rx7speed

that doesn't prove the displacement arguement

again try reading the question I asked



what do all those things have in commong

stu

I already answered this question.

Let's stop being dumb already. In real life, you'll never be able to compare two perfect set-ups that have every ounce of power squeezed out of them. Despite all the theoretical crap you want to spew, the truth of the matter is, the motor that can flow the most air will make the most power. That still doesn't even make it the faster engine either. Theoretical situations are stupid and I'm surprised that the word "theoretical" even appears in this forums title, as every other board I've ever posted on has moved away from theoretical magazine racing long ago. I think we should do the same.

What if you drove a shark powered wheelbarrow and raced a twin pony powered wheelchair? Who would win?

Answer: Who cares, you'll never find out because it will never happen.

stu

I already answered this question.

Let's stop being dumb already. In real life, you'll never be able to compare two perfect set-ups that have every ounce of power squeezed out of them. Despite all the theoretical crap you want to spew, the truth of the matter is, the motor that can flow the most air will make the most power. That still doesn't even make it the faster engine either. Theoretical situations are stupid and I'm surprised that the word "theoretical" even appears in this forums title, as every other board I've ever posted on has moved away from theoretical magazine racing long ago. I think we should do the same.

What if you drove a shark powered wheelbarrow and raced a twin pony powered wheelchair? Who would win?

Answer: Who cares, you'll never find out because it will never happen.

Orr89RocZ

iTrader: (20)

LMAO, i never heard it put that way. duhhh, the ponys cuz the shark cant move on land!!

rx7speed

you might of answered the question
others don't seem to get the idea though that displacement isn't the end all.
the only thing they see is there is no replacement for displacement.


since some of them don't get the idea I will answer the question for them just as you ahve done.

all the above: cams, heads, displacement, boost, nitrous, intake, exhuast all those do one thing. get more air into the motor.
more air means more stuff to burn.

displacement is NOTHING MORE THEN A TOOL to get more air into the motor and is JUST LIKE ANY OTHER MOD. it is replaceable and is only a means to get more power not the end all of having power.



as stu also said just because you have a bigger motor doesn't mean you win. there are other factors involved

weight, gearing, power band and stuff like that even play a factor.


but again displacement is nothing more then a tool not an end all be all of making power.

Orr89RocZ

iTrader: (20)

i thought you all were talking about HP creation, not winning or loosing based on size of your stroke and the diameter of your bore. LOL

Take my previous example and thats correct for most naturally aspirated engines

Now take my previous example and add 10psi to each motor using the exact kit/blower/all the tunning involved and i can guarentee that the 383 will out power the 355.

Hp creation does favor the larger engine in the right conditions, but doesnt necessarily mean it will win. AS you said, wieght, gears and suspension stuff do play a role.

True lots of smaller motors will make more power than bigger ones.

beating a dead horse here. This argument could go on for years. LOL

rx7speed

true it might be beating a dead horse but you know I have nothing else to do when I sit here at work



but your arguement on the 355 and 383 each with boost the 383 wins


that is like saying though take two 350's add a good set of heads to one and not the other

who will win the one with better heads right?


in each example your 383 vs 350 the 383 will pull in more air

the one with the two 350's what do the heads do?
bring in more air


either way you are using a tool to gain more power





though yes I will admit a perfect theoretical motor will have
infinite displacement
infinite boost
infinite nitrous injection
infinite compression
infinite flowing heads
infinite flowing intake manifold
infinite flowing exhuast
infinite flame front speed
infinite revs
no pumping loss
no frictional loss
no windage loss
no loss due to sealing


but since we can't get infinite on those things and them remove any of the "no" parts from there

we have to use tools to get as close as we can

better cams, better heads, up the compression, windage trays, better rings, better intake manifolds, less weight on the rotating assembly

they all are means and not one by itself is the key.

Orr89RocZ

iTrader: (20)

yeah true again. Everything about engines are tools to combust air and fuel to make force in the name of HORSEPOWER and TORQUE. LOL suprised this arguement when as long as it did without getting locked up.

84firebird383

Ok I supposed I shouldn't even go here but. If bore * stroke is the main determining factor in an engines performance potential then would a 300 ci single cam pushrod 2 valves per cylinder straight 6 have the same potential as a 300ci dual overhead cam 4 valve per cylinder v12?

305q_ta86

iTrader: (1)

Well, no, because, tuning. If the heads on one flow like crap, then it's performance goes WAY down.

84firebird383

I was basically comparing a 4.9 liter straight 6 ford pick up motor to a early 80s lamborghini 5.0 liter v12 just to show that design is just as important as displacement as far as actual potential of a motor might be.You can add cubes to both to make more power, but how many more would you have to add to the fords 4.9 liters to equal the lambos 5.0.

305q_ta86

iTrader: (1)

THe 4.9 would have to be like 49l to make up for it.

ScottyRS

iTrader: (2)

RX7Speed you keep saying that if a guy with boost gets a 350 and a guy with a 350 gets boost that one of them is right. Well then they would have the same damn engine and neither would be right!

