5 Reasons Pushrod Engines Still Exist
Vložit
- čas přidán 6. 09. 2024
- Why Chevy And Dodge Are Still Making Pushrod V8 Engines.
EE Shirts! - bit.ly/2BHsiuo
Recommended Books & Car Products - amzn.to/2BrekJm
Subscribe for new videos every Wednesday! - goo.gl/VZstk7
Pushrod engines typically use two valves per cylinder, and as a result this engine style is often mocked when used in modern vehicles. Fewer, larger valves results in more reciprocating mass which can lead to valve float, and less airflow at high RPM from the reduced area of the valve openings versus four valves. So why are companies like Dodge still making Hemi engines, and Chevy still making LS engines, both of which are two-valve pushrod setups?
Well, simply put, pushrod (OHV) engines have quite a few advantages over their DOHC counterparts. Whether it's the size and compactness of the engine, the simplicity, or the cost, there are real performance benefits to using a two-valve, single cam V engine. As the saying goes, if it ain't broke... Check out the video for five detailed reasons why these engines are still made.
3D Printed LS3 V8 Engine By Eric Harrell:
www.thingivers...
Related Videos:
Why Pushrod Engines Don't Rev - • Why Can't Pushrod Engi...
Why Ford's Flathead V8 Died - • Why Ford's Flathead V8...
Boxer-4 vs Inline-4 Engine - • The Differences Betwee...
How V8 Engines Work - • How V8 Engines Work - ...
How Do Engines Hit 9,000 RPM? - • How Do Some Engines Re...
Why Engines Lose Power Over Time - • 10 Reasons Why Engines...
Engineering Explained is a participant in the Amazon Influencer Program.
Don't forget to check out my other pages below!
Facebook: / engineeringexplained
Official Website: www.howdoesacar...
Twitter: / jasonfenske13
Instagram: / engineeringexplained
Car Throttle: www.carthrottl...
Amazon: www.amazon.com...
EE Extra: / @engineeringexplainede...
NEW VIDEO EVERY WEDNESDAY!
Related Videos:
Why Pushrod Engines Don't Rev High - czcams.com/video/S9E2nCXNHU8/video.html
Why Ford's Flathead V8 Died - czcams.com/video/ixhYVcWwJiY/video.html
Boxer-4 vs Inline-4 Engine - czcams.com/video/mgpDTVBeHOw/video.html
How V8 Engines Work - czcams.com/video/KZLygdpg3LU/video.html
How Do Engines Hit 9,000 RPM? - czcams.com/video/u3EKXGigeTQ/video.html
Why Engines Lose Power Over Time - czcams.com/video/uj8hjAjI7p4/video.html
Engineering Explained you repeat hello everyone for 2 times on the intro !!
Would love to see an ''electronic'' head on gas engine(like freevalve), lots of control, no restrictions on engine, etc.
Is it possible to design an engine upside down where the main crank shaft is on top of the pistons. Instead of a V8 it would it would look like an "A" so it would be an A8 engine.
Piston configuration /\
Possible but not practical since such a design would require a costly oil scavenger sump with pump and lines separate from the engine; would be a packaging nightmare with no advantages.
Poteven
I read an article about that exact thing in 1986 in a magazine. It was sparked by the discussion of the VVT engine that was installed in the Honda Acura NSX.
Now over 30 years ago!! ;-)
Was this video deliberately 7 litres long?
Eliseo Arroyo anywhere from 424 to 430 (6,950cc to 7,049cc)
Lapstone Limousine
Best comment of all time.
Eliseo Arroyo
Or the 427 LS.
Should’ve been 428 like a good old Pontiac
I'm glad I'm not the only one who noticed.
My 6.4L hemi makes me love pushrod engines. It sounds like a gdamn beast!
That’s what allows the corvette to have such a low hood. The front mid mounted boxer in the brz also allows a low profile hood. Which eventually leads to great visibility and drag coefficient.
The engine is in the middle now, so it's a moot point! Both OHV and DOHC engines are now offered in the Corvette with no difference to styling. 🙂
Me: Torque
Jason: Torque
Me: Oh? Finally, someone who appreciates a nice torque curve!
Fr. I'm having my 347 Stroker built for low to mid-range torque and power. Hopefully it works out.
Thanks for a great discussion. Just wanted to point out that 4-valve heads are not synonymous with dual overhead camshafts. See SOHC designs like Honda's J-series V6.
4 valves are synonymous because a single over head would only have 2 valves
@@soncero7398 There are quad valve single cam engines. Honda makes them.
@@soncero7398 No is not
There have been exotic 4 valve pushrod engines too. I think Mercedes had a legendary racing engine designed that way to exploit a rule that allowed extra displacement to pushrod engines and they absolutely mopped the floor with it before it was immediately banned.
@@honkhonkler7732modern diesels are pushrod 4 valve systems such as Cummins 24v
At what rpm does a 3D printer engine have valve float
4
I'd guesstimate probably around 30
I’d love to put a drill on the end of it or a high speed motor and see how long it’ll last. But I’d feel bad because something like that had a lot of time and effort into making
@@gagepuffinbarger6939 I tested it. Spun it on high for 30 seconds or so and it held up, but Im not going to specifically try to break it due to wear. Printed on an ender 3.
3 maybe
I don't understand why people hate on pushrod V8.
It is an elegant engineering solution that matches American market environments where cylinder volume isn't taxed and therefore high RPMs are not required.
Different solutions to diff problems in diff conditions. It is all good!
"It is an elegant engineering" no it´s not.it´s an outdatet system but muricans are to lazy to change it (or to cheap out or marketing whatever).it´s the same why they produced so long hemi engines and somebodys still fit them > marketing and lazyness
it´s okay that they do it (because mustang´s and so on are fking cheap for the power you get) but don´t say it´s elegant engineering
Two of the qualities of good elegant engineering? Not making a system more complicated than it has to be, and engineering with production/running costs in mind.
Like I said in my comment, it is an elegant solution to match American market environments. American regulatory atmosphere is more concerned about fleet MPG & emissions, and doesn't disincentivize displacement.
