Engine Rod #3 Bent 2013 Scion FRS

[guybo]

Originally Posted by humfrz

I reckon you're just ah messen wich our minds, there @guybo ......

Yes, all liquids are compressible to a degree ..... however, the change in density of liquid gasoline with pressure, is so small it's negligible.

WIKI learnt me that ..........


humfrz

No, I'm not. there's no way in hell that gasoline can hydrolock an engine with the starter only. It compresses enough that it can't cause a bent rod. Water won't compress at all and will bend a rod with the force of the starter motor though. Plus the injector would have to be pretty messed up to dump THAT MUCH fuel into the cylinder anyway.

Unpossible.

[justatroll]

Originally Posted by guybo

No, I'm not. there's no way in hell that gasoline can hydrolock an engine with the starter only. It compresses enough that it can't cause a bent rod. Water won't compress at all and will bend a rod with the force of the starter motor though. Plus the injector would have to be pretty messed up to dump THAT MUCH fuel into the cylinder anyway.

Unpossible.

Gasoline is an incompressible fluid.

What defines the "compressibility" of a liquid is the Bulk Modulus.
This refers to how much pressure can a liquid withstand before 'yielding'.

The BM of water is: 3.12 psi, lbf/in2
The BM of SAE 30 oil is: 2.2 psi, lbf/in2
The BM of gasoline is: 1.9 psi, lbf/in2

So sure you could argue that gasoline is compressible only if you consider motor oil to also be compressible.
Are you going to argue that "there's no way in hell that motor oil can hydrolock an engine with the starter only"?

Just as a general rule: All liquids are incompressible (at least as far as the definition of 'compressible' goes).
However even water (considered to be Incompressible) will compress .024% at a pressure of 500kPa (or ~5 Atmospheres)


Now the fact is that all liquids are compressible to some extent, but water, oil & gasoline are definitely in the 'essentially incompressible' category.

[Tcoat]

Originally Posted by mav1178

All you need is about 40cc of fluid to fill the combustion chamber.

http://dsportmag.com/the-tech/tomei-...a20-flat-four/

Thanks. I couldn't find anything. Little doubt the rail could hold at least that much and pressure would not need to be held long to push it through the injector.

Originally Posted by humfrz

I'm still wondering where the coolant went and when (on the timeline) did it escape .......??




humfrz

This is another part of the mystery that bothered me. That much coolant doesn't just disappear. There should at very least be residue left wherever it came out. Can't help but think it factors into this someplace.

[Tcoat]

Originally Posted by guybo

No, I'm not. there's no way in hell that gasoline can hydrolock an engine with the starter only. It compresses enough that it can't cause a bent rod. Water won't compress at all and will bend a rod with the force of the starter motor though. Plus the injector would have to be pretty messed up to dump THAT MUCH fuel into the cylinder anyway.

Unpossible.

Have to disagree there Guy. Back in the day I had a buddy that was trying to get his slant six Dodge going after changing the carb. It wouldn't start and he figured it just hadn't got enough fuel yet so he poured some into the carb (not an uncommon thing to do) to see if it would fire. What he didn't realize was that the reason it would not start was that the float and needle valve were stuck wide open and gas had been literally pissing into the engine. His extra little bit was enough that when he cranked it he heard a horrible sound (I was not there at the time) and then it would not even crank anymore. When we pulled the engine apart we found the #3 rod bent almost to the breaking point. The other cylinder combustion chambers were chock full of fuel. The only reason the #3 gave out was it was probably the first to hit TDC. Since those slant sixes were almost indestructible I think that is definitive proof that fuel can indeed cause hydrolock. IF THERE IS ENOUGH OF IT.

[zc06_kisstherain]

wow..sorry to see this happened to OP. it's very frustrated situation and i had similar case but not car related. everyone saying call there and here and keep circling....
i was super duper angry and told them i was patiently waiting and discussed on solution and i dont see anything going on so i am hiring lawyer if i dont receive confirmed action by xxxx date. i hung up...next few days, case resolved. I am not saying you do this but consider doing it. i dont care about money if this stuffs happens to me. i want to shit the beat out of company like this and ripping customers money, time and mental disorder lol

[mav1178]

Originally Posted by guybo

No, I'm not. there's no way in hell that gasoline can hydrolock an engine with the starter only. It compresses enough that it can't cause a bent rod. Water won't compress at all and will bend a rod with the force of the starter motor though. Plus the injector would have to be pretty messed up to dump THAT MUCH fuel into the cylinder anyway.

Unpossible.

I'm sure you missed the part where OP got the engine to start and idle, but had machine gun noises.

But I'm also sure you think gasoline, in a liquid state, can compress more than water, in a liquid state...

Also: keep in mind that there's 3 other cylinders firing while the engine is cranking. It's not just a starter motor pushing things around in the crankcase...

[humfrz]

Originally Posted by guybo

Gasoline can't cause a bent rod. It is a compressible liquid.

Hi @guybo .........

From your past posts, it appears you usually have your head screwed on straight.

However, if you maintain that liquid gasoline is a "compressible liquid", either you are splitting hairs or you cross threaded screwing on your head on this point and have a massive misconception.

