We teardown the IndyCar Engine to expose its Secrets! Cosworth XD Turbo Methanol V8 

Two things to consider. 1) these engines are never cranked "cold". Only with hot oil and water. So it won't spin very well cold as the clearances are intentionally that tight. 2) Careful with the concept of using exhaust cams as intakes. While the lift target may be right, the timing and duration of the lobes from cam to cam may not be correct/ideal. Machining the intake cam ensures the correct behavior, just with less lift.

I was track support during the XD Era, which was the heyday for champcar. The 4 PCI injectors were giving up to 45 % of fuel at max. The turbo inlet was the IGV which was broken into 4 pie shaped pieces driven by mechanical gearing on the outer perimeter, which, when the throttle closed the turbo, was in a vacuum keeping it from slowing. The nineth butterfly was reduction gear driven for control of the boost. It was constantly whipping in modulation. If you look at the shifter linkage at the handle, there should be a sensor there which, when shifting, that switch closed the nineth butterfly and backed ignition to take tension from the Trans to make the shift. Could go on forever but, great to see you diving in.

At 55:00. The timing chains popping lose is because the timing chain tensioners are a hydraulic tensioner and because there is no oil pressure, there is no tension on the chains. So, the valve spring pressure is make the cams move more then it normally should. Hope this helps!

Rob, In the time of the 80s and 90s Indy 500 races, the target MPG to have enough fuel to finish was 1.8 mpg. That was 1.38 gallons burned per lap. Qualifying was not an economy event so running all 900hp burned even more. This is an awesome thing your doing here and long overdue for anyone to do this. I can’t wait for dyno day and to see how much fuel per pull it eats.

MechE/SAE Project team student here rob, the combination of these crazy projects, off the cuff engineering and shop banter make some of the most entertaining content ever man, keep it up!

This is crazy, Indycar engine tear down? Top notch stuff!

I clicked, expecting 20 minutes with short clips of teardown. I did not expect an hour and 6 minutes of a well-edited, in depth, and still comedic teardown. As always, hats off to you Rob. You've got good people around you, keep at it brother, Merry Christmas.

Okay I've been following Rob's projects for almost 2 years now and this is the video I've been waiting for this whole time. Rob and Isaiah's explanations and showing how/what to do but now on a piston engine. And it's full length (obviously not 100% uncut but not shrunk down to nothing). Thanks guys! Merry Christmas 🎉💚❤💪🏽

Awesome teardown! This engine is art in motion, So much engineering goes into INDY for the top cup win, OEM piston engines are nothing like this Cosworth. FYI, To find the correct rotation look at the chains, Chains ALWAYS pull straight, the idler side is always the return. Happy holidays!

The only thing that could top this is a 90's F1 engine teardown. Since that's not Gona happen anytime soon....this is the most fascinating engine teardown series on the internet. Amazing to see this in detail and go on the journey with you. What a series. Amazing!

It’s incredible to see the similarities between this cosworth v8 and the Volkswagen 5.2l v10 out of the r8. The oil pump and the coolant pump are almost identical, same with the oil passages in the camshafts. Same with the timing chain layout. I used to build engines for sheepy race, this is so wild to me

This is legendary! I've seen these cars race at Surfers Paradise Australia for many years & to hear one of these little 2.65L monsters roar to life again will be a very special day for me. Kudos to you guys, BIG TIME!!

Rob, your stuff has to be one of my favorite youtube channels out now, You learn so much and at the same time have a good time. Thank you from us all and merry xmas..

You guys are the furthest thing from half assed RU-vidrs. Even with a million subs, your channel is so underrated. The passion that goes into it is so inspiring man.

I have to say this is currently my favorite series on RU-vid. My dad worked on these when I was a kid, and this brings back so many memories. Some of the stuff you were doing initially that wasn't wrong but you didn't know how to do it, I'm sitting here watching the screen realizing how much I've learned from just being around this stuff as a kid. I just love seeing it now as an adult now that I've had a couple decades of actually learning about engines and race cars.

Probably one of the first hour long videos I couldn't wait to finish on RU-vid. Love all of this, more please!

Great way to start Christmas morning with an 1 hour Rob Dahm video... haha

Petition to call it the RAWR XD V8

Amazing content. When that engine was raced, getting a look inside was all but impossible, to see one opened up like this is fantastic.

