Just wondering on people thoughts of which is better, I can see the advantage for relative low Rpm street engine like under 6000 rpm. One day I wouldn't mind turning my 5.9 jeep into a 408 for better towing and off roading but for higher rpm and horsepower doesn't 340-360 have the advantage with the better bore to stroke and rod ratio. I always thought that was one of the main advantages dodge had over the other car makers, when you see engine shoot outs dodge usually wins especially when using mainly factory parts.
340-360 vs 408-414
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805moparkid
Slant and AFX Guy
cubes will always make more torque lower, easier...
I do it a different way.What are you installing it in,and are you willing to commit to hook it up.If you say yes to the second,go stroker.
1970Duster
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I'm not a big stroker fan. I don't get/understand why the hell you should have to pull the motor to "freshen" it up. Sounds like a great way to piss more money away. A stock stroke motor well built can and will give you 100k miles but it depends on what you're doing with it.
All that said I always like screamin engines! Something about the way they sound turning 5-6K RPMS.
All that said I always like screamin engines! Something about the way they sound turning 5-6K RPMS.
OldmanRick
Well-Known Member
I'll just add, imo....other then the 59 degree lifter angle, the smallblock mopar is the best factory produced smallblock muscle car engine on the planet................
Rodzilla
Well-Known Member
Red line on my stroker will be close to or on 7k....thats getting close to screaming. 5-6k is a squeel lol
I've read that Chryslers engineers said that the stroke shouldn't be more than 92% of the bore for best horsepower to friction so a 400's bore shouldn't even have a 4" stroke and all but the 225 /6 don't go over this bore to stroke % and have high rod ratio I don't see you would want to build these features out if you need 400+ CID wouldn't make more sense to build a big block?
Lots easier to control valvetrain at 6K vs 7k+
There are real world parameters,unless you have serious coin.There is a reason mopar ran the tall decks with a 6.123 rod.Is this a theroitical question or real world?
805moparkid
Slant and AFX Guy
we have a 472 and a 528 hemi's (hand built not crate motors) that bing 7 no problem... the 472 is a stick car running 10.3's and the 528 is running 9.8's... and all they need is an oil change and a bearing check after every season...
exactly... and have more cubes...
Abodybomber this theoretical I don't on plan on a building 408 except maybe one day for my jeep for my Cuda I'm building a 273. It just it goes against what I've learnt so far about engines, I understand this probably only comes into effect when every last HP counts but if bore and rod ratio don't really matter what's dodge's main advantage cylinder heads?
moper
Well-Known Member
Everything is a give and take, and while there are empirical values that go with them, a lot of things people worry about are simply not that big a deal when compared to the benefits of a non factory stroke. Friction is important, but it's not a big loss an can be minimized further if you're really wanting to. Factory engineers were looking at warranty periods and emissions/economy, and these engines were designed in the 50s and tweaked in the 60s. Many of the truths they held in high regard have been replaced by newer thinking and technology.
So in regard to the OP - the 340 bores IMO are the only difference int he two choices (408/416) that will make any type of measurable difference between them. The larger bore is better for airflow and that can be measured. The main bearing size, additional piston material making the 4.07 piston heavier, additional friction due to more skirt/ring contact area, and the casting cores used when the blocks were cast all have very, very, very small affects on total output. Everything else is the same once you use the 4" stroke.
So in regard to the OP - the 340 bores IMO are the only difference int he two choices (408/416) that will make any type of measurable difference between them. The larger bore is better for airflow and that can be measured. The main bearing size, additional piston material making the 4.07 piston heavier, additional friction due to more skirt/ring contact area, and the casting cores used when the blocks were cast all have very, very, very small affects on total output. Everything else is the same once you use the 4" stroke.
I'm to the point where I really don't give a damn about all out power. All I want is something that sounds nasty, runs pretty good and is reliable. Not saying strokers caint be all that, surely they can. A simple stock bore and stroke warmed over rebuild is where I'm at now. For me, it's financially doable, will be relaible and I can make it sound nasty. Won't ever be the fastest thing around, but I've won my share of races so that part really doesn't matter to me anymore.
340sFastback
Well-Known Member
If you are on a budget a good 360 build is where it is at.
cannucky
The Guy With No Birthday
build for use , my stroker puts out over 500hp/tq but it's geared for the highway not the strip , I live beside the rockies and when I cross Canada in it I am able to cruise up the side of the mountains at 70 mph without a change in engine temp , that's build to use ,build to brag cost money for nothing IMHO
moper
Well-Known Member
Amen brother. Preach on.
cannucky
The Guy With No Birthday
yeah it's nicer to have the power { with dyno sheets to prove it } when you want it than not have it when you need it , as for durability well 4000 miles the weekend afterr it came out of the box and a year of driving the snot out of it later and no signs of smoke or oil loss yet . All it takes to sound nasty is a missing muffler , maybe you should try a fart pipe and some spinny wheels on your hoopty
67Dart273
Well-Known Member
'n mention the word "dyno" a couple 'ha times
OR JUST CLAIM you have a stroker.
"Yeh. It's a stroker."
Wasn't THAT easy!!!
lol
Piston would be really short, actually too short, for any kind of street use. Compression distance would be very close to 1" whereas most std rod length 4" stroker pistons are in the 1.4 CD area.
Stock rod length 6.123ish work ok with a 4" crank. IMO, it's something that isn't really an issue with SB mopars. Look over some of the SB chevy stroker combos/rod lengths. Those have some really short rods for the longer stroke set ups.
1970Duster
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If stroking it is your thing (pun intended :twisted
why not go big or go home? Screw that 4" baby crank and go with the big boy 4.250" crank!
why not go big or go home? Screw that 4" baby crank and go with the big boy 4.250" crank!
cannucky
The Guy With No Birthday
If stroking it is your thing (pun intended :twisted
I've been mulling that one over for a spare engine to play with at the track but I think then you have to go with a Ritter or R block and thats a $3500+ extra hit ,tough for a working class stiff to justify eh?
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