It still boggles my mind how that guy machined all of this. That thing is a work of art.

This is my guess why he gave you the engine. He wanted someone who knew rotaries and could continue to develop it. Good on you for taking it on.

not that this isn't already ridiculous, but can't wait to see this pushing something

I feel like watching Rob dahm is another level of content creation. His videos are so indepth, and I feel like I learn a lot about not only rotaries but also mechanics in general. I love this content, man.

Kinda neat seeing the generational knowledge being handed down. Saves a lot of time in iterating through failure 😊

the fact this dude made this engine back in 2008 is WILD - don't think many people realize how much of a feat that was. And on top of that how much he got right with minimal mistakes. Obviously as time goes by things get better technology advancements etc. This thing is going to be insane.

It's so cool getting a proper video showing the inner workings of this mythical motor and I'm super excited to see it go together and hopefully fire up soon enough. There are so many weird myths and claims about this thing, just yesterday I saw someone claim this exact engine had been dynoed at over 5000hp with turbos, which is funny because it has never had turbos mounted to it.

I love how Rob isn't stressing about the complexity and instead he's exited by it. Best of luck with assembly!

Even if it's not perfect, this engine is legendary, can't wait to see it run, also taking everything learned from this engine and the 4 rotor, how about a fully inhouse build twin turbo 8 rotor 🤔

Definitely can confirm. My GTU FC lasted over 300K with minor repair. I really miss that car.

The fact that you aren't afraid to go into full detail in your videos at the expense of a little extra time is perfectly suited for the rotary community. Your videos have peeled back the veil on what many people (myself included) thought to be a complex/mysterious engine... only to reveal how simple and powerful they can be. You are the inspiration that will keep the rotary scene alive for years to come

2008? Damn, that engine was designed & make 15 years ago? It's genuinely impressive considering there were limitations on some knowledge & machine. I honestly want to see Rob Dahm make a 3-bank 3-rotor (3x1) version of this engine himself, a revision 2 of this 12 rotors engine but corrected everything that is wrong.

this was basically a engineering course in college. But the professor can ACTUALLY EXPLAIN THE MATERIAL IN A WAY THAT MAKES SENSE. I love this channel

This is absolutely fascinating, and I love that you're pointing out a whole lot of things that I wouldn't have thought about. Not too many people understand engines that well, let alone rotary engines, let alone custom-built 12-rotor rotary engines. Great video!

Shout out to the owner of this wonderful engine for bringing it to a platform where we all can enjoy and learn about it. 👍

I love how you come across so humble and you give others credit where it’s due. Keep it up Rob

The only thing that confused me was when Rob was talking about the engine being out of time with the timing gears. Wouldn't he just machine the splines on the inside of the gear to be 3 degrees offset to the outer teeth to eliminate the issue? assuming all 3 sets of rotors are only connected by those gears? Just a thought. This thing is so fascinating I can't get enough of it, what a machine.

Rob it's impressive what you have learned (From a fellow IT guy) who loves Engines. The fact that you do not hide anything is also respected.

time each bank as a traditional 4 Rotor, then set one bank to 0 degrees, the next 30 degrees out form the first, and the third an additional 30 degrees. every rotor should fire independently and a combustion should occur every 10 degrees of crankshaft rotation. the sound would be absolutely legendary.

When I first saw the 12 rotor a while back, my wish was to see Rob get his hands on it. Holy shit I can't wait to see the learning journey building this and what he's gonna do with it.

should talk to your local industrial bearing supplier R.E the end bearings - there are angular contact ball bearings that can handle relatively high (for a ball type) axial loads, and are normally same overall dimensions as standard ball bearings, and (usually) have a higher ball count due to their construction

Rob has us wrapped around his finger with the 12 rotor content, lol

I think ol dude knew it needed some finicky little touches and you were the perfect finicky little dude to make it happen. No one else on earth would or could enjoy this engine as much as you are enjoying it right now, you definitely deserve to have it.

I can't believe the guy designed this with so few problems first go. Massive engine knowledge and creativity...Genious level stuff really. Clearly it's not going to run a long time as it is presently built but with some design adjustments it looks capable of being a solid functional block. The value of taking it apart, seeing his design and how it started failing is off the charts. In a marine application this engine has serious potential as well.

This video is badass, Robs shirt is badass, and this engine is badass. Excited for more of this

Just a quick comment on the teeth timing issue. The problem as you describe it only exists when the gears are identical and on a radial angle divisible by the tooth pitch this issue could already be solved by the gears position relative to each other but could equally still exist. I hope I explained that well enough! :-)

All of this tells is that you aren’t going to quit until all 12 are singing together and insane a Mazda box good luck hopefully in 3 years this beast be on the track.🤟🏼

The machining on this motor is so insane for back in 2008. People in 2023 still can't do this style of work. Amazing work man. Stoked to see the rob touches on it

I’m glad you got ahold of this thing….also I’m sorry for all the sleepless nights ahead of you. Thanks for the infotainment guys :)

That motor in the Continental would be nuts.

