Reminder that a turbo pinto engine ran circles around V8s and didnt anything fancy like VVT or DOHC...

>his engine cover doesn't say "WARRIOR" in 80's as fuck letters

the g/o/d engine

It's there any common engine layout more retarded than the crossplane v8?

You are gonna need to rebuild a turbo engine more than a naturally aspirated one.

You know those new ford GT? 700 hp from a v6. I bet theyw ill be recalled or have major problems down the line. Getting that much power from them. I bet you.

Please kill yourself

You too

>thinking DOHC is better

What a bunch of retards. Hemi 2 valve per cylinder is always better

Why did you kick off another shitfest? Is this what you do for fun?

>ran circles around V8s
>posts drag racing times
user, I don't think you know how drag racing works.

Because due to thermal efficiency and compression rate hemi 2vs are always better.

DOHC its fine for high revving. For anything else its a meme

>Because due to thermal efficiency and compression rate hemi 2vs are always better.
>Mercedes got a four valve race engine to do better than 50% efficiency
Your move

But turbo V8s do less than 8s all day, supercharged ones do sub 4
>implying fuel isn't more important than engine layout

>muh german prototype almost works as well!

Fuck off. they were making fantastic engines since the 60's. People were too dumb and focused on
>muh moar valvz

>muh moar valvz
Allows more flow with less lift comrade, your theory about 2v hemi being the best layout is rooted in 1930s engineering. Last time I checked a reciprocating gasoline engine never beat 45% efficiency until this year. Hemis dont even have good burn characteristics
>needing 2 spark plugs per cylinder
toppest kek

DURR MUH HEMI
Pushrod valvetrains are extremely good at making large displacement V engines fit in small spaces, offering compact things with roughly even peak torque and peak up and usually flattish torque curves. However, if space isn't a concern or it's inline, DOHC is the better choice.

Flow depends on valve size, and most of the time 2 valve design can fit bigger intakes than the 4valve design.

Nothing wrong with 2 plugs per cyl

>and most of the time 2 valve design can fit bigger intakes than the 4valve design.

Did you fail geometry in school by any chance?

implying you still wouldnt have a solid 12 inches or more all around with it fully dressed

>Flow depends on valve size, and most of the time 2 valve design can fit bigger intakes than the 4valve design.
You need size and lift for flow, the issue with 2v heads is packaging once you start getting into big valves, as well as having heavy valves as a direct result. If 4 valve engines weren't more efficient the market would have never shifted.

we had this exact thread yesterday except backwards
sage

>the issue is literally weight

just use lighter shit lmao lol rofl

Size too, twin cam heads are already mahoosive compared to OHV ones before you start adding fancy valve control systems. CoG could also be a concern although boxers then come into their own in such applications.

Its all about the god damn size. That has always been the issue. you need big intakes but the reason why you cant just have most of the space be filled with intake valves is due to the thermal efficiency of a hemi head combustion chamber.

The combustion chamber dictates the most efficient valvetrain setup for the engine.

>electric rx-7
sounds like a 70/30 weight distribution

What a dumb sperg

>Flow depends on valve size

No you inbreed faggot, it depends on valve area, are you the same idiot that got BTFO in the LS bait thread?

>HEMI engines
>Not fucking massive

A hemi head is bigger than a coyote head

You keep bringing up chamber efficiency like it's the be-all-end-all when wedge chambers have been blasting hemis away for decades now.
>splayed valves
>more complex rocker system
>heavier heads
>higher engineering time
>more costly manufacturing
>two sets of plugs, wires
Hypothetically they could be more efficient but in reality they've never been. The actual hemi chamber shape was abandoned in the 70s because there are better layouts.

ok retard.

Reply to me once you actually know what you are talking about

I don't know about that, the coyote block is small so they don't take up as much room as they would sitting on a big block

>Reply to me once you actually know what you are talking about
Point out where I'm wrong and we can talk it out babe, you keep trying to strawman me by saying their better because they can fit bigger valves. Little more to it than that champ.

Literally the only things that matter is valve size (area, to be specific).

Every other issue is just gonna be about weight. Lets ignore weight. For hemi combustion chambers the 2 valve design would allow the highest airflow without creating pockets of high pressure where the energy is wasted.