305q_ta86

iTrader: (1)

That's the point. They would have the same engine, making the same power.

rx7speed

they woudl have the same engine your right.
so in the end boost and displacement are about equal in this situation
in any situation the sum of the parts rather then who has the bigger motor

stu

Looks like I'm right as usual.

Orr89RocZ

iTrader: (20)

I got lost. I dont feel like reading thru the rest of the posts to find my way back. LOL

Metal383

comes down pretty much to this, the more displacement you have (as far as same design engines) you have more potential for power. Proper tune to proper tune with the exact same parts, the bigger (still same motor except for bore, stroke or both) will make more power. Its like most other mods, you can compensate with some other pieces but in the end its still a pretty good idea. You can tweak a smaller motor to kill a bigger motor but its not apples to apples, its apples to oranges at that point. Not to mention all turbo/super chargers are positive displacement pieces, the add more area for air to take up, doesn't up engine displacement but it still adds area.

305q_ta86

iTrader: (1)

Well maybe not so much area as moles of air. As I recall, if you were to put 7PSI into a motor, it would be comparable to increasing the engine's displacement by 50%, because normal atmospheric pressure is about 14 PSI.

rx7speed

to comprae small tweaked motor to a untweaks larger motor and say that is apples to oranges is about as much of a apples to oranges comparison between a stock small motor vs a stock large motor.

and yes having a larger motor makes for the potential to create mow power just as more efficient heads do or larger cams or more compression. they all add more potential for more power.

in the end we still end up with displacement is a tool not an end and still hasn't been shown to be "no replacement for displacement"

Orr89RocZ

iTrader: (20)

you can look at it both ways as a tool or the deciding factor

Both a tool and factor of production of power.

take the 305 TPI and 350TPI
same L98 cam, and intake, similar compression and air flow. 350 out runs the 305 because more cubes delivering more air and fuel.
Therefore its a tool to add air/fuel, but also "no replacement for displacement theory" as well.

305q_ta86

iTrader: (1)

Umm I think the 305 and the 350 have a few more differances. And dont forget about the different bore and stroke. Longer stroke creates more tq.

THEGENERAL

before i explain the stroke differences in a 305 and 350 read this there is none...LMAO

http://www.darklair.com/monte/BxS.html

305q_ta86

iTrader: (1)

Ah. Well, the bore is different. Theres the HP difference LOL

rx7speed

so in your example you leave only one variable

now lets change the variable but leave everything else the same
two motors both 350's both l98 cams and such

one has boost one doesn't
[b[ no replacement for boost[/b]


or here lets do this
both 350's
one has the peanut cam one has the good l98 came
no replacement for a good cam


or lets go to heads
one has 8:1 the other has 11:1
no replacement for compression


the list can go on here

when you have only one variable which you keep wanting to place on displacement the motor with more displacement will win
but then again in each of the cases I listed is as you like to do
each time the one with the larger cam, or more compression, or boosted wins


not trying to be rude but can you get that point?


anytime you leave only one variable the one with the better part of that variable is going to have more power
be it displacement, cam, boost, or anything else

still

Orr89RocZ

iTrader: (20)

yeah, i was agreeing with you on my last post.

just showing that displacement is a tool like you said, and you can see how some people twist that into "no replacement for displacement" Displacement was my variable in that case.

i see what your saying, too many variables when comparing motors. Its too hard to compare. LOL more displacement, more cam, more boost, more flow etc..... You throw that together and you got a mess!! LOL

rx7speed

oops ok

what can I say I'm sitting here at work on the phone doing tech support for dsl... fun stuff just get distracted easily and so sometimes miss things



no worries though I hope

305q_ta86

iTrader: (1)

DSL tech support eh? Sounds like an awesome job. Especially if you can still go on TGO at work LOL

ljnowell

Everyone has explained it. He just wants to argue. If everyone would just drop it, he can argue with himself.

305q_ta86

iTrader: (1)

To each his own, I guess

305q_ta86

iTrader: (1)

..Also note the turn this thread took from it's origional subject, and it still avoided the lock lol. But that's because it's theoretical and a really good discussion lol

rx7speed

I'm not just trying to argue but make a point. ( well that and I am bored)....


but as far as how off topic this has been. we have all remained respectfull of each other, no name calling, all staying theoretical, and can be applied to thirdgens, we have followed the rules and so far has been kept very clean.

but yeah we did get a little off

305q_ta86

iTrader: (1)

Well said. And I agree with most of your theories, but rather than just saying outright what I dont understand or believe, I think it out first lol.

Screw getting off topic. This is fun.


And once again, I still think it's displacement x tuning x boost = power

custom88camaro

I wonder where this thread would have gone if I had never mentioned whether there was a replacement for displacement.