This is one of the few blogs that genuinely makes me feel as if I’ve gained knowledge as well as being entertained

You need to flip one of the drive gears over to get all 3 banks timed perfectly. If each gear is off by 1.5 degrees, say clockwise, then flipping one gear over would make it 1.5 degrees off counterclockwise. A drivve gear mounted backwards would cancel out the timing offset.

Its definitely mind blowing seeing this 1 of a kind piece of engineering. The old man who built this is a genius he gets an idea for a motor that he wants to put in a boat of all things and completely re-engineered a rotary engine. Then the 12 rotor rotary engine was born. Now thats how you follow through on an idea 😂😂

This motor must have torque up the butt.... since it's firing 2 rotors at a time!! This is going to be a neat build indeed, thanks Rob and crew!!

To solve the 3* timing offset in the gearing, would it be beneficial to have another custom gear made with the inner spline for the shaft to account for the 3* offset? seems like you might be tinkering with that idea already from the marks you made on the inner spline circumference. anyways pls throw this 12 rotor in that boat of a Lincoln lol!

Love that you show and explain all of the technical things on your channel. It's car nerd heaven.

I'm loving this, it's great to see your accrued knowledge coming into play here Rob, you've come so far since I began following you and it's really great to see how far you have come. You're like THE rotary guy now!

I’ve never been a big rotary fan but you talking about the physics and the way this whole system interacts has got my engine/physics geek brain going for wanting more of this build this is going to be epic!

Hey rob, love to see how far youve came. Youve inspired me to get my build going as well as start a youtube channel myself(have yet to start it but getting footage) thank you for being you man! Keep inspiring others.

6:36 Otherwise called Positive Crankcase Vacuum ports, on any other engine. Typically has lines run to it with a PCV valve that regulates the direction the air flows and helps to prevent oil from going places it shouldn't (like the intake plenum or right behind the throttle body on most cars along with the EGR stuff.... )

I'm wondering if those stationary gear bolts could be extended to thread into the center the side plates and keep them from bulging. Not sure if they would need to be blind holes or if through holes would work and not damage any of the side seals of the rotor.

A 24 rotor powered boat would be incredible. Even if each rotor only managed 110hp the boat would make as much as 6 mercury 450Rs with probably 1/3 the weight.

Can’t wait. Learning about rotary engines has been cool but learning about a 12 rotor engine is a once in a life time experience

You're right in that the first thing I thought when I heard about this engine was, "How do you remove all that heat?". And, since I want to see this thing powering a classic Chevy muscle car, I'm still asking that question.

Regarding the timing of the shafts. This could be changed with the position of a 'key' in the sproket, or even by rotating the cavity slightly in the block. If the key is not aligned centrally with a tooth (or valley) then see/check if the sprocket can be flipped over.

I know that Piston engine guys normally do cold treatments on parts to prevent breaks warps and stuff like that im curious if Doing that to parts in there would help

This whole clip is a show-off of what a genius and a master Rob Dahm is.

Rob, I know you have dial indicator. Not trying to tell you to do anything, but I would mount a mag-base. Then you can see how much spring you get back. Seriously brother. I cant wait to see this motor run. If there is anyone that can do this, it has to be you. Great job explaining everything. To be as 100% technically correct, and bring it to layman's terms. GOOD LUCK!!!

Love that you got this engine and you are bringing it back to life! Tech for days....keep it coming!

This is fairly crazy, and knowing Rob is crazy enough to take in this challenge only enhances the craziness.

Been watching you for a while now and your recent content made it to the new heights. You are really number 1 youtuber on my list now. And the fact you have so much experience... Thank you Rob.

Rob is the saviour of all rotaries, can't imagine him doing all this several years ago but I'm happy Rob chooses this path, cause honestly no rotary shops are ever gonna give this level of details to their customers, let alone on KZfaq. Just keep doing you Rob and share what else you know on the engine, looking forward to the firing up on the 12 rotor!!! ❤

The Eunos Cosmo was supposed to come with a V12 for the American market, however this 12 Rotor would be amazing inside a JC cosmo chasis, maybe a cool widebody too. The long hood/engine bay is perfect

Cool commentary Rob. Very interesting issues that have to be solved.

This is something I really want to see and I’m so glad someone is working on the problem, and such a well equipped group of people at that. Thank you

Passion for your craft is what keeps me coming back to watch everything you do, keep at it and don't stop!

19:21 a potential solution would be to either have bolts, bolting it down to the aluminium all the way around the inner lip, machined flat with the item installed and sunk from the face by a fraction of a mm. The rotor shouldn't care. OR an intermediate plate that sits on the inside of the aluminium, is bolted and has a machined thread that accepts a ring, which itself is threaded and meant to suck the plate in.

how anyone could say that all that man's insane engineering and mill work was fake, is just bonkers...

