Here are a few other videos you may find interesting! How Do Engines Hit 9,000 RPM? - kzread.info/dash/bejne/p2d5rbqAmcrLhLQ.html Why Engines Lose Power Over Time - kzread.info/dash/bejne/p55sysx6mqydoJc.html How V8 Engines Work - kzread.info/dash/bejne/fY6A28mdoMqZfLg.html Boxer-4 vs Inline-4 Engine - kzread.info/dash/bejne/n5ukpraPcsiuf9o.html 10 Facts On The Hellcat Widebody - kzread.info/dash/bejne/kaaE1a-NmMvOfZs.html I'll also be making a video very soon on the benefits of pushrod engines, because they're actually pretty brilliant designs, despite the banter often surrounding them. Hope everyone's having a solid day!

@michaelblacktree

6 жыл бұрын

My project car has a solid day every day, because it has solid lifters. 😎 BTW, that 3D printed engine is really cool!

@sidneyisais8862

6 жыл бұрын

Engineering Explained what I want to know is where do you get those 3D printed engine models?

@TalladegaTom

6 жыл бұрын

And that small engine cam has a compression relief device. When at cranking speed, that uses spring force to move that little doohickey that changes the valve timing just enough to reduce compression which makes it easier to crank. Once running, it uses centrifugal force to return the cam to its original configuration. These are on many Briggs and Stratton engines and some others too. When that breaks it can easily trick people into thinking they have a bad battery or starter.

@calholli

6 жыл бұрын

You forgot piston speed... The reason why diesel engines have such low red line is because there is a much longer stroke. and the speed of the piston moving up and down is much greater because it has a farther distance to travel in the same time window as a normal gas engine.

@Luck21st

6 жыл бұрын

Engineering Explained AMAZING DUDE ! YOUR MY FAVOURITE !!

The 3d printed v8 is easily the coolest thing I’ve seen on KZread in a while.

Fast Forward to November 2019, and EFI University and Comp Cams have a LS7 revving to 11,300 rpm successfully. Quite an interesting development.

@wrighty338

4 жыл бұрын

for 1 power run of a few seconds....

@nvl2691

4 жыл бұрын

wrighty338 Still impressive honestly.

@tomeverett2212

3 жыл бұрын

My 1992 Honda VFR750 would run at 11,000 all day long achieving 42mpg on RON 84! DOHC V4.

@analog.shootty

3 жыл бұрын

Tom Everett but then again that’s not a pushrod is it?

@tomeverett2212

3 жыл бұрын

@@analog.shootty nope! Gear drive dohc.

*stares at a Chevy small block that revs to the 10k rpm range*

@downloadingutubes

5 жыл бұрын

@Zo Fryer or u do nothing and buy german that revs almost as high. Plus i bet 9k is past peak hp and lbft

@codysides7683

4 жыл бұрын

@Zo Fryer This is the reason GM has stuck with this style of motor. If you mod any other V motor from any other company, your buying 4 cams, that right there is the most expensive part of that build. I can rebuild an entire LS motor with hotter parts for the price of a set of stock 5.0 coyote cams.

@seancolfack8708

4 жыл бұрын

*shrugs* revs 526 blown hemi to 12.5k

@rcatkin1

4 жыл бұрын

Still not high revs though. Would be high for a production car but nothing compared to race engines.

@0hjaa3.06

4 жыл бұрын

@@downloadingutubes Or buy Sweden and rev to 7000 with more reliable engine

Nicely done video, as usual. I think it's important to point out that OHC engines aren't necessarily better (or worse) than pushrod engines, they're just different and each excels in different applications. RPM kills and manufacturers improve reliability by designing the engine to optimize power at the lowest RPM possible. Most pushrod engines are larger displacement engines that make more power at lower RPM's which is especially good in larger North American market sedans and trucks, but even in performance applications cars like the Corvette continue to prove that pushrod engines are still able to compete with and even dominate any OHC engine in street applications. For small, lightweight European cars, lightweight, high revving, OHC engines make more sense and work well. It comes down to weight, where torque rules. Motorcycles being the extreme example on the lightweight, high revving, OHC side. Low revving, big block, pushrod, truck engines being the other end. Right tool for the right job kind of thing.

I just can't believe how much I'm learning with this channel. Not to mention how easy it is to learn these stuff. You're getting better everyday, dude. Keep it up!

@EngineeringExplained

6 жыл бұрын

Very happy to hear it, thanks for watching!!

@vishnusai469

6 жыл бұрын

same review here too . u make it extremely easy to understand from a foreman level. i wished i were to learn automobile engineering supported by Ur videos

@vishnusai469

6 жыл бұрын

master blaster of engines watching Ur videos i have changed my concept of engines i now take good care for my engine hope u make some maintenance videos too for Indian passenger cars.

