If i may offer: There is, in fact, a replacement for displacement and that is compression ratio. You see, average engine displacement from the period of 1918 to 1975 had not changed by very much however by the mid 50's the age of the high-compression V8 began.
Allow me to present an example. Buick's straight 8, the 30's era "Fireball" displaced 320 cubic inches and made roughly 77 gross horsepower. However Buick's 322 cubic inch "Nailhead" V8 produced in 1953 made 162 gross horsepower.
The difference of course, is the compression ratio. Both engines are OHV however the older "Fireball" had a compression ratio of 4.7:1 and the "nailhead had a compression ratio of 9.5:1
The displacement is a mere 2 cubic inches apart. I have thus provided examples that support my position. it is useless to debate me. Before you mention forced induction, please be aware that forced induction also raises compression ratio, thereby you will be supporting my theory. If you attempt to argue, please hang yourself by the neck until dead.
First off, let me start by saying that the increase in horsepower between the Buick I8 and Nailhead V8 is not directly correlated to the increase in compression ratio.
>There is, in fact, a replacement for displacement and that is compression ratio. No, because there is a practical limit to compression ratio, and it's dictated by octane and combustion efficiency. This is a hard physical limit. Is such a limit exists for displacement, it's the standard engine block - but a block can be replaced.
Effectively, there is no replacement for displacement. There is nothing that >Adds horsepower the more you add, with no physical upper limit >Does not add extra parts (such as a turbo) >Does not require you to change the type of fuel
Turbo's, nitrous and compression are all great ways of adding power, but they are in no way a direct replacement for displacement.
Parker Richardson
Sir you are incorrect for you see in 1971 with upcoming emissions, Detroit automakers reduced compression across the board by some degree resulting in tangible power loss.
Ryan Sanders
Nope, you are. The reduction in power wasn't just because of the drop in compression, the airflow of those engines was also choked, mainly by subpar carbs and primitive injecton systems, in order to meet emissions standards.
Compression adds power (up to a point), but to compare a 1930's straight eight to a 1950's V8 and claim that the increase in power is solely due to the increase in compression, is stupid. As is saying that the decrease in power from 1969 to the smog era is solely due to the decrease in compression.
Even if your point were true, it still doesn't make compression a replacement for displacement, because it has a practical limit. It is a merely a substitute.
Noah Foster
Practical limits only apply to the practical world sir. The truth in this is evidenced that Chrysler's 426 Hemi retained it's 11:1 compression ratio despite the upcoming emissions. Further, I will provide that your carburetor example did not apply to the early 70s. In fact it did not apply until the mid to late 70's and that it wasn't the carburetors themselves which resulted in power losses.
William Collins
I agree with this bird, hence why Mazdas' and 86s' naturally aspirated engines with lots of hp for their displacement have ridiculously high compression ratio that become ticking bombs if you slap on a tarbo (which is the point of said cars, to modify your rice burners amirite).
Brayden Hernandez
Horsepower comes from the cylinder head. Commission helps, but if you can't flow, which these old and smog era engine designs couldn't, then you won't make power.
Imagine
Austin Lewis
Stop being pretentious, it detracts from your argument.
>Practical limits only apply to the practical world sir. Which is the only world where engines are built. Sure, you could get a 15:1 compression engine, but if you aren't Mazda, you'll never get it running on pump gas, making it largely inpractical for the consumer.
>The truth in this is evidenced that Chrysler's 426 Hemi retained it's 11:1 compression ratio despite the upcoming emissions. That's because it was dead by the time emissions got around. The 2nd gen Hemi was built up to 1971, and the smog era only started in 1973.
It wasn't just the carbs (although electronic carbs flat out suck at making power), it was also the lack of heads that flowed well, cheaper build materials, smaller camshafts, air pumps - and wde range of choices that made advertised horsepower plummet. It wasn't just compression.
Still not a replacement for displacement, merely a substitute.
