Teardown Autopsy -- How Did Our Record Setting Turbo Jeep Hold Up After Being Pushed Past 1K HP?

[@jeffholmes2861]

Im just floored. As I was young growing up an tinkering with car engines, Ive seen too many of the straight 6 engines an never thought once that any of these mildly modded could reach a 1K HP. Great job. Im very impressed. Keep up ur R+D I promise it WILL pay off

[@teddyjones8027]

I am not a Jeep guy but that Jeep 6 cylinder build is straight up ridiculously bad azz sick and I'm lovin it !!!! Nothing but Mad Respect for those guys they are killing it. Thank you for sharing, love the channel and can't wait to see what's next. Everyone keep yourselves and love ones safe and healthy and remember to SMILE 😊God Bless 🙏

[@TheHorsepowerMonster]

Thanks for the kind words, and thanks for watching!

[@Justin-bz1dp]

​@@TheHorsepowerMonsteris they foor sell

[@BucksSuperStereoWorld]

Damn man! 1,080 horsepower out of a 4.0L inline six...That's a HELL of a feat! Imagine this thing in a XJ...

[@MrRickChase]

Or any smallbody amc. A gremlin ripping down the 1/4 in 1k of inline 6 power... if xj's are pushing 9's at 700, i can't imagine what xj's or otherwise would do with an extra 300. Probably coming up on the aero limitations of the brick, though 😂😂... although... i have an idea for that.

[@mpetersen6]

​@@MrRickChase Remember when GM spent a bunch of money on a Syclone out at Bonneville. The next year or maybe two one of the Jeep powertrain engineers took a Comanche out there and blew the records the Syclone set out the window. And he did it pretty much on his own dime. The KZbin channel AMXJ has a series of interviews with a former AMC/Jeep power train engineer. He was involved in a 4.0 powered dragster that was spinning 9K through the traps. There is a lot of hidden potential here. I doubt this would last very long in repeated pulls or being held on peak rpm. I do know that factory dyno runs with the stock motor could run days at the red line.

[@MrRickChase]

@@mpetersen6 oh definitely not. I've listened to a bit of amxj's interviews. It's nice for the history lesson and can't imagine what it'd look like on the wallet but it'd be REAL nice to see some of this stuff implemented. There's a lot of stuff out there. Newcomer is making the potential of the 4.0 mainstream, but actc in Argentina where i6's are their racing wet dream, indy cars from the 60's with nearly 100psi of boost running thru them, bonnevile, xtreme performance (mexico) akaxauto, it's all coming to light and I wish I had funds and time to invest in it all because I love seeing the limits of untapped potential.

[@Freedomishere-im6ug]

4.0 block 4.6 stroker

[@mpetersen6]

@@Freedomishere-im6ug I was wondering about that. I didn't hear it mentioned. Too many interruptions, honey can you take the dogs out etc. The fully counterweights crank sounds like it can be a combination of 258 throws with the full counterweights from the earlier 199, 232s. Is the crank cast iron or cast alloy steel. Say cast 4140 or 4130. It says a lot about the cast iron alloy used in these blocks in that they did not blow the fasteners out of the tapped holes on the mains or the head. Likely a high nickel content.

[@Soleimpala77754]

This is hands down my favorite youtube channel

[@TheHorsepowerMonster]

Awesome! Thanks!

[@yepitsme431]

over 100 dyno pulls, N/A, and turbo breaking records along the way and this engine looks amazing on the internals.. The jeep 4.0 is truly legendary!!

[@codered7453]

Excellent follow-up. I'm really glad everything held together and it makes me proud to drive a 4.0 ZJ. Congratulations again to Newcomer and many thanks for letting us all watch 2 NC Boys talk about motors.

[@andyclemente4205]

That's just beautiful. Shows one more time that jeeps 4.0 is a beast and not only it has torque but it can be a great platform for horsepower

[@bentboybbz]

I would love to see keith test intakes stock then modify them to try and fix the lean issues with the middle cylinders etc. I love to see engines run hard, testing new combos, high horsepower, low horsepower too, and then see the teardown and inspection afterwards. Thank you for your time and effort!