I just gotta say, this is the most excited I e ever been for a KZfaq project, not just for cars, but for pretty much anything, super stoked for how this behemoth performs after all the TLC is taken care of

Good luck guys, hope your patience and dedication paies off in the end !!! First start first sound, fear off blowing somethin'!!! This is exiting !!! Good luck guys !!!

It needs to go into the Lincoln. Even if only for show.

I still cannot get over the fact that this was cnc machined in 2008 and with such precision and complexity

I've been waiting for more 12 rotor! THANKS ROB

Im speechless… this channel is literal rotary heaven

Hi rob just love your enthusiasm for rotary engines I love them and have learnt a lot from watching your videos thank you and keep them coming can’t wait to hear and see that 12 rotor running all the best from the UK

Man I'd bet the guys at haltech are crazy enough to want to help with some bonkers custom solution to this. If I were an engineer there I would definitely be trying to get someone to let me work on some monster frankenstein ECU for this thing.

AAAAAHHHHH ITS FINALLY HERE!!! been waiting for this upload ever since the first video was out!

That’s a beautiful engine. Thank you Rob for such a great description of what needs to be done. Impressive!

that's dope. I admire your informational retention and ability to break down the inner workings and mentally comprehend it, and analyze not only you're own understanding of it, but also where it could be improved upon based off the issues that have shown.

Absolute madness. So excited for future videos on this!

If you can figure out all the challenges, my vote is to put in a old Rolls Royce like a silver shadow and drive around like an actual turn of the century supervillain. Love the content!

I don’t comment much but I couldn’t resist tonight. This will be an epic experience!!! I can’t wait to hear this fire and run!!!! Thank you for all your incredible videos. This is Gas Pump Rob also in Southern California - Rotary enthusiast and old gas and oil collector.

How are you able to explain something so complex.... and I actually understand! You continue to impress. I can't wait to see what becomes of this !

At 13:25 A lot is being made of the 3 degrees timing misalignment of those gears, but the gear to shaft interface is splined. You can tell the spline count from the shot in the video, but I'd reckon that it is 120~ spline so that you can clock the splines to account for the 3 degrees and also play with shaft phasing.

You’re such a humble man and I really appreciate that about you. A lot of us could learn.

I'm beyond excited for this series

Massive props keep up the project. I feel like you've got an engineering powerhouse building up across many domains, and I like it.

I'm excited to see this thing run. I remember seeing videos of it when KZfaq was just starting out.

Rob, I love the way you think, and how you cut apart every single possible problem with that engine. Impressive is what it is.

I've been waiting weeks for this update ! :D

Loving the 12 rotor content. Would be cool to see this engine powering a car, like my benz for example 🤣. Keep em coming rob!

Just wanna thank Rob and his team for everything they're doing for the rotary community and for sharing the knowledge you posses with us all.

You are BRILLIANT! Your tecnichal expertise is second to none.

I can't beleive this is really happening. Thank you so much for taking this on, Rob.

I can't wait to see you fix and put this beast together so glad you are a smart guy

What a work of art, can’t wait to see how it runs and what application you plan to use it with

Rob - with the gearing that drives all 3 rows of rotors. Set the centre gear to zero degrees and also the set the gear which is driven by the idler gear to zero degree. With the gear which is half a tooth out (or 3 degree as you say) modify the inside of the Original gear so it sits on the inside of a stub which has a bolt pattern joining both parts together and that is also slotted (a little like slotting cam sprockets). This will allow you to index your rotor shaft to zero deg and help you hide the 3 deg timing run out you have found in the gearing. Hope the above makes sense and may be of some use to you. Very informative videos and love to watch them 😎👍. Dave.

It's so incredibly cool to get such an in-depth look at this truly mythical engine, thank you Rob!

Man I have been watching you for years. It is so awesome to see how much of an engineer you have become.

I have been waiting for the update on this engine, I find it extremely interesting, it’s a work of art

This is very cool. Can't imagine what sort of power that would be capable of in a marine application if you get her running correctly.

It's pretty mind blowing just earlier this year I was watching videos on that 12 rotor and now Rob freakin dahm has it.. unreal dude psh

An interesting way to look at the way that eshaft is setup would be much like batteries, 2x2 rotors in parallel with 2 in series, or 4 rotors in series like the 4 rotor.

Fantastic job Mr dahm! Really enjoyed this one 👌

I've been waiting for so long for this video series.

THIS is what we expect from you guys. Just WOW!!!!

This is going to produce a new sound that will be magnificent! I appreciate the engine creator for handing his dream to someone that can keep it alive!

I can't wait to hear that 12 rotor fired up Rob, dope 👊

For the oil draining issue for the center rotor, could you have a timed valve that would alternate and let each side alternate vacuum to pull the oil? The valve could even be incorporated into the bronze air screens on the top of the left and right rotors. Love your videos.

I have waited so patiently for 12 rotor content!!!!🎉🎉🎉