Engine Info via Adam Tune+
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Taken from Adam’s Facebook post. I will try and update with photos.
2.3L Block cracking / Headgasket update. This is going to be VERY long, but worth the read.
I have posted about this before, and we have came up with a “fix” for the 2.3L block cracking along the head stud bosses on the side of the block. However this is STILL not a fix for the block cracking issue. After further investigation and testing, we have determined the cause of the factory blocks cracking on the 2.3L variants.
*Deep breath, time to mash the keyboard*
It has been believed that the cause of the blocks cracking have been the fact that the head stud bosses are weak and/or have casting flaws. The upward force from compression/big boost on the cylinder head has been putting stress on the side of the block and causing a stress crack as shown in PICTURE 1 below (factory engine, not built).
This is not the case, in fact in nearly every instance of a block cracking a blown headgasket has accompanied it. I say nearly because not everyone has been documented accurately. On the Focus RS side of documentation there have been mentions of the block being cracked, but never mentioned if the headgasket failed as well. Most of the time when a dealer gets a cracked block Focus RS/Mustang in their shop they simply pull and install a new OEM longblock. Obviously if you follow the Focus RS pages and many blog post you know there is a headgasket problem with the Focus RS.
This blows my mind as I have mentioned it as a problem on the Ecoboost Mustang side, instead people want to blame engine failures on the Mustang 2.3L side on the tune or simply because Ford cheap on the rods/pistons. There are no differences between the Ecoboost Mustang and Focus RS block. The only difference is the block has a machined provision for the PTO/PTU on the Focus RS and the Mustang uses the provisions to mount the engine. (Cylinder head gets different exhaust valve springs, otherwise the same)Yet, it is a HEAVILY documented issue on the Focus RS side but not the Mustang side. Reason? The Focus RS is a limited production vehicle, and nearly every owner is an enthusiast, nobody really buys a Focus RS just because they liked the way it looked on the lot. If they did, they would have just bought a Focus ST. RS Owners are a tight nit group, and as we all know Enthusiast’s love Forums and Facebook groups. So, it gets documented. The Mustang is massed produced, some people just drive their cars and enjoy it and never mod them. So when a failure comes a long it is either documented with a false reason or just not documented at all. So let’s thank the Focus RS group for being logical and sticking together to make sure it is documented (See link below for documented cases)
https://docs.google.com/spreadsheets/d/1Oh8nCvLr1w7SVNUHaO5zI5RQoW6j5SwE2kVxJQQcCj8/htmlview
Since the Ecoboost Mustang came out it has received 5 part number changes/revisions. Some say it is because Ford changed suppliers, some say it is small minor changes to increase efficiency in the manufacturing process. Or maybe it is because Ford was chasing their tail on trying to solve engine/headgasket failures?
Back on topic, so whats happening?
Multiple things, but the root cause (In my opinion) is the headgasket. When the headgasket fails it fails in two parts. This is based on my personal research from the different engines we have disassembled and cars we have had failures on. The gasket fails between cylinder 2 and 3, and it is looking like the headgasket fails majority on the #3 side. When it fails it pushes coolant into cylinder 2. Now there have been multiple symptoms of a headgasket failure. If it fails during normal driving you start to get misfires and smoke out the exhaust. If it fails under load you can have the same symptoms or even worse an engine failure. Going back to blaming Ford for using cheap rods/pistons, this is true, they are cheap, but this is an economy oriented engine and it was never meant to see high horsepower. With that said, when the gasket blows under load the cylinder pressures are increased from detonation and the fact that coolant is non-combustable. So the weakest point loses, and in some cases that is the rod and it shoots out the side of the block.
So, why is the block cracking?
If you don’t chuck a rod, when the second stage of the gasket failing happens all the pressure from the cylinder goes out into your coolant jackets surrounding your cylinders. We are talking an EXTREME amount of cylinder pressure especially if there is detonation from coolant being in the cylinder. The coolant system only sees about 20psi during normal operation, so seeing 1000psi+ of cylinder pressure is extremely stressful on a system not designed for it (Coolant system).
In this case the weakest point is where the cylinder head bolts/studs go into the block. See PICTURE 2 and 3 below, you will see that where the block cracks is located on the exhaust side of cylinder #2. Besides this being a weak spot based on casting design alone this is also the highest area on a block when in operation. This is where the TURBINE side of your turbo sits. So when the recipe for disaster was already at a critical point, we sprinkle a little bit of 1500°F+ into the mix. So the material here is thin, and soft from the heat of the turbo charger. There is a heatshield on the turbine housing on the OPPOSITE side of the block so the heat is being retained in this area.
Now that we went over why the block is cracking, lets go over some headgasket fun.
In pictures 4-9 you will see the revised gasket from Ford on top of the previous gasket that was in the Focus RS. Mustang guys, you have the previous gasket still to this date. I have not disassembled a 2017+ Engine yet to see if the gasket is different but as of recently the 2016 engine had the gasket shown on the bottom (4 pieces).
