Interesting take on ecoboom.

[TorqueMan]

This video popped up on my Youtube feed (I guess I watch a lot of car/tech videos). It's from "Tuned By Nishan," which I've never heard of before now. These guys posit that many ecoboost engine failures are related to exhaust gas reversion, which is caused by running high boost on the relatively small factory turbo.

Exhaust gas reversion occurs during intake/exhaust valve overlap. The pressure in the exhaust manifold is so high that a portion of the exhaust gases that should exit the cylinder either remain, or are forced back in the cylinder by the high pressure in the exhaust manifold. They say they've measured pressure in the exhaust manifold that exceeds pressure in the intake manifold, which is pretty remarkable. The supposition is that if enough hot exhaust gas remains or is forced back in the cylinder during valve overlap (end of exhaust stroke/start of intake stroke) they can retain enough heat to cause a preignition event as they are compressed along with the fuel/air charge.

NOTE: The videographer says "detonation," but I believe he means preignition. Detonation by itself is rarely the cause of internal engine component failure.

BTW, if this claim is proven correct exhaust gas reversion may also explain why many 2.3 engine failures occur on cylinders 2 and 3. Watch the video to see why. (I know it's long, and there is a lot of repeated information, but watch it all the way to the end; it's worth your time.)

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[trippleyelo]

This is why I run a "meth. kit" the insurance for my motor is worth -20 type windshield wiper fluid and one heat in 3 quarter tank .. The cleaning and cooling the block is so important when It comes to high boost engines look at the carbon build up is a flow killer "good oil and coolant" is important on this engine should be change more often like what we have pushing 275 per litter for me is insane ,but oh what fun to see the tach spin like wind meter..:ford:

Yes there on to something but most of what their saying is old school ..:cheers:

 

[Ecoboobs]

Good find. Interesting to see how cyl 2 and 3 are more restricted in the exhaust manifold than 1 and 4. He states that the pressure in the turbine housing can get too great but I'm wondering if a 3 inch down pipe and straight through free flowing exhaust would help combat this issue on the stock turbo? How many ecoboom's that had free flowing exhaust sytems especially turbo back?

Makes me want to get a precision turbo.

 

[Elgyn]

This is why I run a "meth. kit" the insurance

Myself as well. Thinking about getting rid of the catch can since it's no long needed

 

[trippleyelo]

Myself as well. Thinking about getting rid of the catch can since it's no long needed

Its in not hurting anything just inconvenience during oil change and would like to see what you get when on meth?

 

[Brian V]

You believe this guy ? Exaust reversion is ?

There are 2 velocities of exhaust during the process when these gasses are expelled from a cylinder ................................................
These velocities create back pressures at different velocities ..

The statement about reversion causing a detonation could be possible . Altough more likely would burn up the intake valves . Head lifting ... we already know why the head lifted .. to much boost and the block is week between cylinders 2 and 3 .

I am more inclined to think that exhaust ports are not big enough for all that boost .we already are aware the head gasket is not up to par either ..

Whats new ?

 

[trippleyelo]

You believe this guy ? Exaust reversion is ?

There are 2 velocities of exhaust during the process when these gasses are expelled from a cylinder ................................................
These velocities create back pressures at different velocities ..

The statement about reversion causing a detonation could be possible . Altough more likely would burn up the intake valves . Head lifting ... we already know why the head lifted .. to much boost and the block is week between cylinders 2 and 3 .

I am more inclined to think that exhaust ports are not big enough for all that boost .we already are aware the head gasket is not up to par either ..

Whats new ?

Head porting..

One of the most common items that over looked in this forum hot rider's and gear heads been doing this first to make any type HP .

More air in =high HP
More air out= more boost

Let it flow for more HP old schoolers know that:first:

 

[Regs]

Many variables and tolerances are being pushed. The turbo has pretty rudimentary sensors that can push the turbo into overboost, the direct injection might not be covering enough the cylinder/piston in higher RPM causing them to fry, and of course the engine itself has weak spots.

It's not a Twin Turbo V6 BMW or Q60 by any means.

 

[Turbong]

Many variables and tolerances are being pushed. The turbo has pretty rudimentary sensors that can push the turbo into overboost, the direct injection might not be covering enough the cylinder/piston in higher RPM causing them to fry, and of course the engine itself has weak spots.

It's not a Twin Turbo V6 BMW or Q60 by any means.

Of course not, but it also has to do with they just have no incentive to push the their i4 that far with their TTV6 offerings, the difference is though Ford was paving the way to put the 2.3 i4 to stardom with the RS and other models therefore for more effort was put into it to operate at higher power levels than BMW and NISSAN's i4 needs. Still what Ford did doesn't make too much sense splitting the two versions builds only led to disasters as we have seen with QC, ecobooms, RS gasket failures, All bad long term decisions, they should have focused all resources and energy onto making one version for stability and QC and simply just dialed power down on the other offerings with just smaller turbos and such, but keep the core build of the 2.3 the same.

