Dyno Death March! Testing Jeep Engine Combos for Power

[@eieghn]

This is MUSIC to my ears. As the Afternoon Senior Technician in the Performance Test Cell at Chrysler JTE working on the 4.0L, I can not begin to tell you how MANY combinations of intake and exhaust manifolds we tested on this engine. So. All this noise is music to my ears. Some of the music was also supercharged......... The things most will NEVER see before an engine is introduced to the public. BTW, the supercharged engine found it's way into a Commanche, it FRIED the tires off that little pick up! Our Flow Lab man, had a D-Altered with a 4.0L. It spun to 7800 RPM. It made the small hairs on your neck stand on end....the noise? GLORIOUS!!!! AND, did ya know the 1st Vipers had TWIN Jeep 4.0L throttle bodies........??????? YUP.......

[@manfredolson6889]

Sooo…. There are intake manifolds out there with dual throttle bodies??

[@claytonpolly9139]

For vipers yeah...​@manfredolson6889

[@Onewheelordeal]

Somewhere the engineer who put that neckdown in the stock throttlebody has earned a good I-told-ya-so

[@mpetersen6]

It was likely done for a very good reason. Likely hp & torque at certain RPM range. When the 4.0 was first being developed it supposedly put out 242 hp. One hp per cubic inch. But they were breaking drive train parts. Primarily rear axle assemblies iirc. They were spinning the axle tubes in the housings. Dana had been contracted to build the rear ends and the tooling was shipped to them. When AMC built the rear ends* the axle tube was welded at one point into the rear end housing. Dana thought this is what held the tube in place. Actually the tubes had between .005 to .010" press fit to the housing. When the tubes where pressed in it was so loud that area was enclosed. Manufacturing the rear end housings were a PITA simply because of keeping the three bores in proper alignment. Simply having too high of a clamping pressure would result in the parts being out of spec. *we once made Ring and Pinion sets for Ford. The first sets after they came out of heat treat were set-up on the test machines to run them to check mesh pattern etc. They made excessive noise. The Ford engineer thought they sounded fine. The next test machine had a set of our gears on it. They turned it on and all you heard was a low hum. Every ring and Pinion set in an AMC rear end was a matched set because they where run through a lapping operation as the last step of manufacturing.

[@summitlt]

If you look through the throttle body, at small throttle inputs the neck makes it so only one side of the throttle body is letting in air. Helps a lot with driveability with the all torque no real hp 4.0

[@eieghn]

Cylinder distribution played a HUGE part. Curved plenum intakes made more torque, straight plenums made more HP. Plenum volume and it's length made the job difficult for cylinders 1&6. Axles? We tested them by doing forward/reverse shifts at peak torque RPM with the vehicle tied to BIG honking concrete poles. Not sexy. But SO fun to watch them bust shit!

[@peteloomis8456]

​@@mpetersen6 Every gear set that I have bought be it factory or aftermarket like Richmond gear they all are matched gear sets that are lapped together at these factories that make them . I've never had a problem with a noisy set of gears from Richmond or any stock factory gear sets in the differentials I've built through the years as long as you have the gear tooth pattern set up correctly when checking tooth pattern using yellow pattern grease . I've even set up known good used gears in rear ends that weren't used in the same housing and never had issues other than with used ring & pinion gears you check the coast side of the ring gear pattern more than the driven side because with used ring & pinion gears the driven side is worn more than the coast side of the ring gear and this gives you a more accurate gear pattern . I get what your saying as far as maybe some differential housings can be not exactly the same which is true but that's why different thickness shims are used to adjust for this by either moving the pinion gear in or out more to get that in spec or by shimming the ring gear closer our further away from the pinion gear to achieve the correct tooth pattern. Granted some differentials don't use shims and have adjusters on each end of the gear housing like the Ford 9 inch & Chryslers 8 &3/4 uses where you just turn what sides need to be turned to shift the gear housing in the direction it needs to go to get the correct gear pattern for the ring & pinion . I had GM 12 bolts that were spot welded like you were saying that those welds broke on the 1/2 ton 4x4 trucks and on a Elcamino I worked on & had to pull the rear end out and use a big pipe wrench with the rear end mounted solid so it wouldn't move to a fixture I made to then used the pipe wrench to turn the axle tube back into its correct placement again then re welded those spots again & welded around the axle tube and housing right where that axle tube is pressed into the housing and had no issues with a noisy rear differential. As long as the housing itself is machined correctly for the gear sets and the concentricity is spot on you really shouldn't have any issues with gears not being able to be shimmed or adjusted correctly for the desired gear patterns be it with new or a known good matched set of used gears that were taken out & swapped for a different gear ratio for either a performance gain application or for a fuel milage gain with lower rpm while cruising. I'm sure especially now that there's probably been instances where someone bought a brand new gear set that weren't properly lapped in and they installed them to spec and checked gear tooth pattern and it looked good but the gears whined and made noise because it was a set of gears that got by inspection and quality control but in all the years I've built differentials I've never had a problem like this with a gear set that wasn't lapped in but anything is possible now that most things aren't being made here like they used to be.