[@iceman45ification1]

Wow! I'm very impressed at how well the internals were. The bushings all looked brand new. With the exception of the head gasket issue, that thing is a dream. Makes me want to go out and buy an old Dodge truck and stuff a Jeep 4.0 in it. Nice video, my friend!! 🏆🏅🥇🎖

[@TheHorsepowerMonster]

Thanks very much! And thanks for watching!

[@steveshoemaker6347]

l like R&D tear down on this AMAZING ENGINE VERY WELL = What a fine engine builder Keith is.....Thanks guy's from an Old F-4 Fighter jet Shoe🇺🇸

[@88349]

Im impressed but not surprised as a long time offroad xj jeep guy id love to see more aftermarket internal upgrade support this engine has proven its self and we are only scratchin the serface in its potentual thanks for these great inline 6 motor R&D VIDS love it keep it up🔥🔥🔥

[@the_munkee_ranch]

AMC (+Nash/Kaiser/Jeep) is truly the most underappreciated car manufacturer ever!! Bravo, boys.

[@FUNKYTEE540]

Epic power from an old school straight 6 with 2 valves and pushrods! No, it's not a 2JZ and never will be so lets not even start comparing at any level... It's in an entire different realm. I believe this engine platform was based in 1964 starting with the 232. That's pretty incredible in itself that it stayed together at that power level. I'm anxious for the next dyno session..

[@JayGuitars1]

Keith, that is really incredible. Well done!

[@WilliamDundon]

Thanks you guys for sharing all this info on a completely miss understood engine.

[@TheHorsepowerMonster]

Hey thanks! And thanks for watching!

[@harryfeld1786]

Damn, You would’ve thought that would have grenaded far before that kind of power number. Beyond impressive!! Great video.

[@maldo72]

Great build great content ... please keep on giving us updates on this project

[@TheHorsepowerMonster]

Thanks!

[@matiasdamian8106]

Man... I can't wait for keith taking this engine back together now with even More solid components and internals, EFI to get that crazy number he mentioned during the video😅 Love this builds, and all the straight six's, thanks for share this content!

[@frfrpr]

That was awesome! I always wondered about that motor. Now I know. Keith was about as cool as an ice cube breaking this world-record engine down,

[@Ep1cPvP]

This R&D video is awesome! Love to hear what they're thinking about it, their experience and considerations are valuable.

[@PROSTREETS1096]

I've been waiting on someone to do this with the 4.0 and I'm really not surprised how it came out....I know they are a great eng.to build.....thanks waiting on the next video

[@kevinzimmerman2304]

Fun watching the progress on the Jeep engines!

[@derikwooddell3135]

Awsome boys. Big of yall to share the teardown. Gold in the fast jeep circles.

[@juliantullier5610]

the little engine that could. seriously impressive performance out of an engine with way more stock parts than most people would be comfortable with

[@scottduthie2912]

I could see that evidence of blow by on the bottom of the head as he was carrying it over to the bench. What an incredible build though!

[@mpetersen6]

Its visible in the thumbnail to the video. If they were building the motor for repeated runs on a race track l think they would likely cut O-ring grooves in the block. The sleeved 199 blocks (1) Navarro prepped when he tried running one at Indy in the 60s had copper O-rings. 1) The original heavy castings. Sleeved down to 3.598 from 3.750

[@mpetersen6]

I'm amazed the bottom end of the block held up. Of course how long it would last is a question. Just a 💣 waiting to happen. I can think of a couple of modifications. First a stiffer crank girdle. I always thought the factory one was rediculous. Second would it be possible to run a support rod down through bearing center of the rockers.

[@RedLP5000S]

The Jeep 4.0L straight six is a beast of a motor. I'm not surprised that it can hold up. So much torque too. ✌🏻🇺🇸

[@crebbsjd]

So cool!!! I definitely want some of these built engines in my future. Great video! Thanks guys, keep it up.

