This Tiny Engine Part Changed Everything - Flathead vs OHV vs OHC!

[@EngineeringExplained]

How cool is it that such a simple part swap can have such a dramatic impact: it enables more power, decreases wear, improves reliability, reduces friction, and can help improve emissions. Engineering is awesome! This is my last video of the year - hope you’re all enjoying the holidays and have a Happy New Year!!! *Edit 1:* As several have pointed out, and was not discussed in the video (though it should have been!), some flat tappet designs use a tapered cam and a specific shape on the tappet to encourage it to spin as the cam rotates against it, reducing wear. It isn't as effective as a solution as a roller, since there's still going to be relative motion between the two parts, but it certainly does help with wear. A roller takes this idea much much further, reducing the relative motion between the cam and lifter as much as possible.

[@krusher74]

Mobil 1 Classic only seems to come in 5/30. what about us classic owners that need something like a 10/40 15/40 20/50? 5/30 isn't a very standard older oil grade.

[@unadultratedtrini]

The one issue I can see with rollers vs tapid would be the pin keeping the roller intact needs to be high quality otherwise you've introduced a massive failure point.

[@Robbobshiskabob]

Whats your thought on motorkote?

[@stefanmargraf7878]

But the roll got an axle and there is friction too! And it adds moved weight.

[@stefanmargraf7878]

You may ask Mobile, why they give no information about zinc in their (single) motorbike oil. The informations you gave are important for motorbikes.

[@Meatball2022]

So - flat heads have heads that are flat, and overhead valves are overhead. And overhead cams have their cams overhead. Proving your educational value every day!

[@EngineeringExplained]

Spend tens of thousands for an engineering degree and you too can acquire this unparalleled knowledge!

[@Meatball2022]

@@EngineeringExplained thank god you picked up on this sarcasm. Love your channel! Don’t recall you using much humor in the past. Don’t shy away from that - you’ve got a somewhat dry sense of humor that conveys well in this video Hope you had a wonderful holiday

[@falxonPSN]

​​@@EngineeringExplainedAnd of course your observation holds true for other engineering disciplines. For example after many years of studying electrical engineering I can tell you that alternating current... alternates. It's pretty complicated stuff but after a few years you pick up on things like that. 😂

[@Dom-dr4pl]

@@EngineeringExplained do pushrods have some sort of rods that get pushed???

[@tubaman66]

Here in UK flat heads are called 'side valve' as the valves are at the side of the piston.

[@WyFoster]

The zinc is a carrier for the bonding agent, phosphorus. The phosphorus is what is actually protecting the engine. Not the zinc. The phosphorus with it's molecular composition is attracted to ferrous surfaces. It bonds and makes a couple micron thick layer of protection. The surface reduces wear but actually increases friction. Fascinating stuff.

[@EngineeringExplained]

Yep - there is an excellent paper covering the mechanism and molecular makeup of the tribofilm. Has a great diagram of it as well. If you want all the nerdy details, check this out: link.springer.com/article/10.1023/B:TRIL.0000044495.26882.b5

[@leonardcollings7389]

zinc additives typically come as an organic compound that contains zinc and phosphorus known as zinc dialkyldithiophosphate (ZDDP).

[@rolandotillit2867]

How do you feel about other types of sacrificial layer type anti-wear additives like Tungsten-disulfide? Not good for motor oils due to poor miscibility, or propensity to drop out of suspension? I know that's one of the benefits of ZDDP. I also know Mobil started using Hexagonal boron Nitride.

[@Your_Paramour]

@@rolandotillit2867 Tungsten disulfide is often used in chain waxes for bicycles.

[@valentinuiliqnow6198]

Please can someone explain to me , why All American call , OHV push rods engine whit only 2 valve per cylinder Small block , because is obviously that you have cam shaft and push rods in the block, and this make bigger, on the other hand the head is small because it does not have cam shaft in it , is have to called, Small Head , not Small block because the head is smaller,the block is actually bigger

[@leftcoaster67]

Did I just watch a video on rollers, or a video on Mobile 1 classic?

[@stuckinmygarage6220]

Haha. I use Valvoline 20V-50 classic. I didn't know Mobile 1 had similar

[@Mayamax3]

Both.

[@TESI303]

"Yes."

[@EngineeringExplained]

Yes.

[@braedonsz]

Rollers, and ZDDP - brought to you by Mobil 1

[@xuevgermanist]

1:40 "This moves the valves..." [Jeremy Clarkson pause] "...overhead"

[@nathanwilliams8458]

These are the most overhead valves...in the world.