It always blows me away that the motor is actually part of the structure of the car. It's is the frame & the power plant. The Hoonagins Honda drift truck build taught me a ton too! Between the these two they are so much more technical than ever though. Thanks for the video great job 👍 👏

Honestly, these are the kind of videos that get the the most excited to sit down, grab a drink and just watch beginning to end. Sure, the tech and methods used on this engine might not be cutting-edge anymore, but seeing and learning about how problems were solved once back in the day really helps to open up avenues of thinking that I would otherwise struggle to get to based entirely on my own thought process and conclusions. Looking at videos like these, I get the chance to remove my bias and potentially learn concepts, design and reasoning for engineering design choices. Thank you Rob. A video like this is priceless for someone like me. All I really want to do is design and build an engine from the ground up, and videos like this one that can teach me portions of the do's and do not's of advanced engine design would've cost me significant amounts of my own money in a college or other classroom setting. Greatly appreciated. On a side note: It's pretty easy to determine the direction of rotation for a RWD/AWD platform engine if it's installed the way this engine is installed. All RWD engines rotate clockwise from the perspective of the snout (front) of the crank due solely to the way a rear differential works. The diff only has one configuration that works to spin rear wheels forward, and therefore rwd engines can only spin one way. This is the primary reason why Honda's B-series engines can't be used in RWD applications. The engine spins counterclockwise from the perspective of the crank snout and thus would spin the rear differential the wrong way after moving through the transmission.

Now this is a Christmas present. An in-depth into some engine anatomy. Love it

You guys' excitement is contagious! Despite having endless problems with my project car, I can sit down, have a laugh, and learn something when I watch you guys.

If i had to complain, itd be over the fact that i just want more more more! Amazing content. Could literally watch all day like a fly on the wall. Wish i could be like an intern to someone such as yourself. Keep up the great work. You are learning and teaching at the same time

Hey Rob if you read this, im almost willing to bet that the oil/air separator in the valley of the engine. The reason of the oil going in through center then out the side instead of reverse order is to allow the oil a chance to reform and not be Frothy which will be helpful with the Methanol situation

I have so much respect for the insanely talented and knowledgeable engineers at Cosworth. Thanks Rob for sharing this experience with us.

Very nice to see this teardown done slowly and explained by people that haven't done it before. so thanks for including all of us!

Just a gorgeous mechanical work of art. Thank you for taking time to look carefully at each part and explaining the basic engineering behind the design of the motor.

>Rotary cavemen discover pistons for the first time

It’s so cute seeing how proud Isaiah is about his welding capabilities 😂

Question about finding torque settings. When torquing a bolt to specific torque setting, you're overcoming the friction between the male and female threads. As soon as the rotating action is done, when your torque wrench says "Enough", your kinetic friction coefficient turns into a static friction coefficient. When you then apply pressure with your torque wrench again to get the number, it will read higher since you now also have to overcome the bond between the two surfaces (which can be quite a bit of surface - thread and block/bolthead mating surfaces combined). This especially in Robs motors case, when it's been sitting for long time giving the surfaces plenty of time to get really intimate. Watching a teardown like this is absolutely awesome.

The pure amount of thinking these guys manage to capture in a video is unlike anything ive ever seen, i feel like im actually watching the thought process rather than just watching someone cut to when then know whats going on, its really awesome to watch!

You are a true car youtuber my guy. You don't got the extra hype except for the added enunciation lol, you are informative, and learn with us. I appreciate your effort man. Merry Chrysler!

The 4 rotor is amazing, but these videos are my favorite content. Cool to see you hunt out the parts and share the engineering that went into one of the premier racing series

Watched the first half last night. Watching the second half first thing Christmas morning. Your videos bring joy to my life dude! I appreciate what you guys do! Thank you!

Hey Rob you hiring good buddy... this is like the dream shop and group of guys to build with! Love the videos helps keep spirits high in my builds when I see others struggle with some similar issues.

My best Christmas gift was a Rob Dahm video

It's strange seeing Isaiah just observing and learning instead of explaining what's going on. Thanks for another amazing video, merry christmas!

First time watching this RU-vid channel (RU-vid recommended) like a lot, it's how I learned mechanics etc, parents always said give me a toy/present/electronic device, first thing I would do is take it apart to see how it works 😃. Stripped many engines/gearboxes/anything really, learning along the way (nothing compared to this) and now run a small repair workshop still learning along the way 😀. Good job proving you don't have to know everything before commencing any works required 👍

This engine was made before pacalloy valve springs were a thing. That’s the alloy that revolutionized nascar engines in the late 90s. I bet some custom pacalloy valve springs would get better life than the original ones, and probably cheaper.

