Ford Powerstroke Diesel Forum banner
1 - 19 of 19 Posts

·
Premium Member
Joined
·
161 Posts
Discussion Starter · #1 · (Edited)
I figured I would keep this in my year range because the turbos change later. Emissions in place. Not doing any work just making sure I have a very sound understanding of how my truck works because its important. I've been reading up on things but its just hard to get like a specific thing answered. Plus me writing about it helps to enforce what I read. So please school me professor!

So we'll start at the intake filter where it goes into the lower intake.
Lower manifold feeds the compressor side and the hot side pipe sends it to the intercooler and returns cold side back to the lower manifold... is it mixed with the EGR at this point?
Then through the upper manifold to the valves. Why is there a upper and lower seems overly complicated? I know with aftermarket kits you delete the intake all together and have a new piping into the valve cover but of course have no EGR.
Now it's all combusted out the exhaust manifold. I have the VGT and it seems the design of our turbos has 2 exhaust flanges. Is this just because of the reverse flow manifold design? Its not a twin scroll designed turbo, just exhaust flows through the vanes on both sides, correct?
Is only the passenger manifold feeding the EGR?
All the spent air goes to the downpipe and that's where class will end because no one wants to talk about cat piss.

What did I miss...
 

·
Premium Member
Joined
·
161 Posts
Discussion Starter · #3 ·
Ok so yes the EGR gets mixed after the intercooler.
Between now and posting that Professor YouTube schooled me some more on turbo design and I answered a question and edited my post a little. Still helpful for me to write it all out.
 

·
Premium Member
Joined
·
11,370 Posts
What truck year again??
-2011-2014 used the same turbo.
-2015-2019 are basically the same turbos. It was even from Ford that the 2015-2016 models would receive a 2017-2019 turbo as needed under warranty replacement at some point.
-There is always some sort of point at which in a V motor ( V6 or V8 ) you need to combine the exhaust flow. For the 6.0L motor they used a Y-pipe, on the 6.7L there is a passenger side and driver's side exhaust manifold pipe that feed their own connections on the turbine housing on the 6.7L turbo.
-The exhaust manifolds ( for that matter the 6.7L motor ) are NOT "reverse flow". That is a HUGE misconception of the 6.7L and how a true reverse flow system works.
You missed the throttle body that is part of the cold side piping before the EGR, as well as the EGR valve playing a role.

From the Coffee Table Book:

Intake Side: Air is drawn through the air filter then past the Mass Air Flow (MAF) and Intake Air Temperature (IAT) sensors. The MAF sensor measures the mass of the air entering the engine and IAT obtains the temperature. Next, the air enters the compressor side of the turbocharger through the lower intake manifold. The air is compressed above atmospheric pressure. The compressing process causes the air to heat up. Directing the air to an air to coolant Charge Air Cooler (CAC). From the CAC the air passes the CAC temperature sensor and through the intake throttle body and into the other side of the lower intake manifold. Inside the lower intake manifold the air mixes with EGR gases (if EGR valve is open), travels to the upper intake manifold, and through the right and left side rocker covers to the intake ports of the cylinder heads.

Exhaust Side: Exhaust gases exit the exhaust ports into the inboard exhaust manifolds. Exhaust gases are directed to the dual inlet of the turbo via the right and left side up-pipe. The exhaust spins the turbine wheel inside the turbocharger. The turbine wheel spins the compressor wheel(s) via their common shaft. Some of the exhaust from the passenger side manifold is directed to the EGR valve through the EGR inlet pipe. When the EGR valve is being operated, exhaust flo goes through the valve then either through the EGR cooler or bypassing the cooler. This is done by the EGR cooler bypass valve. The exhaust gas enters the lower intake manifold and combines with the fresh air.
 

·
Premium Member
Joined
·
161 Posts
Discussion Starter · #5 ·
Mine is 2014. So these turbos are NOT twin scroll even though there is 2 exhaust inlets. Ford just decided to combine both side of the exhaust in the turbo instead of a through a combined up pipe?
I don't know what a real reverse flow head does... but maybe better said a reverse cross flow design then?
The more I understand how the exhaust gasses are routed the more an EGR seems pointless and harmless to me lol.
I did forget about the throttle body. Must be deleted when you delete the EGR and get an aftermarket intake piping?
 

