Redpill me on pushrod engines

>makes power and all this but weighs more than a nuclear airplane carrier.
An aluminium big block can weigh less, and fit in a smaller package, than a DOHC Modular. Pushrod engines are, by their very definition light, it's just that the Americans made some huge 7+L ones out of pig iron. Sure, those were heavy, but imagine a 32v 426 Hemi. Imagine that pigfat.

Monoblock designs aren't needed as much nowadays, with modern head gaskets. When you can push 30+PSI through a 2JZ, or 100+PSI through a Cummins, those head gaskets can take a beating.

Ford's flat head V8 was the epitome of simple and compact construction, too bad they're heavy and can't make modern power.

A 32v T-head V8 can work, but and inline 8 is more practical. Given the status of inline 8's right now, that says a lot about how practical a 32v T-head V8 is. You wouldn't need supercharging per se, a popup piston might be enough since the chamber volume should be somewhat similar to an L-head.

>DOHC Modular

You are referring the the ford 4.6 specifically?

>Ford's flat head V8 was the epitome of simple and compact construction, too bad they're heavy and can't make modern power.

The thing that made the flathead V8 so popular was the fact that it was powerful for its packaging size. It was larger and more complex than the average flathead i4's used during that time.

Inferior tech made to seem good by engine building not always being a dick measuring contests and companies daring to make DOHC engines that aren't beasts, and some companies make pushrod engines that actually do make power, albeit not as much as they could if they were DOHC

also I guess the rules in some drag racing series require them, and that leads morons to believe that they are good for making power. kind of like carbs.
>WELL IF CARBS ARE SO INFERIOR WHY DOES THIS DRAG CAR HAVE ONE

but anywhere engineers are given a choice and just have to make as much power as possible they go with DOHC

>You are referring the the ford 4.6 specifically?
Also the 5.0, 5.2, 5.4 and 5.8. They're BBF-tier in terms of packaging and weight.

>>WELL IF CARBS ARE SO INFERIOR WHY DOES THIS DRAG CAR HAVE ONE
Because carbs have superior fuel atomisation, that's why. Nothing else matters in drag racing, unlike in road racing.

>but anywhere engineers are given a choice and just have to make as much power as possible they go with DOHC
If I want as much energy density as possible, without caring for MPG's, emissions or whatever, I'd go for a pushrod engine. Do the maths on the current F1 V6 engines, and you'll see that you can easily break the minimum weight limit just by switching to pushrods. Given that their practical RPM limit is abour 12K RPM thanks to fuel flow, you can bet that a pushrod valvetrain might even survive that. Pic related was one of the smallest racing motors I've ever seen, despite being large (in displacement) for the racing series it's in.

t. engineer

>modern head gaskets
there has been good improvement since the 1970s
but head gasket is a weak point even at boost below 3 bar
the oil galleys and water transfer ports seem to be the cause

disadvantage with mono block is having to assemble the pistons and valves from the crank case up

>32v T-head V8 can work
going towards that is T head giving assess to valves from above
that and the exhaust cams being low down

all be it with a weird arrangement putting more spring force on the intake cam
intake cam sorting out 16 valves
exhaust cams handling 8 valves each

>in-line is more practical
definitely

>Given the status of in line 8's right now,
even by the 1930s the in-line six and v8 were replacing it

Not worth it's own thread so this seems like a good place to ask

Why did inline 8's die? What is it that makes them bad, but inline 6's are great?

Inline eights died because they were too long. A V8 has just as much cylinders, but the crank doesn't want to whip around as much. The length makes it weak, as it tries to form a sinus-shape under normal loading. Also, the block is terribly long, which makes for bad handling because all that weight is over or ahead of the front axle.

The inline six has similar problems and is therefore also inferior to the V6, but it has survived because the V6 isn't as well balanced. Now that that's not a problem anymore (we can make a VR6 work), you'll slowly see the I6 disappear except in manufacturers who have made it their USP (BMW for example). That's a good thing, because the same bad crank loading and the same bad overall engine length that killed the I8, also apply to the I6.