@konaguzzi1

6 жыл бұрын

I had previously thought your videos to be quite well thought out and very well researched alas not on this occasion cbr250rr 19500 red line 410 chev motors used in jet boats regularly rev to 10,000 rpm the old f5000 race cars of the 70s regularly 8,000-8,500 and the cross plain chev from that era 10,000 most production cars do little over 7,000 rpm (yes some will and can go higher but most do not) and pneumatics has little to do with high revs in f1 cars either it makes it easier to eliminate cams and/or have better valve timing variation

@DENicholsAutoBravado

6 жыл бұрын

konaguzzi1 I figured the pneumatic valves gave more control as you say. Just because he only mentioned one aspect and reason for them doesn't mean he doesn't understand them. I appreciate your comment however as I was only guessing at the other reasons and you have confirmed it.

Piston Return Springs would fix all of these issues! :D

@Xx1SailorScoutxX

6 жыл бұрын

Brett DiMichele Studios Hey guys; Chrisfix here!

@shabutir1820

6 жыл бұрын

Except air flow. Even if you get valve float under control your cam profile, valve area, and lack of the ability to have a proper VVL system means that power at high rpms would require you to sacrifice your power at the low end.

@IhateYoutube

6 жыл бұрын

You just have to use High Flow Piston Return Springs.

@chrisschristov475

6 жыл бұрын

Chris fix the best

@IhateYoutube

6 жыл бұрын

*Hey Guuuuuyz!*

These videos with the 3D-printed engines are *so* helpful to me. I cannot learn unless I put my hands on something or see every component of how it works. Thank you for making these, seriously. Keep it up.

I'm really enjoying this channel, sure I've read about most of these discussions in numerous magazines over the years but it's really useful to see it explained in video with working models.

This channel is a MUST for every car-enthusiast :)

@EngineeringExplained

6 жыл бұрын

Thanks for the kind words, and of course for watching!! :)

@fakhrizzaarrifi9375

6 жыл бұрын

and every automotives teacher in the world. great videos, love from indonesia

@lorenreece1665

5 жыл бұрын

@@EngineeringExplained very informative video for everyone.

@fluffigverbimmelt

5 жыл бұрын

More really more like "Combustion Engine Explained"

@brandonlittlejohn8055

5 жыл бұрын

Sadly not enough "car" people care about how a car works. Just want it to look good

I appreciate all the videos you do, I’m a gear head myself and love the 3d models you use and technical logic you introduce, thank you

I love this channel, I've learned so much about my vehicles. This just explained so much about my truck. It's my first RWD V8 vehicle and I love it so damn much. It just grunts at 2k rpm and I rarely have to go higher to get up to speed.

Great information. I love your manual demonstration of the push rod and rocker pieces.. that was a great way to illustrate.

Two valve hemi heads are pretty much the ultimate in airflow, because of cylinder head & valvetrain geometry - its basically a strait shot into the cylinder, combined with massive valves - Alan Johnsons billet hemi heads, intended for top fuel, flow in the mid 500 cfm range at max lift.

@Prestiged_peck

26 күн бұрын

Ask any top fuel engine builder why they don't use overhead cam and see what they say

thank you for making these videos, it's awesome that you take the time to prepare those visual aids. keep up the awesome work!

I love learning from your fantastic videos! Please keep it up my friend.

Gotta admit, though, that a 5.8L NASCAR engine revving to 9500+ RPM and not grenading is impressive.

@ThisGuyDrives

6 жыл бұрын

jmurphy1973 with 800hp N/A and by chance it does fail, because eventually it will, it can be easily rebuilt in basically no time at all and the driver will be back out to finish the race.

@brrebrresen1367

6 жыл бұрын

fun fact, some places in Europe you are required to drive with bulletproof dragrace with motorcycles since some have been killed by the valves going straight up... so engines literally going "grenade" is a thing.... not so easy to finish a race again even if the engine is rebuilt if your body is full of holes...

@ABArsenal

6 жыл бұрын

on top of hours at max rev

@danielanderson2030

5 жыл бұрын

About 17k per motor from roush. They're actually pleased for x amount of races. They're a hell of a motor though. Once I win the lottery I'll buy myself one or two and build some bucket list rigs.

@hooyabaaa2

5 жыл бұрын

Another thing to consider isnt only the type of engine (OHV) but the mass of the system is a thing too... Formula 1 engine has tiny pistons moving up and down. Nascar have imense pistons moving probally even faster than an Formula 1 engine. Top Alcohol Dragsters are the ''miracle'' of the OHV engines. They rev as high as 11K RPM being 9,5 to 10K their peak power. This in an massive engine... 8.2 to 8.7L You can talk about endurance, but still.. More than 3K HP reving a LOT in an jurassic engine lol

A while back Hot Rod and Super Chevy magazine built high revving LS3s. Hot Rods was more budget oriented and used a forged 4.8 truck crank to destroke the LS3 to about 5.5 Liters. They used off-the-shelf AFR heads and Brian Tooley cam/valvetrain. It made 600 HP at 8000RPM and was supposedly able to spin up to 9k safely.

@aklip

6 жыл бұрын

LS7s have been built to hit 10,000 RPM as well.

@t1ny7ank

6 жыл бұрын

Finally someone that did some research. 👍🏻 NHRA Pro Stock used to go to 13k rpm. Btw.

