How to Build a Big Power, Reliable Rotary Engine (with Rob Dahm)!

We're back at Rob Dahm's shop again but this time we're picking his brain on how to build a rotary engine that can not only make big power, but do so reliably!
Guess what? We sell parts and MotoIQ merchandise! Now you can buy all the same aftermarket parts we use on our project cars and features from the brands we trust! Buying your aftermarket parts from us is the easiest way you can help help support our channel and make sure we can continue making content like this! Check it out at shopmotoiq.com!
LINKS:
BUY MotoIQ Merchandise: shopmotoiq.com/collections/ap...
SHOP for parts: shopmotoiq.com/
READ MORE on MotoIQ.com: www.motoiq.com/
FOLLOW US on Instagram: / motoiq
LIKE US on Facebook: / motoiq

[@Sl4sk1]

Man i was getting ready for bed

[@zionbarragan4311]

😂

[@ThatV12MiataBruh]

You mean ready for beddy

[@OO-un8ks]

Mute the volume and with auto generated captions and a nice zoomed ratio screen I doze off

[@ardhifarhan4821]

Fr

[@jasonruch3529]

Me 2😢......😊

[@FFalin]

I dont even have a car w/ a rotary but im still gonna watch this vid as if im gonna be tested over this info

[@graemescott1140]

I watch all motohq videos like that aswell haha, I mostly came to let everyone know Rob is obviously on stimulants haha

[@WildDanHibiki]

Same

[@tokirak]

After so many years, Rob finally reveals his apex seals of choice.

[@scotty305]

I immediately wrote that down, in case this video gets lost.

[@noname-sd5dt]

Again though, his choice specific to his application.

[@tokirak]

@@noname-sd5dt for a street car with maybe some light track work, which is what 99% of rotary owners use their cars for nowadays

[@pastaalalamborghini]

29:08 - you know Rob has this clipped and plays it when he wakes up in the morning for inspiration. Imagine getting to a point in your nerd hobby where youre not only making a living from it but realize youre a peer of an engine master and have valuable insight to share

[@DoktorBayerischeMotorenWerke]

Rob Dahm is the guy that posted a video high out of his f'n mind bestowing the vitues of mixing of Adderall and Coke for recreational use

[@scotty305]

@@DoktorBayerischeMotorenWerke I need a link to that video

[@DoktorBayerischeMotorenWerke]

@@scotty305 Are you kidding? KZbin blocked that video a long time ago!

[@jakedougherty6000]

I've been lusting for a FD RX7 for such a long time, now suddenly a bunch of random coincidences make it pop up in normal conversations and day to day, and now THIS video. I think the universe is telling me to go for it 😅

[@noir-kx8ku]

Get an rx8

[@jakedougherty6000]

@@noir-kx8ku I would, but the FD being one of the most beautiful cars ever constructed is part of the selling point for me 🤷

[@HaHaThatIsFunny]

I agree the FD is a beautiful car, but they are so problematic. My friend has had one for 25 years or so, seems like that thing is broken more than it runs... But it's a beautiful sage green color

[@jakedougherty6000]

@@HaHaThatIsFunny I think its one of those cars you really have to be in love with to be a longtime owner. I romantize car ownership just enough to be willing to deal with it

[@HaHaThatIsFunny]

@@jakedougherty6000 just make sure you've got a daily driver and it's your weekend car and you'll probably be very happy

[@burtonjim0254]

Holy shit. I've never seen anyone but Rob match your absolute nerd energy about the specifics of motors! This is fucking awesome!

[@feenyx6394]

I read MotoIQ for many years before I discovered Rob, and I've been waiting for this moment for exactly this reason ^^ The desire to *know* is so strong in Mike and Rob both, as well as wanting to educate others. It's a great match, and I look forward to seeing both builders benefit down the line!

[@DoktorBayerischeMotorenWerke]

Nah, thats just Robs substance abuse problem... dudes a total crackhead.

[@Dewree69]

I just love how quick Rob locks in after every laugh 😂🗿

[@DoktorBayerischeMotorenWerke]

Cocaine is a hellva drug

[@dingus153]

Man, I feel so lucky having watched Rob go from someone who was kinda laughed at for having unreliable 0PSI cars to the absolute mad scientist he is today. Such a glow up!

