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Step in...lets discuss the 426 and 440 Hemi's!!!

7K views 44 replies 20 participants last post by  scjeep4.7HO 
#1 ·
ok....not doing this for the current truck...but I am seriously looking at buying the 2011/2012 WK2 with the 5.7 hemi. But I want a total sleeper beast with this one. Lets discuss the 426 and 440 hemi upgrades. Best, shops, mods etc etc!!!!
 
#2 ·
Well, I won't pretend like I know a lot about engines/performance, etc... but I think it would be good discuss what supporting mods would be necessary or recommended to go along with such an upgrade.

It'll be nice to know what transmission will be in the WKII, rear end, suspension, etc.

Just tossing out some ideas... not really going to be able to participate, lol.
 
#3 ·
the 5.7 WK2 will use the same drivetrain...pretty much. But that is a good point.
If there is a 2012 SRT....it looks to have the 392 hemi 6.4l)

I cant wait for BJB and some of the others to chime in. I'm just now starting my research
 
#6 ·
Well he could easily get to the 426 with a 392 starting point. The obvious big things are bore and stroke. Who knows what heads and Cams will be available by then. Then you would need the typical performance stuff. Intake, headers, exhaust, and a way to tune.
 
#10 ·
yeah....I may have confused you guys. I will go the crate route with all supporting mods. Not sure if I will start with an SRT or 5.7 hemi.
 
#13 ·
Honestly Scott, tuning will be a real big issue because the WK2 is new from the ground up. Also as you well know, when you upgrade an engine, you need the rest of the train to be able to support that power. With that being said, everything (trans, Tc, rear end) will need to be custom made because the WK2 is so brand new. It will cost a buttload of money.

IMO if I were you, I would get a 2010 SRT and upgrade that. Call Builder Bill and Arrington up and hook up that Jeep.
 
#20 ·
With my current truck I have formed many relationships.....Minerich engines, K1 tech, B&G etc. I am pretty confident what is needed will be found/built.


As far as the 2010.....I dont want what i pretty much have setting in the garage now. I hate to say it...but Matt is right....5 yr old platform doesnt appeal to me. I need new blood.
 
#16 ·
Matt- That could be true Captain Obvious. lol :D

But I was trying to sway him back to the old friend. :D


Whatever he wants to do to that Jeep will have to be custom. He wont be doing any modifications to that vehicle for at least a year and a half after he gets it. Look how long it took for Diablo to come out with something for us 5.7's. Do you think they will be any quicker for the new stuff? I think not.
 
#17 ·
Matt- That could be true Captain Obvious. lol :D

But I was trying to sway him back to the old friend. :D
hehe

Joe has a good point though, if the Wk2 will be all new from the ground up, all the companys that will produce upgrades will have to start from the ground up as well to support the new stuff. Right? lol
Whatever he wants to do to that Jeep will have to be custom. He wont be doing any modifications to that vehicle for at least a year and a half after he gets it. Look how long it took for Diablo to come out with something for us 5.7's. Do you think they will be any quicker for the new stuff? I think not.
I seriously doubt he will be using a handheld tuner to tune a new engine. That would be something done at a shop on a dyno.

Again, I'm not the most educated when it comes to this stuff, but I'm not sure how much relevant stuff is actually changing. Motors are the same (at least the 5.7, which I assume equals a direct swap for a larger motor, as far as mounting). Transmissions are going to be the same.. 545rfe (or whatever it is). It seems like not too much relevant stuff is actually changing. Body style, interior, I mean obviously they don't matter.
 
#23 ·
I'm hoping some 6.4's(chally's etc) will be avaiable from wrecks in early 2012. Then a little stroking and caressing from there....LOL
 
#24 ·
Reviving an old thread as I am also tossing around this crazy idea. Basically I am thinking if it's possible to drop in a SRT 6.1 engine in a WK chasis. What are the pro's & cons? What else is needed besides the engine. I figured the transmission as well but maybe not? As Scott mentioned, I also kind of like the thought of having a ride that's a sleeper (beast in sheep clothing). Not looking to add a supercharger or turbo or anything like that. Just straight 6.1 SRT engine. What would it take to support that? Oh, and I have an Overland model in the event any parts are different from standard Wk.
 