[@AndyFromm]

Sweet build

[@tylerboyer2006]

Great video!

[@TheHorsepowerMonster]

Thanks!

[@classicmonty5728]

Tip of the ole 🧢 to Mr. Newcomer and his apprentice, hell of a build gentleman

[@anasevi9456]

thank you for a nice cohesive follow-up.

[@richardmeadows1911]

I'm following y'all now, just to see where you go with it from here! I want to see how far y'all can mod this thing out and push it up to as far as output goes.

[@joefarmer4238]

I want one....bad!! That's an awesome accomplishment and seems like there's room for these "experts" to re-evaluate the 4.0 and it's potential

[@boostedgringo5885]

Havnt finished the video yet but maybe you address it. I have had fantastic results using the isky o ring tool to cut the block for a copper ring .020 proud. Has completely fixed my HG issues all the way to 70psi so far. I used to have issues around 40psi.

[@merr6267]

Fantastic. Nice work.

[@jimamizzi1]

Now this is what I like, relatively stock engine making big power, don’t need to spend huge money just a quality build 👍

[@abnpthfdr2934]

I've known for a while that the Jeep 4.0L straight 6 is a beast; It's been said that it's the best Jeep engine built to date. What they did, and where they took this 4.0 is straight up awesome!!! I don't have the pleasure of having that type of engine in my Jeep; (I own a 2009 JK), but I'm wondering if they have done anything to beef up a 3.8L which is the engine my Jeep came with. Thanks for sharing the videos and the info.

[@That_Ryan_Guy]

Ingenuity and trusting the factory might know a thing or two is real bad ass talent! It's too easy too make big power with a unlimited budget. I am also shocked and surprised to learn the internet doesn't know everything. 🤣😵‍💫

[@sHoRtBuSseR]

Also wanted to add, with those edelbrock heads, I've had to surface them right out of the box before. Also, you can tighten down the ARP studs quite a bit more than spec, if you're going for huge power numbers. A little additional torque can go a long way. I'm willing to bet that head needed milled before it was ever installed, lol. Had a lot of issues with brand new edelbrock heads and intakes before. Not a big deal, a surface job only isn't a problem honestly. Just more time.

[@larrywinn2941]

Loved the info in this video .

[@1320pass]

My first run-in with this 6 was a 232 in an AMC Gremlin. Currently running two 4.0s, one in a 2000 XJ the other a 2004 WJ. The engines will outlast 2 Jeep bodies with ease.

[@Gotzy392]

Great stuff, surprised you’re not using oil analysis since it’s a development engine to know what is wearing inside

[@AnyoneSeenMikeHunt]

Amazing to think this engine design just turned 60 years old starting life at 90hp.

[@riogrande163]

Indeed, I wonder what those original AMC engineers would say if they saw this now...

[@glenbjack]

I like this guy! Reuse stuff and see what happens.

[@raystevens687]

I was wondering if you also used ARP head bolts. I know ARP bolts 🔩 where used on the rod bolts 🔩.

[@Iowa599]

You should make a crossflow ohc head fit. I wish I had kept my XJ when it got totalled. It was a good car.

[@erikphariss7349]

I know Keith is already thinking of redoing the first MPFI version of this with huge injectors and an iron head. The question is when do we get that video ? Looking for that 1498 hp inline six that will do 90k trouble free miles. 😂❤🎉

[@danhambrick6331]

Just awesome..👍👍💪

[@bcbloc02]

Time for some ARP 625+ studs and some more bolt torque! Maybe fire rings? looks like the bottom end can take 1500hp anyway.

[@martymurphy7477]

Is a form of this engine combo going into the Rambler or have I missed a video?

[@ShaneEstabrooks]

Awesome.. some day in the future the 4.0 is going in a project, definitely not as extreme but still worthy

[@pudermcgavin4462]

I've always said if you want a 4l it better have 200k before you buy it! But this is awesome!

