What's new
By:
Filters

Building power with the Jeep 4.0

This just popped up on my Youtoobs. I don’t recall seeing it in the thread, but I’m not gonna look through all six pages.



They say the only downside to having non-crossflow head is heating up the intake, which can be solved with shielding. Claim it flows just fine :confused:
 
Chkn said:
Updates?:flipoff2:
Click to expand...

I have a huge parts pile, but I've been slacking on actually getting rolling with the engine assembly though. Everything is still a go, just...slow haha. Too many projects.

Thatg9659 said:
This just popped up on my Youtoobs. I don’t recall seeing it in the thread, but I’m not gonna look through all six pages.



They say the only downside to having non-crossflow head is heating up the intake, which can be solved with shielding. Claim it flows just fine :confused:
Click to expand...


That series of videos are by an admin of the Boosted 4.0 FB page, good dude. He asked if he could use my renders so I said by all means. The guy he's interviewing, Rick Mudge, was an engine designer at Chrysler back in the day and was heavily involved in the 4.0. While all of the knowledge is incredible, some of the performance related stuff is a bit...antiquated imo. The concept that you could theoretically build a non crossflow head with impressive flow numbers is accurate, but that's not the case with the 4.0 just due to the port shapes and lcoations. The port locations are so low on the cylinder head, they have to make a very sharp turn to direct the air down to the valve, versus modern engines where the port location has been getting higher and higher. The best 4.0 heads built with LS valves and ported to the absolute maximum are still outflowed by LS/LT heads, even in stock form
 
Yeah, them talking about this dog leg thing in the port that increased power, but didn’t increase flow and they were all confused by it.
 
This is all super awesome tech, I really hope it works.

However, GM already kinda did this and sold thousands of them.

Look at the GM Atlas 4.2 engine. There's guys making well into the 600s with those engines on the stock bottom end.

I've been wanting to put a GM 4.2 in my jeep for a while now, which would let it run normal Holley EFI stuff.
 
  • Like
Reactions: DMG
1702745910932.png

Saw this today on Facebook. Reminded me of this thread and I figured I’d give this a bump.
 
Badass. Small block heads have found their way onto a handful of 300's from what I've gathered, honestly a noteworthy part of the motivation for this project!

I hate to admit that it's been on the backburner, but not forgotten. I've been waiting for the engine in the XJ to show more signs of death, but it just keeps on going even with the nasty piston slap :lmao:. I do have just about everything I need except a camshaft though, so I can't wait to get it together in 2024.
 
AgitatedPancake said:
Badass. Small block heads have found their way onto a handful of 300's from what I've gathered, honestly a noteworthy part of the motivation for this project!

I hate to admit that it's been on the backburner, but not forgotten. I've been waiting for the engine in the XJ to show more signs of death, but it just keeps on going even with the nasty piston slap :lmao:. I do have just about everything I need except a camshaft though, so I can't wait to get it together in 2024.
Click to expand...

Pull the oil pan drain bolt, it's like taking someone off life support.:flipoff2:
 
Those headers look like they are just waiting to Crack apart.
 
Hell yes, great video! I'm really glad Newcomer was the guy to do it, he has driven the advancement of the 4.0 for a long time.

Though it also shows how damn inefficient those stock style reverse flow heads are with sharp intake manifold bends. It took like ~25 pounds of boost to double the horsepower from 400 to 800. In a perfectly efficient world it would only take 14.7 more psi (double atmosphere), with the rest being efficiency losses. So that thing is being bottlenecked to hell. Just means it's still itching to breath easy :grinpimp:
 
Gordon-B said:
This is all super awesome tech, I really hope it works.

However, GM already kinda did this and sold thousands of them.

Look at the GM Atlas 4.2 engine. There's guys making well into the 600s with those engines on the stock bottom end.