[@valentinuiliqnow6198]

Please can someone explain to me , why All American call , OHV push rods engine whit only 2 valve per cylinder Small block , because is obviously that you have cam shaft and push rods in the block, and this make bigger, on the other hand the head is small because it does not have cam shaft in it , is have to called, Small Head , not Small block because the head is smaller,the block is actually bigger

[@willhooke]

@@valentinuiliqnow6198 because there is a series of larger blocks called the big block It's relative

[@fermillo65]

That alone was worth watching this video.

[@physicswithpark3r-x3x]

don't credit that tosser with that move

[@SomeNameGoesHere]

I love the commitment to the 3d printed engine models to include a proper engine stand.

[@ebigford34]

You missed the part with lifters: Cam lobes have a slight taper that promotes the lifter to rotate on the lobe, that helps with wear and using the entire face of the lifter over time.

[@Southghost5997]

Is that why it needs regular adjustment?

[@rolandtamaccio3285]

Somewhat of a guess , but it might provide better oil coverage . In a successful installation there is very little wear beyond break in . So no that is only a very minor part of the necessity of adjustment .

[@chadcoady9025]

Most engines use hydraulic roller lifter nowadays though.

[@scotte2815]

@@Southghost5997 Flat tappets aren't flat! They have a 30 inch radius on their face. They seldom need adjusting. They do need to have the lash set when first installed. Any adjustment after that should be a rare operation. Butt, then the very very early tappets were flat and did require regular adjustments, but they were replaced, upgraded, and phased out fairly quickly. The hydraulic lifter took up the lash with a hydraulic cushion.

[@MyWasteOfTime]

Also rotates the pushrod too right?

[@sparklawns3433]

Everyone saying they could do better, so can the engineers, the issue is they aren't restricted by thier own ideas, they're restricted by budgets and at the end of the day even the best ideas get thrown out when they exceed the budget for a part the company has allocated. You want better engineering than go buy a Pagani or Koenigsegg and see how much a limitless engineering machine costs.

[@patrickcannell2258]

Restricted by budgets and regulators like the EPA.

[@850r2]

Emission regulations are quite literally choking these Engines, particularly in Europe and the UK etc. 60K and a lot of modern engines are shot at that point.

[@ghoulbuster1]

Koenigsegg makes works of art that will outlast humanity. A better achievement that numbers on a bank account.

[@Modikie]

​@ghoulbuster1 so what? you're not gonna buy it because you can't. When I was a wee little lad I loved hypercars. But once I became an adult and realized there's no point being fantasizing about something I'll never afford is useless. Even if I do get to that point, being so obsessed with it now doesn't do anything since by the time I could afford it, its gonna be 20 years old and I'm gonna be wanting the new thing most likely.

[@Yielar1]

And even those machine break down. Heck even Nasa has things that wear out and break and they constantly improve designs over time based on experience and data.

[@mnmetalhed1]

I was taught thatflat tappet lifters are designed to rotate in their bore on the cam lobe. When breaking in a flat tappet engine the higher rpm helps getting that lifter to spin as it breaks in

[@G5Hohn]

That is correct. Flat tappets aren’t really flat- they have a very large radius (like 100”) dome. The “crabwalk” across the cam lobe, like you might do if having to move a really heavy drum of oil, spinning along the rim instead of dragging across the floor.

[@61rampy65]

The other reason for keeping RPM up while breaking in is that the crank will toss a whole lot of oil right at the cam.

[@halcyonoutlander2105]

But what advantage does this have over say, a train which I can also afford?

[@PSA78]

That's why people sometimes also change valve springs and/or rockers to have less load and to help it rotate. Specific break-in oil that's pre-heated can help as well.

[@nick540g]

Fantastic lesson - brief but suitably detailed and wonderfully narrated. Great job.

[@EngineeringExplained]

Thanks, appreciate the kind words!

[@pawebogusz8753]

Also in some engines flat tappet lifter isn't in the center of cam. Cam hasn't flat cross section and create rotation of the lifter to prevent wear.

[@jericho86]

I really appreciate the discussion about the size of the total engine package. The smaller package of an OHV engine design really is a legitimate benefit that a lot of internet opinion spreaders like to forget.

[@nicholas_scott]

pro tip. For years, those of us with old V8s would use oils designed for diesel engines, like Rotella, Delo, or Delvac. They have a much higher level of zinc and moly

[@stanleyspadowski235]

*VGG has entered the chat*

[@MDAdams72668]

HAD even they are low now

[@oneninerniner3427]

Yes. But did you know diesel oils have been reduced of zinc now too.

[@SteveKluver]

Yes, this is true, and I have to completely agree with the others stating that diesel engine oils are now also low in zinc. This zinc (ZDDP) issue has been so misunderstood or unknown by so many, for so long. Most people cannot imagine how many ruined cams and lifters that small engine repair shops have gathered up over these past 25 years, in 55 gallon barrels set aside for scrap metal behind their shops.