[@alltheboost5363]

I'm really surprised there was no dowels in the block to hold the head from shifting. Maybe get everything cleaned up and a little thicker head gasket and try again and turn it up

[@carldietz9767]

Isn't core shift a problem after machining/running then heading to blueprint?

[@oldsman4446]

Thats beyond crazy on a stock block holy crap!

[@georgespain6121]

Is it possible to build a 350hp/350tq 258cid engine using a carburetor and 93 octane gasoline. How many miles could an engine such as this last with no racing just Forrest roads in the mountains of Tennessee (1200 - 5,000 ft elevation)?

[@haroldjayhoover5370]

Would larger head studs be possible and helpful? Edit... Re: "....tractor motor" I'm pleased to learn that I'm not the only one who refers to it that way. I love the sloppy tractor sound of the big bores at low RPM and the angry scream of the six cylinder at the higher RPMs.

[@davidswanson5436]

What are kind of pushrods?

[@Levibetz]

The lack of main wear with the rpm and power it's making indicates to me that the crank harmonic issue that's much discussed is not present here. Either it never matters much, or that ATI damper is doing it's job well.

[@leeeagle5994]

made 1,000.80 ? HP

[@jamiemeyer8289]

So Many people are Lazy , Or Ignorant, on how to speak a whole number ... it seems to me , like bible grammar

[@adamspencer3620]

I can’t wait for the next level of this monster

[@David-xh2yt]

The oil and oiling system certainly seems up to the job.

[@cesarbarrios1378]

Wow i love this engine

[@ryanrivera7156]

I’m building a 258 with edelbrock head, Clifford intake, mid length headers,comp cam, roller rockers and Holley hyper spark distributor

[@jesuscastro8690]

I like the videoa just one thing why didn't they use a heat shield?

[@kiiiisu]

this is cool stuff!

[@robertwest3093]

Jeep put a decent sized exhaust header on these from the factory instead of using a boring cast iron manifold. All those 90 degree turns required by the stock single carburetor intake manifold design is a major hp limiter. Notice how the Clifford intake uses generous radiuses.

[@raystevens687]

Is Keith going to do more things to this engine maybe a different grind on the camshaft or maybe port fuel injection 💉 I think it would be really cool if he did.

[@TheHorsepowerMonster]

Hopefully! I'll update with another video if he does.

[@maya00795]

Awesome........ Amazing......... Greetings from india🇮🇳🤠🤠🤩🤩🤘🏻🙌🏻

[@aidanhamilton9859]

My turbo 4.0l even always has fueling issues with #1 and #6 91 pump gas and water meth, only single nozzle right now. Going direct port with the water meth, got the holes drilled and plugs for now.

[@scotteric8711]

In a forced induction setup, this engine would benefit greatly from 2 throttle bodies or 2 sources of intake air. The problem with one much larger TB is then 3 & 4 have shorter runners and get too lean. A better linear distribution would be better IMO. Think hilborn or single fire throttle bodies.

[@aidanhamilton9859]

@scotteric8711 the tuners are actually all equal length, the intake manifold was designed to swirl the air in the middle before it gets distributed. The distance from the back portion of the intake is the same on each port. My issue is #1 and #6 run hotter due to lack of even water meth distribution. 1 port in charge pipe. Ive only ever had issue on #1 and #6. My fix is direct port water meth to ensure there ie even distribution.

[@aidanhamilton9859]

@@scotteric8711 2jz style manifolds work better on these

[@DanielBowlden]

how did the cam and lifters look .I have had to replace to many dead junk lifters

[@TheHorsepowerMonster]

They looked good. The springs weren't especially strong, so other than having to open against more cylinder pressure the cam and lifters weren't really stressed any more than normal. Thanks for watching

[@raystevens687]

Buy chance do you have a Scat crankshaft

[@Travis.H]

Where do I sign up? I need one for my TJ. 800HP would be good. 1000HP would be better.