IOW - if a 6.3 liter V8 with low rpm gets the fuel economy and emission result as a high rpm V8 small displacement V8, that engineering solution isn't punished by the regulatory framework.
There are a lot of bad cars built by GM, Fiat. But pushrod V8s aren't inherently inferior or out of date - they're just a different solution method, and in this case? Elegant because it is effective, cheap, reliable. It is like a mass damper - simple and obvious once you understand it and figure out how to implement it.
But something tells me you're more interested in nationalism than engineering. So have a good life.
The OHC engine was actually developed at a similar time to the OHV engine so the OHC engine is far from space age technology,OHV works,it's a great rugged design,what more is there to want?,I understand OHC makes perfect sense in tiny super high revving ultra powerful bike engines but most average car drivers struggle to cope with 200 bhp,what would be the point of a 6.2 litre OHC engine making 600 bhp,the extra complexities would just be a talking point at the bar......and Mustangs have had OHC for years now.
Graham Smith welcome to America
600hp isn't *that* hard from 6.2L with modern heads. Even a Gen1 design has little problem developing 600hp below 6500rpm from 6.6L with a set of 300cfm heads and a cam with around .600" lift. Shinybaldy is correct, it's really just about European and Japanese nationalism and elitism. Thing is... I'm rather sick of their high prices, huge engines with tiny little lungs, goofy 7 cam chain drive mechanisms that fail requiring engine removal (whaaaaat???) and front wheel drive with strut suspensions. You go buy a used Corvette and you get an aluminum SLA suspension, giant tires, giant strong 6spd transaxle, awesomely powerful 430lb V8, and looks that kill. What am I missing? Why would I want a goofy sounding I6, strut/trailing arm suspension, AWD (what fun is that?) tall, narrow tires, cab forward design, more weight, a paddle shifted automatic, transverse ANYTHING, and all with a higher price?
I liked how easy it was to replace the head gasket on my boat. No having to play with the the timing or anything. I just pulled the head off and replaced the gasket and put that push rods back in
Just make sure you put them back in in the right order and bleed the lifters and check the valve lash.
Sometimes it’s just easier to put a couple dowel pins in and put a belt on.
Bartonovich52 you don’t worry about lifters on a pushrod engines for a head gasket job and yeah setting rockers my be intimidating at first but after you learn to do it once, it’s easy
Kart racers with the Honda GX engines have alot of experience on doubling the 3600 rpm stock limit. To get to 8200 rpm, all you have to do: lighter flywheel, connectrod with bearings, stronger springs and rockers, and a slightly larger intake-exhaust valves (1mm diameter difference). Lighter-stronger pushrods, port polishing, flat top piston... all that is for the longevity. To push past the 8000 rpm barrier... that requires roller rockers, special pushrods, maximum size valves, full billet parts with harmonic balancing etc... So there is no reason a pushrod could not be made to rev as high overhead cam.
Another fine presentation! I own an in-line 6, 4.0L push rod engine in a Jeep Cherokee XJ and a DOHC 1.8L VTEC in-line 4 in my GSR. The advantages you list for each are fully and marvelously realized in each of these engines!
Awesome vehicles, both. Take care of them!
This video's length is 4.27, that reminds me the displacement of LS7
1969 Central Office Production Orders (COPO) 9560 427 ZL1
As much of a Blue Oval fan I am, the 427 Ford didn't measure up to be 427 cubic inches. Just sayin'! Although, I wouldn't mind having one. There's just something about FE engines that I always loved.
+Joey Garcia... Side-oiler FE's were/are respectable, but the ZL1 was/is a better performer.
The COPOs were mainly spread around through Fred Gibb, Don Yenko, Dick Harrell, Baldwin/Motion, Nickey, Berger and Bale.
+David Laurie
It is a mix of OEM tooling and aftermarket/reproduction tooling.
My understanding is the front bulkhead/firewall, siderails, front sub-frame, roof and a few other components are being produced using aftermarket/reproduction tooling.
The majority of the remaining components including trim are being produced using OEM tooling.
The 427 ZL1 is available as a crate engine and the remaining powertrain components are available from Chevrolet/GMPP.
The durability of these engines is legendary.
Thiosemicarbizide Benzoyl Alcohol
Damn right plus Murica!!!
lat woods
Below 5000 rpms, and two most day to day driving is done under there anyways unless you take it to the track which 90 percent of people don’t.
lat woods no reason why a well balanced engine with lightweight lifters an stiff springs can't do 6500rpm
tyler a
That engine would be more expensive and that cost is going to be past on to the consumer.
I've got an old Silverado with the 5.3 in it, I put stiffer valve springs in it back when I got it. Beat the hell out of it, shifting at 6500, has 335k miles on it and still going strong.
One tech that has GREATLY extended the flexibility of larger pushrod engines is Variable Valve Timing. When Viper's 8.4 liter V10 got VVT, the redline extended to 6,600 and it gained 90 hp. Now the V10 actually weighs less and produces 62% more power than that first 1992 engine. In 2018 every American pushrod engine has VVT. Great simple and direct video EE.
The viper engine is a monster.
How to achieve VVT with push rod?
Lawrence Fearon but the viper was a joke!! A big cubed v10?? The Zr1s have been faster with much less.. just imagine if chevorlet produced a big cubed v10....
PhillLsx Ga. yeah ? Joke on those 3 back to back Lemans wins or those still unmatched 12 track records. ZR1 isn’t really a track car with 300lbs extra weight.
The zr1 needs a supercharger to match that 8.4 liter v10. The ACR was making over 600 hp all motor. I like corvettes big time but a 6.2 liter engine is not gonna compare to an 8.4 without having more mods like supercharger
He said it at the end, COST! In the American auto company there is one voice that in the end is louder than anybody else's. That voice belongs to the person they call the "Bean Counter"
if companies can save 1$ pr engine they will do it.. even whit development, that's why US cars where/are loosing marked shers all over.....
I can think of other names, but bean counter is politically correct.
