How To Spot A Fake Mugen Formula Valve Cover…

Okay, being that the reference article on King Motorsports’ website is nearly a decade old, I figured now would be a good time to update that “Fakespotting” piece. As we are getting older, Mugen products seem to be going up in price with no signs of slowing down. Mugen stuff has gone from quality aftermarket parts for Honda enthusiasts to full-on collector’s items now. With collectors driving the prices up as the parts are becoming more scarce, more counterfeiters are trying to cash in by selling their own versions. This is done in hopes of fooling potential buyers or people who are none-the-wiser. Sure, these types of parts have been out in the market for years but counterfeiters are getting better with their replicas. There has recently been an influx of counterfeit parts in Japan too and many of the enthusiasts over there are getting fooled because they haven’t been as exposed to all these copies like we have here in North America. Being that I have my finger on the pulse in both countries, maybe this will help everyone.

Here’s the original article documenting the intricacies (back then) of certain fake Mugen valve covers that were floating around…

Fakespotting: Mugen Formula Head Cover 12310-XF0-K1S0

I couldn’t have put this piece together without the help of Jay Powers from ATS Garage. Jay is an avid collector and enthusiast who is always on the look-out for rare parts. On his quest to attain these parts, he often comes across A LOT of fakes—some that would actually fool some of the most-experienced car person. Since he has access to his collection to compare and study even the most minute of details, he’s become a bit of an authority on all things Mugen-related. He often shares things that he finds and points out counterfeit parts when he’s searching for parts so I asked him if it would be okay for me to share this particular finding….


The above was a listing for a “Mugen valve cover” that recently went up on Yahoo! Auctions Japan. Despite being shared on social media that it was indeed a counterfeit, it still ultimately sold for 602,000 Yen (which is roughly $4,204 USD). It probably would have sold for more had it not been circulated that it was fake, but $4,000 USD is still a lot for a valve cover that probably cost next to nothing without the logos on it. Mugen collectors are a different breed of collectors so some legit Mugen Formula Head Covers will go for $9,000+. To be fair to the seller, it was listed in the description that it was purchased second-hand. So maybe even the seller did not realize that it was a fake. Who knows? They could have also said that just to protect themselves and hide the fact that it was a known fake.

When you just look at auction listings and aren’t very familiar with the nuances and differences between real and fake, you might get fooled and scammed into buying something that isn’t legit. Hopefully this post will be circulated and will stay on the internet in the future years so it can be used as a resource to protect buyers from being duped.

Once again, huge thank you to Jay Powers for providing all the information. He is doing a hero’s work and has a healthy collection of Mugen parts to compare these fakes to.


At first, the kanji is what they want you to see. The old real/fake comparison is no longer enough to tell with these. The kanji is also off on these too but I’ll show you how and why that is later.

This used to be the obvious tell-tale sign that a Formula Head Cover was fake:


The alignment of the “N” in relation to the bolt hole on the bottom right of the valve cover was a dead giveaway. However, over time, obviously the counterfeiters have caught on to that so they’ve updated their versions. I’ve received a lot of messages saying that the cover posted above had to be real because the “N” was in the right position, but there’s so much more to them now that makes them obvious fakes other than a simple alignment of the logo.


Here is one of the dead giveaways. Let’s start with the facts; Genuine Mugen Formula Head Covers are all inside. The baffle is zinc-coated and there are so many casting flaws that it’s too easy to spot that this one is counterfeit.


The casting tab above the ground tab should be raw metal and not coated.


One of the easier ways to tell if a cover is counterfeit is to look at the cam gear ‘moons’ the side. Genuine covers have much bigger ‘moons’.


Above is an example of what the side of the valve cover should look like and how the cam gear ‘moons’ differ.


Here are a couple more.


Next, the spark plug holes on the fake are too shallow. There should be a lot more depth to the hole before the raised plug body. Also from this angle you can see that that distance from the “M” to the grommet hole is too low. The genuine one would have an “M” that is much closer.


