Dodge Challenger Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
69 Posts
Discussion Starter #1
I'm considering a stroker kit or even a long block purchase. I notice that the 426 seems to be a more popular choice for those adding cubes. I would think the larger 440 would be the way to go. More is better right? Or maybe not. Which is why I'm asking those that have more experience. Is the 426 more versatile or reliable? Is it a nastalgia thing?
 

·
Banned
Joined
·
1,655 Posts
Andy should chime in but Im pretty sure the 426 is better due to it having thicker cylinder wall thickness but if your gona go boosted in the future,the 397 is the better choice. Having a more square motor (i.e. same bore size as stroke) is the best way to go.
 

·
Registered
Joined
·
382 Posts
I'm considering a stroker kit or even a long block purchase. I notice that the 426 seems to be a more popular choice for those adding cubes. I would think the larger 440 would be the way to go. More is better right? Or maybe not. Which is why I'm asking those that have more experience. Is the 426 more versatile or reliable? Is it a nastalgia thing?
Both are great legendary motors however the issue you have to address if you go with the 440 is will the K-Member hold up that beast. I shouldn't be a problem but definitely worth checking out. The 440's back in the day were all cast iron and I believe todays 440 crate is has a cast iron block and aluminum heads. To answer your question i would roll with the 426 because of its versatility. If this is simply a drag/show car then go with the 440
 

·
Registered
Joined
·
382 Posts
I'm considering a stroker kit or even a long block purchase. I notice that the 426 seems to be a more popular choice for those adding cubes. I would think the larger 440 would be the way to go. More is better right? Or maybe not. Which is why I'm asking those that have more experience. Is the 426 more versatile or reliable? Is it a nastalgia thing?
Sorry for my other reply did not realize you were looking at a stroker kit. Just disregard my other quote/reply lol. So I guess my question for is do they have 93 oct where you live?
 

·
Registered
Joined
·
69 Posts
Discussion Starter #8
We do have 93 octane where I live. I need it for my current tune. My plans are to probably remain N/A for now. But we all know how that goes. I wont be taking it to the strip cause I'm on my 3rd diff and second tranni (25000 miles) I just want a weekend driver with a nasty cam lick that turns heads when I fire it up.
 

·
Premium Member
Joined
·
338 Posts
My son has a PWR 426 in his Magnum SRT8 running 9:1 compression. With stock throttle body the beast made 450 RWHP and 456 RWTQ. With a 90mm TB, we will be closed to or over 500 RWHP. His plan is to put a Vortech Vsi V7 on the car and make at least 700 RWHP. I have a NA 426 with a mild cam putting out 532 RWHP and 542 RWTQ running a 11:1 CR. The point is the 426 gives you the option to go with boost or stay NA.

From what I have learned the iron block 440 is recommended NA only due to cylinder wall thichness. Not sure about the aluminum blocks with siamese bore, best to ask some of our vendors.
 

·
Registered
Joined
·
3,881 Posts
Some things to know regarding 440 vs 426.

Iron 440:
4.25" crank: 2.560 main, 2.00 journal, and a 4.25 stroke you get .155" of overlap.

Iron 426:
4.05" crank: 2.560 main, 2.00 journal, and 4.08" stroke, you get .255" of overlap

Iron 392:
3.795" crank: 2.560 main, 2.10 journal, and 3.795" stroke, you get .430" of overlap

Iron 6.1L:
3.58" crank: 2.560 main, 2.10 journal, and a 3.58" stroke, you get .540" of overlap

Here is the equation for determing Crankshaft overlap.
((Main + Journal)/2)-(stroke/2)

Crankshaft overlap is simply how much of a crank's main and rod journal diameters overlap each other. As stroke is increased, moving the rod journals farther away from the main journals reduces overlap and compromises strength and durability. Likewise, smaller rod and main journals reduce bearing speed and friction, but also reduce overlap. The reason why GM increased the size of the mains to 2.65 inches on a 400 SBC compared to 2.45 inches on a 350 was to maintain journal overlap with the longer 3.75-inch stroke.


Another thing to consider is Compression Height.

All figures below are assuming 0 deck height.

4.25" stroke pistons: 1.000"
4.05" stroke pistons: 1.085"
3.795" stroke pistons: 1.152"
3.58" stroke pistons: 1.217"

Equation for determining Compression Height.
(((Block Height-(Stroke/2))-Rod Length)-Deck Clearance

When Compression Height gets as small as 1 inch, it often requires narrow piston rings or ring buttons over the piston pin. It may also require the rings to be closer to the top of the piston than you may want for nitrous or endurance use. Short piston height means lighter weight, which is good, but it may also give up reliability you need. Sometimes a compromise for less stroke or shorter rods is prudent.


One last option is a new 440 that we just started building recently. It has more overlap than the current 440 and also has more compression height and a better rod/stroke ratio. Its still not as good as the 426, but its a much better option than the current Iron 440 that is out there.
 

·
Registered
Joined
·
69 Posts
Discussion Starter #11
So there it is. Thanks Andy and everyone else that took the time to respond. So the 426 is gonna be more reliable and versatile for boost/nitrous etc. A 440 badge on the side of my car has a better ring to it. Sounds more bad a$$. But for that level of investment, I have been sold on the 426.
 

·
Registered
Joined
·
3,881 Posts
they are 4.06" bore where stock is 4.055". Just a slight clean up like we do on all our 426's which are actually 419 and 423 cubes.
 

·
Premium Member
Joined
·
1,045 Posts
I always thought it was a good rule of thumb to never have the stroke larger than the bore or you seriously decrease the longevity of the motor.

When I upgrade to larger cubes, I was also going to go to the 426ci..
 

·
Premium Member
Joined
·
1,949 Posts
I have read and heard enough bad things about the "regular" iron 440 that I wouldn't get near it. Stick with the 419/426.
 

·
Premium Member
Joined
·
148 Posts
Ya, JR Krueger at InDepth Motor Sports built my long block and he highly recommended the 4.08x4.08 set up. (square). We're pushing about 14# of boost out of the Techco. Probably all i'll get out of that blower with out cog pullies and belts. So i'm told.
 
1 - 19 of 19 Posts
Top