@aklip

6 жыл бұрын

Luke Z actually the shorter stroke/ big bore reduces the piston speeds/travel distances. This results in a reduction in friction and reciprocating mass. I'm not saying longer strokes can't rev high, just that it would typically require more maintenance and 'exotic" materials

@eb110americana

6 жыл бұрын

Of note, the LS7 used titanium connecting rods from the factory to reach those RPMs. Impressive nonetheless.

@ericross6995

6 жыл бұрын

I built a small block 350 for land speed racing. Forged steel internals, solid roller cam. Shift light came on at 9200 RPM. Only thing semi-exotic was the shaft mount rockets. 4 in bore, 3.48 stroke. It can be done.

Nice video! A little off topic but one of my favorite engines of all time was the Ilmor Mercedes pushrod V8 used in the Penske PC23 chassis that decimated its competitors during the 1994 Indy 500. Those pushrods fit perfectly through a rule book loophole.

This is one of the most informational and easy to understand videos on this channel! Also very interesting

thank you! you explain this stuff in a way that anyone can understand it :) thanks to you I'm able to accurately answer all the questions my younger brothers ask me about engines

@EngineeringExplained

6 жыл бұрын

Very welcome, thanks for watching!

Best explanation ever. Well done sir 👍

Thanks for explaining this question has been on my mind for a while.

Always wondered why these engines are called "pushrod" but never exectly understood why, this is by far the most clear AND simple explanation I got, thank you!!

Great job as always! I think you've tought me more then half of what i know now. Im in no way a true gear head. But i at least understand things better. Which helps in all kinds of ways.

Bro, I'd watch a channel where you just take different motors apart. Love your videos. Thanks!

I was wondering about this the other day, but couldn't find anything on it. Thanks!

I like your video clips explaining the mechanics of car engines. I am an electrical engineer and a car lover too. Thanks for the great job

Why don't pushrod engines rev very high? Reason 1) Valvetrain mass. Reason 2) They generally don't NEED to rev high in order to make power... because their displacement relative to external dimensions tends to be higher than OHC engines.

@markusgarvey

6 жыл бұрын

Higher revs= more wear.

@ltsjoke5443

6 жыл бұрын

Mark Estrada well said

@gotjuice7160

6 жыл бұрын

and more pumping losses

@jdrok5026

6 жыл бұрын

Technically a dohc engine has more valvetrain mass. Just they don't need to be force up and down.

@nunyadambinnes8723

6 жыл бұрын

True, and a fair point. Amended Reason 1) *Reciprocating* valvetrain mass.

Pushrods can rev high but they require a little more work because there is just more reciprocating mass to control.

@ristekostadinov2820

4 жыл бұрын

ls3 with 4.8L crank you got around 600hp and 7800-8000rpm revving, write on youtube search "SHORT STROKE-AN LS MONSTER MYTH? " the channel name is Richard Holdener he is doing lot of videos with junkyard ls engines.

Outstanding videos, man. The explanation of prerequisite concepts, for me at least, is spot on.

Why did I only find your channel today? This is the best thing on KZread. Awesome content, applause!

you'll soon hit 2 million subs. thats awesome

@EngineeringExplained

6 жыл бұрын

Very cool indeed!!! :) Thanks for subscribing folks!

You've explained to me more mechanics and physics than teachers at university :P

I learn so much from all of your videos! Thank you so much!

That little 3d printed motor is a beauty! Thanks for the clear and informative video.

Beautiful explanation of an apparently difficult operating mechanism, even for those/us not “mechanically inclined”. I am convinced that certain people are gifted to become engineers, but to be able to explain it in a fast, easy way to grasp, making the complex understandable, sure adds an extra notch to that gift. I’ve watched many videos on different subjects, but this series has become my favorite, “forcing” me to look forward on more future installations. Perhaps you may tackle turbine engines in the future, like the M-1 tank or jets engines in general, even rocket engines and how they work. As always, a pleasure!! Keep up the great work!!!

@EngineeringExplained

6 жыл бұрын

Thanks for the very kind words, glad you’re enjoying the content!

Your videos are gold! So much knowledge clearly explained.

@EngineeringExplained

6 жыл бұрын

Thank you so much, happy to hear you enjoy them. That’s the goal! :)

That is the best explanation I have heard to date. Cheers😊

How can someone dislike such a correctly informed and comprehensive video ?

Dam learnt so much. Always wondered why on engine masters the motors didn't spin very high. Thanks Jason.

@eaglefat9398

6 жыл бұрын

what? there 377cid made peek power @7,000 and will rev to 8k, ford voodoo 5.2L makes peek power @7,500 and red lines at 8,250, that only 250rpm higher for a 1 liter smaller engine

Title should say "Why It's Harder for Pushrod Engines to Rev". It's not that they can't rev, it's that its much more difficult and expensive to engineer them to be able to.

@fredl.c8029

6 жыл бұрын

MoutainMan3000 or you can get a rotary...sounds cooler too!