·
Premium Member
Joined
·
11,370 Posts
  • 2014 had a dual compressor wheel setup. Exhaust side ( turbine ) has nothing to do the the intake side ( compressor ).
  • The engine exhaust is key to feeding a turbo. So yes, the 6.7L turbine housing has two connections for the exhaust manifold piping compared to other turbos which a fed by a y-pipe. Y-pipe still has two connections for the exhaust manifolds. Just changes how it's connected to the turbo on the turbine side.
  • Reverse cross flow is even worse terms to use. Just forget that terminology...it's just easier.
  • Throttle body just ends up as collateral damage when deleting the truck. Just gets removed or not really needed for use.

EGR is all about making the emissions "more better" for the environment.

So where are we now in your info gathering?
 

·
Premium Member
Joined
·
11,370 Posts
Here's a cut away of the 2014 turbo:

Image uploading. Refresh page to view
 

·
Premium Member
Joined
·
161 Posts
Discussion Starter · #8 ·
I know my turbo has the SST thing going for it so there's dual compressors on that side. I was just trying to make sure I understood what was going on with the dual inlets for the turbine side. When I see 2 inlets I just think twin scroll and that confused me because its a VGT. I didn't know if the answer was literally as simple as up pipe design. I am also seeing Duramax does a very similar turbine design.

I just like to be able to open my hood and know what every single thing is doing. I probably am 65% of the way there haha without getting engineer level detailed. I'm currently learning all about exactly how the push rods are transferring its motion to the valves and all the little parts between so valves airflow included.

My current understanding is traditionally the intake ports are on the valley side of the heads. On the 6.7 the exhaust is on the valley side and the valve cover has a design that is kind of routes air over the cylinder heads to the intake ports on the other side. This makes it so the intake and exhaust manifold both sit in the valley. So Ford swapped that. Are the intake valves still the forward most valves then? 6.4 and earlier had exhaust manifolds on the outside.
Is the exhaust valves the forward most valves on both heads?
I have no idea what real reverse flow heads do. I read a press thing from when the 6.7 was coming out where they talked about the difference in exhaust port locations and described it as reverse flow.
 

·
Premium Member
Joined
·
1,034 Posts
Inboard exhaust gets to the turbo more quickly, (closer/ less travel) which then makes for faster spool up.
 

·
Premium Member
Joined
·
161 Posts
Discussion Starter · #10 ·
Any reason there’s 32 pushrods instead of 16 and a bridge for the intake and exhaust valves?
 

·
Premium Member
Joined
·
11,370 Posts
32 push rods = 8 cylinders x 4 valves per cylinder
4 valves = 2 intake valves + 2 exhaust valves

I might have it right: Pushrods move along the lobes of the cam shaft. The pushrods use a lifter to move the valve.
 

·
Premium Member
Joined
·
161 Posts
Discussion Starter · #12 ·
Yea I get that. Wondering why have a pushrod for every valve instead of bridging the 2 exhaust and 2 intake. 4 rockers on every cylinder is a tight squeeze.
 

·
Registered
Joined
·
145 Posts
32 push rods = 8 cylinders x 4 valves per cylinder
4 valves = 2 intake valves + 2 exhaust valves

I might have it right: Pushrods move along the lobes of the cam shaft. The pushrods use a lifter to move the valve.
Not sure if this was in error or not, but, typically lifters ride on the cam, then the pushrod is between the lifter and the rocker, then the rocker moves the valve.

Yea I get that. Wondering why have a pushrod for every valve instead of bridging the 2 exhaust and 2 intake. 4 rockers on every cylinder is a tight squeeze.
I'm going to guess that this was Ford eliminating a failure point. The 6.0 and 6.4 has had some lifter failures, which puts metal through the engine and pretty much takes it out. The same exact lifters in those engines, last pretty much indefinitely in the 7.3. Difference? The 7.3 has each lifter acting on 1 valve spring, others have bridges and 2 valve springs. Effectively doing more work. That's my take, I have no actual insider information...
 
1 - 19 of 19 Posts
Top