Is OHC superior to pushrods?

Is OHC superior to pushrods?

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yes

Maybe?

troll threads are against the rules outside of /b/

What bus service do you use?

I don't know.

...

Triggered cuck detected

Pushrods have pretty much no advantages. OHC is better in nearly every way.

>his valves are activated mechanically

An engine harnesses power from expanding gases. To do this it must contain and control the gasses using seals and a form of piston. In order to reduce wear and friction it is best to have the highest volume increase to seal travel ratio. A linear motion has the highest possible ratio. In order to further reduce wear and friction its is also best the have the highest piston surface area to seal length ratio. A circle has the highest possible ratio. Therefore a round piston traveling in a linear motion is the most efficient and the most durable combustion chamber design.

Can you repeat the question?

OHC, especialy DOHC, allows for a better cylinder head design since it is possible to fit a larger valve area into the cylinderhead without needing to lower the compression ratio.
The valves are smaller and can therefore open and close at a higher frequence.
OHV allows for variable valve timing and lift as well, wich is hard to realise with OHV engines.

Camless engines are the future.

When OHC is OHV

>Not shoving reed valves in your pee hole

why shill lmao, is it worth the hotpockets?

Learn to sage red.ditor

. 3

>get more vague and make 2 threads next time.

pushrods are superior because they cost less than a set of four cams

>Having two banks of cylinders

Lel!

>He thinks people voted for Trump because they liked him, not because they disliked Hillary
This is why it should be illegal for foreigners to comment on American Politics.

You do realize Trump has only been president for 4 months, right?
>Trump's inauguration audience was small
see pic related

. 7ebz

And he already backed up from most of his campaign promises lel

>Americans got cooned

lol

oh, sorry that image is wrony. he replaced obama care with something worse, lel

>Americans got cooned
In 2008

dont u work at autozone lol

>OHC allows for better cilinder head design
Wrong. For example,. a 6.4 Hemi will outflow a Coyote, despite the Coyote's massive advantage in valve skirt area.

>Valves are smaller and allow for higher RPM.
True, but useless if you have 24-25m/s piston speed @7000RPM. On engines with such a long stroke, who cares about higher valvetrain redline? It's the bottom end that dictates redline on 95% of all commercially available engines.

>OHC allows for VVT and VVL, OHV does not
Wrong. VVT is piss easy to implement on a single cam engine, since you only need 1 phaser instead of four. Sure, you can't separately phase intake and exhaust with that 1 phaser, but 80% of VVT's power/economy gains can be achieved by that 1 phaser. For separate intake/exhaust VVT, you can use the Viper's cam-in-cam system. Two phasers, for some extra reduced costs compared to Ford's four phasers.

VVL on pushrod engines is still theoretical, I'll give you that one. However, you can hydraulically collapse lifters very easily in an OHV engine, which gives you variable displacement. This gets 90% of VVL's job done - having an economy-focused airflow (half the cilinders), and a power-focused airflow (all cilinders). It's just a matter of time before we don't just shut the lifters down, but we can also collapse them as a percentage.

Stop

>Cilinders
>>>/gradeschool/

My bad, it's cilinders in my native language.
Off to >>>/Basisschool/ it is.

.

how would you even know since you're illiterate?

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flathead masterrace

>6.4 Hemi will outflow a 5.0 Coyote
The Hemi on the other hand has a insanely high inner surface and needs special pistons and a long stroke to get a semi decent compression ratio, breathing isn´t the only factor in cylinder head design.
Also the 6.4 is a larger engine.
>24-25m/s @7000rpm
That is unusual.
>It's the bottom end that dictates redline on 95% of all commercially available engines.
I won´t go that far, but the Valvetrain is indeed not the only thing limiting your rpm.
But to rev decently, you´ll need either OHC or verry strong valve springs to counter the inertia of the valve, the rocker and the rod.
>you can use VVT on OHV
As I wrote, it is harder to build, not impossible.
>don't just shut the lifters down, but we can also collapse them as a percentage.
The lifter would impact the camshaft, wich would cause insane wear or destruction.

Anybody who's done any basic research realizes that its a fucking miracle that Cheetolini still has any money at all.......

I was thinking of a camless system like this the other day, why doesn't any engine do this? I'd imagine its not a particularly original idea, so i guess its something else stopping its use. The koenigsegg is meant to have some pneumatic variant of this.

I think the valve itself is the blockage and should be replaced with something like a ball valve or a gear.

It is expensive and complex.

>hurr durr muh monies genius!

fortune.com/2015/08/20/donald-trump-index-funds/

making money off real estate is literally the lazy, rich man's way of making money

Why don´t you do it with your savings if it is so easy?

Pushrod motors are much smaller physically than OHC engines in the same configuration. I'd like to put a 1uz or something in my turd gen but it's just too big. Can't even put most aftermarket intake manifolds and carbs on it because they're too tall.

yeah sure let me borrow a couple mill from my dad oh and also let me use my rich daddy's business connections

If it is so easy to make money with and Trums is so stupid, why did he turn millions into billions while you can´t turn 10k into 100k?