Picture 4: Shows original gasket versus revised gasket
Picture 5: Shows layers held together by Brass Rivets versus a dimple press. Brass rivets are a MUCH better way of assembling layers on a gasket. Just watch out in swap scenarios where the brass rivet might sit on the block and head mating surface.
Picture 6: Showing the original gasket has more coolant holes than the revised gasket. The revised gasket is has blocked off these ports from flowing coolant from block to head and vice-versa.
Picture 7: Showing the original gasket has two coolant relief holes on both the intake and exhaust side (Exhaust side hole is covered by the revised gasket). Revised gasket only has one MUCH larger hole on the exhaust side.
Picture 8: Showing both gaskets disassemled
Picture 9: Showing what I believe the cause of the failure is on the original gasket. This thin layer that sits between the layers is obviously only “working” near the bore. This layer is .0015″ thick, and the relief holes are also present in this layer. This means the material between the HIGH pressure of the cylinder and the coolant relief is only .0015″ and .1345″ wide.. Not much sealing surface to do such a strenuous job. The revised gasket does not have this layer, instead it has a full-size layer that is 3x and thick doing the job and the distance between relief hole and cylinder is doubled, and eliminated on the intake side.
The original gasket I pictured below came off an engine that showed signed of seeping in cylinder 3. Luckily we caught it before it completely failed. The revised gasket came off the engine with “ORANGE” pistons in it. That orange is from race-gas, so that tells you the engine was ran pretty hard and it did not fail. The revised gasket is doing it’s job, so far. This is also the gasket that is present on Arthur Bianchi’s car that we made 520whp/500wtq with. His engine was built before we had our hands on JE gaskets. So again, so far so good.
Now, previous fixes, and fixes moving forward.
As most of you know we use 2.0 blocks for all of our builds for the Focus RS. The 2.0 block is robust in this area of cracking, and on the entire side of the exhaust side of the block. Though it is a 2.0L block, the displacement is 2.3L just like factory as we use all 2.3L internals. This completely eliminates the block cracking issue, and gives us a closed deck block versus an open deck block. For the 2.3L blocks, middle of 2017 we started welding the blocks in the area of failure to hopefully eliminate the cracking issue. However, this was wrongly diagnosed as the mountain of text above disclosed. So welding on the bolt/stud bosses did not fix the issue.
See PICTURE 10 below, this was Version 1 proposed fix. We welded the void under the bosses and the bosses themselves.
PICTURE 11 and 12 below shows that with Version 1’s fix the block still gets hairline cracks on the SIDE. So we just moved the failure point, so this is not a fix.
Picture 13 shows Version 2 proposed fix. This is a SOLID option, however it does not address the sides of the bosses that also crack as shown in Picture 11/12.
**Below is going to get into TunePlus, Inc customer territory, so if you aren’t a customer or have no desire to be a customer (Steve Tabe, hate you) stop reading here unless you want to see what we are offering**
All of the above proposed fixes were for something that wasn’t even the root of the problem. Not to mention it was just moving the point of cracking to the next weakest area. The problem is the headgasket itself, keep the headgasket from failing, and your golden. However, as an extra step of precaution we are also going to start using 2.0L blocks in the Ecoboost Mustang as well. We will be making a jig that holds a 2.3L Block just like the factory mounts do, then mocking up the 2.0L block and building mounts for it to drop in without any fabrication on the customers end. This eliminates the need to replace the 2.3L block if you magically pop a JE Headgasket (to date, no JE gaskets have failed, even beyond 600whp) and crack the block and the added benefit of a closed deck block.
So, while it does suck that we had to build a few engines in late 2016, early 2017 with OEM gaskets, we had no choice as there were no other option available on the market. Blaming the fact that the block wasn’t welded isn’t going to fly as you can see. So for any customer that has a built engine by us with a OEM gasket we will send you a JE Gasket for F-R-E-E. If your OEM gasket failed on your built engine and cracked the block we will build you a new 2.0L (2.3 Displacement) shortblock 100% AT COST. If you ship the car to us we will give a significant discount on labor as well. Other companies would just say “Ford’s Fault, we built with what we had available”. While that is true, we never want anyone to regret any purchase decision they made so we are offering to get you up and running for as little cost out of pocket as possible.
If it weren’t for the Focus RS group having shared their different types of failures it would have taken us longer to come up with what we think is the linked cause of failure. So shout out to those guys/gals!
@ Bob Riley… just to rub it it in !!! 😎
and more recently with longer inlet manifolds/ shorter rampipes..
No nothing.
No Mods. No rockers. Just a chunky knob, thats now been replaced by an RS knob innit.
No tackiness.
Std as Ford intended, but with a space saver wheel and jack and nuts and wheel brace. oh.. and flaps, a man has got to have flaps.
Innit?