I followed rob since i first saw him on tv lol but ever since that man its been so incredible seeing what he has done and how much passion he puts on what he does its so inspiring

AN HOUR LONG VIDEO BEST PRESENT EVER 🎄🎊🎊 MERRY CHRISTMAS

0:30 regular muffler rotation is key👌🏽

Watching you take that race car apart makes me unbelievably jealous. I can see you’re having the time of your life and I would be too. Holy shit. So cool 😲

Merry Xmas Rob! I'm so stoked to see the car running soon :D

I’ve been watching you for years Rob, from the sidelines at least, like when you were first figuring out how to build a 4 rotor, all the heartache of the parts, the BS of hunting them down, people screwing you over. Fascinating journey and this is a really interesting video, congrats on following your dreams

Appreciate the longer video and how in depth it is! Love learning how everything works along with you! Can't wait to hear that beast!

Love the deep dive into all the tech within an engine like this! Aren’t you rotating it backwards though? That might explain the chain skipping/crunching noises. Often chains and tensioners aren’t happy having that done to them.

I'm going to bet there is a torque order as well as inch pound torque rating on those underside bolts. Reminds me of aircraft bomb rack torque specs.

That snap over on the rotation is the mega valve springs. That slop in the chain will go away when it is all hot. :D Merry Christmas. Thanks for another year of badass videos. Love from New Zealand.

This is by far the best "Rob Dahm" video ever. Thanks for sharing.

The pop-off valve took time to reset, so you didn't want to blow it off during a race. Despite being issued by Indy Car they had minor variations, so as part of a tuning stage on race day they would deliberately blow the valve to find out how much boost that specific one would allow. If it's the one I was told about it is actually two stage, and the plenum pressure sensor could spot when the first stage started to move. Knowing what they could do the boost controller would be adjusted up almost to that limit.

Hey Rob. Love your builds as always man, this video was super enjoyable. I noticed around the 33 minute mark, you had to modify a wrench to fit into that gap. Years ago, I bought a Snap-On wrench set (part number OXIM707SBK), it is used extremely rarely in my world of automotive, but when I need it, they work fantastic. I figured I'd spread the word for you. They are literally no bigger than my pinky but are great for extreme tolerance situations.

You are the gearhead friend I wish I had. I've come a long way teaching myself this stuff, but you are just on a different level. Super stoked to see how that 12 rotor build goes and I'm happy I subbed. This is quality content!

I loved all your longer content before, but this hit just in my alley. I might have to start working on my spare Miata 1.6 block sooner than I expected, thank you for the motivation

You guys should definitely put Joel in a hood and let him watch you pull a puddle and I bet he would get it super fast just to show how easy it is and that anyone can do this stuff if they put their mind to it

Hey Rob, remember, static friction between two objects is always more than kinetic friction, so measuring the torque specs on those bolts the way you did it might result in overtorquing.

Absolutely loving this series of videos! Can’t get enough. I’m glad it’s you putting it back together though. It’s like a mechanical Rubik’s cube.

Rob, love your channel. I am a licensed A&P. From my perspective, a lot of the way the engine is engineered to aviation standards. With that said I would recommend replacing any dynamic bolts due to torque stretch. Also recommend looking into initial torques followed up with an digital angle torque, so that all of your torques are evenly distributed. Something to look into. Again love your channel.