[@DGM218]

If was for noise reduction

[@Carstuff111]

I am nearly 40 years old, and have been a nerd since I was 4 years old. I absolutely LOVE videos like this! Yet another channel I am so glad I found :)

[@nasty3145]

This was like engine masters. But i didn't have to pay 4 bucks a month to watch it. Thank you so much

[@andyclemente4205]

I love this kind of videos, it shows that the amc 4.0 can be a beast

[@tedium37]

Sounds like I'd be happy with any of these on the big displacement engine. Great job Newcomer doing all this work and thanks for sharing the results.

[@XxMusclecarsxX]

I swear you make VERY high quality content, sir!!! Always good stuff, very informative, good pictures and fun

[@dilsher12]

Always cool to see back to back testing on the same engine combo . The engine sounds nice under load too. Thanks for the content.

[@kylemandt527]

I have several Newcomer Racing products on my 4.0 Jeep. I like their products and they are good quality.

[@JeepinJoe]

My boys and I enjoy our stroked 4.6 producing 352HP/350TQ from Keith in the LJ.

[@darkcorpd]

Great job! I have a 4.6L stroker and bore TBs for Jeep 3.7/4.0/4.7/5.2/5.9. I always knew that the 62mm TB is the best choice for stock 4.0 Jeep.

[@Jacobwafflez]

How did you tune it

[@Scrambler85]

Great video, I have been waiting years for someone to do this 👍

[@TheHorsepowerMonster]

Thanks a lot!

[@slantedperspective]

Very excited another Jeep 4.0 motor vidieo! Was looking faward to this!!!

[@levitezoe1804]

I love this channel the possibilities for my 2000 Grand Cherokee are endless just takes knowledge a little bit of money and patience

[@gizmothewytchdoktor1049]

and then there is the SOUND of the different intakes....of which the fabbed straight runner unit sounds sweet!

[@zachkearse]

How have I never seen this. Love watching this kind of stuff

[@tombrown879]

Thanks for letting us GEEK out guys. Great vid.

[@racerd9669]

I think you will find the carb set up had the dip because of engine vibration at that RPM. I have a video up on an Iron Duke w a carb and we had the big dip problem also. No mater how we changed the tune it just would no go away. Love your stuff, doing an awesome job for sure.

[@TheHorsepowerMonster]

Probably right. Thanks for watching

[@davidjpaddock]

Would've been really cool if there was a clean way to test this against an offy or clifford 4bbl intake. Awesome video, great job from Newcomer as always. Your videos are why I started buying parts from him!

[@brianhatcher7183]

Would like a carb intake shootout! 4.2 Stock intake with a Weber 38, vs Clifford/ Holley 390, vs Offy dual plane/ Holley 390. With timing and carb tuning done.

[@tkmad7470]

Great tests! These kinds of comparison videos are extremely helpful!

[@1990smitch]

Love these dyno days

[@TheHorsepowerMonster]

Thanks!

[@nutsandbolts432]

Can you show how to make maximum power and torque around 2500 rpm? I rarely rev my Jeep over 3000 rpm. I don’t need to know how to make maximum power at 6000 rpm.

[@SlenderRogerOficial]

Camchaft and crazy supercharger

[@jeremyparsons2944]

seems to me the "curved runner" intake is the the way to go for most jeep/amc 6's I would like to see a extrude honed curved runner vs. the cut open ported short runner

[@MyLonewolf25]

Agreed.

