why was the 383 such a torque-monster?

[Mike DC]

What the title says. 

I know the standard reasons given when talking about this motor.  But it's not really satisfying to me, simply because the torque peak on the 383 magnum was at such a low RPM range and the motor still made good power higher up.  When people point to some kind of sub-400-inch smallblock (any brand) that makes a high torque number it will typically be compromised in one way or the other.  Either it's a motorhome engine with no higher-RPM horsepower, or else it's a very hi-po engine and the high torque peak occurs high up in the RPM range. 

The 360 is only 23 inches smaller, burns a ton of gas for its size, and it still won't produce low/midrange-RPM torque numbers near what a stock 383 Magnum will do.  Why such a difference? 

[Cooter]

Piston diameter comes to mind, as well as incorrect way of measuring torque output...I mean, a SB Chevy 350 has more crank in it than a 383 Chrysler...(3.380 VS 3.480)...I always thought the 383 Mopar was a high windin' BB, that was mainly happy in the upper end of the scale Myself...

[bull]

I don't know but I love the 383. All I can say is that it's an excellent combination of stroke and bore that winds up fast. I think of it like I think of the underrated .40 caliber pistol round. It's one of the largest bullets that travels more than 1,000 feet per second so it's a good combination of big and fast. Big is good and fast is good but an equal balance of the two is better IMO.

[doctor4766]

Piston diameter comes to mind, as well as incorrect way of measuring torque output...I mean, a SB Chevy 350 has more crank in it than a 383 Chrysler...(3.380 VS 3.480)...I always thought the 383 Mopar was a high windin' BB, that was mainly happy in the upper end of the scale Myself...

So what should a non magnum 383 rev to in relatively standard form?
My rebuild was just +0.30 , standard crank, Crane H272-2 cam, rebuilt 906 heads with standard valves.
I'm running a 750 vac sec Holley and although it seems to go well I feel (when manually changing) the need to change up a little over 3000rpm.

[elacruze]

Piston diameter comes to mind, as well as incorrect way of measuring torque output...I mean, a SB Chevy 350 has more crank in it than a 383 Chrysler...(3.380 VS 3.480)...I always thought the 383 Mopar was a high windin' BB, that was mainly happy in the upper end of the scale Myself...

Correct, an engine with larger bore/shorter stroke will have a higher peak port velocity at a given RPM than it's counterpart. That improves cylinder filling up to the point that the port cannot support either the total flow requirement or port velocity created.

[BSB67]

"Why was the 383 such a torque- monster?"

It wasn't

[firefighter3931]

"Why was the 383 such a torque- monster?"

It wasn't

The 383's short stroke handicaps bottom end power.


Ron

[RallyeMike]

Mike, have you ever driven a 440, even just stock or mild build? THAT'S torque!

Not too detract from the 383 - it's a great motor for many purposes.

[elacruze]

I think the gist of your question has been missed.

You're comparing the 383 to other similar displacement engines, which are mostly smallblocks.

The 383 uses the same heads which feed 440 engines, so the ports have significant capacity for displacement. However, in the grand scheme, the Chrysler ports are relatively small for a 440 (or 413) so they are not overly large for the 383. A very good compromise between low RPM velocity and high RPM capacity. Additionally as stated above the 383 has a very good bore/stroke ratio.

Compared to say, a 400 smallblock Chevy-the Chevy has heads designed for a 327/350" displacement motor. Works pretty good but limits high-RPM capability. Also, the 400 was never a performance engine in GM's lineup, and smog-era too so they were pigs stock. Don't ever put a built 383 up against a built 400, you'll get your ass handed to you.

396 bigblock Chevy; in 'standard' configurations, the ports are a little big to have the 383's lower RPM torque, but overall a decent match. In it's high-performance configurations, bests the 383 every time. Stock, as-delivered of course. Built 383 vs. built 396; GM win again.

389 Pontiac; I don't know, never drove any. 400 Ponchos I believe are a bit stronger all over, but I've only seen non-stock motors. I don't know the internal configurations, either.

All the 350" motors just give up too much displacement to compete in torque.

Just my  

[SRT-440]

Luckly for us 383 owners, we can build them to make plenty of power for the street. Besides, putting the power to ground is half the battle.  