Very good vid. A DFV used in vintage F-1 was under my watch for quite a while ~20 years ago; fascinating to see the differences and I'm envious of your ability to record vids of the process; stills do not provide the same info. Cosworth held to front-face cam timing for quite a while after Illmore showed better timing off the rear of the crank. Looking forward to seeing the chambers, and the piston domes; I got greedy once and found it very expensive to build a 13:1C/R DFV on race gas. Also looking forward to assembly; setting the valve clearances and then timing the cams was pretty much a two-day job to get them done properly Thanks. 13:30 - Didn't see the fastenings. On a DFV there were 4 #10-32 screws around each port and none had clearance such that they could be turned more than 120* per each wrench engagement 15:35 - DFV had a roots 'blower' to exhaust the oil from the sump and then, in line, a centrifugal pump to separate the liquid from the 'air'. The oil came off the periphery, the 'air' from the center 16:53 - Was called 'pickling" the system. You did NOT want methanol left anywhere near Mg. 18:21 - DFV had an offset bolt, and there was a batch of flywheels which got drilled such that they could only be installed friction-face-to-the-engine! 19:53 - There were only a couple of parts which were 'lifed' on a DFV, notably the quill from the timing gear train to the injector/alternator/distributor; it flexed in operation. 20:13 - Evidence of a lot of top-end fiddling and little total disassembly. 21:18 - There were 8 exhaust gaskets on the DFV - all else was O-ringed. 21:28 - That's how the injector base bolts were configured, except they were cap-screws. If you see an allen key, very short short--end with a bend on the long-end close by, you're looking at a DFV tool. And if the person R&Rd those screws on a regular basis, there will be some sort of a tether to recover it from what you saw at 20:13 26:07 - Outfit called "Analysts, Inc." did ours, after every meet. 31:12 - "Quill Shaft". 33:06 - DFV had those, but arranged differently. Kept the pebbles out of the oil exhaust pump. 33:27 - You'll get used to what needs to go in a bucket. 34:20 - Smaller, but similar to the DFV, but it was fitted on the lower left, just after the pressure pump. 34:54 - Pretty sure it's the other 'way round; every filter I've seen takes the pressure on the OD and exhausts out the center. 37:08 - DFV had a 'gerotor' pump, per Ford practice; seems most newer street engines do also, 39:50 - No chains on the DFV, all gears. 39:53 - IF IT WERE ME, I'd mark the crank right now with respect to the case. Your vid has record of that cam timing indicator with the crank where it is, and that's worth keeping. Chains each have a pin painted red (I used nail-polish), cam gears are marked per location, two red stripes on the circlip'd bosses, bolts off-center on two idlers; heads black-striped, 41:07 - On the DFV, that was a 3-pc compound idler, fitted with 6 (?) little torsion bars driving the fore and aft gears from the center gear; it was fitted to reduce the spike loads to the gears further up the train. The original design had a solid part, and the cam gears were not at all reliable until Chapman came up with that gem. You might find some mutated version there. 42:25 - The chamber is what makes rotaries non-functional; it's two continuous 90* sharp internal corners, and the flame front will not propagate into that geometry. 45:46 -- Many red marks inside the cam box, near the lobes; 'this clearance set' notation? 49:16 - Plugs out? (nope; 54:30) 49:49 - The same claim was made regarding the DFV valve springs but Young's Modulus shows that all crystalline materials must cross the elastic/plastic threshold to fail in that mode. (I still turned it over). 50:56 - Way more to a cam than the max lift; get the curve/specs before swapping. 55:36 - Backward rotation releases the tension on the chain; be very careful now; you've got an intake and exhaust out of phase with each other. 59:14 - Pretty sure Cosworth will provide torque specs. 1:02:22 - The DFV used vertical "colletts" to locate the two main caps not part of the sump; you had to know to loosen the cap-screw and tap on them to allow removal. 1:02:52 - Standard V8 practice, single-plane crank or otherwise. 1:04:21 - That was fitted to the top of the center main (part of the sump), held in place with a coating of grease. Turn off any audio, make sure there is no testing on the track; if it falls during assembly, you want to hear the "tink"; finding it loose later means an extra *lot* of hours. 1:05:07 - Looks like it ran hot in the last race.

the clicking sound when you turned over the engine was the chain jumping teeth on the cam gears, it should only be turned clockwise

It isn’t often I sit through a RU-vid video this long but goddamn if this wasn’t an absolute pleasure to watch start to finish. Fascinating and so impressive seeing what this thing is all about. Just goes to show just how many levels above racing engines are compared to street cars. Like a Swiss automatic watch compared to a Casio. Spectacular series.

Great video and its amazing of such a technology engine. I have worked on many and I would have to not have any distraction. I'm very impressed with your group of people helping you.

You are meant to preheat the oil so the block expands before your turn the engine over

Watching Rob discover rotational forces applied to the timing chain because of the spring force on the cam lobes for the first time is like watching the birth of an animal thats on the top of the food chain lol

What’s amazing is the brilliant minds and research that went into building such a perfect system. Incredible motor great content

This is an awesome video. Seeing you tear this down makes me wonder how you are going to reproduce or obtain all of the special gaskets, o-rings, etc. Keep up the good work.

An hour-long video, it's a Christmas miracle

His never taken a piston engine apart🤯

I'm glad I stumbled across this channel. Much love from an Aussie dude. My understanding is the Cosworth Indy engine was a direct transition from the Cosworth DFV F1 engine. It would be interesting to compare the original 1968 DFV valve train to see how much changed over the years between 1968 and 1997.

