CS EBCS Failure Analysis, Prediction and Troubleshooting

This isn't a callout thread; no accusations are being made here on any party at all.
The goal is to figure out what might be going wrong with these EBCS, to form hypothesis on possible resolutions, and to provide a centralized location for testing and further analysis.

That said, let's get started.

First off: Links.
Store page: https://corksport.com/mazda-boost-control-solenoid.html
CS Blog: https://corksport.com/blog/an-inside-look-at-the-corksport-ebcs/#content
Whitepaper: https://www.corksport.com/support/instructions/GEN-6-710-WHITEPAPER.pdf

Now for a teardown of one of the bullet valves.

Here's what it looks like with the valve removed from the valve body. Note the electrical cap (part with the wires) is removed because I'm a savage cave dweller that doesn't give a shit.



There's a secondary endcap as seen below that was removed; this doesn't need to be removed to access the rest of the guts of the valve, but I didn't know that at the time so here are the pics anyways:


Endcap removed:




Now for the interesting bits.

Note that I basically had to destroy this thing because I didn't have the right tools to take it apart properly; the donator of this part to me said they don't want it back, so a worthy sacrifice to science.

The solenoid unscrews from the main valve body using a 14mm wrench and a pair of pliers:



The valve body is also two piece. The left side unscrews out of the right side, which releases the poppet.

Left side + poppet:


Right side + poppet (It's fucked lmao):



Analysis time.

I'm no expert on solenoid coil resistance, but 37 ohms is neither zero nor infinite, so I'm gonna say this part is fine; maybe someone else can chime in here. Note: This was measured at the coil leads, so measuring from a pigtail will likely see different numbers.

There are 9 total seals on this thing. The design is pretty complicated going purely on shape, but it's actually pretty simple in operation.

The big black part in the middle of the poppet is very likely to be machined steel coated with a very thin, hard rubber to facilitate sealing, and the two orings just close off the ends to prevent leaks out of the valve body.

The small hole seen in the middle is essentially a gun-drilled hole, probably to reduce mass without sacrificing strength, while also allowing for a path that air can flow through so pressure doesn't build up and impair operation. It runs through the entire body of the valve, from wired end cap to the opposite side.

The amount of movement required to operate the valve is extremely small, which would allow for very fast response time and higher frequencies of operation.


As for how it actually works:

Let's defer to my shitty MS Paint drawing; note that supply air would go in through the center section where the poppet plug is, and NO side is on the left with NC side on the right:



As seen above, a tiny speck of dust can cause the poppet to sit open; even a slight amount of clearance between seal and seat means a significant amount of open area for air to escape. Since the poppet is so small and moves so little, there's not a lot of inertia that can build up to forcibly dislodge stuff stuck in there.

As a side note, and this is hardly worth mentioning, but there was some little scraps of something in the valve when I removed it, but that doesn't actually mean anything since it could have come from anywhere at any time or even during shipping. It's also worth mentioning that the valve is directly exposed to the ports in the main valve body (the part you connect hoses to) so using teflon tape, threadlocker, or anything that can dry out or leave behind small specs of hard material is probably not a great idea.



Potential problems:

1. Dirt/contaminants.
Again, even a small spec of something could result in a relatively large leak.

2. Heat and tolerances.
The insides are tiny with a complicated internal structure, and there are at least 3 different metals/alloys in play regarding the operation of one of these things.

3. O-rings.
While there are a large number of them in this little device, only two actually move at any given time. It's possible that they are either sticking for some reason or swell due to oil and/or fuel vapor from manifold/source gasses.

4. Lubrication.
It's possible that whatever grease is being used has issues with high temps.

5. Wrong part.
Since there's no sticker on these from the MFG, I can't cross reference the part number. There are both 12v and 24v versions of these, however, so that is potentially a factor.



Potential solutions:

1. Filter.
A high flow inline filter that's heat tolerant could help here. In the MAC documentation, at least one of the valves I looked at references 40 micron filtration.

2. Remote mounting to a cooler surface.
If this is the issue, moving the valve away from the turbo and intake might help, but that kind of defeats the purpose of a high speed valve.

3. Slightly undersized orings or dimension modification.
If this is the cause of the issue, either reducing the diameter of the existing orings or carefully polishing the friction surfaces may help. I'd probably leave this as an absolute last resort.

4. Different lube.
Not sure what these come with, but it should be pretty easy to test new lubricants. My initial suggestions would be teflon oil for short term or white lithium for longer term operation.

5. Provide info...?
I'd understand totally if CS wanted to keep the actual part number under their belt; doublechecking against supplier documentation would be a good idea though.


Okay.
I think I've taken this far enough; the floor is now open for further discussion.