[@Mercmad]

I wondered how something like the intake on the Mopar SL6 would work when i saw the hand fabbed unit. It looks like the curved runners are almost the same length and Mopar back then had discovered the formula to determine the length of intakes and exhausts ....which I suspect was shared with Mercedes.

[@vw1320]

Would liked to have seen both headers tested on the best of ported stock intakes to see the differences.

[@Randomgearhead]

Can't wait for a stroker in my MJ and in my amc eagle

[@vrm86gt]

looks like that big manifold likes that Holley 4 barrel! I'd like to see that combo dialed in with a matching cam!

[@paulplack490]

@3:05, Keith says the stock throttle body necks down to 54mm, but in several subsequent comments you said 58mm. I'm left wondering which it is. But this is a very cool comparison! It's waaay more data than most of us could ever hope (or afford) to gather on our own!

[@brianfarrar3594]

My 72 IH Scout with a 4.0 in place of the 258 and a FAST computer handling injector/spark duty is in love! This stuff is yum!!😉👍

[@Redheadedwizard]

I've Tracked Down 15 of these in my area with broken piston skirts I can't imagine stressing these things on a dyno

[@slavleader4645]

This was so cool to see on my recommended I got a factory purple 96 xj that I’m trying to research building her and I’ve been having a lot of trouble, she’s been mad at me and I need to rebuild the transmission soon and I want to figure out what else I can do to her.

[@manitoublack]

great test. If only there were DCOE's or ITB's as well :)

[@TheHorsepowerMonster]

Thanks! And I agree

[@emadalbalushi2080]

@@TheHorsepowerMonster Can I get your contact info..

[@RadDadisRad]

The last Jeep video you did it ended up as an Engine Labs article and you covered a record hp run. I know this is going to be good even tho I know nothing about this motor.

[@TheHorsepowerMonster]

Hey thanks! And yeah, they cover a lot of my videos. I know several of the guys over there and they are good folks. Thanks for watching

[@misterrc51]

@@TheHorsepowerMonster 2005-2006 has a different throttle body because of the IAC valve, I have both earlier and later 4.0 L and they will not fit. F&B also makes 66-68mm throttle body for early 96-04 Jeep 4.0, I have one for over 18 years now.

[@Sauceyjames]

Heck yeah another Jeep video!

[@stellingbanjodude]

I’m surprised he hasn’t made his own cross flow head yet for these things

[@young11984]

Yea really, then he can make some good power with just the cross flow alone and same volumes of runners

[@jonathanelser590]

Can you imagine how much business he would get?! That would be so cool.

[@richardprice5978]

ford 300? bolt on ? as i think the two are cousins design wise

[@richardprice5978]

add jag as well?

[@eieghn]

How about DOHC crossflow. Yea, we looked at that at JTE....... Beau Coup HP, but torque down low where Jeeps are used? Not much to be gained. Bear in mind, that is where most Jeeps were being used at the time. This was being done on 1990's level engine controls. NOT the 21 Century as is today......where you can dial in SO much.

[@acemobile9806]

I'd like to see this dropped in a Fox or SN95 just for fun 🤔 Then boost it after the novelty wears off for some real fun! Edit: if I'm not mistaken right before they went to the curved manifold, the factory rating was 195 HP there for a couple of years. I'm guessing they went curved to slightly enhance torque output or for emissions purposes. Strange why they even bothered to mess with what already worked. Great testing, love hearing the pulls!

[@Gaston.-]

I love these series.

[@TheHorsepowerMonster]

Thanks!

[@kiiiisu]

that last setup on dyno looks badass :D

[@tonyking9235]

NICE TO SEE R.D GOOD WORK BOYS

[@AridCustoms]

Please do this with the stock 4.0 engines.

[@kurtboudreauxjr7688]

I'd love to some pulls with individual throttle bodies

[@johnbehneman1546]

THANK YOU SO MUCH!!! I LOVE THE JEEP ENGINE!!!! THANKS FOR SHARING!!!! I LEARNED SO MUCH!!!

[@TheHorsepowerMonster]

Thank you! And thanks for watching!

