Why do people still use pushrods? OHC engines seem to be superior in every way at this point

>implying pushrods don't make more torque than an OHC engine

>but torque doesn't really matter

Bullshit. Straight up bullshit.

Jesus fucking christ you are actually this retarded. Displacement is the largest factor of torque.

How?

>Displacement is the largest factor of torque
lol no

Pushrods don't directly make torque more torque than their OHC equivalent.

However, there's two things you need to take into account here. First of, intended use, secondly, maximum RPM.

Intended use for most current pushrod motors is either ponycars, trucks, or Corvette/Viper. All of these, mostly trucks (which account for at least half of the sales), profit from having a good torque curve. Hence, the average pushrod V8 is designed to give more torque, using cam selection, head design, and tuning.

Second, hp = tq * rpm. HP usually stays identical for any given head flow, and pushrod engines cannot reliably rev extremely high. Because of the lower RPM, you can give them a longer stroke, which, in combination with good head flow, can create gobs of torque.

Basically, pushrods don't make more torque, but the way they're designed nowadays, pushrod engines make a lot of torque.

>Displacement is the largest factor of torque.
Nope.

Stroke is what makes torque. Also, head flow, cam selection and timing.

>implying the pushrod Silverado 4500 doesn't get destroyed by the OHC F450
Pushrods are shit either way.
this.

packaging

>>Displacement is the largest factor of torque.
>Nope.
>Stroke is what makes torque.

Technically stroke is part of displacement but I will admit I goofed a bit.

Displacement = stroke * bore
Therefore, displacement =/= stroke

Simply put, two identical engines, say 1L in displacement, one with a 1'' stroke, the other with a 2'' stroke, then the 2'' one will make more torque, given the exact same head flow.

Sure, adding displacement via stroke adds torque - but that's only because you're adding stroke. Bore increases do not increase torque, barring any headflow gains.

OHV can profiles are tuned to make more torque because they're more limited in the RPM levels they can operate at. You could use a similar cam profile in an OHC engine to make just as much or more torque than the OHV engine, but it would be stupid because you've got all those extra RPMs, why not use them?

sure thing m8

Uh, OHV usually tends to produce more torque because of the larger stroke and bore it allows for in a given amount of space.

Bore has nothing to do with torque. You're right about stroke though.

>filename being wrong
That's alphonse you dufus.

Both have the last name elric.

The point being is this IS a shitpost thread.

That's why he used a Alphonse image.....

>lol no
lol yes

>Stroke is what makes torque
lol no

>4" bore x 3" stroke pruduces the same torque as 2" bore x 3" stroke.
Rocket scientists up in here.

Given identical head flow, yes. The 2' might actually make more, because it'd have less ring drag.

However, in the real world, a 4'' bore head will flow better, hence more torque.

Basically, just because bore causes headflow, which causes torque, it doesn't mean bore causes torque.

Looks like DOHC I think

Remember that one time when Ford and their OHC BBF Hemi cucked everyone in nascar and nhra?
Lol good times

No, Ford cucked themselves. They complained and complained about the Race Hemi, Nascar forced Mopar to homologate a Street Hemi, and then Ford though they could get away with not homologating the Cammer. Wrong, Nascar told them to homolgate it, and then Ford realised it'd cost ludicrous amounts of money, and then payed Kar Kraft to homologate the 428 (It's not a Hemi guys, it's a Crescent! We swear we didn't rip off Mopar!) in the Mustang, to be used in the Fairlane.

Meanwhile, in dragracing, they didn't give the Cammer the factory support it needed (and the chain sucked), and it got outdone by the Hemi within a decade.

As for why the Cammer was never homologated in Nascar: it'd be ludicrously expensive. Iirc some surplus ones went for 2300 back then, which would've got you a pretty nice compact car. Cost for the factory was likely even higher. Also, weight over the nose was increased a lot, which certainly wouldn't help on the track, and the timing gear wasn't exactly ideal.