[@RobDahm]

This means more to me than you know. It’s so weird to look back. Honored it’s gotten to this point

[@martynclinton8092]

So good to watch rob become a engineer - through trial error failure adaption and LISTENING but not believing other engineers! A clear minded thinker!

[@darrylcavanaugh9465]

These 2 are so great together- Humble, SO willing to share their knowledge, and are in it for US. I’m going to their stores, and will proudly wear their merch. Its the least I can do. So much great info shared. My first car was a 73 Rx2, and I put a street ported 12A into it (Side draft DeLorto, Header, 1st gen electronic ign, etc), with a gen 1 Rx7 5 sped, and a GSL limited slip (direct bolt in for the Rx2), and CRUSHED 5.0 Mustangs and Camaro’s of the day, stop light to stop light. You would not believe how many guys pulled up next to me, PISSED, asking ‘what is in that thing?’, and my reply was always ‘1.2 liter’s of fury.’ Not to be obvious, but I wish I had that car today…. SO fun. Today, I could afford to have Rob build me a monster, but, if that car had 300hp, you’d struggle to drive it. More collaborations, between these channel’s, PLEASE.

[@randoawesomemix9501]

Do it. Support Rob and get a customer build!

[@thumbtak]

The crossover event of the century

[@maisteer]

My biggest takeaway: 2-stroke pipes should also work on heavenly ported rotaries with lots of overlap and someone should try it ^_^

[@fuckyougoogleupthearse5725]

My man, I've never thought about that but that makes soooo much sense. Like it is a 2 stroke engine and after riding dirt bikes and denting my pipe and been able to feel the difference in power. Good idea

[@RubTdi]

It actually works pretty well. On our PP 13B we run should primaries around 270mm into a 11* cone into a 4’ diameter resonator. This came from the master himself from Miami Florida. It makes over 300 hp NA at 8500 rpm w gasoline

[@seabid8462]

I've been following robs rotary journey for some time now. We need guys like these two teaching automotive classes in high school man. They're so knowledgeable

[@DoktorBayerischeMotorenWerke]

You have to be drug free to be a teacher

[@mtech1961]

I think Rob is the man for rotaries and he is humble and not scared to share his adventures and tweaks he has found over the years.

[@DoktorBayerischeMotorenWerke]

When his not popping Adderall and sniffin coke!

[@rotaryperfection]

I 100% agree with Rob on the 90psi numbers. That's what I've always gotten with a piston engine tester on ALL my basic rotary rebuilds at 2,700ft above sea level.

[@alejandropadilla3511]

It's 4 am right now on the dot this was my front page. Guess I'll suffer at work tomorrow.

[@bockhouse]

Two of my favorite techie nerdie car guys! Love that they are at Rob's shop as well where it is nothing but a dorito bakery

[@spazzologist]

Rob dahm nerdery for an hour is the best thing on KZbin. Watching him pack a rotor is so satisfying ! Please build one.

[@MR.ROBOT...76]

Dude rotary is my FAVORITE engine. Ik watching today because I didn't know these collab for a talk. I'm all ears for this.

[@joonlee2031]

Prices of rx8s going up on Craigslist as I watch. Great education for potential rotary buyers.

[@timh6977]

Rob Dahm has a wealth of knowledge of Rotaries. He is Awesome at explaining his knowledge!! Tim Australia.

[@mitchelllucier6930]

QUALITY CONTENT STAMP OF APPROVAL

[@InsideOfMyOwnMind]

Rob has enough humility that he will not call himself a rotary guru but damn.

[@mchristr]

The Rotary subculture reminds me of the Flathead Ford cultists. The engine has been tried and found wanting but there are still passionate adherents. It's a strange world.

[@noname-sd5dt]

It is a flawed and inefficient engine that has the mpg of a v8 but power of a v6. It's maintennance schedule includes a complete rebuild. The only thing it offers is a lower centre of mass and output for its physical size. Those that think a rotary engine is an engineering marvel are mislead and misguided. Then there are those that are truly delusional that will try and refine a flawed design and chase perfection, and justify it. But hey, Some people dance Some people sing Some like cats Some collect pokemon. You love what you love. I have an RX8. And i love it.

[@averyingegneri5983]

@@noname-sd5dt what a rollercoaster of a comment.

[@kuholgarage]

No interest in rotary engines but that hour went so fast. Thanks Rob and Mike for the insights!