[@jeremypike9153]

I think an individual throttle body/carburetor setup would be easy enough to fabricate and would increase airflow immensely. That would in my opinion be the best option that wasn't looked at🤫

[@Levibetz]

Love to see more AMC I6 stuff! I always want to see more camshaft and RPM with these things. What's with Jeep guys and wanting torque anyway? haha

[@richardprice5978]

um the engine's habits for one and 2 what do expect a linebacker to turn into a ballerina cheerleader character ? that's why i feel the 4.0L works better with a manual transmission than a automatic transmission as the potential power band lines up better

[@dbizm]

Port match straight runner for an off road set up. That's the one for me.

[@jayjones1644]

Get the banks header, port your straight runner, 4 hole injectors,port the throttle body, relocate the intake air temp sensor to the air box, use lead foot to go fast!!!

[@Adam-nv9zo]

Awesome video man

[@michaeleads957]

Yes I am ready to see more of this

[@cerberes]

Great video! My head was playing thought experiments seeing the throttle body plenum vs runner lengths. I wonder if the carb test fell over because 2 of the runners were so short vs the much longer runners.

[@AntiPattern328]

That crazy manifold didn't do enough to impress... The bigger throttle body was cool.

[@joeymccullough2716]

Just a thought-has anybody extrude-honed one of these intakes to open up the areas that can’t be reached by hand?

[@hardtarget22]

I know they mentioned that the increased plenum manifold was mostly beneficial at higher RPM on highly modified engines but I'd like to know how much of a difference in throttle response it produced, particularly down low and with rapid throttle changes. Maybe a real world (non-dyno) type test for next time.

[@witcher71]

That much spring pressure seems like it would wipe out a flat tappet cam pretty quick.

[@MyLonewolf25]

Not even that much spring pressure on base my guy

[@1320crusier]

That tq issue with the TB's seems to be a velocity issue. They should build an ITB intake with some GSXR600 tb's (with intake trumpets)..haha. If they could come up with a way to keep the velocity up near stock while getting the improved flow they would see much more interesting numbers. I wonder if the cam was also a limitation for the tests.

[@timcouch2037]

What did you use to program the ECU?

[@Alicia-kd6vv]

I would love to see a turbo version of this comparison, especially for the higher flow straight runner intakes.

[@utahcountypicazospage5412]

They have one it’s on a old episode

[@nickfindsgold9788]

Is Newcomer still playing with that cannon style front entry intake ? I think your having issues with too much air volume and little venturi effect. I would like to see the 68 throttle body on the straight runner with a 62mm port matched spacer between it and the manifold Awesome work by the way, this is really good data

[@danmccarthy2213]

Not many of us with this engine care about power at 5000rpm. We want max power and torque at 1800-2400rpm do you have a video on that?

[@plumbs7199]

Be great to see Newcomer play with the Aussie I 6 turbo Barra ! Look it up ?

[@billpower-j2d]

amazing video! I have one sharp question...I Addes banks headers and rough country cold air intake to my 96 xj, sounds and feels quiet powerful, along with a high flow cat and a cat back system...now what i need to know is should i upgrade to a 62 mm throttle body from bbk, my stock tb is 60 mm, is the power of headers and intake too much for a stock...i do feel a restriction at times...some people tell me a 62 mm wont make a difference, but i rather hear it from you, someone who reallys knows the horsepower game!

[@steveshoemaker6347]

This is AWESOME😃....l like straight 6's🥰....Thanks guy's👍

[@johndorflinger2344]

Did you ever think about using a 5.2 /5.9 V8 throttle plate and welding the top of the large plenum with an adapter?

[@wowcolors]

The fabricated intake should use dual throttle bodies each feeding three cylinders to keep the intake runners equidistant

[@steveschwab922]

Seems the stock parts are good enough?

[@TurbineResearch]

Love me a good jeep L6

[@mohawkmike142]

Where can I find a straight comparison between a 91-6 straight runner vs a 99 up curved ? No other mods. Big flow yes for big hp is true for all engines. Low end torque is what most need.

[@sock979]

Love the straight sixes miss my old 300

[@passion-pilotagedriver1770]

Hello, I am French, I have a four-liter Grand Cherokee ZJ from 1994 with a manual gearbox, and I really like this engine. I have modified it, but I wanted to know how do we modify the ecu? thank you to you

[@danhambrick6331]

That was awesome...😁😁👍👍

[@TheHorsepowerMonster]

Thanks a lot!