[@thatmand4542]

i cant wait to have my block machined for my 4.9 stroker project for my daily LJ,dont plan on using an aluminum head just a clearwater head with Ls sized valves but i do plan on running newcomers Balancer,rocker arms,cam and some other misc. stuff ! This wont be happening soon but maybe in 2 years or so i plan on having this type of setup either N/a with intentions of a turbo later on ! :D Edit- 11 months later, Messed up said clearwater head when porting since it was an aftermarket casting but anyways, Got the Aluminum head ive wanted. Not too afraid of warpage....not planning on 1K Hp anytime soon so it'll work for me 😁 The way i "Messed up" my head from Clearwater is that i went "too wide" on the walls in which i only went a bit over an 1/8" on the walls (vertical) but the stock head casting i did after messing up the CW head it took it no problem!

[@sHoRtBuSseR]

How did you guys deal with the vibration that comes into this engine in the higher RPMs? I used to build a bunch of these, but haven't for a few years. Really interested in this build! My next one will be a stroker, I doubt I'll boost it. Although, it's not out of the question... Edited to add that I think the vibration was camshaft related above 5500 ish rpm but it's been awhile since I got to play with one that would even try to wind up to 6 grand lol

[@scotteric8711]

What ia your thought on a gear drive for these engines? What's the engine with the closest Cam/ crank center line where one could reasonably make their own? I think a Geardrive would really solidify their place in durability.

[@sHoRtBuSseR]

@@scotteric8711 I think you could do a custom billet timing cover with a gear drive built into it. That or you'd have to make some mounting solution for the engine block.

[@michaellawrence3796]

That 4.0 isn't stroked right just a plain 4.0 no 4.6 bc even stroked or stock that is awsome I plan on building a 4.6 turbo stroker soon for my ax15 zj and would love to make it a little street/track car like I had planned

[@David-xh2yt]

I can see O-Rings, a copper head gasket and more boost in its future. Might do 1200hp and still hold together.

[@rustygehl]

Rick Mudge had issues with his Cylinder Head Gasket shifting. Ended up using a Carbon gasket? I forgot, lol. Someone in here would know.

[@kurt5490]

Would like to see a turbo engine build for an rv that tows a 2nd vehicle. After watching these videos i know it can be done for not a lot of $.

[@blown572hemi]

Much like ferds and LS, the 4 bolt per cylinder isn't necessarily bad until you get into boosted 1khp realm. Waiting too see if the bottom end moved around with stock part's. Amazing how a non crossflow head design can make these number's. My 2001 xj would smoke mustang gts (not that impressive for a 4.6l car's) until you factor in 320k miles on that jeep with 4.10 gearing. Automatic transmission too

[@zackhart4698]

This is a great video

[@Hitman-ds1ei]

Still on the low end compared to other 4.0L engines out there isnt it ?

[@scotteric8711]

I love all the surprised comments. Having owned one for over 325k miles in some of the worst conditions, I'm not shocked one bit. Keith, is this engine running a stock or high volume Oil pump?

[@NewcomerRacing]

Stock

[@itseithergonnaworkoritaint7852]

Here's an idea for those guys; Some Ford 300 guys are cutting and welding a set of LS heads to bolt on the 300. These guys can do the same thing with a set of sbc heads. The only difference is there would be 2 seams instead of 1. One head would need the 2 outer cylinders off and the other head would need to be cut in half. The 2 halves would need to be welded to the one with the 2 ends cut off. They might even be able to use the extra head bolt holes the sbc heads have? To surpass the CFM they're already getting out of the Jeep head, they would need to get an altered angle sbc head like the 18° or 14° or one of the other altered angle heads that would fit their needs. Some of these heads flow over 400 CFM out of the box.😯 Or possibly a set of used NASCAR heads, the MOPAR P7 P5 ones would probably be the best bet but would be 4 weld seams but they flow over 400 intake CFM.😎👍

[@mpetersen6]