@markoz673bajen8

6 жыл бұрын

VTec braaaaaap. Not fast enough.

@johndessire399

6 жыл бұрын

Fred Larsen C. Rotary engine give twice the revs but three time the unreliability.

@acmadniturner1668

6 жыл бұрын

You dont need a rotary when you have huge cams:) they almost sound the same at idle. check my channel to see what im talking about.

@5tarstriker78.

6 жыл бұрын

Fred Larsen C. APEX SEALS!!!!!

Great vid. Valve float explanation was excellent.

Wow man, wow. Never have had such a clear view of innards of a pushrod engine. Thanks for it.

With every revolution of the crankshaft, an internal combustion engine is trying to tear itself apart. And high RPMs are the enemy of your motor's durability, so low rpms usually leads to long engine life. Focusing on making good power at lower revs means less time under the hood with a socket and ratchet!

@JosephArata

5 жыл бұрын

That's an idiotic statement. It doesn't work like that with the laws of physics. Heavy Duty Turbo diesel engines run 1,500 RPM up and down the road all day every day, producing 1,600-2,000 ft-lbs of torque in that RPM range under full load. The reason they last long is keeping the engine lubricated, filtered, and combustion temperature from becoming too hot. Something unobtainable by gasoline spark ignition engines without a massive cost to fuel economy to keep the engine temperatures down. RPM has nothing to do with engine durability, combustion temperature, lubrication, filtration, do.

@finharms9439

5 жыл бұрын

@@JosephArata are you high? Lol i mean you're both right.. hes right in saying that is most definitely a factor and comparing gas to diesel is apples n oranges... But why do you think that as soon as overdrive transmissions became a norm engines began running alot longer because of less rotations and stress... Same with oil quality, the oil now blows away the stuff they had in the 70s or even 80s

@waysideme

5 жыл бұрын

Race car. Dont care about long term durability. Just need to finish the race.

@wedge4hire

5 жыл бұрын

@@waysideme True. But even owners of race cars want the bottom ends of their very pricey engines lasting as long as possible.

@waysideme

5 жыл бұрын

@@wedge4hire Not necessarily. At most for racing an engine is needed to finish a season. My team is done with an engine after a single race

Why can’t Chevy and Dodge push rods rev high? With variable valve timing now they all rev past 6000 rpm. But these engines are so big, they really don’t have to. Put DOHC on a Viper V10 and it’s gained 100 lbs, which definitely isn’t worth it. Increasing compression or running a longer stroke [9.0 liter] crank adds 100hp without weight.

@josechirimoya

6 жыл бұрын

Well put. We all drive on the street. Why put the peak of your power band up around 8000, when you are driving away from a stop light at 1500?

@Bartonovich52

6 жыл бұрын

Josechirimoya. So you can get good fuel economy going around town but you can hold gears while passing or accelerating.

@Ricky-tp2qj

5 жыл бұрын

if it had DOHC it wouldnt need to be 9 litre in the first place

@DENicholsAutoBravado

5 жыл бұрын

Bartonovich52 exactly. Plus variable valve timing decreases pollution.

@edism

5 жыл бұрын

LOL! @Ricky

I have to say your video explanations have gotten a lot better.

So much good information great channel learned a lot just watching a few videos!

Ok before watching, i'm gonna guess something along the lines of valve floating?

Seems to me that everyone in the comment section is forgetting the most important equation. HP = (($ x in^3)^2)/5252

@nathanhiggins1438

4 жыл бұрын

Funny

@IvelLeCog

4 жыл бұрын

Where does the 5252 come from?

@nathanhiggins1438

4 жыл бұрын

@@IvelLeCog horsepower is somewhat but not totally arbitrarily defined as 33000 ft. Lbs of work per minute (had something to do with a horse and a bucket and a well) so horsepower is ft. Lbs per minute ÷ 33000, or POWER÷33000. At some point in deriving an equation for the horsepower at a given rpm of a car you get HP= torque x RPM x 6.28 ÷ 33000. For some reason the fact that 33000 ÷ 6.28 = 5252 means HP = TORQUE x RPM /5252. I realize my explanation is incomplete but I can't totally remember and I'm hoping someone finishes the explanation to remind me.

@chickenfixn4439

4 жыл бұрын

@@IvelLeCog all you need to know is 5252 is a constant. Every number will change when finding horsepower other than 5252. Hp= Torque x RPM / 5252. Torque and RPM can be variable. 5252 never changes

@xriex

4 жыл бұрын

@@chickenfixn4439 It depends on units being used (as Nathan explained) - you would use a different constant if calculating in Nm.

Dude...your videos are AWESOME! THANKS!

I have learned more from your channel, than the 4 years of shop in highschool i took! Thanks!

Gets to show how such a small detail can have a large effect on performance!

Could you do a video on ducati's desmodromic valve system? Does having no valve springs at all automatically mean that you could (theoretically) rev them higher than a regular dohc engine?

@EngineeringExplained

6 жыл бұрын

Yes, with a purely mechanical opening and closing, you wouldn't have to worry about valve float at all. There are of course other limitations in revving high, but that's one box you could check.