 

37 ohms seems high for a solenoid. I know it isn't a VVT solenoid but on a GM those VVT solenoids have a spec between 6-13 ohms. Not saying that's wrong but just seems like a high reading.

Do you think an inline air filter going into the solenoid could increase longevity or would the debris you found be considered something during the manufacturing process?

 

Would that seem right for a 24v solenoid? It's one of the points I brought up in possible failures. I'll go re-measure just to be sure.

I don't think it's a longevity issue, as failure from shit keeping the poppet open is likely easy to fix by removing the solenoid and blasting it with air. You can actuate the valve with a finger at the end that comes out of the main valve body to check.

 

Verified; roughly 37 ohms. I've got photos if it matters.

 

love how im reading this now and i just walnut blasted my intake valves (nuts got everywhere) guess ill verify if dirt gets into mine. Its very new so if it fails its most definitely not the O-rings unless manufactured wrong. Ill keep ya posted

 

It's a nice looking EBCS but for the cost you could buy multiple of these

https://www.ebay.com/itm/2547625752...R4cfQQjBl7dN+8sTGqYyJWZ7m2rt|tkp:BFBM2NiT-phg

Been running one of these off of eBay on two cars now for years. Never a single failure. Even if it did fail, the cost is so minuscule that it doesn't matter.

 

This was my 2nd CS ebcs that failed on me. To add to what enki said above, I did use thread sealant adhesive and both were mounted right on the valve cover utilizing the cam shaft sensor location.

Sent from tapioca

 

Can we start tagging people in this thread and/or get more info from those that aren't here so we can start figuring out commonalities?

 

Do it

 

I would but I don't know who's had issues other than Iam.

 

What is the actual failure mode you are experiencing?
Has communication been made with CorkSport directly? If we can get the valve back we can work with MAC directly to troubleshoot the failure mode and then improve.
At this time, we are not getting reports of issues other than the typical "ripped the wires out"

 

Not this time, it's torched.

 

Both times i had the same failure occur. Zero boost control with the ability to only hit wastegate spring pressure. This happened on two different engine builds. Both times 12v was applied and confirmed the valve actuated. It's all documented in my BW s257sxe build thread.

 

I do remember a while ago I compared all the information CS gives you about the EBCS from the white paper, their blogs, and the product page with the bullet valve catalog from MAC and found what I thought was the exact valve CS uses. Once I put my computer back together this afternoon (on my phone ATM), I'll post another reply if I can manage to find it again.

 

So voltage would actuate but function was not occurring. Thats an odd one. How long were they in use?
Did these get sent to CS for investigation?

I personally have not had a failure or issue with one of our EBCS units nor have we in the company. Not saying its not possible, just been very rare. In our assembly process each units is tested to actuate with 12v applied and to hold pressure in the NC and NO positions.
If for some reason we find an issue we troubleshoot and resolve it (typically a broken o-ring). Rarely do we see an electrical issue and those are not used; they are sent back to MAC.

 

He said earlier his was bolted to the valve cover. Was that a fully tested use case for these? I'd assume the severe vibration and heat could be problematic.

Again, not pointing fingers, just asking questions.

 

That was our main test location and the compressor housing like OEM. The MAC bullet valves were designed for high vibration and varying temp locations and working at a much higher duty cycle then we put them through.

Also jsut a note: CS is not the only company using the bullet style for this application. Perrin is using the same style with their own manifold design as well.

 

What did you use for sealing the nipple connections? Teflon tape? Something else?

 

Bear with me. This is going to get confusing.
1. It seems from a photo on my build thread, i ran the 1st CS EBCS on my stock motor (for how long? i cant recall) It was also mounted on the HPFP bracket at that time.
2. First keefover special goes in along with same EBCS (THIS time mounted on the cam sensor location)
3. 1st EBCS failed and was replaced towards the end of the tune before motor "melted' cyl 2 & 3 (just before 7k miles)
4. Second keef special goes in along with (2nd) replacement EBCS mounted again on cam sensor location.
5. Motor only makes it to 1200mi due to spun bearing (we didn't even start tuning, really)
6. Same 2nd EBCS transfers to current built engine and was discovered faulty around 1500 miles. Mounted on cam sensor location.

I obviously don't have your typical scenario going on here. But, i'm lead to believe the cam sensor mounting location has something to do with it. I cant recall if after the 1st failure, a warranty claim was opened for a replacement. Or if i just bought another new one. I'm sure CS has some purchase history tied to me.

just your standard thread sealant with PTFE

 

if my ebcs from corksport does fail id be more than willing to ship mine to you if thats something you would like to ponder and tinker with.