V6.
At least a cross plane V8 is perfectly balanced

The extraordinary league of tryhards, the thread.

the pinto is the glock of engines

it will explode
hell i witnessed one explode

>Literally the only things that matter is valve size
Holy ol fuck you just keep saying the same thing without quantifying it. Yeah hemi heads flow good but they don't make more power or use less fuel than a four valve or wedge chamber 2v. Shit, the Coyote makes almost as much power and torque at 5L(435/400) as the 6.4L Hemi does(470/470).

Explain yourself retard. As long as the thermic efficiency and compression is good enough the only thing that matters is the valvetrain

to be fair the 2.3 later used 2 plugs per cyl

Higher thermal efficiency means you can either:
>make more power for a given mass of fuel
or
>use less fuel to make equivalent power to less efficient engines
Hemis do neither. The example I gave demonstrates a smaller engine with more valves and non-hemi heads making more power per displacement (87hp/L to 76hp/L). The 5L also get better fuel mileage in the F150 than the 5.9 Hemi in the Ram while making the same torque. Tell me more about how much better the hemi is.

You idiot, there are several fuckton of factors influencing MPG of car to car. Aerodynamics, weight, rolling resistance, internals weight, weight of the engine, etc.

You need to take a look at the torque of the engine per powerstroke with a given amount of fuel

You still haven't shown how the hemi is the most efficient design yet my friend, just thrown around red herrings like its Friday during Lent.
>inb4 muh bigger valvz
I'll take real-world examples for 800, Alex.

Because of the SHAPE of the combustion chamber, my dear niegger.

The entire fucking point of thermal efficiency is the way the piston and combustion chamber is set up in such way that the heat can only be used to push the piston down and create torque.

If it's the most efficient design then why are the most efficient engines NOT hemi? What you're saying is the chamber shape is more efficient by itself relative to other designs, not that "2 valve hemi is always better ()", because no single design is "the best" for every application as you insinuate. It's worse in more ways than it's better I think we can safely say, otherwise it would be the only design, or at least the most prevalent.

Holy shit I didn’t know they made a 5.9 hemi lmao

Most efficient at making peak power it should be said before that point gets thrown around too much

Nah I fucked up it's 5.7 lel, 5.9 was the old Magnum

Hahaha I know I was just giving you shit

Happens literally every time I talk about fucking hemis rofl

And isn't the hemi the best one for torque?

A weird combustion chamber doesn't magically increase torque at a certain RPM or thermal efficiency. It all works through physics and heat dissipation. That's why i vouch for hemi so much

>.....combustion chamber [shape] doesn't magically increase torque....or thermal efficiency
Wrong

Nice way of twisting the part where i said "magically", faggot.

v6 that is transverse mount

It's not magic, it's fucking physics.

Also hemispherical combustion chambers have trouble with high compression, modern head designs have far surpassed them in efficiency. Furthermore the Chrysler Hemi marketing campaign is a huge meme. Many cars used similar head designs at the time and some still do. There is nothing particularly special about a Chrysler Hemi engine other than its output and sound.

Ok then. Lets ignore the name calling for a bit and explain it to me how do modern combustion chambers can get better at thermal efficiency, creating more torque, without using spherical combustion chambers.

Sufficiently advanced technology is indistinguishable from magic, and sufficiently advanced magic is indistinguishable from technology. Bazinga!

...

Reduced volume to surface area
improved squish volume
central plug location
improved fuel mixing due to tumble swirl and improved squish
greater mass flow through increased valve area and increased discharge coefficient from improvements in port geometry
decreased tendency to knock allowing advancing of ignition timing
piston crown geometry does not interfere with combustion

See, it all gets boiled down to how the change of geometry in the cyl head and piston help with power but i just dont get how having a low squish volume area and a higher one is better than a hemi having a centralized equal squish volume all around

You can do a volvo head swap on them for pretty cheap. Surprised nobody posted it yet.

>best american engine is one designed in Europe

this guy explains it
youtube.com/watch?v=xFm00wHlUZg&t=653s

4valve dohc engines have been proven to outdo 2 valve engines more than 100 years ago.

...

...

but i still dont get it. What's the point of disregarding pentroof pistons other than
>muh homogeneous ignition
?
you would have a combustion chamber absolutely spherical and with a twin spark setup you would have no weird ignition timing issues.

>i still dont get it
don't worry about it

As in, what if you mix the pentroof design and make the combustion chamber a little bit hemispherical to reduce the high pressure zones?

