurt anything. Now lets run a motor on 1 1/2 quarts of oil, with all the water you want. Tell me how many minutes you get before the motor sticks. 1 1/2 quarts is enough to keep everything lubricated, but not everything cool.

a : direct, firsthand <primary sources of information>

Oil directly comes into contact with the hottest running parts of an engine. Water does not. So tell me how water cools a lower end, or how water cools a piston. I'd love to hear how it's done.

b : preparatory to something else in a continuing process <primary instruction>

Ahhh... preparatory, there's a word. That means to come first, or to act first. And lets talk also about a "continuing process"
I think you'll agree with me that cooling an engine is a process that involves many different things. I think you even tried to spell it out to me. I'm sorry but oil is the preparatory coolant in an engine. How can you say that air cools an engine first? How can you say that water cools an engine first? In this cooling process, oil clearly is preparatory, oil clearly is primary.

c : belonging to the first group or order in successive divisions, combinations, or ramifications <primary nerves>

We already said cooling is a process that involves different things. Since the word "things" is pluralized I hope we can agree it means more than 1, and since it's more than 1, we can probably assume it's part of a group.

So now in order for the cooling process to work many things have to happen correctly. Through conduction the block gets hot as a whole, Air lets the block heat radiate outward, water conducts heat away from the block as too.

But it all starts with oil. As soon as you start a cold engine, there is trememdous amounts of heat in the combustion chamber, the piston, the crank journals. oil conducts heat from the hottest areas of a block, and transfers that heat back to the cooler parts of the block via conduction and radiates some of that heat away as well. The water doesn't even start to flow until the block is hot.

So how does the block get hot in the first place then???
Metal to metal conduction, and hot oil to cold metal, good old fashion conduction as well, until everything is a nice toasty 160-180... then the waterworks start. But the oil doesn't stop doing its job once the water is introduced into the group, it's still in there... transfering heat, and cooling the engine

Black and white, I don't know how else to spell it out to anyone. By textbook definition oil is the primary coolant of any engine. If you don't see that... then you clearly do not understand what the word primary means. Primary does not mean more or less, primary means first. Good grief you guys.

 

[achris]

Re: Blown Head Gasket

....

Or get a bung-hole like this one.....It's what I have in mine.......

[size=+3] ... Run away!!!!![/size]

These things [size=+1]SINK[/size] boats!!!! [size=+1]NEVER EVER EVER[/size] put one in!!!

 

[Bronc Rider]

Re: Blown Head Gasket

If you ran an engine low on oil it would run hotter due to increased friction between parts. I don't think it has anything to do with the cooling properties of oil. Metal on metal contact with no lubrication will cause lots of heat.
What keeps the oil from getting too hot? Is it not the water in the cooling system that keeps everything from getting too hot? If that's the case, I can't see how it wouldn't be considered the primary coolant.

 

[achris]

Re: Blown Head Gasket

I don't want to get into this one way or the other (I have my own thoughts)...

But consider this...

On my previous V6 (1994 4.3LX) I considered the oil filter to be in a stupid position... A real b1tch to replace (I hate it when they **** out words! Besides, 'b1tch' is a real word, check it out, 'female dog', so there!!!). So I got a couple of adapter fittings, and some 1/2" hose, about 1 meter in total length. After I plumbed it all up I added 1 litre of oil to the engine. Why, you ask. Because the extra volume created in the hoses.

What surprised me was the next time I tool the boat out the engine ran considerably cooler... Why? Greater oil volume, to carry engine heat away....

I'm not saying that I would consider the oil as the main coolant, but it does contribute significantly (and importantly) to the lower end of the engine running cool. It is also the way that the heat is transferred from the piston to the cylinder walls, so the water (on the outside of those walls) can then carry that heat out of the engine.... (and that was taught to me by a Merc technical trainer).

Draw your own conclusions....

Chris.......

 

[TilliamWe]

Re: Blown Head Gasket

I don't know about you but on just about every engine i've ever worked on, when you run the motor without the valvecover, it certainly sprays and makes a mess. That's the reason they sell the little plastic clips for when your adjusting the valves, to control the spray...