@abepowers4379

6 жыл бұрын

no "valve float" has been a high selling point of Desmodronics.

@generalrodcocker1018

6 жыл бұрын

it has springs

@williamwagner8017

6 жыл бұрын

foo bar The springs in desmo engines are only there to hold the valve closed during the very short time when neither cam is in contact with the valve. The closer rocker is what actually closes the valve.

@1barnet1

6 жыл бұрын

yes it means Ducati didn't have to go pneumatic in moto gp compared to their japanese counterparts. Obviously you'd also need an oversquare design in order to keep the piston speeds manageable. However there is problem. Ducati's need frequent valve adjustments.

I don't know ANYTHING about mechanics and stuff.. but you are so good explaining that i completely understood everything

I know I'll sound like a broken record, but you really do make the videos easy to understand, keep up the great work!

When it floats: Those little keeper things fall out and the valve gets sucked into the cylinder.

where can we buy one of those 3d printed engines? 😃

Simply amazing. Straight forward explanations

Great explanation very thorough and made it easy for everyone to understand.

Valve float is just the poor man's VTEC.

You should compare this to ohv and explain their operation as well

@archygrey9093

5 жыл бұрын

OHV (over head valves) are pushrod engines OHC ( over head cam) engines with camshaft in head. DOHC ( double over head cam) engines with 2 camshafts in the head.

This was really awesome, never realized how these worked

Nice work, good analysis.

What is that spike thing on the crank shaft?

@user-po6hn9id1t

6 жыл бұрын

godaboss oil splasher

The fastest race cars use push rod engines. Top fuel uses push rods and redline around 9500 rpm and make 11,000 hp. A 5000 hp 481X can spin 9000 rpms with push rods.

@Duskconqueror

6 жыл бұрын

While that is true, those are purpose-built engines. High revving daily driver pushrods are possible, but used to be inefficient and expensive to manufacture and maintain. Nowadays, with lighter materials, pushrods start to become interesting again because of their small package, relatively low weight, plus they are less top-heavy compared to OHC/DOHC engines.

@Benedocta

6 жыл бұрын

They are rebuild after every race. You could probably spin a truck engine 9000 rpm for 5 seconds as well.

@calebnation7797

6 жыл бұрын

I don’t think it’s fair to cite top fuel.... those engines get rebuilt every pass pretty much, and replace a crankshaft every 5 passes...

@AmericanLocomotive1

6 жыл бұрын

Yeah, but those valve springs on a top fuel engine are only good for one pass. That 481X engine might get a season on a set of springs at best. A Honda S2000 engine can turn up to 9,000 RPM reliably for 200,000 miles.

@OzarksWildman

6 жыл бұрын

I do agree with Jason though, OHC has many advantages.

Great visual illustration!

Thank you for the time you put into these videos. It makes it extremely easy for me to understand and comprehend what you're teaching the way that you do it. It's helpful also that I've been working on cars my whole life of course but the way that you describe things and explain them just clicks with me and I appreciate that. Thanks man!

What are the advantages to using a push rod engine? Also, thanks for these videos. I'm a civil engineer but have always had an interest in cars and up until recently all my knowledge was on small engines. I've learned a lot from you and I plan on watching all the videos you put out.

@redmanaaron97

6 жыл бұрын

Simpler and more power at low engine speeds

@YouNeedToCalmDown76

6 жыл бұрын

Power and cheap/easy power

@Conservator.

6 жыл бұрын

Push rod V8’s are far less complex to build and maintain, so the are cheaper. Also there package is much smaller than a V8’s with DOHC’s. When the volumes are the same a push rod engine will have less power than a DOHC because the latter will be able to rev faster. But I think it will make more sense to compare a push rod V8 with a smaller inline 6 with DOHC, twin turbo and direct injection. That would give a comparable amount of power in a comparable package size. (But no doubt at much higher costs)

@efcodpalama

6 жыл бұрын

Packaging and weight are much better for a pushrod. They are also often more fuel efficient because you don't need crazy cams for high revs. This only holds for v engines, though.

@Hrithik_Jayanth

6 жыл бұрын

iam just like you greg

Mainly because they do not need to, they make sufficient power at lower rpm's. If needed they can rev, look at a NASCAR engine. Over 9000 at times with pushrods and rocker arms.

@EngineeringExplained

6 жыл бұрын

As discussed in the video! :)

@charliedee9276

6 жыл бұрын

Yes it was. Outstanding video BTW. As an Engineer also, (retired), you explain things very clearly.

@MrCuervo22779

6 жыл бұрын

charlie dee pro stock engines were turning somewhere in the neighborhood of 11k rpm or more the last time I was into it. They run huge springs and massive amounts of open and seat pressure. Seat tends to be 500lbs and open is around 1000-1200lbs. Pretty impressive in my book.

@joeinmi8671

6 жыл бұрын

500 cu. in. with over 1" lift cams and a single throttle body... Try doing that OHC and DOHC... F1 cars are unreal but they dont hold a candle to pro stock. Also NASCAR engines are flat tappet.