I've been wanting to put a GM 4.2 in my jeep for a while now, which would let it run normal Holley EFI stuff.
Click to expand...
I dont understand how the 4.2 has such a great reputation for being stout. The Atlas family has 2 others, the 4 cyl and 5 cyl. The 5 cyl is literally the same engine minus 1 cyl and is a POS. Any time I have seen someone put the slightest amount of boost at it failure happens.

I wonder if it's a balancing issue?
 
06h3 said:
I dont understand how the 4.2 has such a great reputation for being stout. The Atlas family has 2 others, the 4 cyl and 5 cyl. The 5 cyl is literally the same engine minus 1 cyl and is a POS. Any time I have seen someone put the slightest amount of boost at it failure happens.

I wonder if it's a balancing issue?
Click to expand...

The 4.2 Atlas are pretty sweet from what I've seen as Gordon noted. There's a guy named Calvin that has been pushing them to new heights over the past few years, to the point that they're finally getting aftermarket support seemingly due to his adventures. People are jokingly calling them the "ameribarra" engine, the closest thing the US has to the Ford Barra motor from overseas. From what I recall it has an odd bellhousing pattern (Gm 60*?) that can't directly bolt to most common transmissions, but I believe some options have been expanding in recent months/years.

I wasn't overly concerned about them here because it kinda turns into just another engine swap, so at that point other engines like LS and 2JZs are fair game too. Not that there's any logic in the path I'm going down with the jeep motor :grinpimp:.

What kind of failures are you seeing when the 4 and 5 cylinders get boost?

https://www.youtube.com/@Calvin-Nelson

 
the 5 cylinder had cylinder head issues in factory form that would cause misfire issues. It was a factory defect issue. They would usually fail a leakdown test and that was in stock form.

Any time I have seen some put a turbo on an H3 3.5 or 3.7 I5 Atlas with 5-6 lbs of boost parts came out of the oil pan. It would trash everything so its tough to say what happened first. This wasnt on one or two. This was commonly found with I5 turbo kits. Its tough to say, is it tuning? IDK.

The colorado guys have some 4 cyl Atlas engines and they seem to hold up better.

Everytime I post in the american barra facebook groups I get shunned away with basic answers like you dont know what you talking about. These kick ass.

Yes, they do, the I6 does.

Being an H3 owner, I know many I5s that were bone stock that never made it past 150k miles, mine included.
TrailTamer AgitatedPancake
 
AgitatedPancake said:
The 4.2 Atlas are pretty sweet from what I've seen as Gordon noted. There's a guy named Calvin that has been pushing them to new heights over the past few years, to the point that they're finally getting aftermarket support seemingly due to his adventures. People are jokingly calling them the "ameribarra" engine, the closest thing the US has to the Ford Barra motor from overseas. From what I recall it has an odd bellhousing pattern (Gm 60*?) that can't directly bolt to most common transmissions, but I believe some options have been expanding in recent months/years.

I wasn't overly concerned about them here because it kinda turns into just another engine swap, so at that point other engines like LS and 2JZs are fair game too. Not that there's any logic in the path I'm going down with the jeep motor :grinpimp:.

What kind of failures are you seeing when the 4 and 5 cylinders get boost?

https://www.youtube.com/@Calvin-Nelson

Click to expand...

I like that dudes shit, right amount of DIY homebrew tech and bling.
 
06h3 said:
Any time I have seen some put a turbo on an H3 3.5 or 3.7 I5 Atlas with 5-6 lbs of boost parts came out of the oil pan. It would trash everything so its tough to say what happened first.

Everytime I post in the american barra facebook groups I get shunned away with basic answers like you dont know what you talking about. These kick ass.


TrailTamer AgitatedPancake
Click to expand...
The Atlas engine platform is not a very qualified candidate for reliable power. It's amazing how one YouTube channel can erase the decade of embarrassment surrounding GM's failed attempt at 4 valve per cylinder inline 6 and it's variants. All of the engines on that YouTube channel have failed catastrophically while operating well under 1000HP, one failure nearly cost his father his life. Yet, folks maintain fandom.