>remember that time ford cucked everyone with an engine that never ran a NASCAR race

t. Pushrod fangirls

Remember chrysler begged nascar to ban it

>Remember everyone begged nascar to ban everything

That's how it worked back then. Only Nascar had every right to refuse the Cammer, since Ford never homologated it - and it was Ford (and GM) that had actually demanded the homologation process, ever since the hemi came to town.

Ford sold enough engines for homologation

Keep memeing

>Ford sold enough crate engines for homologation
However, they didn't sell them in cars (like they did with the Boss 428). Therefore, it wasn't homologated.

On a sidenote, I'd love to know how much Cammers Ford originally made.

all eles being equal displacement is what makes torque. whether it's by bore or stroke doesn't matter

Because there's a good engine that still uses them

>you could
>in theory
>but what if
The only arguments to be made are motors that exist in the market today. The LS exists. Therefore people will use pushrods because the LS has them.

Some hot rod article claimed 650

2 were factory aluminum blocks.
I'm not saying where either one is sitting today for obvious reasons.

>whether it's by bore or stroke doesn't matter
Bore by itself does not increase torque though. Bore only increases torque if you utilise it to improve headflow. All else being equal, including headflow, an increase in bore does not increase torque.

Link to the article? Genuinely curious.

I'd also love to know what happened to them. At least a big chuck probably had some excessively self clearancing conrods, or DIY crank inspection ports.

>that image
calhager is that you?

>All else being equal, including headflow, an increase in bore does not increase torque.
All else being equal - including head flow - any increase in displacement increases torque.

Why do people still use combustion engines? Electric engines seem to be superior in every way at this point.

Are there any actually worthwhile reasons to use combustion over a electric engine?

>any increase in displacement increases torque.
>any

No. As stated before, an increase in bore will not add torque, it might actually increase ring drag and reduce torque.

why wouldn't it increase torque? increasing stroke also increases ring drag

Yes, but stroke increases the leverage the piston has on the driveshaft. It isn't called ftlbs/Nm without reason: the pistons provides lbs/N's of force, and the crank throws add ft or m to that to create a unit of torque.

Making the piston bigger does not change anything, because force equals pressure times area. The force remains constant, because it is equal to the combustion energy of the air and gasoline in the chamber. Making the surface bigger simply reduces pressure on the piston.

The only way a bigger bore could make more torque is therefore by adding more air and gasoline, which is theoretically possible: a bigger head can have bigger ports, valves etc. and therefore will usually flow better - more air, more torque. However, if you consider headflow as a constant, a bigger bore does not equal more torque.

>Making the surface bigger simply reduces pressure on the piston.
this is where you fucked up

>this is where you fucked up
Explain me how.

Simple, peak average cylinder pressure doesn't drop due to an increase in bore size (assuming the cylinder head can keep up).

Average cilinder pressure isn't piston pressure though.

>assuming the cylinder head can keep up
Assuming head flow stays the same, the chemical energy contained in 1 compressed chamber stays identical. That same chamber full of air and gas creates a force, which is distributed across a surface. Pressure = force divided by surface. Bigger bore means bigger surface, therefore, pressure across the chamber should be lower.

Assuming the head delivers additional flow (which is a more practical example), then the force may increase, therefore, pressure may remain reasonably constant.

So:
All else remains equal: no higher cilinder pressure.
Headflow increases: Identical or higher cilinder pressure.

I guess that's another thing you're wrong about.

Torque figure is basically a representation of airflow/engine speed ratio

>nearest ski resort is 180 miles away.
Good luck getting there on a battery.

Battery is only good for old people in villages or office workers who live within 30 miles of their job.
Imagine an electric uhaul.
Imagine going to visit grandma for thanksgiving and it takes 4 days to get there because you constantly have to stop for "3 hour rapid recharges"

Explain it then! I want to learn, so try explain what you're saying. Simply saying I'm wrong is extremely frustrating.