@t1ny7ank

6 жыл бұрын

Engineering Explained maybe the take a look at NHRA pro stock motors. Currently 10500 rpm. Used to be 12-13000. And they are 500 cubic inches.

Great content , learnt heaps

Yeah my dads grand Cherokee with an i6 red lines at 5k rpm.. Great explanation!

I beg to differ the title. I have a 525ci bbc wich is a big block with push rods and still revs to 8500rpms

@inanismailov

6 жыл бұрын

blanky blank i think he means stock ones, if you use much stiffer springs itll still rev high

@kingjeff3688

6 жыл бұрын

Inan Ismailov ya i didnt watch the vid yet hHahah. $18k just for the forged rotating assembly. Iron block. Aluminum heads. 805 hp 800 lbs

@kingjeff3688

6 жыл бұрын

GlassTopRX7 sorry lad it was a typo i edited it

@philtripe

6 жыл бұрын

a 525 cubic inch SMALL BLOCK?? i would have posted a video of that before my RC car...ive never seen a sbc clear more than 455 ci, which is amazing but 525? psssht! i wouldnt believe you if you showed me in person until i saw it draw that much air in one gulp

@kingjeff3688

6 жыл бұрын

stickloaf it was a typo...

That’s why we need Koenigsegg’s FreeValve technology.

@jdrok5026

6 жыл бұрын

Zoltán Juhász so pneumatic actuators? I mean we don't need it more valve surface area displacement revs and air/fuel is all we need.

Thank you for your very clear explanation Sir. 👍

GREAT explanation. Coincidentally I had just been exploring what "dual overhead cam" engines are (trying to learn about Alfa Romeo Spider engines) and they point out exactly the same things but from the sligthly different perspective of showing "why DOHC supports *higher* RPMs than push-rod (less mass so less float and more valves for more air/exhaust flow, flexible intake/exhaust timing, as you nicely explain) But your explanation really explores and illuminates the push-rod engine side so I understand both a lot better. THANKS! Subscribed and looking forward to more of you great explanations!

Simple answer: Because they don’t need to.

@jamest.5001

4 жыл бұрын

Exactly!

@ronalddaub7965

3 жыл бұрын

Exactly

@LITTLE1994

3 жыл бұрын

Yeah, because it is possible to actually make them rev super high, but it's not a must.

SOHC seems like a good compromise if you want something simpler and lighter than dohc while also delivering peak power at 6000 rpm without a sweat.

HI thanks for this. I've been lurking your channel for a while so I thought it was time I subscribed. I love what you do, I'm an old school knuckle draggin gear head from back in the day but I love learning about new tech as well as reviewing the old school stuff. I would love to see you do a video on Ducati's Desmodronic valve train system. I have been riding motorcycles since the 60's. I love Ducati's (only had a chance to drive one, a 70's era 750? Up in Fairbanks Alaska, it was a beast!) I never owned one after reading about the Desmodronic valve train that use's no springs to return the valve but instead has a Second cam operated lifter that close's the valve. It's a beautiful system but like any thing Italian very high maintenance . I've always thought of it as the Rolex of valve train systems. I understand you had to adjust the valve lash every 3000 mile's or risk burning an exhaust valve and the dealers wanted north of $500.00 to do this. A lot of money back in the 70's. What is your spin on this system? Thanks

You did a great job explaining

Direct valve from Koenigsegg that would fix all the problems

@wazzzappening4848

3 жыл бұрын

Free Valve for all four stroke engine perfection. Agreed.

This video is kinda misleading. With modern pushrod engines, the valvetrain components have gotten to a point where they can easily rev past 9000 rpm. The use of light weight metals in the valvetrain such as titanium allows this. Also the 2 valve per cylinder fow is bunk since if you look at the LS3 head flow characteristics vs the Ford coyote head, they are comparable and this is due to the runner design and large valve diameter that the LS3 head has. The limiting factor for an engine like the LSX is not the valvetrain or head flow but rather the stroke of the engine. The piston is a large reciprocating mass and with a longer stroke, at a given rpm, the change in velocity is immense compared to an engine with short stroke, hence most high revving engines, especially f1 engines, have shorter stroke. In fact, a common failure point in older LS1 engines was rod bolts, which would stretch with sustained high rpm or mechanical over rev and cause the rod bearings to spin. This was remedied by using stronger rod bolts but its still a limiting factor.

@devil0373

6 жыл бұрын

4 smaller circles in a given area will cover more area than 2 large circles. The advantage of the LS is that its had around 60 years of development and aftermarket support in the cylinder head, whereas DOHC has only recently come into the mainstream. A 4v head should theoretically flow more air than a 2v head with identical port characteristics. The issue with pushrods is they are ALWAYS heavier as a valvetrain than OHC due to the inclusion of pushrods, so will not rev as hard. For an apples to apples comparison rather than this coyote vs ls war, look at a Jack Knight BMC a series head vs the regular pushrod configuration. There is a night and day difference.