[bull]

Yea, screw you guys. I like 383s.

[ACUDANUT]

 383 engines are awesome. My 383 feels like it has more power than my 440.

[Mike DC]

I think the gist of your question has been missed.

You're comparing the 383 to other similar displacement engines, which are mostly smallblocks.

Yes, that's what I was getting at.  Of course a bigger motor has more torque in total.  But the 383 delivered a lot of punch for its size. 

[1974dodgecharger]

All things being equal financially 440 can do what the 383 does, but better.  Most Joes probably have 3k in cash to build a engine so they opt for the 440 more bang for the buck. 

Nothing wrong with the 383 of course it can be built up, but still will lack the torque the 440 has 

[JB400]

It takes quite a bit of oomph to get something like this to move:



Apparently, the 361 didn't meet the expectations of Dodge, thus the 383.

[1974dodgecharger]

and tows the boat 

[440]

I haven't really driven my 440 charger but have had quite a few small blocks. The Ford 400ci is a torque monster. It was designed to do the duty of a big block and it shows. While not a performance engine when they are built right they haul ass. Mine is mild but moves a big lifted 4x4 F150 with authority.

I'm about to get a built 351c back on the road so it will be interesting to compare.

I look forward to the day I get my 440 6pack on the road, I've never driven a tripple carbed car.

[69wannabe]

Like Cooter said and alot of the other guy's mentioned from my experience the 383 I had suffered in the lower rpm range and loved the higher rpm range. It would turn up pretty hard and would move out ok too but after the 440 went in it moved out better with alot less effort!!!! The 383's are very durable and tough. I treated my old B engine with no respect at all since I had a 440 almost ready to drop in but it took the abuse and then some!! I didn't spray it since the factory rod's were still in it but I thought about it and it would've still held together I bet!! The 383's were not monster's but for the cubes they were impressive!!

[c00nhunterjoe]

In most of my dealings, when you have the same exact parts used in a 440 vs 383 build, yes, the 440 will obviously make more power then the 383. The 383 has a higher powerband then the 440 due to both its cubic inch and stroke difference. Again, in an exact same parts scenario, its not a huge difference, but the 440 is usually easier and cheaper to build then the 383, hence why 90% of people go that route when starting from scratch.
  My opinion has always been, if you already have a 383 in need of rebuild, then use it for a stroker build. You dont have to run out and buy a 1000 dollar 440 core unless thats what you really want.
  Im not going to argue that the 383 makes more power then a 440. That is absurd, but to call it a turd is an unfair as well. The 383 has got a bad rap over the years thanks to crappy aftermarket pistons that gave you 7.5 or 8:1 compression ratios. A good 383 piston is going to run you alot more then a decent 440 piston and the bottom end is where the big cost difference between a 383/440 build come into play.

[1974dodgecharger]

Maybe that explains why my engine costs k to rebuild. ....my 383 never understood it.  Thats why I go around telling people just get a 440 and be happy.....more support.

In most of my dealings, when you have the same exact parts used in a 440 vs 383 build, yes, the 440 will obviously make more power then the 383. The 383 has a higher powerband then the 440 due to both its cubic inch and stroke difference. Again, in an exact same parts scenario, its not a huge difference, but the 440 is usually easier and cheaper to build then the 383, hence why 90% of people go that route when starting from scratch.
  My opinion has always been, if you already have a 383 in need of rebuild, then use it for a stroker build. You dont have to run out and buy a 1000 dollar 440 core unless thats what you really want.
  Im not going to argue that the 383 makes more power then a 440. That is absurd, but to call it a turd is an unfair as well. The 383 has got a bad rap over the years thanks to crappy aftermarket pistons that gave you 7.5 or 8:1 compression ratios. A good 383 piston is going to run you alot more then a decent 440 piston and the bottom end is where the big cost difference between a 383/440 build come into play.

[c00nhunterjoe]

Well the pistons are the only component that costs more in a 383, and thats only a variable in a "budget" or "mild" rebuild. If you get into the more expensive lines then the prices are really the same. The 383 and 400 is just lacking a good midgrade piston and with the more recent explosion of the affordable stroker kits for B motors, i doubt we will ever see it.