#26 ·
Reviving an old thread as I am also tossing around this crazy idea. Basically I am thinking if it's possible to drop in a SRT 6.1 engine in a WK chasis. What are the pro's & cons? What else is needed besides the engine. I figured the transmission as well but maybe not? As Scott mentioned, I also kind of like the thought of having a ride that's a sleeper (beast in sheep clothing). Not looking to add a supercharger or turbo or anything like that. Just straight 6.1 SRT engine. What would it take to support that? Oh, and I have an Overland model in the event any parts are different from standard Wk.
there is currently a 6.1 engine out of a jeep srt on ebay with the transmission and transfer case.
 
#29 ·
Agreed! If you want to go that big get the real deal.

I wouldn't go any bigger than a 392 on our current small blocks as your going to start to run into geometry problems on the crank/rod - axis/angle and thermal stress due to thin sidewalls.
 
#28 ·
So here's my thoughts here:
The new 6.4L SRT8 (when it's officially announced) will have over 525 HP. A 426 (7.0L) aftermarket motor is rated around 585HP (ie, Arrington). Consider the price of the 426 + install for the extra 50HP and you'll see it's pointless.

Now if you're talking about building a WK2 Limited into a sleeper for instance . . .
The 5.7L motor will be the same motor running in today's Challenger with VVT heads so tuning and accessories should be there (to a degree).

If you go with a stroker motor, you will need to upgrade the tranny at the least. Transfer case eventually.
 
#34 · (Edited)
I think there is 3 different levels of modding these Jeeps...I'll give you my opinion because I've done or am in the process of doing all of these mods........

Level 1- CAI, Headers, Exhaust, Thermostat, Tune
(Low maintenance and very reliable)

Level 2- Heads, Cam, Forced Induction, Nitrous
(Still kinda low maintenance but need to watch several things)

Level 3- Stroker, Tranny, Transfer Case, Rear Diff., Fuel System
(High Maintenance, Not very friendly as a daily driver sometimes,Lots of $$$ involved, Lots of down time and patience. Also dealing with finding the weak links in your build and constantly fixing things that break)

It's tuff to decide where you want to fall with your build but the deeper you go into the Jeep ..The deeper you'll be reaching for $$$,and it gets frustrating sometimes.

BUT...It will "payoff" in the end.....
 
#37 ·
The Srt Ocho is at level 2.5 as of right now, Built 392, so far the trans is holding up well, and it is my wifes DD, So far maintenence has been a non issue, just dialing in Johan's tune, but tha has been as much fun as it has been work. I am guessing the trans will need some help in the next year, and I personally think the TC will be fine stock. I'm trying to get Wavetech to do a diff for our rear axle. That with some good 1 piece axles and I think the drivetrain will be set, We'll see.
 
#38 ·
If your gonna spend all that money, why not have the looks and performance already there? Buy the new SRT8 in 2012! :)
 
#41 ·
From what I've read/heard...there aren't any cams available for the new VVT HEMI's. Well, there aren't any cams that are worth the money (in regards to gains) to put in there. If you want to go the non-VVT route in a VVT engine, you need to replace th cam gear and reflash the PCM to a non-vvt version to be able to tune it.
That being said, and going with what I stated is true, flash the PCM and throw a new block in there and go fo it.
From my personal knowledge base:
High boost: 392 (more material around the cylinders)
Low boost or strong NA: 426
NA only: 440
 
#42 ·
You are mostly right, except for the reasoning of the 392 being better for high boost. Most rebuilds include an overbore, so that is a moot point between the 392/426/440. The Big advantage of the 392 is better bottom end geometry, they run longer connecting rods and a shorter stroke than the 426/440 so they have a better rod ratio and help the pistons from trying to drive themselves sideways out of the thrust side of the cylinder wall. The 392 should theoretically be more durable as far as longevity is concerned as well.
 
#44 ·
The problem with the "true" 440 is finding a head that will flow anywhere near what a ported 6.1 head flows. I'd take a boosted 392 stroker over a boosted RB 440 any day.
 
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