@@julemandenudengaver4580 when you make 20 million engines, that $1 an engine adds up
@Random Hoerse exactly,same story with corvettes,
Yep,the very same reason is behind the "wisdom" to overload BMW engines with plastic, CHEAP plastic....
I used to think this technique wasn't only old-school but also inferior to so-called modern engines. Even being an engineer myself, I didn't think twice and totally fell for the "progress". But some years ago, I'd take a second look and nowadays I'd rather take a modern "old-school" American V8 over any "modern" European models, talking about cars like Camaro's, Mustang's and Challenger's or even CTV's. So thumbs up for your video.
I would like to give you a slight correction.pushrod engines are not all 2 valve engines. and making a 4 valve engine isn't very complicated.exhibit A: the 24 valve 5.9 Cummins is a common push rod engine with 4 valves per cylinder. however the camshaft is almost identical to the older 12 valve Cummins. the difference is they use a small bridge between the two intake and two exhaust valves. so each pushrod and rocker are pushing against 2 valves. this makes the valve train only slightly more complex then the older design and adds only one small extra moving part to do it.being that I'm currently building one of these engines, it's rather painful to hear someone say that that style of engine doesn't exist.
The thing that makes them legendary, it's how upgradable they are for the average mechanic
Upgradeable, serviceable and reliable.
Outside of the US, these engines don't make as much sense, they're heavy and use tons of fuel for the power they generate. They aren't cheap outside the US, I can get similarly capable European engines for the same price that have far better power:weight than LS engines will ever get or if I'm not feeling insane I could buy a very decent 6 from a Skyline or Supra, which are a dime a dozen here, modernize it with a custom ECU and coil on plug ignition and new injectors and a new turbo and still have a ton of cash left over to buy extra bits.
I know you American guys won't understand terms like cornering or handling, so won't be able to understand why people in the rest of the world care about power:weight ratio. Vintage V8s are probably ok on straight highways with meandering bends, but on a really twisty road any mid nineties Japanese mid ranger will destroy anything powered by a pushrod V8 outside of million dollar jobs that use that engine just to prove a point like the Ford GT
@@theParticleGod arrogant much? Most of us know about the problems of these engines but keep them around for the fun of it.
@@theParticleGod ok im european but your comment doesn't make total sense in terms of cornering. Camaro ZL1 had solid lap time (24th ranked) on Nurburgring for sub 80 000$ car, better than many 200 000+ $ cars. In terms of fuel don't know about the Hemi's but LS1/3 were getting 30-32mpg (US mpgs not UK) on highway which is better than 3-3.6L v6 with direct injection dohc engine. I won't argue about price LS engines are not cheap in europe, you can get used engine and supercharger from e55amg for 2000-3000euros.
@@ristekostadinov2820 Imagine how much better that Camaro would have gone if it had an engine that was designed in this century.
camshaft is lower so the oil gets to it way sooner when you start up the engine
Probably true, but probably inconsequential.
Overhead cam engines have far less valve spring pressure to achieve the same RPM so even though pushrod engines do have the camshaft lower in the engine they have much more stress because of the valve spring pressure required. But you already knew that. I'm a pushrod guy and when top fuelers start running overhead cams well that would say it all wouldn't it.
Anonymike
No... definitely not inconsequential. It’s been made even worse with VCT which require expensive oil filters with silicone anti back flow valves.
I’ll give you a less extreme example. Horizontally opposed aircraft piston engines. They all use pushrods and a single camshaft. Lycoming mounts their camshaft above the crank. Continental mounts theirs below. One guess which one has chronic camshaft issues?
@@georgehoffman7846 well now top fuel is using pushrods, so here we are. Guess that worked out
The best thing about small block pushrods being more compact? You can swap them into places where you normally only find OHC four cylinders... like Miatas. Or vehicles originally equipped with an older design SB. That's one of the reasons LS swaps are so popular, although cost, power, and availability of parts/upgrades are some other good reasons. They're shockingly efficient for the horsepower too, especially when you consider how simple they are (in relative terms). :P
+1 for a pushrod V8 stuffed into a Miata! The resulting low end torque gives it Monstrous acceleration!
Good instructions on the venerable and indestructible Pushrod V8 engine !!
Jason, just get an LS car already. We all see your newfound interest in them
Yeah given his age he wouldn't look out of place in a corvette
yeah for a 65yo I would say yes.
What does LS stand for?
Adrian Kinny LS originally stood for "Long Shaft". Now it is just a term used to describe most of GMs v8 engines
Jason looks more like a ZL1 type of guy to me. Just do it, you know you want to
Cam shafts are made of very hard steel, and require complex machining operations to create the lobe profiles. A single large camshaft is much cheaper than 4 smaller camshafts.
The air velocity argument is more about valve quantity and size (2 vs 4) than the type of camshaft used to control the valves.
if a timing chain/ belt goes in a DOHC with turbo/ biturbo you will understand the pain of complexity.
Are you saying a broken timing chain in a pushrod engine doesn't damage the engine? I have seen many bent valves and pushrods and cracked piston over the the years.
Chris Daigle he’s talking about the complexity.. not reliability
I don't find either overly complex. Look at Honda and Toyota and the other Japanese manufacturers mostly OHC or DOHC and variants of both. Most reliable vehicles on the planet and best resale by far are Honda and Toyota . But Honda still makes push rod engines for their power equipment as well as their engine business. Additionally for over 21 years they make an OHC single cylinder, aluminum bore general purpose, timing belt in oil engine that's used in their mowers and other products and as a general purpose engine horizontal or vertical shaft. It works fine for the application intended. The engine used for this video as a push rod example appears to be a Honda GX160 commercial engine or it's a Chinese copy.
Push rod engines have their place just like DOHC and OHC ones do. If you like it great that's your personal preference. Maintain your brand of engine properly and it should or will stay reliable and live.
Try having a mechanical fuel pump on each bank too 😅
Chris Daigle true but I guess it depends sbc 350s are non interference engines and you’ll mainly just be stranded as opposed to having engine damage like a jaguar DOHC V8 if a timing chain were to break
I've noticed a stability difference between my OHC Honda 1100 (V-twin) Shadow and the lower CG of a similarly sized pushrod Harley, with its cam(s) down low.