Such a long video…. And I happily watched every second 😁 Thanks for a great upload Rob. Merry Christmas!

In my opinion, those bottom end bolts worryingly torque critical, would have been better measured by position marking, loosen, then increase torque turning until they end up in same original position. Then you do not have to overcome the “stickation of the bolt head against surface. Really enjoying the vid, most interesting seeing inside and much details. Nice one

Thank you for giving us the best Christmas present ever, Rob. This is what we call car porn, and it was the best ever. Thank you for bringing us the best content on RU-vid. I can’t wait to see what the new year will bring. Whatever it is, we will be here for all of it. I hope you, your family, and your team have the best holiday. Stay safe, and we’ll see you on the next episode.

Beautiful! I really would like to see this this engine reassembled and running. Such a great learning experience for a person schooled in rotary powerplant technology. PS don't turn it over ccw or cold. Thanks for sharing, J.

Been waiting for this one!! So cool

A gift from the heavens!

41:06 That “central piece” is what drives the camshafts and produces the camshaft speed reduction. That “central piece” has 3 gears stacked together. The larger center gear is driven by the crankshaft. The 2 smaller gears (the outer one we can see, and the inner one which we cannot see) drive the camshafts. The outer gear drives the left side camshafts (from our perspective) and the inner gear drives the right side camshafts.

You can also determine the correct rotation direction based on the timing chain layout, noting that the drive gear should pull the chain directly from the cam gears, not against the timing chain idler bearing.

This is so fascinating! I heard somewhere that F1 engines are built to such high tolerances that when cold they are virtually seized and need to be pre heated before starting or they wont move?

I pulled an engine down before Rob Dahm, the difference is that he expects to be able put it back together.

Truly some of the best content on RU-vid… keep it up rob!

I'm from the UK so don't get to see v engine often , when took the cover off I was like ohh it looks like a coyote

I think oil pressure tensions the chains and is he turning the engine the correct way?

"It isn't a structural piece, it's just going to hold up the car" --Rob Dahm

You know watching this makes me appreciate haw insane super bike engines are. Great video can’t wait to see more!

Love the series. Learning a lot about how the 90's Indy cars were put together.

Rob, I could be completely wrong as I have never worked on an Indy car engine, or even seen one in person, but on most if not all piston motors, v8’s and v6’s, their is normally an even and odd bank or side of the motor. I just want to put that out their as it would change your firing order that you have determined for the motor.

Jeeze the oil inside that beauty is minging. What an amazing machine, to think that a human being has designed every single part of that engine, I’m just in awe.

This is very close to the Cosworth HB V8 2.65lt (1/3?) from the late '80s to mid '90s, which I worked on, It's basically the same engine that Michael Schumacher won the F1 world championship in 95, it's the Ford Cosworth design 90* XB or XD I don't think it's an XF?

Pulling this apart was really fun. Rebuilding it is going to be a complete other level. In terms of time and expertise. Good luck to you but man, what a project!

Rob & Joel yes! I'm sure those dowels on the mains are for preventive cap walk and maybe a torque stop?... although the whole pan is a structural girdle, main cap and dry sump all in one. As a sbc/ ls builder I am amazed at the tech in a 30 yo Cozi. Wrapping me brain around the complexity is more than food for thought. Thank guys for showing us this...made my day!!

I'm surprised you haven't been sent a cease and desist letter yet.

Ironically the one car Rob’s done that would most benefit from a rotary swap.

Hello and greetings from central Ohio. I live close to Mid-Ohio Sports car course, and have had the pleasure of watching crews work on indy/ champ cars for many years. Thank you for sharing your content.

Me watching ads on this video '... They've earned this.' Best car channel on yt

There has to be some modern valve springs available or even a company 20+ years later that has a solution spring wise. Surely technology has advanced enough to allow a solution that provides considerably longer service intervals at a decent price point. Retro fit some sportbike valve springs in it lol

😬you're rotating the engine the wrong way causing less chain tension and the cam is skipping teeth, the engine will need to be retimed now, chains already looked kinda loose though time for a new set

When rob says ls cam shafts are in the head and oil sprays to them 😂 love it. There’s only one, it’s dead smack in the middle of the block, and it has supply oil to each bearing.

That engine is one bad unit! Loved seeing it. Thank you for taking the time to show us

I can't imagine what this is doing for the 4 rotor build