The primary issue is how these engines were cast via lost foam. Lost foam casting of engine blocks and heads have been obsolete since. GM's original decision to cast the engine via lost foam were "a 27% energy savings, a 46% improvement in labor productivity and 7% less material usage compared to other casting processes." Strength and thermal expansion are not part of that equation, which of course is the major problem with lost foam casting. Lost foam castings feature high surface fracture porosity, which a high thermal expansion coefficient is a byproduct of. Worst case scenario for an engine block.

Folks that recommend this engine for racing all seem to forget to mention that they have unusually tight oil clearance specs, and piston to bore clearance. Under .001" vertical oil clearance on both the mains and rods! They forget to mention that they're insanely tough to turn over by hand when cold. It's all due to the castings. They expand like balloons and they will all fail tragically.
 
Randy Bobandi said:
The Atlas engine platform is not a very qualified candidate for reliable power. It's amazing how one YouTube channel can erase the decade of embarrassment surrounding GM's failed attempt at 4 valve per cylinder inline 6 and it's variants. All of the engines on that YouTube channel have failed catastrophically while operating well under 1000HP, one failure nearly cost his father his life. Yet, folks maintain fandom.

The primary issue is how these engines were cast via lost foam. Lost foam casting of engine blocks and heads have been obsolete since. GM's original decision to cast the engine via lost foam were "a 27% energy savings, a 46% improvement in labor productivity and 7% less material usage compared to other casting processes." Strength and thermal expansion are not part of that equation, which of course is the major problem with lost foam casting. Lost foam castings feature high surface fracture porosity, which a high thermal expansion coefficient is a byproduct of. Worst case scenario for an engine block.

Folks that recommend this engine for racing all seem to forget to mention that they have unusually tight oil clearance specs, and piston to bore clearance. Under .001" vertical oil clearance on both the mains and rods! They forget to mention that they're insanely tough to turn over by hand when cold. It's all due to the castings. They expand like balloons and they will all fail tragically.
Click to expand...
Good points on castings but with no other block choices they have to make the best of it.
 
CarterKraft said:
Good points on castings but with no other block choices they have to make the best of it.
Click to expand...

If you know it's going to fail catastrophically why bother in the first place? That is literally the definition of polishing a turd. Daring to be different is one thing but lighting money on fire just to say you did it seems very non productive unless the only goal is to make big HP numbers on a dyno and blow shit up over and over again.
 
SLOWPOKE693 said:
If you know it's going to fail catastrophically why bother in the first place? That is literally the definition of polishing a turd. Daring to be different is one thing but lighting money on fire just to say you did it seems very non productive unless the only goal is to make big HP numbers on a dyno and blow shit up over and over again.
Click to expand...
It's never stopped Ford guys :lmao:

Shit man I know 1000 HP is the new 383 stroker but a super light 1000 HP power plant used to be a big deal in a light weight chassis.

If I recall those failures where all stock rod/bottom end failures on junkyard engines.

If those where 4.8/5.3 LS engines that died would the response be the same?

Also it ran a 9.12 @ 149mph and using the normal et/speed calculations that's a sub 2200 lb car, I'd say a very decent combo.
 
Last edited:
CarterKraft said:
Shit man I know 1000 HP is the new 383 stroker but a super light 1000 HP power plant used to be a big deal in a light weight chassis.
Click to expand...

Speaking of turd polishing....

I don't get why everyone tries to build 6L+ cubic on smallblock platforms. It's fucking stupid when larger bore spaced and therefore larger bore big block shit is available. The bigger bore and spacing means valves and heads are less of a cluster fuck resulting in equivalent flow out of a more mildly cammed and therefore mildly build and therefore substantially cheaper and probably more durable and longer lived engine.

Seems to me like a stupid nostalgia boner or hangover from the 1960s when smallblocks topped out around 5L and you could bore/stroke beyond that without rapidly getting into diminishing returns.