[@GIGABACHI]

Love watching these Dinosaurs being hurled into modern times when it comes parts and tuning.

[@utahcountypicazospage5412]

head and camshaft with stock everything else because that would make killer torque early that would be a cool comparison

[@eliasmelendez1271]

Sucks that the throttle body isn't available anymore... just went to their website and they don't use that part number anymore.

[@MS-nk4xb]

- Å fan! 👍

[@shawnriddle3018]

love your channel. Lets me learn engine design and structure. Where does the pressure go thats under the piston and crank case?

[@snoofayy6150]

Positive Crank case ventilation system!

[@shawnriddle3018]

@@snoofayy6150 so it's recycled through the manifold? in measured amounts?

[@marvinheyd28]

I was very much be interested in seeing what a air filter does to these tests

[@oskarrecon8151]

i guess thats why a lot of intake manifolds have secondary valves today,.

[@brunopacheco2483]

Hello sir stumbled upon this video trying to figure out if these rockers would fit on the 2.5l 4cyl TJ I just recently turbo charged it and would really benefit from this upgrade . You think I would be fine getting clearance from the valve cover on the 2.5l ? And honestly wouldn't they fit bolt on? Thanks so much 👍

[@darrinleazer6784]

I have a 2002 Jeep Grand Cherokee Overland, with the 4.7 H.O. and would love to get more horsepower and Torque from it. Is there any way I can find a better way to get more from it now. It's just stock, with what it came with, but' and the motor is still in the Jeep. So' is there anything I can do to help it again more, while it's still in the jeep. ???

[@richwood8650]

So if all versions nosed over at the same point, why didn't you show the first version all out? I bet it made more power out longer as well. You could see it on the screen.

[@stevensprojectgarage99]

Time to add some new parts to the XJ

[@deanstefaniw8596]

I'm wondering if you have built a 2.5 yj engine. I know it's a turd but my old 94 still has a lot of life in her. Any ideas for more power. Thx

[@intrigue175175]

Great video.

[@garyh4458]

What's the point? I'm driving around at around 2K RPMs most of the time.

[@eliinthewolverinestate6729]

You build a custom intake but leave the air making a 90 degree off the throttle. Why not straight flow through? Less drag means more power.

[@magnusdanielsson2749]

Such a small plenum volume those intakes have. Even the modded one seem small in comparison to other engines.

[@raubindustries9426]

How are are you able to rev such high Rpm’s if you could tell me that would be much appreciated.

[@farhenheit628of1200]

Is there a turbo kit available for the 4.0 inline 6?

[@williamperry4238]

Did it ever occur to these people to priouce a cross flow OHC cylinder head for the AMC engine?

[@autotek7930]

What aftermarket 68mm throttle body is that? I got a 4.7l stroker and im looking for more air lol

[@VinnyMartello]

Has anybody tried putting a carburetor on these EFI intakes?

[@jessejames9420]

New to jeep, any t/b options for the renix?

[@SinisterBlackShadow]

Hey there hi there y'all. How does one tune the stock ECU? I thought those were locked out?

[@SteveEddy-od7fb]

The good old cast iron Straight. six cylinder engine! Kinda Clunky but very durable and reliable

[@Project-gr6zy]

You guys need to grab a 300 i6 ford and a pair of ls 5.3 heads made into an i6 head will blow your minds, some even push 3hp/cid

[@johnpublic168]

Did you try a spacer under the tb

[@2000hdfxdx]

So how do I get ahold of a 300 hp engine for my 2000 XJ?

[@wranglerfreak6263]

This is what we all wanted the horse shoe vs the log

[@offroadyaris5257]

Thanks for this!!

[@jamesmontes7551]

Hey guy i need help i have a 04 tj 4.0 and i changed the intake exhaust manifold gasket and now my jeep is reviving to red line on its own so please if anyone has a idea of wat is happening please let me know

[@derekcruz7576]

I would like to see 6 wide bands with that homemade one.

[@tomashton1781]

I own a 1990 YJ with the 2,5 pussy motor , single GM throttle body, I was thinking about swapping the the intake to the one that has bigger and better ports , and just plugging the electric fuel injector boss,s (ports) and putting a 1 inch spacer under the throttle body