Battle: small block vs big block

[chargd72]

Read ALL before you get frustrated...

Let's say our Charger without an engine or tranny weighs 3,000 lbs.  I got some numbers of engine weight from the web (I'M NOT CLAIMING THEY ARE EXACTLY TRUE) but close enough to make a case.  440 is roughly 670 lbs, 340 is roughly 525 lbs.  727 Trans is roughly 136 lbs, 904 is roughly 95 lbs.  That brings our BB combo to 806 and our SB combo to 620.  A difference of 186 lbs.  Pop the BB combo into the Charger and get 3,806 lbs.  I'm going to use 1971 HP numbers and the BB unfortunetly gets the low compression version (just to make this a little more fair).  The low comp BB put out 330 hp and with weight of 3,806 that gives us a power to weight ratio of 1:11.5.  Now, replace the BB/727 for the 340 and 904  but it had to get some additions to reach the 330 hp, which if very possible, and now our Charger weighs 3,620.  Since our built up SB produces the same HP and weighs 186 lbs less, we get to add the effects of 1 HP for every 11.5 pounds it lost which is 16.17 HP.  Kind of cool!

Now, before everyone gets upset and says a lot of factors were not taken into account, I KNOW.  The TQ humbers haven't been considered, the BB could easily be build up too, etc, etc.  This is merely just to open up descussion.  And so some people put some thought into purchasing any old 440 or considering sticking with their SB. 

Sincerly,
A Small Block Fan

[Ghoste]

So you suggest that if you have a smallblock, it's better to build it up to a higher performance level than to get a low compression big block and just leave it stock because the built up sb will outperform the stock low comp big block?
That isn't exactly news.  I suggest getting the big block and putting an equal amount of money into it and enjoy the torque. 

[chargd72]

Nope, not suggesting or even trying to debate which is better.  Maybe only trying to go against the "there's no replacement for displacement" theory. 

I suggest getting the big block and putting an equal amount of money into it and enjoy the torque. 

I absolutely agree that this will always outperform   

[68X426]

Small blocks are fine ...... in grandma's four door. 

Just joking!!!!

It is a very good discussion. Lots of advantages to SBs. Look at what Brand X has accomplished for years. Mopar SBs are certainly under valued, unappreciated, and yet full of potential. Go ahead, keep making your case.

[Ghoste]

I think you've twisted too many things in your effort to make it a "fair" comparison.  For starters, the 340 came with a 727 so add a minor amount of weight.  Next, no matter how you slice it, you still have to factor in torque.
If your question was merely two identical 1971 Chargers, one equipped with a 440 and the other a 340 which would perform better?  Then you would open up some interesting comparisons.
Stock for stock and all things being equal, I'll put my money on the 440 with it's torque. But I'm just barely smart enough to know a good 340 may take my money.

[tan top]

seen 440 sb crate motors ,      paint them up to look like a 318 at a quick look    & supprise a few bigblocks 

[Ghoste]

Yes but a stroked out 500 cube big block looks like a lowly 383 at quick glance too.

[tan top]

Yes but a stroked out 500 cube big block looks like a lowly 383 at quick glance too.

D'oh 
good point Ghoste  

[BSB67]

Generally for B body type weight, 10 hp = 100 lbs = 1 mph = 0.1 sec for a high 12 sec street car (tire, converter, and gear).  The 186 lbs will be equivalent to about 20 hp  (your formula is 16 hp - close enough).

Also, generally speaking, making .9 hp/cu.in will cost about the same for each engine and is realistic to achieve.  So, if you already have both engines, after spending about the same amount of money to get to .9 hp/cu. in. (395 and 325 hp respectively), you'll have 70 more hp, the car will run the quarter 5 mph faster, and be about .5 sec. quicker with the 440 and the 186 lbs disadvantage.   Of course, the gap gets even wider as the hp/cu.in goes up.

[Troy]

In the same car, the 340 (275 hp) could typically hang right with the 383 (330-335 hp) in the 1/4 mile - and generally leave it in the dust through the twisties. Maybe the bigger/heavier cars didn't follow this pattern? Your 300 hp 440 would be mismatched but probably still has a big torque advantage. The 340 in the Challenger got the heavier suspension but I'm not sure about the other models so that also negates some of the weight not related to the engine/trans. The 340 always got upgraded to the 727 so you have to factor that in. Going completely non-stock would allow anything you wanted I guess. Stick an aluminum intake and heads on a 440 and you lose about 60-70 pounds. Add an aluminum water pump, radiator, and headers while dumping the power steering and brakes and you can really lighten up the front end. This works with either small or big block though so the weight advantage evens out.