Hmmm, well my 1997 Mercruiser 5.7LX EFI Gen + didn't make a mess at all, when I ran it without valve covers to adjust the valves. It didn't "spray" oil anywhere. A little bit kind of splashed over the outer lip of the head into the rag I had tucked between it and the exhaust manifold. Not enough to make any mess at all. It wouldn't have been a big deal if I hadn't put the rag in there, either.
It wasn't very hot either, but then again, I had just started the engine, and it only ran for about 3-5 minutes. With it doing all that cooling, should it have been hot?

 

[HT32BSX115]

Re: Blown Head Gasket

[SIZE=+3] ... Run away!!!!![/SIZE]

These things [SIZE=+1]SINK[/SIZE] boats!!!! [SIZE=+1]NEVER EVER EVER[/SIZE] put one in!!!

I didn't say that I leave the plug out!!

 

[JustJason]

Re: Blown Head Gasket

If you ran an engine low on oil it would run hotter due to increased friction between parts. I don't think it has anything to do with the cooling properties of oil.

A GM 350 only needs 2 quarts of oil to be adequately lubricated. So why do we put in 5 to 6? (sometimes more on racers) Answer to follow

What keeps the oil from getting too hot?

Radiation and conduction. Think about the heat transfer when 350F degree oil hits 180F cast iron.... what conductions heat to where? Then radiation, a big old puddle of hot oil is going to radiate heat out. When the entire rig is engineered, the engineers put what size oil pan they think is best, 5 or 6 quarter, and the run the snot out of the engine. If the oil is radiating heat satifactoryily to a temp the engineers like, then great, if its not (and there can be many reasons why), the engine gets an oil cooler. That's why the nascar boys run 12 quart oil pans, thats why diesels hold 3 gallons of oil, if you have more of it, it takes longer for the overall quantity to heat, and radiates it faster (usually because of more surface area in the pan.)

Hmmm, well my 1997 Mercruiser 5.7LX EFI Gen + didn't make a mess at all, when I ran it without valve covers to adjust the valves.

Well why did you do that? Roller rockers get TQ'd down to 20FTLBS and called a good night. There's no adjusting needed. As far as why you didn't get spray... i dunno, maybe you were low on oil They all make a mess, doesn't matter which engine.

You guys are all getting confused. I never said oil was the main coolant, I never said oil with water is why he popped a gasket, I had said oil is the primary engine coolant, which I hope that at this point you can see that. And I had said water in the oil will cause all sorts of gremlins. I take no responsibility that you inferred a different meaning to what I wrote because you do not understand the true meanings of words in the english language. Primary means just that.... Primary.

 

[achris]

Re: Blown Head Gasket

OK... this is getting out of hand.. The original poster has a blown head gasket on his engine... We don't want him to have a blown head too.

I am with Jason on this... But maybe you've misunderstood what he's trying to say... I did initially...

I believe he's saying that (and I don't think there's any dispute about this) that the oil is the primary cooling system for the lower end of the engine. I haven't seen many engine with water galleries in the crankshaft...

He's also saying that oil plays a significant role in cooling of the top end of the engine too.... Which it does. The way heat gets out of the pistons and into the water that is flowing around the head and cylinders is by transference in the oil, and in that respect the oil is the PRIMARY cooling factor. It's not to say that it is the MAJOR cooling factor. That would be the water.... BUT, the engine needs BOTH the oil AND the water to be adequately cooled..... If the engine didn't need the oil for lub, then the loss of EITHER would lead to overheating.....

Can we leave this now, and go back to Nauticool's problems?

Thanks,

Chris......

 

[JustJason]

Re: Blown Head Gasket

Can we leave this now, and go back to Nauticool's problems?

hehehe.... Nauticools the other guy in the other overheating thread with the bad thermostat.

 

[bruceb58]

Re: Blown Head Gasket

All of us engineers are shaking our heads but you can believe what you want.

 

[Don S]

Re: Blown Head Gasket

Can we leave this now, and go back to Nauticool's problems?

I think that would be a good idea Chris, but you will have to go to Nauticools post to answer his question, over here.
So far, he just has an overheat, but I doubt it's the oil flow causing his problem. This is mark_fitzy's thead

 

[bruceb58]

Re: Blown Head Gasket

Come on Don. Jump on in! The oil...I mean the water is warm!