[@sasukekiller420]

Perfect timing, I’m tearing apart a 13b I just got for my FD. Thank you for all the helpful info.

[@johnrborowski]

Long live SPORT COMPACT CAR!!!! SCC :)

[@banzaibankai2671]

I like the idea suggested about doing thermal coatings on the combustion faces of the rotors, never seen it done before.. that way the rotor and the oil doesn't get so much heat transferred into them.

[@nickwest932]

I had a supercharged 12a fb RX7, and it was quick and fun. 300hp in a first gen was more than enough for smiles per gallon.

[@Knucklehead4400]

THIS IS ONE OF THE VERY BEST ENGINE/ ENGINE THEORY VIDEOS I HAVE EVER SEEN, Thanks gentlemen!

[@mervynmontague1811]

This is easily the most informative and fascinating discourse to date on the rotary engine, by 2 data and technical oriented geniuses. I couldn't stop the video for a second. I learned so much. Thanks 🙏

[@swalox9112]

Please do make a video about injection timing! Pretty sure that's the reason i heard knock a couple times now.

[@bobbyj045]

These two make my love for knowledge even stronger

[@cossavard]

I don't even have a rotary but this vid made me feel like I climbed the mountain and was granted an audience with sages.🙏🏾🙏🏾🙏🏾🙏🏾

[@cctrans29]

Love those rotaries. My friend has a 76 RX3 with a mild bridge port and Racing beat header and exhaust. Nice FC parked in the background. Looks like a Turbo II. Always great videos👍Keep em coming.

[@rocketmail125]

Documenting for the future is amazing.

[@cingkole7893]

I LOVE ROB DAHM!

[@lezzbmm]

this is amazing esp loved the explanation of the overlap/fuel timing/lore abt having to run rotaries too rich etc

[@kowalskitk4]

Many, many, many, many, many thanks for sharing! I do not have rotary, but knowlage is great. cheers guys!

[@irsever]

The word tribology derives from the Greek root τριβ- of the verb τρίβω, tribo, "I rub" in classic Greek, and the suffix -logy from -λογία, -logia "study of", "knowledge of". Peter Jost coined the word in 1966, in the eponymous report which highlighted the cost of friction, wear and corrosion to the UK economy.

[@Sleepy_Otter]

I could listen to both of you nerd out about this stuff for hours, thanks for the video!

[@tonem427]

From Dade county Miami, we in the Chat😂🤣🤙🏾👏🏾👍🏾🇵🇷

[@josesupra]

Love this. So much knowledge between the two of you.

[@howiizitt5460]

I have a Nice day at school today if you ask me thanks Rob 😊

[@holmd90]

The discussion around turbocharging efficiency has me wondering how effectively an F1-style turbo/MGU-H could be effectively integrated into a rotary/hybrid build to recover excess energy from the exhaust once it hits boost

[@benburris4735]

Post rather pre-combustion chamber is what it sounds like.

[@notomatoesbbq]

Man this was amazing.

[@AnthonyGriz]

Awesome video guys! Would be great to see you both do a 13B project build for the average Joe that want's to run a nice and reliable 450 to 500hp rotary!

[@randoawesomemix9501]

"your apex seal has exited the chat" 😂

[@TheExcarlos]

Build one Mike! 🎉🎉

[@Popes_Projects]

Loved this, some great info in there. How does one calculate injection start time for secondary injectors to account for the time it take for the fuel to get down the runner and into the combustion chamber and how that will vary with both rpm and boost. Especially if one can’t trust the O2 sensor

[@G_Ozare]

The Rotary "gatekeepers" are punching the air right now. Let's goooo!!!!

[@CrazyCat229]

I have a fd3s. Sadly bad tuning ended the 2 rotor. One day I hope to get it back on the road.

[@VertigoGTI]

56:20 had me dying!

[@claudedottin1312]

😂 same

[@jesse9638]

Was there a problem with audio on this recording? It’s has a bit of an echo and makes it difficult to listen to which is unfortunate because I’m super interested in this video and excited to see more collaborations in the future!

[@motoiq]

it's the dual lav mics... Rob's mic will pick him up talking and then milliseconds later the sound will go into Mike's mic creating a little echo effect. not the ideal recording setup but we don't normally shoot multi-speaker vids.