@AmericanLocomotive1

6 жыл бұрын

Those engines cannot rev to 9,000 RPM reliably, for 200,000 miles. The valve springs simply will not last revving that high. The spring pressures also start getting outrageously silly. My Honda CRF450 has a 3.75" bore, and a 4-valve SOHC head design. The max-lift spring pressure on the intake valves is just 175 pounds. It will reliably turn 12,500 RPM all day. To get an LS engine to turn 10,000 RPM requires open valve spring pressures approaching 1,000 pounds. At those pressures, the spring, rocker, pushrod and lifter life are extremely short.

@eaglefat9398

6 жыл бұрын

dude you can't compare bike engines to car engines, how many Honda street car engines rev to 12k...none and theres a good reason for that it makes zero torque thats why car engines don't go over 100hp/liter unless it weighs sub 2,500lbs and even then people complain its slow like a honda S2000/240hp@9,000rpm 0-60 in 5.7sec/14.2 which is slower then a 1985 corvette/230hp@4,800rpm 0-60 in 5.5sec /13.9sec and the corvette weighs around 1,000lbs more but is faster with less power . and bike engines don't last 200,000miles more like 20k miles.

@AmericanLocomotive1

6 жыл бұрын

No one is talking about power, acceleration, or anything here. We're strictly talking about valvetrains. The facts are that a pushrod engine with a 10,000 RPM capable valve train will not hold up. You will get extreme wear on the rockers and lifters, and the valve springs typically can only take 5-10 hours of sustained high RPM operation before they need replacing. On the other hand a DOHC engine can utilize lightweight valve train components that can easily deal with those sustained high RPM operation. Bike engines, and engines like the S2000 engine are perfect examples of this. The S2000 engine can last for hundreds of thousands of miles. I'm not sure where you figure bike engines only last 20,000 miles. Many people put tens of thousands of miles on bikes - there are many Yamaha R1s with over 50,000 miles, including some over 100,000. Like I said, on my Honda 450 (single cylinder), the valve-springs only have about 60 pounds of seat pressure with the valve closed. Pushrod engines that turn similar RPM require closed seat pressures of over 400 pounds, and open valve pressures that exceed 1000 pounds. In comparison, the open seat pressure on this Honda 450 is only around 175 pounds. That results in far less stress on every component of the valvetrain, allowing it to last longer at high RPM operation. NASCAR valve springs are typically only good for a single race, top-fuel valve springs only last a single pass. A Yamaha R1 valve spring can be expected to last 50,000 miles without issue.

@JoseLikesCars-ln9qc

6 жыл бұрын

Dude where are you getting your figures from? You don't know what you are talking about. First off, even the S2000 has valvetrain control issues. its a common problem they experience at track days where they have valve float and this causes piston to valve contact and may even drop a valve. Check out ZentRose channel, its what happened to his. Also the 1000lbs valve spring force your talking about is nonsense. PSI1511ML springs, which I run on my z06, which are probably the best beehive style spring you could run on a LSX, are rated at 370lbs at 1.175" and 130lbs at 1.800". You do realize that spring force depends on how compressed they are right? its not a constant "1000 lbs" like you are implying. Finally the fact that you are bringing up motorcycle engines shows me that you are missing the point of my comment. Motorcycle engines have short piston strokes, therefore the velocity of the piston is lower at a given rpm compared to an engine with longer stroke and there is less force on the rods.

I had a BSA A65 Lightning production-race M/C, which was red-lined at 8750rpm. Standard is 6000rpm. It was raced in the 1973 Production TT by Peter Bates, a 114 mile race, and finished 13th. Beating several works machines which DNFed! Std points ignition so no rev-limiter! It had a 740cc barrel kit, making it oversquare, slipper or reduced skirt pistons to handle the higher piston speed, which are common now but not then, lightened and balanced crank, ported head, std valves and springs but quite drastically lightened rockers, the top and bottom edges of the std cast-iron rocker arms were knife-edged, and the screw-adjustment bosses were greatly thinned. So very light rockers, a very long and careful job, the main reason it revved so well I think. The rockers were quite beautifully sculpted, and were not the first try I suspect. A top-half fairing was fitted, but std frame, wheels and mudguards, to comply with race-regs. It was raced in the 1973 Production TT, a 114 mile race, and finished 13th. Beating several works machines which DNF. Including the Monocoque Factory Nortons of Peter Williams and Dave Croxford. I used it as daily transport for 2yrs or so, after a rebuild as it was on Castrol "R", which I was told sludges badly if left in. It had bog standard transmission. I was never late for work! It was very torquey off the line, wheelie-ing easily, and a wickedly fast top-end! Timed at 147 mph at Snetterton. So over 150 on a good day. Probably 160 mph downhill if pushed. I still miss it.

Like all your video this one is super informative. Just one comment. Stiffer valve springs don't usually result in power loss due to the "regenerative" properties of valvetrains. When one spring is compressing another spring is decompressing somewhere in the valvetrain. So set springs as stiff as is needed to not float for your given cam profile.