 

[achris]

Re: Blown Head Gasket

I think that would be a good idea Chris, but you will have to go to Nauticools post to answer his question, over here.
So far, he just has an overheat, but I doubt it's the oil flow causing his problem. This is mark_fitzy's thead

It's late, early, whatever...

 

[wire2]

Re: Blown Head Gasket

.....I believe he's saying that (and I don't think there's any dispute about this) that the oil is the primary cooling system for the lower end of the engine. I haven't seen many engine with water galleries in the crankshaft...

"cooling system for the lower end of the engine"???
There's only highly polished con rod and main crank bearings running in oil. There's virtually no heat produced. What's to cool?
That's a solution to a problem that doesn't exist.

 

[JustJason]

Re: Blown Head Gasket

All of us engineers are shaking our heads but you can believe what you want.

Meh... Whenever somebody throws out the old "but i'm an engineer line" all I can think of is this.

Engineers built the leaning tower of pisa

Engineers designed the 470

One engineer said, "Hey guys, let me tell you about my new L drive"

Then there was the engineer that said Monorails are the future... and that was like a fat mans bellyflop.

There was this engineer once who said my AT&T phone would have the fewest dropped calls... ya right. And you wonder why I quit the service and i'm not paying my bill... credit or not.

How about that engineering marvel of a bridge in minnesota that colapsed a few years ago... killing god knows how many people.

Then there is the engineering feat that is the Big Dig... in my neck of the woods. The 2 billion wonder, that sparkled into a 14 billion debt. It leaks during a drought, needs pumps to keep from filling with seawater, has killed a person because the cieling fell off.... Seriously.... What engineer decided that using concrente to use as an asthetic cieling tile was a good idea???? That could be a whole thread in itself.

This is not a personal attack on you, But to many an engineer in this world throws out the whole "i'm an engineer" line, and it's crap. Being an engineer doesn't make anybody high and mighty...

A whole bunch of engineers designed the FICHT fuel injection system... what a winner that was

Then there was the engineer who said the titanic couldn't sink

I could go on and on....

I asked this before and i'll ask again. Forum elders (Don, Bondo, Rodbolt...) (and I don't mean that in a bad way!!)
Settle this one so it can move on. If i'm wrong tell me to stick my head up my exhaust tube and i'll humbly do so.
This is fitzys thread, and I want to keep it that way, and also keep it civil and polite, yet I wont stand for it when I throw something out there that I was trained in, and absolutely believe to be true, only to have 10 people come back and say "no it's not true" and that the humility gods are upon me.

How about Don gets a vote,
Bondo Gets a vote,
Rodbolt gets a vote....

2 out of 3 wins. And before anybody votes guys... please keep in mind the textbook definition of the word primary as I have used it.

 

[JustJason]

Re: Blown Head Gasket

There's only highly polished con rod and main crank bearings running in oil. There's virtually no heat produced. What's to cool?

You better bet money on heat being produced on the crank and rod journals.

Pressurizing anything creats heat. 50psi is a nice healthy number so we will start with that. Any time you put anything under pressure, you increase it's temperature. Ever hear of Boyle's law? It was written for gases, but it applies to every form of matter to a degree.
So lets say we are running a constant 50psi... that is the average pressure. Every rotation there is a swing in the crank from top to bottom. At that instant of the swing the oil pressurizes much more than the 50psi, and this is just a guess, to many thousands of psi, and on the reverse stroke, the pressure comes down to it's average again. This happens in an instant. The crank doesn't actually sit on the plane bearings when an engine is running. Its sits on a very thin film of highly pressurized oil. When you push or pull on that thin film, the film pressurizes, and that thin film gets hot.... now multiply that by 5000 RPMS.

 

[achris]

Re: Blown Head Gasket

Jason,

I think you're talking to a few 'flat earthers'....

Let's just agree to have different opinions on this one and let it be...

It's getting to be a case of an immovably object meeting and irresistible force...

Everybody has their own beliefs and will use whatever means to justify hanging onto them. So let's all just walk away from this without further discussion.. Please?