Better angle and side-by-side comparison.


Yet another key identifier is inside the Mugen kanji itself. This is commonly referred to as the ‘three dots’. On the counterfeit, they are much more raised and separated…


On the real one, the dots are more ‘smashed’ down. This is an obvious giveaway whether or not the cover is authentic. Over the years this seems to be one of the more important details that counterfeiters have not been able to get right…


The “G” is another obvious tell whether the valve cover is legit or not. An authentic piece has a much smoother cut in the lettering. The counterfeit “G” doesn’t even look to be the right size and not only is the alignment slightly-off, but the cuts are very harsh and lack the right curves.

Now let’s go back and look at the underside of the counterfeit cover again and point out some key differences…

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1. The casting edges here aren’t sharp like the genuine Mugen cover.

2. There is a missing casting impression tab that should exist here but since it’s not legit, that mark is non-existent.

IMG_6551~photo copy

It’s not an obvious detail unless you know all the nuances of the real Mugen cover. This one is key though.


This is the underside of a authentic cover. Not only will you notice the casting impression by the ground , you’ll also see how the real cover is properly-coated and the baffle is cut slightly differently.

There are also times when some counterfeit copies will have grind marks by the grommet holes. They cut these down so they’re more-rounded and resemble the real cover.


The above photo is from a different cover that was sold a few months back which was also counterfeit but from a different seller.


The inside of this particular fake also shows a possible welding mark where they would have attached the “Mugen” logo. Authentic covers are casted with the logo already and aren’t welded-on after.


The authentic Mugen cover also features a baffle that is zinc-coated with sharp casting edges.

IMG_6516~photo copy

Again, sharp casting edges on the real deal.


Notice the depth of the spark plug hole and how much deeper it is than that fake one.


Here is another angle of the spark plug hole depth and a better look at the distance between the “M” and the grommet opening.

Rocker-Valve-chamber-cover-engine-cover-For-Honda-Civic-B16-B17-B18-VTEC-B18C-GSR-with.jpg_Q90 (2)

Rocker-Valve-chamber-cover-engine-cover-For-Honda-Civic-B16-B17-B18-VTEC-B18C-GSR-with.jpg_Q90 (1)

Now if you’re wondering where all these fake covers are coming from and how people are so easily making them, it’s because companies in China have been manufacturing fakes for years now. They’re very easily accessible from sites like Aliexpress/Alibaba. They even pop-up on Yahoo! Auctions Japan and eBay all the time. All you have to do is strip them and add that “Mugen-style” touch to it. These are cheaply made with cheap metals and come uncoated inside.

Obviously if you don’t care about real or fake parts, then you can choose whichever. I am merely putting this here for reference and for those who don’t want to get scammed when they looked for authentic Mugen Formula Head Covers. Thanks for looking folks and be on the look-out for counterfeit stuff!

Here are a couple more photos of an authentic cover for reference.



Of course there are obvious details to differentiate real from fake but the copies are definitely getting more detailed. We also have to remember that there are a whole new generation of enthusiasts from all over the world who don’t have enough experience to recognize the counterfeits. It’s a shame that there are those out there who are trying to scam enthusiasts and not letting people know they are selling counterfeit parts just to make money.

Again, thanks to Jay Powers for the information. You can follow him on Instagram HERE

Buyer beware, thanks for looking!!!

Categories: Counterfeit ProductsTags: , , , , , , , , , , ,


  1. I’m not sure who bothers me more, the people shilling the fakes or the “enthusiasts” who don’t care and just want the hood pop clout. Thanks for the heads…up. Damn sorry, dad jokes.

  2. Like this post. Learn a lot.

  3. Good writeup of the tell-tale differences. We need these specifics as the scam-market is gearing to capture our hard earned investments. They will circumvent the fakes to us enthusiasts to the best of their abilities. We need to continue to work together as a community to share the knowledge and not get manipulated.

    FB: Sou Saelee
    IG: souswerkz

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