The 4.0 hore center is 4.380". Same as the Ford Windsor and Cleveland. The SBC and LS are 4.400". Also the same as the LQ-1 DOHC 24V V-6. Cut one cylinder off of opposite ends on two heads, machine and weld. One seam. The big issues of course is head bolt positions, oil/coolant passages and on both the Fords and GM you are going to need a new cam. This due to the intake/exhaust valves alternating vs the 4.0 being set up with paired intake and exhaust valves. There may also be an issue with pushrod clearances. Roller lifters would help. The lifter bores are the same as Chrysler at .904" so there are likely roller lifters that would fit the bores. Getting them in might be an issue. I'm not sure but l think there was somebody that was offering them for the 4.0. In the 90s l do know there were 4.0s built with roller lifters for test purposes. The system used for maintaining lifter orientation mounted on the crankcase side of the lifters. Not adopted as the cost vs benefit didn't pay. As to matching various machined and cast features on one of the Jeep forums years ago there was some imagery posted showing the differences in head bolt locations, coolant and oil passages. Plus on the V-8 head you would likely need to weld in a bar of material to fill any gaps in the pushrod areas. As an aside l used to work with a guy that wrenches for a race team out of NE Illinois. They run open wheel and sports racers in road racing. Including endurance events such as the 24 hour Daytona. Some of their cars use Hart 4 cylinder engines. They needed new heads. Unavailable. They had the heads copied with 3D printed patterns, cast in aluminum and machined. Given enough money things are possible. And now the kicker. In Argentina they race DOHC 24V versions of the 4.0, Ord and Chevrolet inline 6's. These engines used in road racing put out around 500 hp using 2 2bbl carbs. Heavily modified they feature dry sumps, new griddled bottom ends etc. According to AMXJ's channel they are working on getting their hands on some of these.

[@itseithergonnaworkoritaint7852]

@@mpetersen6 The way I mapped it out they wouldn't need a custom cam. Also the center two cylinders would only be off by .010" per cylinder as would the 1 & 2, 5 & 6, being there would be 3 pairs to weld together.😎👍

[@mpetersen6]

​@@itseithergonnaworkoritaint7852 The Chrysler Nascar head has a larger bore center. 4.450". Same as the New Hemi. To get the most out of any one of these with a new head on it you're going g to need a new or reground cam anyway. Especially natural aspirated. One of these in a 66 to 69 American 2dr hardtop or a Hornet Hatchback. Up grade the suspension and brakes. Replace the rear end with an IRS unit. Stiffen the body structure up and take out any extra weight. Then go autocrossing.

[@seanbragg1696]

Do itb type plenum on that too feed those center cylinders or roll valve

[@jerrodbeck1799]

Straight six is the best configuration but I want longevity in a power plant!!!

[@erickbernard8208]

I hope Richard Holdner get one for his big bang video series

[@jeffm234]

Jeep engineers had their sh#t together when they designed the 4.0!

[@RAWRMotorsports]

1080 on half compression on half cylinders

[@MsKatjie]

In the world of V8's, it is easy to forget about the inline boosted 6 and value for money.

[@scotteric8711]

Funny, in building a stroker 4.0 over a mild ford 4.6 2V, I can say this 100% accurate. A stroker 4.0 costs not much more than a high end stock rebuild. A modded 4.6 2V with a saleen supercharger (All ford based) is more than the whole car.

[@agustin8868]

miren el caño de esape! le estaba llegando mas combustible a ese cilindroo!!!!

[@rickyfulks889]

Key words, n live

[@davian157]

👍👍👍👍

[@autonomous_collective]

World Record??

[@jamesgeorge4874]

I would expect a 4.0 to make 500 hp, and 500 ft/lbs pretty reliably, if you didn't hold it at the limit for extended periods. In any Jeep, that should be enough. 1000 is pretty impressive, for a 2V head.

[@futten3230]

time for some firerings

[@alexjuarez1247]

Yes 🫶🫶🫶🫶🤟🏽❤

[@michaelatkin9649]

That wont last long in that power range. You'd get 5mpg as well.

[@seniorxj2931]

TAKE MY MONEY AND PUT THIS IN MY 98 XJ PLEASE!!!