So, after reading threads from several others (especially @justatroll 's post), do you still maintain that liquid gasoline is a compressible liquid ..??




humfrz

[guybo]

I know if I flood my engine in my old assed car (in the days when we could flood the engine by pumping the gas before turning it over)that I don't have to buy a new engine. It just won't start. No bent rods, just a huge PITA getting it to start.

[Tcoat]

Originally Posted by guybo

I know if I flood my engine in my old assed car (in the days when we could flood the engine by pumping the gas before turning it over)that I don't have to buy a new engine. It just won't start. No bent rods, just a huge PITA getting it to start.

Like I said above there needs to be a lot of gas. Flooding it is not enough. Catastrophic failure of the fuel delivery system however can indeed pour enough in. I am sure it is not common but can and does happen. Much like many other "impossible" things that can happen to engines and cars in general.

[wbradley]

Id be interested to know if there have been confirmed documented cases of a DI sticking open and completely filling a cylinder, resulting in hydrolock in other vehicles. Is open a grounded live circuit activated event? Can that even happen with the ignition swich off? The DI atomizes the pressurized fuel so how fast could it fill? Could the line pressure (up to say 1500 PSI) in the fuel system push out enough fuel? Also, for an injector to open electrically, does it not need to be powered the whole time? Could Techstream detect any artifact of this occurrence? Could a car with zero coolant in the engine just have bent a rod from heat after a while and still not show any other clear indication something was wrong before this incident?

The OP for sure has a fight on his hands. Good thing there are lots of salvaged twins, perhaps if there is no remedy here, think about locating a capable Subaru independant shop and a motor. People here will find you a motor, I bet. This will be a 5-6K hit but if you keep the car a year or two longer than you might have it will even out in the end. Hopefully you have access to the funds, credit or otherwise.

[Brandond15]

Originally Posted by wbradley

The OP for sure has a fight on his hands. Good thing there are lots of salvaged twins, perhaps if there is no remedy here, think about locating a capable Subaru independant shop and a motor. People here will find you a motor, I bet. This will be a 5-6K hit but if you keep the car a year or two longer than you might have it will even out in the end. Hopefully you have access to the funds, credit or otherwise.

As a college student, I'm sure that answers the last part of your comment.

[Tcoat]

Originally Posted by wbradley

Id be interested to know if there have been confirmed documented cases of a DI sticking open and completely filling a cylinder, resulting in hydrolock in other vehicles. Is open a grounded live circuit activated event? Can that even happen with the ignition swich off? The DI atomizes the pressurized fuel so how fast could it fill? Could the line pressure (up to say 1500 PSI) in the fuel system push out enough fuel? Also, for an injector to open electrically, does it not need to be powered the whole time? Could Techstream detect any artifact of this occurrence? Could a car with zero coolant in the engine just have bent a rod from heat after a while and still not show any other clear indication something was wrong before this incident?

The OP for sure has a fight on his hands. Good thing there are lots of salvaged twins, perhaps if there is no remedy here, think about locating a capable Subaru independant shop and a motor. People here will find you a motor, I bet. This will be a 5-6K hit but if you keep the car a year or two longer than you might have it will even out in the end. Hopefully you have access to the funds, credit or otherwise.

Digging around yesterday (it was a really slow day for me) I found that the default for the injectors is of course closed. I would be exceedingly rare to fail open but rare does not mean can't happen. Since the system is very high pressure and that pressure is not relieved when shut down it could indeed force fuel through a stuck injector. It would not last long as the pressure would drop fast but it could. The only thing I could not find was the volume of the combustion chamber and that was provided. Since it is only 40 cc and you don't have to fill the whole thing for hydro lock I think the theory is sound. Probably a one in several million chance but reasonable.

The over heat of course is possible as well but to have no signs of heat anyplace else would be even greater odds than a stuck injector I would think. An engine overheated enough to bend a rod would almost certainly be easy to spot right away. I have not watched the video (probably should have and will) but an overheated engine usually makes a very distinctive sound ( heard it way to often) and there should be steam coming from someplace even if almost dry.

One thing we do not know is the condition of the rod connection to the crank. I have seen those let go, rod go off center and top out the cylinder bending the rod. Those usually showed clear mechanical damage where it hit though. Oh and that was on oid school big blocks so not even sure it is possible on a boxer.

With the info we have my money remains firmly on the most unlucky fuel hydro lock in history.

[FirestormFRS]

Gasoline will hydro lock an engine. A faulty injector will leak enough gasoline into a cylinder to hydro lock an engine. Gasoline will not compress. There have been parts that have gone back to oem factories that have had this exact condition. The RCA revealed a faulty port injector stuck open dumping fuel into the cylinder. Uncommon? Very! Possible? Absolutely!

[mav1178]

Originally Posted by guybo

I know if I flood my engine in my old assed car (in the days when we could flood the engine by pumping the gas before turning it over)that I don't have to buy a new engine. It just won't start. No bent rods, just a huge PITA getting it to start.

Also don't forget the FA20 is high compression in small displacement, which means very little cylinder volume when at TDC.

Old engines have much lower compression ratio and larger displacement.

-alex