 

[TorqueMan]

You believe this guy ?

I dunno. I'm looking for corroborating evidence.

Exaust reversion is ?

Exhaust reversion is when relatively high pressure in the exhaust manifold causes exhaust gases to reverse direction, going back into (or never leaving) the cylinder during valve overlap--when the intake and exhaust valves are both open. In normally aspirated (NA) engines, reversion can be bad enough to force exhaust gases back up the intake tract. Hot Rod magazine published an article describing exhaust residue on the back side of the carburator on a particularly troublesome engine.

Pressure in the exhaust manifold on a turbocharged engine is even higher than on a NA engine, and much higher than the pressure in the intake manifold. The greater the difference in pressure, the greater the reverse flow. The 2.3L Ecoboost uses a small turbo attached to an exhaust manifold which is integrated into the head. The integrated exhaust manifold reduces the volume of exhaust area that must be filled with gas to power the turbo; the small turbo has less mass and is therefore easier to spin up than a large turbo. Together, the integrated manifold and small turbo is intended to reduce/eliminate spool-up lag at the relatively low boost pressures used with the factory tune, but such a setup tends to increase exhaust manifold pressue because a small turbo is more restrictive than a larger one. When you crank up the boost on a small turbo--say with an agressive tune--exhaust backpressure further increases as well. This article does a pretty good job of explaining why doing so is a bad idea:

https://ls1tech.com/forums/forced-induction/911023-turbo-sizing-backpressure-explained.html

There are 2 velocities of exhaust during the process when these gasses are expelled from a cylinder ................................................
These velocities create back pressures at different velocities ..

I'm not sure what your point is. Can you clarify?

The statement about reversion causing a detonation could be possible . Altough more likely would burn up the intake valves .

I don't follow this. Reversion doesn't increase exhaust temp, it just affects flow direction. Are you saying the valve would be exposed to exhaust gas for a longer time and that might burn them up?

Head lifting ... we already know why the head lifted .. to much boost and the block is week between cylinders 2 and 3 .

There is a difference between head lifting enough to blow out a head gasket, and head lifting enough to leave the impression of a mounting bolt shoulder in the metal of the head. The engine in the video experienced extraordinary cylinder pressures far beyond anything you might see from turbo boost; it's indicative of preignition.

I am more inclined to think that exhaust ports are not big enough for all that boost .

This was mentioned in the video as an explanation for why we see more failures of cylinders 2 & 3 in the 2.3L Ecoboost. The manifold volume for cylinders 2 & 3 is lower than for 1 & 4. It's logical to assume reversion would be worse where the exhaust manifold volume is lower. This assumption is bolstered by the fact the 2.0L Ecoboost has lower exhaust manifold volume for cylinders 1 & 4, which is where they see the failures with that engine.

Whats new ?

Well, this is the first I've heard anyone articlate a logical reason for the numerous failures of tuned engines involving cylinders 3 & 4. A "weak block" doesn't explain con rod and piston failures. Preignition caused by exhaust gas reversion does.

 

[Elgyn]

Its in not hurting anything just inconvenience during oil change and would like to see what you get when on meth?

My guess is not much to nothing at all. Not tuning for it...yet. It has the Roush tune and is still under warranty. Mainly using it for charge temp cooling when the inter cooler decides to heat soak itself out of any usefulness

 

[ZenkaiRacer]

I believe it.

From my experience with tuning DSM's, pushing a turbo with a smaller exhaust housing to reach a certain hp number on pump gas was always much more difficult than one with a nice flowing housing.

For example, a PTE 6262 with a dsm bolt-on housing (restrictive) was much more prone to knock and could not reach the same pump gas numbers as the same 6262 with a proper T3 housing.

 

[1QwkEcoBoost]

I believe it.

From my experience with tuning DSM's, pushing a turbo with a smaller exhaust housing to reach a certain hp number on pump gas was always much more difficult than one with a nice flowing housing.

For example, a PTE 6262 with a dsm bolt-on housing (restrictive) was much more prone to knock and could not reach the same pump gas numbers as the same 6262 with a proper T3 housing.

You would get a lot more boost creep with a smaller housing as well if I remember right? 1994 Talon TSi, 1997 Eclipse GSX, 2003 Evo.

 

[Marvinmadman]

3 Gvr4s and a 3000gt vr4 :cheers:

 

[ZenkaiRacer]

You would get a lot more boost creep with a smaller housing as well if I remember right? 1994 Talon TSi, 1997 Eclipse GSX, 2003 Evo.

From the dsm bolt on housings yes. If you were using an internal gate with a bolt on housing the gate port usually couldn’t flow enough to regulate boost well. Was mostly a problem with internally gated 16/18/20g turbos with mistu turbine housings.

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