[@klean_upguyza6461]

legends

[@BeFree0_0]

The port overlap is very interesting and made me think what rocket anti lag would be like on a rotary

[@motoiq]

Dosent need a rotary is like rocket antilag

[@BeFree0_0]

@@motoiq I guess knowing the overlap percentage you can calculate the fuel requirements and if running ethanol the extra fuel on overlap will help cool the rotor face too

[@brandon_buildsDIY]

Rotary swapped 2nd gen MR-2 using a kseries trans. I think this is the vision for my Mr2 now. Very expensive tho😊

[@omnificent9946]

I wonder, with the overlap between intake and exhaust port would a rotary benefit from a resonance exhaust pipe like a 2-stroke engine? wouldn't that fix some of the 15% loss of port timing and injection period?

[@motoiq]

I thinks so and so does rob, the trouble is fitting it into a car.

[@rocketmail125]

X-ray fluorescent equals awesome

[@dandiegidio7729]

I friend of mine had a 79 rx7 with a non turbo rotary and he would put 2 stroke oil in the fuel and it would rev to 11k.

[@papapetad]

Long story short, Mazda just doubled the price of crate motors 😭Just in time to curb my enthusiasm for a potential engine swap that would be baller...might have to wait a while. sigh...

[@FG-418]

I'm wondering if you could braze in fins within the coolant passages to help increase the thermal transfer from the housings to the coolant.

[@motoiq]

Some people machine fins in the passages on the combustion side as we talked about in the video.

[@scotty305]

KZbin might not allow links, but there's a thread on rx7club named '#1 Rotary Problem Fix' by Barry Bordes. He discusses that Mazda made some sacrifices to the coolant passages near the spark plugs in an effort to improve combustion efficiency, and how the passages can be modified to help address that.

[@motoiq]

You tube allows links.

[@southpark159753]

Sweet videos as always, robs audio is eco'ing a bit and sounds hollow

[@zetawolfgang5106]

WHHHHHHATTTTTTTTT!?!?!?!?!? SO STOKED FOR THIS

[@steverielly]

Definitely have to test thermal coating, and it would be on the rotor itself.

[@StanleyKubick1]

if you're building a track day car and keep it 2200-2500lbs, 350-400hp's should be more than plenty to have some fun

[@SpectreFleet]

Hell yeah.

[@sakochristopher3967]

rotary engine and reliable in the same sentence. Ive got to see this

[@user-pg8ii2qf8q]

I could watch this the whole day

[@G_Ozare]

Same here!

[@spaceonix_5882]

It’s like when Mordecai and Rigby get so smart they operate within the astral plane

[@ThatV12MiataBruh]

05:57 😂😂😂

[@trentdavis9809]

When we getting new video lol😅

[@ThatV12MiataBruh]

@@trentdavis9809 damn dude. Realistically probably in the next month or so

[@jtso7636]

Has Dahm tried WPC treatment? I know Kojima has done a couple of videos on it and rotary drifter Kyle Mohan swears by it.

[@adamrandell7946]

I want to see the housing for the rotor on the shelf...

[@sentree9857]

In the beginning what does Mike mean when he says “you don’t want to hear my opinion” I’m assuming he’s not a huge fan of rotaries?

[@RadDadisRad]

3 rotor mid engine car like a boxster or nsx would be neat for a track car

[@plav032]

Theres a guy in Alberta that has a 3 rotor mid engine kit car, looks almost like a stretched out Cayman, really cool, forget what the car is called tho.

[@RadDadisRad]

@@plav032 I want to build an SLC roadster with a mild 3 rotor in it.

[@grapeape780]

I was gonna mention that to Vtech academy but, I didn't have the heart.

[@fosterengelman7656]

So funny watching Dahm avoid talking in memes

[@Hakiri27]

Ahhhh shooot, what a collab

[@CSIGrissom]

Thank you MotoIQ, Mr. Kojima and Mr. Dahm…the car knowledge you share with us is Priceless.

[@specialK319319]

Does anyone know what the red tool box brand/model is in the background? I've been looking for something with shallow drawers like that forever, and it looks perfect.

[@scotty305]

I think that's Teng Tools, Rob's channel had a sponsored unboxing video about it 2-3 years ago.

[@specialK319319]

@@scotty305 Thanks!