I think the biggest bang-for-the-buck is a 'B' engine stroker since it's only about 130 pounds heavier than the small block and can be built with more cubes than the big block in a smaller package.

Troy

[Cooter]

I go through this one about once a week with the import VS Domestic guys...Yeah, that little 2.0 liter puts out 600 HP...And my 440 "Only" puts out about 400 HP...Your import is quicker right? Well, let's see what's being compared here..I think it's apples and oranges....


2.0 liter import making 600 HP is all but MAXED out, with a mondo TURBO that sounds like a twin engined Cesna when you give it throttle.
Lemme get the SAME mondo TURBO and we'll see who's got the upper hand...


Lemme see, a Small Block that's maxed out making 800 HP is quicker than say a 500 C.I. stroker Big Block making 600 HP right?

Well, let's see here...
Let's max out the Small Block Mopar @ 440 Cu. In. You guys have any kinda idea what kind of rod to piston ratio this motor has? It CAN'T be good...Gotta be trying to shove the piston's right outta the side of the block..This costs HP...(Friction loss, or Parasitic drag)

Now, this engine making say 650 HP MAXED out...All it'll do...DONE without a power adder right? Hell, let's give the lowly Small Block a chance, and give it 850 HP MAXED out, without a power adder, at something like 9,000 RPM...

Now, let's max out a Big Block @ say 655 Cu. In. (Afterall, the 440 SB has an after market block, so we gotta give an aftermarket block to the BB guys as well to be fair)
Now, this engine MAXED out, best effort without a power adder, say 1200 HP? @ say 7500 RPM?

There is a replacement for displacement in some folks eyes, it's called Nitorus, Turbo, Supercharger....Just remember the next time you are thinking that, that the BB Also gets whatever you give the Small Block, the BB just BEGAN with more....Handicaps have no place in the SB VS BB...All is fair...
SO, Torque is what gets that heavy beast of a 1972 Charger moving, NOT HP...
And with the advent of lighter rotating assy's, blocks, heads, the Big BLock can actually weigh the same as a small block...
There will always be people that tend to lend their loyalties to the "underdog" and in the eyes of collectors and gear heads, the Hemi and BB 440 is king, with the lowly smal lblock running a close third...I simply go for the biggest and baddest engine to come from the Mopar family..the 440...,

Bottom line? When all else is equal, yee who begins with the bigger engine, ends with the bigger engine...No Contest...

I know guys that will spend $30K in order to be able to say these few little words come race day...
"Wow! I just CRUSHED your Big Block Stroker with my "Lowly Small Block!"
Ok, so you just out ran an $8000.00 Big Block stroker, with a $30K Small Block?...Hmmmmm, Even I can see this one...

[RallyeMike]

Nope, not suggesting or even trying to debate which is better.  Maybe only trying to go against the "there's no replacement for displacement" theory. 

Have you noticed the explosion in stoker crate motors and kits (big and small block)? Y

ou might get more people to believe the sky is green that small displacement is where it's at.

[chargd72]

Once again I'll state the purpose of my post wasn't trying to argue that small blocks are where its at. I was simply impressed that 186 lbs would even yeild that much difference lugging these big boats around. I know that 340s came with 727s, I just used the 904 because it CAN work. I should have used the engine combos in a little red wagon to be more clear.
I hope it's obvious to anyone reading this that the same amount of money put forth in any build it's always best to start with a larger ci if you're looking for all out performance. Bsb67 took the discussion in the direction I was looking for.

[Tom Q]

it's about horsepower to weight ratio

How much does an an aluminum head bb 505 six pak stroker weigh vs an aluminum head sb416?

I know a 416 alum head sb 6 pak will make 400 reliable rear wheel hp at 6000 rpm

89 cubic inch difference

Assuming the same hp vs cubic inch ratio the bb will make 485 rwhp at 6000rpm. 85 more hp or so lets say 100 for argument sake. How much more weight for the extra 100 hp? 

[Ghoste]

Torque will play a role too.

[chargd72]

I should have used the engine combos in a little red wagon to be more clear.

That didn't make it anymore clear...  I actually meant a red wagon like a radio flyer, not a power wagon, oops.

And yes Ghoste, going head to head tq will always play a significant role and that's the huge divider between the two.  Even with the power to weight ratio Small Blocks will always lack in that department even when matched with a low HP big block. 