The Holy Grail for 60s car enthusiasts, when every American car was OHV w pushrods, was an OHC engine with an aluminum block and heads. Now OHC and aluminum are all over the place and cast iron w pushrods are the in thing.
Another benefit of a pushrod V8 is a great exhaust note.
lol the 5.0 sounds way better and also the 5.2 is a beast
Pushrods have absolutely nothing to do with exhaust note... similarly sized and arranged valves on an overhead cam will sound exactly the same. Even if you had some type of pneumatic or electrically actuated valve it'd sound the same. What opens the valve has nothing to do with the sound, port geometry/volume, combustion chamber, literally pretty much everything BUT the method of opening the valve has effect on sound.
maybe he means they rev lower so they have that lower note.
I disagree, with the exception of old detroit diesels
@@salvadordollyparton666 engine configuration changes it to I believe
I just want one of those sweet 3D printed engines. Good coffee table piece.
Great video. My GM 3800 Series II V6 in my 2005 Buick LeSabre still outperforms many newer designs and gets about 22mpg in city/highway driving. It has plenty of power, smooth acceleration and is relatively quiet. I can't find anything wrong with this pushrod engine.
Aaron Alter
My 1998 Lesabre currently has 247,000 original miles on its 3800. Still doesn't burn oil. Gets great fuel mileage. Smooth and very quiet! ;-)
Aaron Alter outperforms them how? Those old GM boat anchor V6's make less power and worse fuel economy than almost any other V6 on the market.
jsquared1013 I would say that's true for most of gms v6s but most definitely not 3800. That is a hell of a engine. I would take it over any v6 I've ever come across
jsquared1013
If I hold my Buick under 60mph, it easily gets over 30mpg. I have gone over 500 miles on a single tank of gas.
I had a 2005 Pontiac Grand Prix. It had the 3800 series 3. I bought it in 2007 with 110k. Ran nothing but Mobil 1 are royal purple in it and just traded it in. Had 247k, I didn’t cut it any slack either.
Roughly 50 yrs ago a friend of mine argued against the pushrod and in favor of the OHC engine. The subject was the Sebring international race and why the Corvettes were getting trounced by the foreign cars with their OHCs. Thanks for letting us know that the pushrod engine has advantages and still has a place in cars today.
Weirdly enough, it's the Pratt and Miller ALMS Corvettes kicking ass at Le Mans
When it comes to reliability Simplicity is the key . Also if somthing should go wrong you can figure it out and fix it in the field and you also don't have to be a rocket scientist to do that
Pushrods make much more sense...and cents. Modern computers keep them efficient and their simplicity makes them more durable and reliable. Plus packaging is a big advantage too. Only neophytes knock them.
great explanation even my cat could catch this
Cats are great at catching things. instagram.com/p/BiLfadXAAYz/?taken-by=bucketron
Yes! Thanks for this video! This is why previous GM cars with the 3800 series "Buick engine" are ideal sleeper cars. GM should have that opportunity to bring those sleeper cars back! If they can't get the Buick Grand National to fruition, they can revive the Oldsmobile brand and have it specialize in sleeper cars.
The GM 3.6 is terrible. Imagine if the Buick 3800 got another series with an aluminum block and heads, VVT and direct injection like the LT V8s. I know it wouldn't be making over 300HP but with modern improvements, it would at least be making 250-270HP with fat stacks of torque and excellent fuel economy and that engine could fit in pretty much anything.
You nailed it with the cost factor, choose cubic inches or cubic dollars.
Technologically your S2000 is superior in every way. The cylinder head has narrow placed cams. Although it's VTEC is designed towards high rpm, VTEC/VTC can be used to actuate 2, 3 or 4 valves per cylinder and utilize different valve lift to optimize low speed air flow/swirl/torque characteristics. Variable intake runners are one inexpensive method for improving low end torque, even Hyundai uses it.
A V8, V10 or V12 with all that technology would be quite expensive, only high paying Ferrari, Infiniti, Lexus, Mercedes, etc buyers are willing to speed that sort of money.
Follow the money.
Reason pushrod engines are still around, the LS is a fricken monster
Nothing beats a good DOHC
In most pushrod vee engines, the left cylinder head and right cylinder head are identical, interchangeable parts. Chevy pioneered this with their small block.
Pontiac went a step further than all of you and built lots of interchangeability into their V8 blocks ranging from 301-455. Taking the 301 turbo out of my old 80 Turbo Trans Am and replacing it with a hopped up 455 (including 400 heads on the 455 and hooking up to the original trans) was all done with the turn of a wrench.
Chevy hated Pontiac. They hated them bad.
@@HAL-dm1eh Chevy engines are great, but what a loss when Buick, Olds and Pontiac stopped making their own engines.
Excellent, informative, accurate, brief and to the point. Thanks for this.
I have told people for years that in low to mid RPM applications that pushrods are every bit as good as any DOHC design. I would add a sixth advantage as well and that is the reduced friction of a single cam as opposed to 4 separate cams, that may in part account for GM and Dodge small blocks consistently getting better fuel economy then their Nissan and Toyota pickup rivals as they have for as many years as I have been in the business, not knocking the imports I actually own one, but I won't use it as a daily driver because it gets 14 real world MPG, I got over 20 in a chevy with a 5.3L.
The claimed torque advantage of pushrod engines could equally apply to a single overhead cam engine or any engine with a similar combustion chamber design. You can also go DOHC 4-vales per cylinder with VTEC or similar technology for torque plus top end if you want. The single overhead cam design is very simple, just one more camshaft in a V8 and no extra camshafts in an inline engine and you get rid of all of the pushrods too - 16 pushrods and associated hydraulic lifters in a typical V8.