CarterKraft said:
If I recall those failures where all stock rod/bottom end failures on junkyard engines.

If those where 4.8/5.3 LS engines that died would the response be the same?
Click to expand...
Of course not because fanboys gonna fanboy
CarterKraft said:
Also it ran a 9.12 @ 149mph and using the normal et/speed calculations that's a sub 2200 lb car, I'd say a very decent combo.
Click to expand...

Randy Bobandi said:
The Atlas engine platform ...blah, blah, blah, shitty block, blah, blah.
Click to expand...
I'm not saying you're not right about that but an I6 is way, way less demanding of the engine block than a V8 of similar power, rpm and displacement because the harmonic forces that the block has to resist are much less severe.
 
arse_sidewards said:
Speaking of turd polishing....

I don't get why everyone tries to build 6L+ cubic on smallblock platforms. It's fucking stupid when larger bore spaced and therefore larger bore big block shit is available. The bigger bore and spacing means valves and heads are less of a cluster fuck resulting in equivalent flow out of a more mildly cammed and therefore mildly build and therefore substantially cheaper and probably more durable and longer lived engine.

Seems to me like a stupid nostalgia boner or hangover from the 1960s when smallblocks topped out around 5L and you could bore/stroke beyond that without rapidly getting into diminishing returns.


Of course not because fanboys gonna fanboy



I'm not saying you're not right about that but an I6 is way, way less demanding of the engine block than a V8 of similar power, rpm and displacement because the harmonic forces that the block has to resist are much less severe.
Click to expand...
That last part :lmao: you’re saying it would be easy for GM to make a strong, in-line six engine block, but they still failed to.
 
Thatg9659 said:
That last part :lmao: you’re saying it would be easy for GM to make a strong, in-line six engine block, but they still failed to.
Click to expand...

Bean counters gonna bean count.

"let's cast this one out of garbage because it doesn't need to be as strong"

Seems to generally be fine in real world service.
 
arse_sidewards said:
Speaking of turd polishing....

I don't get why everyone tries to build 6L+ cubic on smallblock platforms. It's fucking stupid when larger bore spaced and therefore larger bore big block shit is available. The bigger bore and spacing means valves and heads are less of a cluster fuck resulting in equivalent flow out of a more mildly cammed and therefore mildly build and therefore substantially cheaper and probably more durable and longer lived engine.

Seems to me like a stupid nostalgia boner or hangover from the 1960s when smallblocks topped out around 5L and you could bore/stroke beyond that without rapidly getting into diminishing returns.


Of course not because fanboys gonna fanboy



I'm not saying you're not right about that but an I6 is way, way less demanding of the engine block than a V8 of similar power, rpm and displacement because the harmonic forces that the block has to resist are much less severe.
Click to expand...


Look at a modern "small block" LS based motor thats capable of making 3k horsepower all day with boost, is several hundred pounds lighter and is much easier to package than a big block and you will understand why you thinking is all wrong.

If an I6 was a better platform to make power there would already be aftermarket blocks like the big hp 4cyl crowd has access to.
 
arse_sidewards said:
Speaking of turd polishing....

I don't get why everyone tries to build 6L+ cubic on smallblock platforms. It's fucking stupid when larger bore spaced and therefore larger bore big block shit is available. The bigger bore and spacing means valves and heads are less of a cluster fuck resulting in equivalent flow out of a more mildly cammed and therefore mildly build and therefore substantially cheaper and probably more durable and longer lived engine.

Seems to me like a stupid nostalgia boner or hangover from the 1960s when smallblocks topped out around 5L and you could bore/stroke beyond that without rapidly getting into diminishing returns.
Click to expand...

Packaging and weight are the only reasons I can come up with.
Also, the wet intake of any SBC / BBC just plain suck ass. An LS is a lot better this way.
 
You must log in or register to reply here.
Top Back Refresh