[@jamesdickerson4825]

These 2 guy have the combined knowledge of Thanos, I feel like when they are together their combined power could compare to the infinity gauntlet with all the power stones😂

[@exothermal.sprocket]

Let me walk you through the Donnelly nut spacing and crack system rim-riding rip configuration. Using a field of half-C sprats, and brass-fitted nickel slits, our bracketed caps, and splay-flexed brace columns vent dampers to dampening hatch depths of one half meter from the damper crown to the spurve plinths. That's primarily what supplies the go-force through the triangulated hexagonal viscous hatch ampler.

[@motoiq]

Only if its an automatic transmission.

[@shaidensmillie2218]

Really great video guys, awesome collab!

[@samfiester2953]

Two of my absolute favorite car nerds 😊 just need Richard holdener on the dyno❤- absolutely love learning from these guys

[@RubTdi]

Cool video. I must agree with 99% of the content 👌🏻. Only about the nitriding I must say it aint that hard to properly nitride them and on a PP NA engine for circuit use the side housing wear (and side seals) is actually the only wear when running ceramic tip seals. For putting the dowel between the spark plugs how would one notice the flex there leading to a real issue?

[@fawnn1644]

From what i found online it seems like uneven apex seal wear, chatter, or even total failure but only becomes an issue for turbo charged engines at like 17-20 psi of boost (400-450 hp-ish)

[@RubTdi]

Hmm ok. What always wondered me is that the housing is alu and the side plates are cast iron so lets say from cold to hot there is about 80K temperature delta which will make the alu grow quite a bit more then the cast iron. W the 2 factory dowels the rotor housing can expand rather freely but the more dowels one adds the more restricted it would become. Maybe this is no issue at all. To machine them in the housing I would assume one can just helix mill the holes in the side plates and would use a drill followed by a reamer to make the holes in the rotor housings. Or what is the proven way to do it?

[@fawnn1644]

@@RubTdi Just fyi, I am not an expert. Just did some research because you made me curious but... the rotor housings have a steel liner on the inside that the aluminum is then cast around and there is a constant flow of coolant through the aluminum part of the housing and the outside of the side plates. I think the coolant distributes the heat evenly enough that it doesn't become a big issue. Also most of the heat is concentrated in the combustion section (where the spark plugs are, hence the warping issues) and gets absorbed up by the rotor which is oil cooled on the inside as well as the water jacket. Basically the steel parts take most of the heat so the aluminum doesn't expand that much more than the steel That's my best guess anyway, I could be entirely wrong, and when it comes to machining I have no clue

[@ZEPRATGERNODT]

Great episode

[@RDGarage]

I haven't built a rotary motor yet but now I kinda want to lol

[@MR.ROBOT...76]

Lol that's what I said I started searching eBay for a full motor and trans to go with. I'll build one and put in my B5 lol . Just bc 😅

[@RDGarage]

@@MR.ROBOT...76 LOL keep me posted

[@Edison73100]

2 cool

[@OO-un8ks]

So excited, there's blogs vlogs and step by steps that aren't idiomatically precise and demonstratively relative. More videos similar, to this one because we all love entertainment combined with serious curious precision engineering. Please include the possible alternate applications installments as always thank you very much

[@motoiq]

You need to subscribe to our channel

[@camrongoodall]

Oh shit the 6 rotor crank

[@plav032]

In before for more Rob & Ryan dramas 🤣

[@claudedottin1312]

Ryan?

[@blairdoe6764]

Go get yourself a cheap low compression rx8 now! and then watch some Rad potential. brappy days cheers NZ

[@rocketmail125]

Maybe the pressure was too low for the oil injection?

[@bobwire3310]

Great Info DAN 🤘🤘🤘🤘🎣🎣🎣🎏🎏🎏🎏✨️✨️✨️✨️

[@holdenhartley1837]

Does anyone know who Rob is speaking of at 58:42?

[@bradlywalsh5786]

where would a guy go to purchase a rotary engine or part one together? for experimentation.

[@motoiq]

We get our core engines on ebay a lot of the time.

[@chuxdelux7139]

I love this

[@ioriOki]

We need a live step by step build. I’ll let you guys use my 13BREW 🥰

[@lordpantsington]

What is with the doubled audio?

[@filepz629]

❤️‍🔥

[@covaundermix]

RoB Please you need Ernie Brink in you channels

[@jamesondewitt1076]

I would love for you guys to employ Rob as a consultant, so that we could get the revolutionary Robs built engines with all motor Iq's tricks to each component.