Chris........

 

[wire2]

Re: Blown Head Gasket

You better bet money on heat being produced on the crank and rod journals.

Pressurizing anything creats heat. 50psi is a nice healthy number so we will start with that. Any time you put anything under pressure, you increase it's temperature. Ever hear of Boyle's law? It was written for gases, but it applies to every form of matter to a degree.
So lets say we are running a constant 50psi... that is the average pressure. Every rotation there is a swing in the crank from top to bottom. At that instant of the swing the oil pressurizes much more than the 50psi, and this is just a guess, to many thousands of psi, and on the reverse stroke, the pressure comes down to it's average again. This happens in an instant. The crank doesn't actually sit on the plane bearings when an engine is running. Its sits on a very thin film of highly pressurized oil. When you push or pull on that thin film, the film pressurizes, and that thin film gets hot.... now multiply that by 5000 RPMS.

Agreed, increasing pressure converts mechanical energy to heat. There is *some* heat produced on crank bearings, that's why I added the word "virtually".
If a con rod is ~ 1" wide, and ~2?" diameter, it equates to a total bearing surface of 7.85 sq inches, so the upper half is 3.92 sq inches.
A SBC at full throttle produces about 275 ft lbs of torque. The piston stroke is 4", so the con rod journal has a 2" radius. That means the pressure exerted by a firing piston to the crank is a maximum of 1650 pounds. Divided by the 3.92 sq inches means 420.9 psi, not "many thousands".
Pulsing a thin film of oil 2500 times a minute (for 5000 rpm, 4 stroke) to 421 psi will not create a significant amount of heat. Small hydraulic power packs operating at 1500 psi or more don't even bother adding a cooler.

BTW, Boyle's Law deals with volume vs pressure. Motor oil, (and most other liquids) can be pressurised but volume won't change.

 

[mariner1900]

Re: Blown Head Gasket

After 40 years in the marine engineering game, with the last 32 years as a ship's engineer on ocean going vessels working on engines from 100HP to in excess of 25,000 HP, I have learnt 2 main things.
1. Everybody is entitled to their own opinion (right or wrong).
2. Petrol engines and diesel engines are 2 entirely different beasties.

Justjason you are correct that the majority of diesel engines do have piston crowns cooled by a pressurised oil jet of some sort. Crown cooling is provided on diesels as they tend to operate at vastly higher combustion pressures and temperatures. It is not uncommon to have cylinder exhaust outlet temperatures pushing 500 degrees C. So combustion temp would be near 1000 degrees +. There are also many thousands of diesel engines operating world wide that have water cooled piston crowns.

Petrol engines are different in that the vast majority do not have pressurised oil sprayed on the under side of the crown. Any oil that reaches the under side of the crown, gudgeon pin and bush, cylinder wall and piston is from splash (Mercruiser manual #25 description of oil system). One must wonder if sufficient oil reaches the crown to provide much cooling at all.

The oil control rings function is to scrap excess oil, that has splashed onto the cylinder wall, from the cylinder and wall and to provide a uniform thin film of oil for lubrication of the piston and bore. If the oil ring does not scrap the excess oil you would have a very smoky engine indeed.

In regards to cooling of the valves I would like to know how much oil you think gets down past the valve stem seal, down the guide and onto the valve to cool it. I would think that if the stems seals are in good order minimal oil gets past. In fact if the seals and guides are in poor condition you will again end up with a very smoky engine particularly on acceleration after idling.

I think you will also find that the guides pass through a water cooling space.

A small part of the cooling for the valve heads themselves is done during the valve overlap period where some of the new inlet charge is exhausted. Most of the heat in the valves is conducted to the seats and then carried away by the cooling water. Some of the heat is also conducted up the valves stem, into the guide and then carried away by the cooling water. http://www.aa1car.com/library/ar1192.htm. This overlap period also provides some of the cooling for the piston crown.

Anyway enough of this. You are entitled to your own opinion.

Mark. Feel for you having bought the boat and found that it appear to be money sponge. If you are in Melbourne there is a mob called Victorian Marine Technology that have reconditioned V6 long engine for less than $2800.00