[@WW226]

Very true, I use to run 15w-40 in my 3406 and my 1971 350 sbc. However, diesel engines now have to be carb compliant with their DPF systems. So their oils have a dramatic reduction in zinc, if any. But also, newer diesel engines are commonly roller cams now too

[@fascistpedant758]

The move from flat head to OHV to OHC has been more of a latteral shift than a linear progression. They've all existed for a long time. Flat heads were still the norm for small engines till ~20 years ago. There have even been engines with one valve in the block and one in the head. We still produce many very successful OHV pushrod engines.

[@EbenBransome]

Before WW2, the British motorcycle industry tended to use bevel drive OHC for the sports models. After the war they went back to pushrods. Development of pushrod designs had improved a lot whereas bevel gears were expensive. Engines like the Velocette used pushrod tubes that resembled the prewar bevel drive covers, though some makers like BSA and Norton used holes through the block. Vincent used a design that looked like a WW2 radial engine with 2 pushrod tubes per cylinder. But the most produced 4 stroke engine in the world has never been flathead. The Honda 50 (to 110) cc engine started as pushrod and changed to Morse chain OHC - where it stayed.

The last of the flathead V-8 engines was produced by Ford in 1953. Unless your talking about lawn mowers etc.

[@fascistpedant758]

Yes, that's what I meant by small engines. But the first OHC engines were produced ~1902 and Checker Cabs had flathead engines till 1964. Flatheads may have been used in industrial equipment even later.

[@EbenBransome]

At one time around the late 1990s I had the idea, for amusement, of seeing how much power you could get out of a B&S engine (with a lot of mods including forced lubrication, reworked valves and cams etc.) I couldn't find a B&S engine in decent condition, they were all Honda OHC or Husqvarna 2-strokes. So someone saying "20 years" is I think exaggerting.

[@joejoejoejoejoejoe4391]

Of a big racing V8 can rev to 9,000 rpm, is there much need for OHC for a road car?

[@Flies2FLL]

One of the major detriments of the flat head design is that the exhaust has to travel through the block and thus the water jackets before reaching the exhaust manifold; This causes these engines to run hot. Excessive ZDDP can lead to camshaft pitting. Check out Motor Oil Geek's video on this. Great video!

[@EngineeringExplained]

Great point on flatheads! Also recently discovered Motor Oil Geek, he has some awesome videos - have really enjoyed his channel!

[@OxBlitzkriegxO]

thank you for pointing this out, but i think maybe just calling him Lake Speed Jr. would be something that people would equate to legitimacy.

[@Flies2FLL]

@@OxBlitzkriegxO But then people wouldn't know how to find the video.....

[@nerd1000ify]

That only applies to V- flat heads. Inline flatheads can just run the exhaust out under the intake.

[@peteroleary9447]

​@@EngineeringExplainedYeah. MOG has done a few videos about oil dilution -- in GDI engines and from thin, low-tension piston rings.

[@nothing2seehere.goaway]

I remember building a "streetable" rotary engine (12-A) a few years ago and selecting a similar oil (can't remember if it was Mobile or Valvoline) that also had a significant higher level of ZDDP precisely because of this. It becomes a net benefit for the apex seals.

[@cujet]

Back in the early 80's I worked on a roller cam design for a common 4 cyl eng. It was adopted after much dyno/emissions testing. The OHC engine did lend itself well to the upgrade and HP took a nice jump due to the improved cam profiles. Also, many radial engines from before and during WW-II used roller cam followers.

[@EbenBransome]

The German engines, BMW, Jumo and DB, all had very well engineered roller cam followers. They also experimented with disc valves to try and get the cross-section down. RR used crappy non-rotating flat cam followers in the Merlin. They wore out but were cheap to replace, and minimised the cross section. The engineering that wins wars is the good enough, not the expensive best.

[@erikkeever3504]

@@EbenBransome Taking that note of "good enough wins wars" even further: The Soviet T-34 was designed to last about two months and drive a thousand miles before breaking down. This was not a problem because the average T-34 drove to the front once and was lost in combat within a month.

[@davidpowell3347]

@@erikkeever3504 ? No air filter on it because the snow would coat/clog the air filters and disable the tank during arctic combat ? In warm weather could run an air filter and greatly extend the engine life,especially as compared to running without air filter in sandstorm/desert situation ? I think depending on where and when they were made they could have good engine life. The ones hurriedly finished being put together as the Germans were closing in on the "Tractor Factory" probably didn't run too long or well

[@EngineeringExplained]

Awesome, thanks for sharing - sounds like a fun project to be a part of!