Those high compression engines only become time bombs once you add even more compression (albeit dynamically, with a compressor). Still, with a stroker crank and overbore pistons, you can add horsepower without adding as much strain on the engine, and without creating the demand for a higher octane fuel.
I agree with you sir for you see, the Ford Flathead V8 had at best, 7:1 compression and increasing this compression would result in less power from the fact that the head had less clearance. I would refer back to the "Nailhead". Reversing the valve train resulted in more power from the cleaner exhaust path but airflow is physically limited to the design of the engine whereas CR may only be limited by the quality of gasoline.
>you could get a 15:1 compression engine Sir, you are speaking of the diesel cycle. It is clear you are desperate for evidence. I shant be bothered arguing with a miscreant such as yourself.
>you'll never get it running on pump gas The examples of which i have posted come from a time when Tetraethyl Lead was available.
>That's because it was dead by the time emissions got around Sir, it was only alive for the consumer to further Chrysler's motorsports ambitions.
Aiden Martin
>Sir >shant >miscreant Could you please stop acting as if English is your second language?
>you are speaking of the diesel cycle. Nope. Mazda Skyactiv gen 1 is 14:1, methanol dragsters are anywhere between 14:1 and 16:1 and F1 has gone up to 17:1 when they didn't have turbo's.
15:1 is possible on an Otto cycle engine, is just requires exotic fuels to be viable. Those fuels make it impractical for consumers, and therefore, compression ratio has a physical limit. Even with leaded gas (which you can't use anymore) or LPG, there is a limit.
>Sir, it was only alive for the consumer to further Chrysler's motorsports ambitions. And Chrysler would have continued using it had they not had the problem of the upcoming emissions regulations.
Point still stands, and you can't refute it, that there is no replacement for displacement.
Hudson Martin
There is no replacement You can't be comparing a i8 to a v8 from different eras Take for example a 396 bbc and a 427 bbc Stock the 396 was around 350hp the 427 was around 430hp They are both v patterns built of the same mark iv design with the same stroke with the only difference being in bore and valve train Yes the 427 came with a compression around 12:1 and the 396 around 10:1 but even if you were to make the 2 similar and bring the 396 up to 12 the 427 would simply out preform it because it is bigger, more gas and air are being sucked in with a bigger area to combust
Eli Bailey
>Yes the 427 came with a compression around 12:1 and the 396 around 10:1 but even if you were to make the 2 similar and bring the 396 up to 12 the 427 would simply out preform it because it is bigger, more gas and air are being sucked in with a bigger area to combust I expected proper equations to support your theory.
Colton Reyes
Can't be arsed to redownload D&D, so Automation should do. It'll be accurate enough to simulate this scenario. I picked a 3.760'' stroke for both, a 4.252'' bore for the 427, and a 4.154'' bore for the 396.
Specs for both: >Iron block/head crossplane V8, modern OHV >Billet internals, 0 tech added anywhere >''60%'' aggressive cam, no VVL/VVT, naturally aspirated >Multipoint EFI w/ performance intake >95 RON fuel,12.5:1 AFR, 15% ignition advance, 7K redline >Longtube headers, 3'' true duals, no mufflers/CC
Pic related is the 427CI @ 12:1 CR
Jose Hernandez
no
Charles Rogers
And this is the 396@ 12:1 CR. Clearly, it makes less horsepower.
Brody Reed
fugg dude, /thread
Colton Ortiz
Interesting torque overlays.
Brayden Turner
>uses a game as an example
Easton Price
My bad, I used the 0.060' over as bore size for the 396. Should be 4.094'' instead.
Game or not, the physics behind it are 99% sound, and are perfect to illustrate a point.
If you're so adamant about a perfect simulation, go download D&D and make one.
Jack Carter
>If you're so adamant about a perfect simulation, go download D&D and make one. I have already provided sound examples to my arguments.
Anyway i'm just bs'ing,
Owen Murphy
>There is a replacement for displacement and that is compression
The more compression you have, the sooner your head gasket will begin to fail.