Yeah, but if you're only going to have one cam, why waste so much size, money and weight on an OHC arrangement? It's also increasing repair costs on the engine for little to no benefit. Now, DOHC definitely has benefits, but only if you live in a country that taxes displacement. Otherwise, you're just trading cost, size, weight and complexity for some meaningless volumetric efficiency boast. You could just increase displacement a bit on a pushrod engine, save money, weight and repair cost and ultimately make the same power and fuel economy. IE full size Buick 3800 powered sedans getting 30 highway, on par with many 4 cyl OHC midsize cars of the time while making more power.
You forgot lower hood line is much more easily achieved with pushrod v8 vs DOHC
GM, King of the pushrod V8 tech.
2.25, he says that
GM, king of boat anchors
@@Welcometofacsistube Tell that to the Corvette
We got a dodge over 200k miles I’ve seen some with over 400
Making the complicated easy to understand; Great explanation.
In this case, making the simple easy to understand.
There is an modified LS7 that revs 11200rpm now. It's called spinal tap build by EFI University.
I still rock the 3.3l v6 push rod engine in one of my dodge dynasty's. Then I have its big brother the 3.8 in another one. Always loved these engines, the take off and power they produce makes them perfect for a car that weighs 2500 pounds.
I'm 58 and I remember my grandad telling me about these😁
If the Corvette Z06 uses a pushrod design and makes 650 hp and 650 lbf ft of torque, then it should be pretty obvious that it is a good and proven design.
Main advantage is size and weight of the engine is much less, put an LS next to a DOHC engine of similar capacity and your mind will be blown in the size difference.
Like a 1uz?
Size and weight advantage doesn't seem to matter when DOHC engines are slinging out heaps of power, and manufacturers build chassis and suspension systems around the weight of the powerplant anyway.
It's just minutia after all is said about the differences. Preference. One manufacturer likes one technology, another manufacturer likes the other. It's not like DOHC aren't reliable, as they are the basis for the vast majority of engines on the planet (1 ,2, 3, 4, 5, 6 cylinder engines small and large).
@@exothermal.sprocket sure but that is their main reason for going that way.
@@DabDabGoose Meh. Probably engine cost, more than any other thing honestly. GM and Chrysler bean counters have decided the engine was the place they wanted to cut manufacturing costs.
@@exothermal.sprocket European countires have added tax on cars based on engine displacement. DOHC makes more hp per liters so its good on spec sheet and taxes over there. In the United states we tax based on fuel consumption per mile so there isn't a government push for smaller engines just engines that consume less fuel. They could build DOHC engines but why should they when they can output enough power and fit where they need to fit as well as have a large support network already out there and a large following. It's hard to justify the change unless they think that it would pull in a bunch of overseas sales that with taxes isn't a sure thing either.
1:57 or most commonly 1 long chain that loops around to both heads.
Also slightly before... Valve bridges... Valve bridges let a push rod engine have 4 valves per cylinder while keeping the exact same camshaft as a 2 valve cylinder. Notably the 5.9 and 6.7 Cummins diesel engines use this method.
A camshaft from a 12 valve is directly swappable from a 24 valve and back (note when a 24 valve cam is used in a 12 valve, a aftermarket lift pump is needed because the 12 valve cam had a lobe to run the mechanical lift pump which the 24 valve doesn't have)
You might want to add the fact that for the same bore, a 4-valve head outflows a 2-valve head by only 25% for the same bore size. That means any pushrod 2-valve engine would need a 10% bigger bore, which is very small in the scheme of things. To get a bigger stroke for the same bore on a DOHC engine, you need a longer chain/tensioner, taller cylinder, longer connecting rod, wider intake manifold.
----Pushrod engines offer great simplicity. They use only one cylinder head casting. No left or right head. GM LS3 heads are better than LT heads, because the valves are parallel. You cast the head, mill the rocker seats, drill the valve guides, flip the head over, locate off the valve guides, mill the valve seats, insert the seats, and mill the gasket surface. You don't have to change the mil angle to do two different valve angles for two different planes of valves. All you have to do is set your goal.
----I believe, the pushrod engine will be the only remaining combustion engine if the world electrifies. This is because the pushrod engine is good at what it does. A battery costs over $1300/KWH capacity. A 25 gallon gas tank cost $300. Even at 30% efficiency, that's a 247 KWH battery equivalent for $300, and after three years, it'll still hold 25 gallons.
----You should do videos on taking limestone, pyrolyzing it with CSP plants, and converting it to liquid fuels.
I would love to see how small displacement like 1.6 to 2 liter pushrod V8 will perform
That is a very interesting question. I'm no engineer but it's fun to think about.
Just scaling down from the upcoming LT2 (6.2L pushrod, NA, 495 hp), a 2.0L would make about 160 hp. About on par with most modern DOHC 2.0L (non-performance) engines (Civic, Corolla). So, unimpressive but not bad.
But, would it still weigh and cost less than DOHC counterparts? No idea, man.
I would bet that it's easier to work on though!
Push rod engines are elegant in their simplicity. I'd love to see smaller (3L) V-8 OHV engines with mild forced induction making their way into 3-series format sedans.
I have a 46 year old car with a v4 pushrod engine, and i have rebuilt it in an afthernoon. has like 12 moving parts. Also never breaks down, but valve clearance has to be checked regurarly
@@tavaszigabor5375 excellent. 😇 & it sounds like it'll go forever....
ThTs what hydraulic lifters are for
ThTs what hydraulic lifters are for
ThTs what hydraulic lifters are for
And Cost for Service. Why didn't you have a printed DOHC Engine for Display to see all the parts and size of a DOHC Engine and packaging..
Jason, thanks for your recent thought provoking videos on pushrod motors! Keep exploring this going forward. What I have not seen you mention yet is tumble flow vs swirl flow. These are key airflow features in OHC vs pushrod engines as well as older OHV engines and the latest designs. The landmark engines (Chevy V8, Chrysler Hemi, Ford/Cosworth V8, Yamaha 5-valve Genesis) pioneered and exploited both of these features to great benefit. Tumble-flow is now one of the most important benefits a multi-valve engine offers today, yet it was pioneered over 50 years ago!
Did I miss it? One of the main advantages of a narrower, lower engine is aerodynamics! A lower hood means higher mpg.