As in, what if we pick a conventional hemi and make the top as low as possible (destroying its hemi purpose) but still making it round enough so that its not a pentroof to reduce the pocket heat zones

have legit have no idea what you mean

i uploaded pic related to help you understand a little what i mean.

>do 9s all day.

I don't think folks like Larry Larson or Jeff Lutz are worried.

Manufacturers would have done that already if it were that easy or actually worked.

A better solution would be turbocharging a 4 or 5 valve hemi head; you get excellent flow and more power.

I forgot about the abomination that is V6 crankshafts before making that post.
Inline 6 is so perfect other than being so damn long

Yes, i know. But i dont want to go with the train of thought of "if its not done before its because it didn't work".

I want to know specifically why and how it did not work. Engines follow basic physics principles. There's a why to everyhing and a "how to improve" too with it.

Why don't manufacturers use shaft driven OHC. How much money can that really cost over chain or belt drive when compared to the cost of the entire engine/vehicle. Seems silly to compromise such an important part risking destruction of the engine just to save a tiny bit of weight or money

i dont think axle shaft driven OHC is gonna be more reliable.

i bet it's 50/50, trunk is full of batteries too
5000lbs of perfect weight distribution

Is that a tripple overhead camshaft?

fuckin right!

1. A hemi with a flatend combustion chamber would have significantly less valve area than a pentroof
2. A pentroof head can have a smaller combustion chamber than a hemi without compromising the valve and piston design, wich allows for higher compression ratios and therefore higher thermal efficiency
3. A DOHC head has way less recipocating mass on the valvetrain than a hemi, wich allows it to rev higher with weaker springs

Pic related is how a piston for a roughly 10:1 compression ratio hemi engine looks like, it definitly compromises the combustion due to its increased surface area compared to a DOHC engine, that can still run flat pistons at the same compression ratio.

Is that a VR-6?

I know that. But the issue always remains as the pocket heat zones, the entire point of a hemi being that you eliminate them.

Isn't there a way to modify a pentroof in such way that you can reduce them? taking a theoretical piston head for example?

No. Did you even look at the picture?

Well, there is the Apfelbeck head, wich is basicly a DOHC hemi with 4 valves per cylinder.
It makes insane power, but it so complex, even the germans used it for racing only.

It gives a I-4 engine 8 intake runners and 8 exaust runners since there is always a intake valve next to the exaust valve.

But pocket heat zones are not much of a issue compared to the compression issue of the hemi in modern engines.

Oh lordy,

Not that hard to see that hemi's have worse heat pockets than modern combustion chambers.

Hemi's aren't the magical incredible things you believe them to be. All the most efficient engines use a 4 valve head and all the most powerful per litre, naturally aspirated engines use a 4 valve head.

Valve skirt size matters more than actual valve area and having a central plug is much more important than you think because of even flame fronts

yeah, some weird VR6-derived engine they make for a motorcycle.

Triple overhead cams, because 3 is better than 2, right?

If you think about it, they got rid of the weird valve angles a direct acting DOHC VR-6 has and therefore where able to improve the combustion chamber design as well as valve lift.

Apfelbeck would be good enough for what i mean, the idea of a mix between DOHC pentroof and hemi, or at least semi hemi.

Wouldn't it be much simpler and easier to make if you could still have all intake and exhaust on separate sides and camshafts, at the risk of slightly reducing the volumetric efficiency of the cylinder?

I think Lancia had already experimented with the principle of having crossflow intake and exhaust to have a compact way to power up twin turbo setups.

It is not possible to get the intake and exaust valves on one side only, since the valves would impact eachother.
If you change the valve angle to be parrallel to have them not impact eachother, you end up with a pentroof.

So there isn't a way to keep all of them in one side, and NOT have it semi pentroof semi hemi?

The only way to have intake runners on one side, and exaust runners on the other like that is to build a pentroof head, wich is also way less complex therefore cheaper to build.
For the Apfelbeck you needed special camshafts, wich had to bre grinded precisely with the valve angle, you had double the manifolds and you had double the fuel injectors/carbs.

That is why the pentroof design seceeded over the apfelbeck in comercialy sold vehicles.

They are incredibly great racing engines:
BMW once went crazy and got a small 1,5 L inine 4 engine with a production block up to 1400 hp.

Yes, i know about the inline 4 Formula 1 car.

I just wanted to know this because a boomer got in my mind the idea of a pentroof piston head top, like the pentroof pistons, but still keeping a spherical shape.