[Ghoste]

I hope this doesn't sound argumentative because that isn't my intent, but, I guess I still don't understand the discussion.  I thought your point was that by building up the 340 and adding a lighter transmission that it would be a better choice than a low compression stock 440.  That was what I took from it anyway.   And on that point I (wouldn't everyone?) agree, I was merely replying that you have to compare apples to apples.
I think I missed completely what you are driving at though, haven't I?

[chargd72]

I was absolutely comparing apples to oranges.  Big Blocks and Small Blocks are completely different entities and my point was the obvious one you pointed out.  My interest was only in sharing how much a lighter application can give you in numbers (HP only, not tq), which was surprising to me.             

Also, we see a lot of people think they need a 440 to have a bad ass machine that they are going to be driving on the streets everyday.  I was just pointing out the other areas of potential to consider.  I was not stating that it is an all out a better performing engine, just that SBs can be beastly in their own sense.   

[Ghoste]

Maybe it isn't apples to oranges either, maybe it's big apples and small apples?

[Cooter]

Unfortunately, there's simple "unwritten" rules Mopar people HAVE to face eventually..A Small Block won't hold a candle to a Big Block in terms of originality values, HP/Torque (When everything else is equal), and the HEMI will ALWAYS out shine the 440 even though back in the day, a 440-6 would eat a HEMI's lunch on the street most of the time time...

I thought this one was about "No Replacement for displacement"..The answer is simple when EVERYTHING being equal, there IS NONE..You start with more than the other guy, so you will finish with more..You love Small Blocks, I love Big Blocks..Some will Spend $30K on a 340 some will spend $50K on a HEMI...To try and discuss the SB Vs BB issue in reguards to HP/weight, IMO, is a simple as this...If the SB was all there was a need for, then the 350 Big Block would have never been invented back in 1958...You cannot stack the odds in favor of the small block no matter how you slice it here..The BB will always come out on top again, everything equal...Now a 340 with 275 HP in a Go-Kart against a Smogger 250 HP 1978 440 in a 1978 Chrysler New Yorker? No contest, but here again, the BB and SB aren't being compared equally..

[Mike DC]

            

My two cents is that you can't get an engine too lightweight.  

We think a big block is "light" with aluminum heads & intake but a lot of handling buffs would laugh at the idea.  The guys that are truly into sports cars & handling will look at a 450-lb all-aluminum smallblock V8 and wince at the weight "penalty" over a similar V6.  

Even in a car like an old Charger, it would be a real eye-opener if we could magically try driving it with the entire drivetrain weight taken out.  These car bodies aren't really that heavy for their size.  They just end up feeling heavy because we put a huge chunk of cast iron in the front end.  

[flyinlow]

One advantage of the small blocks in Mopars is that the A 518 or A 500 trans bolts to a 318/360 engine easily. Now with the .69 OD you can run a much lower gear and still have a good all around performing street car.

A couple years ago when I was Painting the car I drove it to a buddys garage. The hood,fenders,bumpers,doors, and deck where off the car, just the basic unibody/powertrain and seats. About 6 miles of  country roads with a car several hundred pounds lighter than normal.  So this is what a 500Hp Dart feels like. Got some funny looks ,none from the cops luckily.

[elacruze]

           

My two cents is that you can't get an engine too lightweight.  

We think a big block is "light" with aluminum heads & intake but a lot of handling buffs would laugh at the idea.  The guys that are truly into sports cars & handling will look at a 450-lb all-aluminum smallblock V8 and wince at the weight "penalty" over a similar V6.  

Even in a car like an old Charger, it would be a real eye-opener if we could magically try driving it with the entire drivetrain weight taken out.  These car bodies aren't really that heavy for their size.  They just end up feeling heavy because we put a huge chunk of cast iron in the front end.  

How about that aluminum-blocked 170" turbo slant 6?

[SRT-440]

So this is what a 500Hp Dart feels like.

Tho not "500hp" I have a '71 Dart with a mild 440 in it and the torque is amazing but it's like driving on a ice patch year around and at almost any speed..LOL.
It's silly fun but a 340,360 or even *gasp* a 383 would be a better overall performer in this light car. So, sometimes bigger isn't always better.

[Ghoste]

If the original question were changed to include handling it becomes a much broader field of discussion for sure.  I wonder if the difference in weight between a stock 440 and stock 340 would make an enormous handling change.