You forgot that pushrod engines have less parasitic drag, fewer cams, fewer valve springs (so less overall spring pressure to overcome).
also they are cheeper to build. less machined surfaces to to deal with
nice one, just repeat what he' said in the vid!
@@Arthagnou nice one, just repeat what he' said in the vid!
@@Arthagnou nice one, just repeat what he' said in the vid!
Spring pressures don’t have to be overcome. On a multicylinder engine, while one spring is being depressed (valve opening, requiring energy) another is valve is closing.
This is something Steve Brule from Engine Masters has explained. He’s the guy who runs the dyno at Westech and has dynoed thousands of different combinations; including back to back tests of a single engine after changing “one” part at a time (“one” since there’s more than one valvespring).
I’ve been watching your videos since you had the integra. I have a 2007 s2000 and i think it’d be so cool for you to do a current video of your s2000 and how you’ve liked it or hated it so far and why. Your tutorials are the reason I always have fresh engine, differential, and transmission fluids lol. I remember coming back to your page after a long time and seeing you got 1m more followers and an s2000 too and I was like damn if this einstein of cars got one I must of made the best choice of my life hahah. I love the s2000 it’s been so fun.
Awesome! And yeah that’d be some good videos to make. I’m currently supercharging it (lots of updates on Instagram). Good on you on keeping the fluids fresh!!
Einstein of cars haha
If it ain’t broke, don’t fix it :D
this is the one that shud not break
The argument for the horse and cart.
@K.D.P. Ross that was broke because of spiders
Also do not forget the KISS principle.
BMW, Ural, and I believe Honda (Goldwing, Valkyrie) still us pushrods for opposing cylinder motorcycle engines. Instead of more engine bay room, it means more ground clearance when leaning into a turn. Weight is a bigger deal on bikes, and some of those opposing bikes are made for off-road where torque would be helpful.
Man, I’ve been watching your old videos for the first time and you’ve come so far from a decade ago. It’s super impressive
Dual overhead cam originally came around in 1912 with the Puegot so pushrod really isn't that outdated
Charles Moore
Pushrod is slightly modified flathead.
Which is older than ohc
Charles Moore And it is Peugeot
older by 4 years
987654321
My apologies spelling Nazi. I will leave it misspelled just for you !
@@user-rb9on3qv9l I mean...kind of? A lot of the original flat head designs had the valve stems operating as the flat tappets as well. If we're saying that OHV is a development from flat head design, OHC is a development from the OHV pushrod where the cam was moved up so the rockers acted directly on the cam.
Also, pushrods came about in 1894 and OHC engines were first documented in 1902 so it's not like there's a huge span of time between them.
Low end torque has nothing to do with whether it's pushrod or DOHC but valve timing, spark timing, intake port length etc etc. All the advantages you mention are basically cost. All performance engines in motorcycles are DOHC. F1 engines are DOHC. Points ignition is simple. Modern electronic ignition is complicated but which is better. It all depends on what you think is important.
Was thinking the same. Not sure why US tend to use SC instead of Turbos, but when doing so, the engine seems to need more total space, so is the size benefit only in the NA and not FI?
Your is correct all performance engines are DOHC type more faster in racing performance
OHV is obsolete in racing performance
Push rod engines still exist because timing guides wear and chains stretch before engines wear out.
James4wd and a lot of cars these days have plastic timing chain guides
Cars are scrapped before than happens.
Best part about this video, it came out 3 days into working on my gen 5 Small block Chevy in my 2015 silverado, this being my first engine tear down, because a lifter collapsed, so replacing the cam and almost the entire valvetrain, not that I needed to mind you, but I have no fear working on this engine despite it being a new iteration of an old line of engines, it's just like a big bunch of legos, because it's simple and straight forward
The Porsche 928 used a single timing belt for both 16v and 32v Overhead cam V8s. Long belt. The were all aluminum, but still heavy.
I'm loving these 3d printed engine models
2 Valves/cylinder can be used in ohc aswell
Yeah I have a 3v 5.4 but that seems really pointless to me.
GM 3800 series 3.
269k miles and strong
J Wagner intake manifold gasket is the only problem
Series II and Series III engines were great engines. It's hard to believe they started off as a failed V8 engine, were sold to another company, bought back and became legendary.
of all the cars i have driven in my life, nothing could take the daily abuse like my L67 (supercharged 3800) did. i would abuse that car and never worry about being left stranded.
There are a great many Series II 3800's that are for north of 500,000 miles and still pull strong. While not a racing engine they had torque and the blocks were near indestructible.
They aren’t any better or worse than any other engine.
Simple fact is they are driven by old people who take care of their cars.
Such as Windsor 302: Light, simple, cheap and low-end - those were the reasons i've scearched for a *'92* Thunderbird, when i needed a good street roller.
Pushrod engines don't intrinsically produce more low RPM torque than any other engine layout. It has nothing to do with pushrods.
The major advantage is that pushrod engines have more compact cylinder heads. You can shoehorn more displacement into a given-size car using a pushrod engine.
Overhead cam designs allow higher RPM for a given cam profile, allowing higher specific power (HP per litre/CI)
Volvo pushrod 4 holds record for most miles on an engine. Over 3 million.
Volvo used to be an amazing company
@@hrbestalkinme3690 you can say that about most companys these days. old cars you could hit a kangaroo it would leave a big dent but it could be fixed but new cars when you hit a kangaroo they crumple so easy most of times it cheaper to get a new car then to get it fixed.
Can't wait to see how good Ford's new 7.3L pushrod engine runs! Code name Godzilla!
I would have liked to see that engine designed for a car!
63ImpFX4 im waiting to swap a big cam on it when i get a 7.3 L
now if only they brought back the Gran Torino and used this engine exclusively would the muscle car era would have a glorious end before circuits and amps uncouthly take over .
As always, good, clear explanation. I always learn something from your videos.