>The only way a bigger bore could make more torque is therefore by adding more air and gasoline
That's what it does. With 100% volumetric efficiency, an 86 bore by 86 stroke bottom end will draw in more air than an otherwise identical 78x86 bottom end.

Yep, but obviously it would "keep up". It's just a matter of where in the rev range VE starts dropping off. That doesn't matter, as we're discussing peak torque, not peak power, which would (in this hypothetical scenario) stay the same.

I don't know what else to say m8, not being funny.
Cylinder pressure IS "piston pressure".

If you consider headflow as a constant, fuel, and ignition are the only things that affect torque.

It wouldn't keep up if you used a 4'' bore spacing head, and then compared a 3'bore to a 3.5'' bore. Headflow would remain identical, and it wouldn't keep up.

Naturally, most engine builders wouldn't do this, because it'd be easy gains. But it stays theoretically possible to actually not make any more torque with a bigger bore.

>Cylinder pressure IS "piston pressure".
So, by making a bigger cilinder with the same explosion in it, we'd be reducing both cilinder and piston pressure.

Wouldn't a larger stroke increase peak torque? Constant headflow means constant horsepower, and since your piston speed is higher with a longer stroke, it'd draw more air from the head at a lower RPM. Horsepower equals orque times rpm. Lower RPm and identical Hp should mean higher torque.

You seem to contradict yourself in the reply you gave to me and the reply you gave to the other user.
What you said in the reply to that user is what I was saying, and is therefore 10/10.
What you said to me is waffle. Why did you do this user?

>What you said to me is waffle. Why did you do this user?
Because waffle are delicious.

>it'd draw more air from the head at a lower RPM.
and it would do the same with a bigger bore
what about this is confusing?

>torque
>doesn't matter

Kys Alphonse

>implying he is wrong

Yea

...

question from uneducated retard

if you increase the bore of a cylinder, allowing it to burn more fuel

what is the direct result?

Ducati doesn't seem to think so but I guess your a engine design engineer that knows more than Ducati engineers.

GM works from the standpoint of, "If it works, leave it alone. Unless we are legally required to change it."

That's why they still have pushrods.

desmos are ohc?????

so to me it seems the the disagreement here comes from a difference in perspective, one of you is real world and the other is stuck in a physics text book, he's right, if you same amount of fuel and air enter a cylinder, the amount of force applied to the piston will be the same regardless of bore, and therefore, the larger piston, with more inertia and more friction, will transfer less of this power, but, all that is meaningless, because in the real word, people don do things like that, people increase bore explicitly to increase the amount of fuel and air being burned, even with the same head and valvetrain, the larger cylinder will create a larger pressure delta, increasing airflow slightly, for which the engine's CPU would provide fuel, and in the case of longer stroke increasing torque, the primary real world torque benefit of increasing stroke is the ability to now fir more air and fuel into the combustion chamber, though what you stated was true, and I've never considered it before, thank you for bringing it to light, I'm unsure if the small percentile increase in leverage would alone be enough to offset the small percentile increase in both inertia and friction, and the ratios which which the 3 vary is certainly different for every engine, so though you're point is valid, it fails to consider possible trade-offs and completely misses the point in the first place, good engineering knowledge though
also, Alphonse shit posting is still a thing? how is it lasting so long?

Boomers

Alphonse king and pretty are all incredibly autistic and have nothing better to do with their lives and the mods are fucking useless, thats how.

ya ohc engines are all they use on drag srips beacuse there better same with funny cars i love seeing a 14000 horsepower ohc engine gets me wet

Boomers

t. assmad gm fangirl

Bump

AK47 of engines. Cheap and just werks.

They're idiots

This

They're idiots

OHC predates push rods

Stupidity

>expecting anyone to read all that

I don't know

Size constraints. That's why the LS motors fit everywhere.

Idiots

less parts and shit
and its fine if your not planing to rev its ring off

Bumpo

Lol

>redditbabby saw some EPIC screen caps and thinks Veeky Forums is only for shitposting

This place was better when no one knee about it.

t. redditor

t. redditor

t. redditor

t. redditor