You really are incredibly fucking ignorant

why was your dad a failure then? i'd ask you if you'll be able to help out your kids but we both know that won't be happening lmao

inherited real estate (the one thing he actually "made" money at)
borrowed millions from daddy
used daddy's business connections
convenient how you forget to mention all the other failed businesses. Again, real estate is the lazy rich man way to make money

>trumptards literally thinking Cheetolini was some miracle rag to riches story

guy was born in 3rd base and thinks he hit a home run.

You didn´t answer my question :^)

because it isn't a "question" xd, you think Average Joe trying to turn 10k into 100k is the same as the son of a real estate mogul turning millions into hundreds of mills (russian loans don't count)

and that's how I know you're just another braidead trumptard

The only significant factor in financial buisness is how much time you need to multiply money.

Pick any single rich person in the world, they've all failed a bunch of times before succeeding.

>The 6.4 Hemi needs special pistons
Nope, it uses regular flattops, since it's a semihemi design. You're thinking about the second gen Hemi, which does need the domed pistons you posted in order to get any decent compression ratio.
>6.4 is larger
So? Despite having less valve skirt area, it outflows the Coyote.

>24m/s @7000 is unusual
Not on truck engines. A 4" stroke already gets you 23.7m/s.

Even with OHC you need 'really strong valvesprings to rev decently. Meanwhile, a well-designed OHV engine can rev to 9K, and that's plenty for most street engines.

VVT isn't harder to build on OHV. It's actually easier and cheaper.

Go look up how displacement on demand works. You collapse the lifters - it stay in continuous contact with the camshaft, it just stops translating any motion at all into the pushrod, which leaves the valves closed and effectively shuts down cilinders. You're a bit behind on automotive tech, it seems.

>headflow
>relevant to the quality of the head

every single time someone discusses this shit you repply with the same dumb fuck statement

cfm is literally irrelevant, a superbike cylinder head flows barely above 200-ish cfm, yet they make outstanding power

>OHV engine can rev to 9K
literally nothing compared to OHC

>Headflow
>Not relevant to the quality of the head
Pick one, one, and only one.

You're confusing me with someone else.

CFM is not irrelevant. For example, that same superbike head (200cfm, 4 cylinder) flows enough to support 200hp. Guess what, they make just under 200hp (the rest of the engine is the limiting factor). A 300cfm 6.4 Hemi can support about 600hp - and it makes about 485 fron the factory. CFM and horsepower are clearly related, since the amount of air you put in an engine determines how much power it makes.

>Literally nothing
Literally useless in production engines.

yes, but the key difference here is that the coyote, a superbike and the 6.4 hemi ARE NOT THE SAME ENGINE

it doesn't matter if the hemi flows bigger numbers, it would be useless on a smaller engine

>CFM and horsepower are clearly related,
correlation =/= causation

>Literally useless in production engines.
It's called the bill of rights not the bill of use

>correlation =/= causation
There's literally a formula to guesstimate how much HP a given amount of CFM can make:
HP=0.25714*CFM*(#cylinders)
CFM causes horsepower - it's simply how our glorified air pumps work.

>It doesn't matter if the hemi flows bigger numbers, it would be useless on a smaller engine
So the OHV Hemi makes more cfm, despite having less valve circumference (something like 165mm Vs 190mm) than, say, a Kawasaki literbike, and you're saying me 'the Hemi head would be useless if we scaled it down!'?

>It's called the bill of rights not the bill of use
Lol You actually think you can take your own OHC engine over 10K RPM

Think again, unless you have a tiny stroke (like a peterbike)

>guesstimate
thats the problem, do you understand how fast you would need to spin a bike en gine to be able to move 400 cfm of air? that formula is over simplified

You run into a similar problems as with intake runner length, you cannot keep ranking up the cfm because you need enough vaccum to make use of it

>scale it down
>OHV Hemi makes more cfm, despite having less valve circumference
oh so you understand that
a) a 340 cfm @ .700 apache head would be useless on a literbike, which means that in this post , where you claim that the apache head is better because it outflows the coyote you are acting pruposely retarded
b) valve area does not determine cfm, which means that in this post you are again bullshitting about how the apache is magically better

we are not arguing whether or not my car can rev over 10k, but that OHC is pretty much a requirement at those speeds dummy

Yes.

> Despite having less valve skirt area, it outflows the Coyote.
The point is, that 2-valve cylinder heads can not fit the same valve skirt area in a cylinder head as a 4-valve cylinder head could.
>Even with OHC you need 'really strong valvesprings to rev decently.
Not as strong as on a OHV due to the reduced inertia due to the lack of rocker arms and pushrods.
> a well-designed OHV engine can rev to 9K
Wich production engine with a OHV valvetrain revs to 9000?
>4" stroke
Pretty much no normal engine has a stroke that long.
>VVT isn't harder to build on OHV. It's actually easier and cheaper.
With DOHC you simply put a phase changer on a camshaft.
With OHV you need a cam in cam design
>displacement on demand
This system only works when the the lifters are either fully collapsed or in normal position, they woul have a hydraulic shock inside them if they would operate in a position between those.

Like everything, depends on your metric. If it's hp/L, then yes, OHC will always be "superior", and since that is all the benchracers on here ever seem to crow about, in the context of this board, the answer is probably yes.