I wonder if I can make a request? My current car is a BMW 540 xi with a straight six. I believe BMW is one of the few manufacturers still using this engine configuration in cars. I understand that the straight six has certain advantages in smoothness over the V6 design, and perhaps other advantages, but I've never really understood why. Perhaps you could do a future video on the pros and cons of the straight vs V6? Thanks.
Stephen Schwarz
He did a video on this. I'll dig it up.
Thanks
Some Diesel engines are still inline. Cummins uses inline for some of theirs as it makes more torque and is even more simple than a V engine
the reason for the torque is due to how long the stroke needs to be. long stroke= more compression => more torque
ʇɥƃᴉɹlɐ ʇou ɯᴉ Longer stroke doesn’t mean higher compression...
You may also want to mention that when performing machine work the DOHC engines are very complicated to ensure correct timing chain length if you alter the deck height to rebuild the engine or change compression/quench height or fire ring it for extreme boost. In a OHV engine you simply need to measure the pushrod length test tool after setting the rockers to have a perfect swipe over the valve stem, on a DOHC engine (Looking right at the BMW N62B44 when I say this) you need to make sure absolutely everything is true and within spec or the engine will have valve timing issues and possibly damage. There is also a huge amount of parts and complexity in the roller follower system most DOHC engines use that are prone to failure.
This is my go-to page whenever I have a repair to do and I really want to procrastinate.
Pushrod is great but from what I read Double Overhead Cam are much older than Pushrod by like 40-50 years, invented in 1910s in France, if that is the case it seems to me DOHC is the old design and Pushrod is the new technology
In 1898, Detroit bicycle manufacturer Walter Lorenzo Marr built a motor-trike with a one-cylinder OHV engine with push rods for both exhaust and intake. Among the first cars to utilize engines with single overhead camshafts were the Maudslay designed by Alexander Craig and introduced in 1902 and the Marr Auto Car designed by Michigan native Walter Lorenzo Marr in 1903. The first DOHC car was the 1912 Peugeot which won the French Grand Prix at Dieppe that year
Another advantage: THE SOUND
No difference once the bonnet is down. Best sounding V8 I've ever heard is a 3.0 litre OHC!
*Laughs in m113*
@@martintaper7997 Best is subjective... do you like a raspy high revving sound or a deep low rumble? I personally think flatheads sound the best of all. Built flatheads have a mean rumble.
@@honkhonkler7732 I like a rumble with an overlay of crackle. a small V8 can give you that.
Makes total sense to me. “Here-here” for the tried/true/proven, push rod engine! (Still always has my vote!).
The 3D models are so useful in your descriptions. Thanks again.
Barry Bebenek Where-where?
True that!!! My Buick lucerne has a 4 speed automatic and a push rod V6 engine and it's extreme reliable! Older technologies are just so freaking reliable they've had so much time to upgrade it
That 3d printed engine is pretty cool. Push rods definitely have a unique sound as well.
My first car was a Skoda Fabia with the 1.4 8v Skoda pushrod motor. She will give peak torque at just 2500rpm! Imagine when i got my next car I didn't realise that some motors were not playing at being diesels. I loved that crappy little thing, 5k RPM and you could hear all the valvetrain etc struggling and wheezing. It output the same emissions as the BMW 520i (2.2) that followed not long after. Was like 2.0 engine thirsty as well. So no never another pushrod for me but what an introduction those decades ago❤
Every time I see a printed internal combustion engine, I'm both really impressed by the likely lengthy CAD work and post-print cleanup/fitting, and kinda sad that it'd melt, blow itself apart, or just hiss menacingly if any combustion took place internally.
C'mon, home DLMS printing! I don't care if it's an unreasonable and unrealistic want. I just want my RC toys to be that much stranger.
Can you make a video on why you decided to go with a centrifugal supercharger instead of a positive displacement supercharger on your S2k.
Most readily available, and fits without altering the hood. I don't know of any roots/twin-screw kits for S2k.
Edit: Follow the build on Instagram for anyone interested! instagram.com/p/Bii1rjeBxTd/?taken-by=engineeringexplained
Engineering Explained Jason you don't have to tell me to follow you... I already am!!!!
Engineering Explained also a centrifugal fits the powerband of the F20C better than a Roots-type 👍
And now the new 7.3 Ford V8.
Another great video. Honestly, I love both the Mustang GT and Camaro SS, but the simplicity of the LS3 in my Camaro was a big reason I purchased it. Look at the timing chain(s)... lol. And low end torque anyone? Yes please!
And people wonder why there's still sooo many buick 3800 engines on the road still. Great vid!
My dual overhead cam 4.7 V8 in my Toyota Tundra is VERY reliable.
Jeff Pittel it is very reliable, however I prefer my 5.7 in my SR-5 Tundra. You can’t argue with 385 horsepower at 17mpg.
Even in v6 configurations as well. You take Literally any Toyota DOHC engine and compare it to what the “American brand” has to offer and Toyota engines will win every single time. Quality and reliability are far more important than displacement or output. What good is a powerful engine if it doesn’t run. My 1999 Solara 3.0 V6 produces 15 more house power per liter than a 2005 4.0 V6 mustang. I have never seen a mustang with over 100K. My Solara has 230K+ still runs like new.
@@noahschaub1984 Toyota engines are reliable but they're far more powerful and fuel efficient engines. The GM 6.2 L86 makes 420 hp and 460 TQ is much more fuel efficient than your 5.7.
@@noahschaub1984 funny you should mention reliability. one of my buddies has an IS300 with the 3UR-FE V8 from the Tundra that he uses as a track day car. he rebuilds the engine after every year because it always ends up showing wear on the cam bearings even with an aftermarket dry sump oiling system.
the car i run with him is an '89 Firebird with a swapped 5.3L LMF V8 from a 281k mile Chevy Express van. it has new gaskets for the heads, valve covers, intake and oil pan, but otherwise it's still using the factory crank, rod and cam bearings. the only thing i've had to do to it after 3 years of track days is air filters, oil changes and spark plugs.
@@Bravo21Niner As soon as someone mentions power per liter as something that matters, you can pretty much consider them beyond being able to be reasoned with.