Then us Aussies have burnout cars running push rod setups revving 10000+ rpm in engines up to 7L

@TheBunnyDeveloper

4 жыл бұрын

That 7L is tearing itself apart

corvette also had a dohc in the 90s

@markusgarvey

6 жыл бұрын

They might be using one for a mid engine C8.

@Gcrilla

6 жыл бұрын

ryan janki yeah in the original zr1 it was actually a lotus or Yamaha built engine I believe.

@eaglefat9398

6 жыл бұрын

The original LT5 had lotus designed heads and was assembled by mercury marine boat engine builders, it was a very trick engine with 18 throttle bodies and half the throttle bodies closed off at low rpm for a vtec like effect , it was super expensive and it was all aluminum but weighed more then the iron push rod 5.7L and the ZR1 weighed 200lbs more then the iron block Z51 , and didn't really make that much more power then the push rod LT4 , 405hp vs 330hp but keep in mind the weight disadvantage which also kill the 50/50 balance the base model had. But it was fast for a 3,550lbs car with 405hp to go 0-60 in 4.3sec and 12.7sec 1/4 mile. GM plained to use it in the C5 corvette but it was way to heavy and didn't fit under the hood and the LS6 made just as much power but cheaper and 150lbs lighter and lower

@jdrok5026

6 жыл бұрын

I'll be Frank I'm Leary about using my name it was a lotus design from ground up when gm bought them lotus loved the time with their engine they offered Chevy a lt5.2 for the c5 Chevy turned them down. Sad that we aren't seeing lotus and Chevy have another love child together.

@eaglefat9398

6 жыл бұрын

that LT5.2 was a beast, it had variable cam lift and made over 530hp @7,800rpm which for 1997 would have been unheard of. Oh the glory it could have brought to this nation, to bad it weighed like 600lbs compared to a 425lbs LS1 and was to way big to fit under the c5s tiny hood.

Nice video! Keep up the good work! :)

I wondered about that. Thanks!

Why don't those racing engines use OHC's?

@mycubehead

6 жыл бұрын

Probably pushrod engines have lover centre of gravitiy compared to OHC engines. Lower CG is better especially in racing.

@efcodpalama

6 жыл бұрын

Also weight, packaging and, often, efficiency.

@efcodpalama

6 жыл бұрын

ZERO94AIC Like Can Am and Top Fuel?

@jothain

6 жыл бұрын

mycubehead That's not a reason. Pushrod design is always heavier than other more modern designs. Reason seems to be always the rules of racing class

@markusgarvey

6 жыл бұрын

Aston Martin, Ferrari, Lamborghini,Peugeot,Audi, Mercedes and most of the Japanese cars do In WEC, IMSA, GT racing. They use SOCH and OHC engines against push rod engines. Corvettes running LS engines would beat ALL of them every time if not for BOP (Balance Of Performance) restrictions in GTLM and GTD classes.

The Chevy 302 V8 used in the late 60’s Camaro z28 could rev past 7000 rpm in stock form.

@eaglefat9398

6 жыл бұрын

it was used in Formula 3 cars and made up to 550hp@8,500rpm from a push rod 5.0L from a production Camaro

@7cperformance314

6 жыл бұрын

now that was a truly impressive little engine,I found one a couple years ago I'm just waiting for the day it is mine

I always learn a lot from watching your videos 👍👍

Great explanation as always.

An over square engine with solid roller lifters, roller rockers, and stiff valve springs will rev pretty high...

@EM6285

5 жыл бұрын

Can beehive style sprongs help push-rod engines to rev higjer?

He has clearly never seen Steve Dulcich explain how to make a push-rod engine rev high.

@xwalcker

6 жыл бұрын

Could you put a link to that video?

@markparker1391

6 жыл бұрын

Alex Walcker it's on motor trend on demand in a roadkill extra.

@AustinHarmon1994

6 жыл бұрын

Alex Walcker Its episode 382

@markparker1391

6 жыл бұрын

Thankyou

@markparker1391

6 жыл бұрын

Umm no, people just dont know how to because they are less common now.

I had a streer rod with 302 with factory stock long block. Never had any problem accelerating to 6000 rpm. Never had a problem, and never needed more rpms than that. Very nice, simple, low maintenance affordable engine.

Very useful. Thank you

I'm going to stick with my ls pushrod motors less to go wrong and cheaper not really any less efficient and can easily make plenty of power

@michaelkuzmadutton7879

5 жыл бұрын

James Holbrook yeah, as long as you don't scream it and you run it normally it will hold up fine.

if only have 1 camshaft no other 3 can make problems ;-) not to mention aabout all these huge long chains and all the stuff to hold them in place ! In a chevy LS or LT you have only 1 short chain !

That was great! Thanks from Texas.

Dang, that was more things than I even knew of. I knew about mass and therefore limitations of the springs (also probably doesn't help that with rocker arms changing the direction of the action of the valves 130-160 degrees probably reduces the overall effective effort of the spring as well, regardless of RPM, yes?). Love it.