Thanks senpai

Have a (you)

the balance is fine
but at higher rpm the crank shaft is so long that it can twist enough to cause torsional vibration
iirc Mercedes-Benz W125 had two torsion dampers to deal with this
somewhat like torsional super damper used with some v8 engines

So wait
What's the best engine?

V8

Aint nobody making 3000hp out of ohc engines, nuff said.

inline 2
flat 2
inline 3
v6
inline 4
inline 6
flat 6
flat 4 with turbo
v8
flat 6 with turbo
flat 8 (till it explods)
flat 12 with twin turbo
v10
v12

>t shit-box enthusiast

Push rods push gods nigga

Pushrod V16 quad turbo

flat 6
accufabracing.com/accufab-mustang
>over 3000hp at 10000 rpm
thats on a stock block as well, not billet

Irrelevant if you have to rebuild it after every race. You might as well just use a top fuel motor at that point. You also can't do drag week with it so it's irrelevant.

>but at least the roof of the combustion chamber can be water cooled
och, thats useful kys

That monoblock is dope

>being this much of a pleb
kill ur self fagit

nice goalpost shifting

>Are you using an inline engine?
>Yes
>Use DOHC

What if I'm mounting the inline engine horitonally so that the pistons are moving parallel with the ground?

The main benefit of this is lowering the center of gravity for improved handling, but DOHC adds width to the engine. More width on a horizontally mounted engine means extra height, so the engine has to be mounted higher up to maintain ground clearance, reducing the primary benefit.

>Pros
Extremely compact
Durable (no timing belt)
Easy to mod, only one cam
Cheap to mod, same reason
Simple, anyone can mod the valve train
Lightweight
If a valve hits the piston it usually bends the Pushrod, not the valve
>cons
Torque or RPM pick one, a Pushrod motor that revs high won't be daily drivable. A torquey daily drivable motor won't rev high.
No VVL
Can be Noisy
Resticts air flow: its hard to use 3 or 4 valve designs (but not impossible) and the pushrods limit your valve angle and port routes.

Pushrods work well for applications where OHCS won't fit, or high engine speed is not needed. They are not good for maximum output with a displacement restriction.

Of course, all of these problems can be solved with money

>a Pushrod motor that revs high won't be daily drivable. A torquey daily drivable motor won't rev high.

Ohhhh hold on now. What's your definition of "revs high" or "torquey". There's plenty of pushrod high compression, high revving torque monster V8's out there. A 700hp all motor LS is still making 600+ ft/lbs and is perfectly daily-able.

They have even better balance than an I6 but the flex of the camshaft and crankshaft is severe due to their length.
It's cheaper to just make a V8 instead

Depends what you want to do with it,
But my personal favorite is a V8

I'm really liking my new Turbo 4 through

8+k
I know you can build some wicked stuff but I was mainly talking factory

Where's the shit posters? This is the only civil discussion of valvetrains and V8 motors I've ever seen

Same, probably going to screencap this and save i to read through later. also don't fucking jinx it.

My rams got a sohc V8 4.7l.
I'm wonder why they're didn't just make it a pushrod why sohc?

I don't see how factory or not is relevant. Literally nobody keeps their LS's stock. The entire point of the engine is it's aftermarket. To each his own I guess, Spend that $10k to rev to 8000 from the factory if you want.

There's a bmw bike (k100 series) that has a i4 longitudinally mounted, but it's horizontal, see pic. It does have dohc, which makes for easy valve clearance checks

I actually don't know, no one seems to really mod those engines and there isn't much about the powertech line as a whole, pretty much just a evolutionary step from the Magnum engines to the hemis though a dohc version would've been neat

they killed themselves due to this
roadandtrack.com/new-cars/a15947346/2019-chevrolet-corvette-zr1-vir-lap-record/

Not saying it wasn't relevant just that my pro and con list was in regards to the factory