Awesome cars btw, that you mentioned.
and surprise surprise, Ford is making a 7.3l pushrod motor for the Super Duty to help with fuel economy
And longevity since their more complex OHC engines have experienced valvetrain related failures
@@stlchucko The Volvo B18/B20/B30 engines are among the most reliable engines ever made and is has even gear driven cams. That's the engine you find in the Volvo P1800 that Irv Gordon drove for 3.2 million miles.
ehsnils
I assume you’re trying to support my statement since those engines have a cam in block. That means they are not OHC (overhead cam).
fitty6pickemup
Do tell... How/why would Ford make that CIB design a 4 valve without making it OHC?
2002 7.3L diesel? That was made by International, called the Navistar. Not until the latest 6.7L has Ford designed and manufactured their own diesel.
GM uses Isuzu.
Dodge uses Cummins.
Top fuel is pushrod and the 3.4 indy motor is pushrod!
Just because the rules.
My GM250 1974 pushrod inline six is still rocking!!
Back in the early 70s I recall having a Honda 50cc scooter with push rods that turned over around 10,000 rpm. That thing would carry me 100 miles on a teaspoon of fuel. I thought the technology had died out...
1. Pushrod design has nothing to do with whether an engine favors low speed power or high speed power. That is completely up to TUNING. It is true however that pushrod engines cannot reliably rev to the same speeds as overhead cam designs. This is why they are typically TUNED for low speed torque.
2. If you examine parts counts you will be surprised to find that pushrod engines are actually more complex than a competing SOHC two-valve design.
3. Pushrod designs are indeed more compact and slightly lighter in weight. These advantages are small, especially considering the mandated hood height of modern cars and their increasing curb weight due to safety and infotainment systems.
4. You hit the nail on the head: The main advantage of pushrod designs is COST. GM and Chrysler have always directed their engineering departments not to build the best car, but to build it as cheaply as possible and still get people to buy it.....
Great video!
the more parts the more chance of failure, tried and true !!!
Then we should go for a 4 cylinder then - much fewer parts?
The old saying keep it simple no need to reinvent wheel over and over this has been downfall of many auto makers, prime example Ford 6.0 diesel the 7.3 was great engine but some computer savvy designer thought he could make his mark with Ford and the rest is history !
I wouldnt say thats 100 percent true, but less parts, especially less camshafts are much easier to work on
Very interesting. Love the 3D motor! 😉👍🏽
Can you explain the 5.7 hemi engin and it's fuel injection system. And why the using sequential variable value system. How does these impact reliability
When over-wound, PCM makes to test mode.
Low end torque is NOT an advantage of pushrod engines, apart from the fact your alleged advantage would apply to an OHC 2 valve, the reality is that a 4v with it’s better airflow can achieve better low end torque through more conservative valve timing if they chose to. The reality is that few 4v/cylinder engines do that so as to optimise the area under the torque curve but some have (Daihatsu fourtrack for example, great low end pull from its low output (90bhp) 1.6 16v engine).
Ford just came out with a 7.3 L pushrod motor!!! In 2019. Like if you are happy with Ford!!!
I was thinking the same thing lol - I'm not a Ford guy but I gotta give them some credit for making a pushrod engine
Yep, and gm came up with the 6.6 pushrod gasoline. Pushrod is making a comeback, if anything👍
That's really unfortunate they are going backwards the voodoo engine in the gt350r is probably one of the best motors the USA has ever made.
They should just increase the displacement on it and keep a flat plane crank and dohc 32 valve. 8000+ rpm n/a absolutely unreal. It's such a shame they are going back in the direction of the less efficient motors. In terms of horsepower per liter you aren't beating a dohc with a flat plane crank. They really should just up the displacement leave it n/a and let it scream. A 7.3 liter engine much less a pushrod is laughable.
Might as well stick a rolls royce merlin in there and let it max out at 3000 rpm. That's kind of a bad analogy the merlin was a fantastic motor ohc and super charged but if you are going for displacement and low rpms look no further.
@@n111254789 I wouldn't say that the Voodoo engine is the best. And besides you're not even throwing FI into the mix. As much as people are tired of them I would say the LS is the best motor all around from the US just due to reliability, parts availability, stock bottom end strength, and price.
@@orficaldari3524 I mean it's good just because it's simple and has a lot of parts but it's very inefficient at making power. Don't get me wrong you can make a ton with that motor but as far as making a lot with a reasonable displacement without forced induction. It's not happening. The main upside to that engine for me is its weight it's not that heavy given what it is and you can make it lighter.
I'll agree through in terms of just sheer upgrades how interchangeable it is and the availability it's second to none. But it's just not really that good of an engine the only reason it's so popular is because of those reasons. Outside of drag racing its just not that great you got better options it's such an old design it redlines low dud to it running out of breath in the high end even if it was destroked and cammed. The design just has bad airflow and that's a big problem with all push rod engines.
They don't breathe well, meaning they can't rev very high. Since hp is rpm x torque divided by 5252 and they can't get rpms they have to go for torque which means increased rod length (lowering the rpms even more) and increase the bore size. So basically they have to have a very large displacement to get any reasonable amount of power and now they have to compound that displacement by adding forced induction. Increasing the weight so it loses its only benefit of being lightweight for its size due to its simple design. At that point you might as well have a modern performance engine and the most modern performance engine the USA has is the voodoo motor. Flat plane, ohv its the perfect base.
Missed the 6th advantage : the exhaust note beats anything. I have Speedster 356 with a Vw air cooled 1600cc. It sounds like a P-51 at the line. Game over (and it's 70hp)
The most powerful v-8’s in the world are pushrod motors
A top fuel dragster makes power that’s only measured by an equation because dynos can’t handle their power
Over 10,000 hp oughtta be enough
Design by rule book. Only one camshaft is allowed. You can try to make DOCH V8 with only one camshaft but i can guarantee that it will be hard to start.
I know a guy who worked on a 1400hp 2.4L I4 DOHC turbocharged top sportsman drag car. Only the best parts, machining and assembly on that puppy. It had to be rebuilt every 20 passes down the quarter mile.