So, after all this arguing and theory and blah blah blah, the original reason I brought up displacement was b/c the question was asked whether he (originator of thread, can't remember who) should build 305 or 350. Basically, building a 305 would be like shooting yourself in the foot, you are forfeiting one of your power makers. It could be compared to building a 350 but using dish pistons and 72 cc heads. He thought he may put boost to it some day and he asked if that would make up the diff. of using 350 over 305. The answer is no, because you would make more power by boosting the 350. The point is no matter what you do to a properly tuned engine to make more power, it would benefit from more displacement. Can you say that no matter how big your cam is you would always benefit by using a bigger one????? NO. Can you say no matter how much you are boosting, you would always benefit by adding more boost?

The point is efficiency. To an extent, a larger cam is more efficient than a smaller one. To an extent, more boost makes an engine more efficient. To an extent, compression makes an engine more efficient. There is no end to the possibility when you are adding displacement.


Later dudes.

rx7speed

eh there is even a limit with displacement or else we all would drive around with 572's under the hood



but yeah with a 305 vs 350 I would say you are shooting yourself with the 305

for one thing as you said you do lose a tool to add power
but also 350's are dime blocks, cheap and easy to grab and can find just about anywhere

why sacrafice it?

kinda like should you get the 212/222* cam or the 198*/198* cam when they both cost the same?

custom88camaro

Well, as for the 212/222 or 198/198 thing, that would depend on where you want to make your power. The bigger inch thing will make more power across the board. I guess that is another argument for increasing CID. You will see power gain across the RPM range, not just high or low RPM.

Orr89RocZ

iTrader: (20)

a limit, well i seen some 700 cubic inch beasts all the way up to Sonny Linston (sp?) 762 crate for 50grand!!

Thats the limit LOL

custom88camaro

Well, my point was that you will always make more power by increasing CID to any configuration, not whether or not you could cram it under your thirdgen's hood or not. Any of the other power adding "tools" have a limit. If you add too much compression, you will detontate. If you have too much boost you will detonate. If you detonate, you aren't increasing power anymore.

Orr89RocZ

iTrader: (20)

If it goes boom, you make lots of power, just not the good kind we car enthusiasts like! LOL ahh, explosives!! LMAO

custom88camaro

LMAO.....Smartas s!!!..LOL

I'd rather my engine not explode any time soon, at least not until I could figger out a way to get my insurance to cover it!

rx7speed

you know out of all the arguements on the board so far yours have been the best and the simplest ones as well


the 198 vs 212 cam I wouldn't think would make that much of a difference as far as power but don't that against me if I am wrong

but there are other things that can add power through the board

heads with a more efficient design have been known to give power through the band, compression can do that different cam grinds, and such. roots blowers are also good at power through the board as well as nitrous (well once activated).

but even with displacement you can see it sometimes bias sometimes low or high end depending on what the rest of the system is like..... look at the l98 with those extra cubes it bias more to the lower end with that crappy intake manifold designed for the 305.... not saying it is always going to be the case but somtimes the rest of the mods just can't support the extra cubes,

but generally you are correct through the rpm range :-)







another thing I wanted to add.... this arguement is nothing compared to one held a few years ago between me and lowstyle in the exhuast board regarding backpressure..... THAT was stupid long but we got through it



and to your last post if you add to much displacement you will suck your fuel tank dry before you get it out the driveway which means no power ... ok so I'm being a smarty here but I'm happy since I only have 30 min left till I get to go home

no more qwest for me till tomorrow

Orr89RocZ

iTrader: (20)

IF GM would only make a big block LS1 with 572 cubic inches and 25mpg!!! Drooling profusely.....:hail: :lala:

custom88camaro

Thanks, I was trying to figger out the best way to get my point across. As for the running out of gas thing.....If you are using up all of that gas efficiently, you would be making a helluva lot of power!!!! As for the heads, an increase in port volume could hurt a small engine, because the velocity in the runners will be reduced. This could take away from low RPM power, but it would increase top end, because at higher RPMs the velocity in the runners is high. Another thing, you can't count solely on displacement. (compare DZ302 vs 305) The 302 stands to make more HP, but at a higher RPM. You would blame that on rod ratio and a better bore/stroke combo. However, the 305 would make better bottom end, and have more torque. Of course, the 302 came with a better cam and head configuration than any 305, so that would be another reason it would be better.

rx7speed

with the heads though not always does more power come from larger runners
quite a few ppl are starting to design heads with smaller volumes yet make for more air flow. it is efficiency in the air flow

I have seen something where they only remove about 2cc of casting yet get another 30cfm.
that will be flow through the board not just up high.

Nutty91RS

Jesus man race this guy!!! let him tune it up yadi yadi yadi, just race him!!! If he wins peice together a nitrous kit on eBay and buy yourself a posi unit spray 100 show to your 305 and see how he likes them apples!!! Tell us how it goes.

THEGENERAL

LOL very well put i like how you worded that .....

305q_ta86

iTrader: (1)

Haha I'll probably have to do that. I have already decided to get a 350 this spring/summer, and he probably wont have the thing running by then, so when it comes time to race, I should have no problem.