[@EbenBransome]

@@erikkeever3504 Back in the 1980s I was involved for a bit in MBT R&D. Several people commented that the NATO doctrine of going nuclear the moment Soviet tranks crossed the German border ws ridiculous: just wait till they'd got far enough to break down and then deal with them conventionally. In the 1990s we discovered that the USSR was expecting to be invaded by the US from Germany, so their tanks were designed for a *defensive* role, on the assumption that when they broke down they would be static artillery, if they survived that long. By the time the USSR was invading Germany the T34 engine and transmission was a lot more reliable because even if the tank was destroyed the engines might be salvageable, as when you are taking territory you can recover them. All about logistics.

[@mrmped1]

You should have mentioned that roller rockers and roller tappet have wear issues on the roller pins which is causing failure rates on certain designs and engines. Basically the wear point on flat tappets was relocated to the rollers and pins. 😊

[@Knirin]

A roller should be the equivalent of a bearing with a heavier built outside race. A lot of bean counters forget that.

[@PSA78]

A lot of regular rockers have issues as well, they aren't machined right and that why some engines wear out guides so quickly.

[@josef5675]

Yes its right, you move only the wear problem. BUT: It is by far easier to change the lifters than the camshaft (and the lifters).

[@orangetruckman]

Those dramatic pauses were a nice touch, chefs kiss 😁

[@bcfr66]

Thanks!

[@YewtBoot]

"Everything is a trade-off." Too few understand that simple engineering need.

[@theoronig6440]

Es ist eine großartige Erfindung und kam zusammen mit gehärteten Ventilsitzen ohne Blei im Benzin.

[@davidsawyer7880]

Not the purpose of this discussion. Rollers are a fantastic solution. Some however use needle bearings. Needle bearings have their place. Inside an internal combustion engine is not one of them. So remember folks,choose wisely.

[@HondaRally300]

Especially if you own a Jeep with a 3.6 L

[@neolerades2987]

Reason ? I know that for example Audi had a problem with rollers due to thermal expansion - when heated, the rollers fell out and the stuck lifter tore off the cam or fell out, which could have caused the destruction of the engine. But if it is designed correctly, I don't see a problem.

[@dbblues.9168]

Zinc oil additives are extremely important in older engine designs for longevity and wear. I've been adding zinc additives to all my flat tappet engines for 30 years. 08:03 When I was learning engines in the 80s/90s the Detergent debate was huge . It was weird lol

[@BlackSmokeDMax]

This may be one of the coolest videos you have ever done. Thank you!

[@EngineeringExplained]

Very kind, really appreciate it - thanks for watching!!

[@The_Pleiades7]

Roller lifters have more of a limit than flat tappet. A aggressive cam is gonna push the roller sideways and damage it. Flat tappet can be extremely aggressive as long and the lifter diameter is large enough

[@EngineeringExplained]

Nah it'll just **puts on sunglasses** roll with it.

[@theshed8802]

It's a fact that flat tappet camshafts can have a much more aggressive off the seat valve action due to the fact that the follower is being lifted as opposed to being pushed sideways by the lobe. Later on the lift profile, the roller follower has the advantage, but initially, the flat tappet can get a valve open much faster.

[@joeyager8479]

If that is true, why do high performance and racing engine builders all use roller lifters? As a former machine designer and race team co-owner, roller lifters are superior to any flat lifter ever built.

[@The_Pleiades7]

@@joeyager8479 I still see a good bit of flat tappet in the high performance na spec classes. Why don't u just put roller lifters on a flat tappet cam then, see what happens

[@jamesbosworth4191]

@@joeyager8479 Roller lifters generally reduce internal friction and reduce cam lobe wear, made especially important with the elimination of zinc in motor oil. The better OHV engines in the 20s also had roller lifters - for the same reason - reduced friction and reduced cam lobe wear. By the late part of the decade, oil had improved enough for them to be deemed unnecessary for street-driven engines, then when engine revs climbed high enough to require stiffer valve springs, ZDDP came to the rescue.

[@Looney21]

at 10:12, the underside view is a Porsche 911 (992)

[@terrybrown8539]

Allison's 1710 V12 aircraft engine from the 1930's has roller cams. Their time between overhaulsl is at least double the RR Merlin so lauded by most. The overhaul time and cost is about half as well. The rollers are a large part of what makes the Allison such a fine engine.

[@1creeperbomb]

"Nothing is as simple as more is better... except horsepower, more is always better" lol

[@adiamondforever7890]

Until something else breaks from too much torque

[@marcomeregalli9828]

I'm Italian, and KZbin decided to start the video on the italian audio track, created automatically with IA I think it's the first time I see (ops, hear) in your videos Anyway, I think I'll continue to hear your original voice :) 1) it's a female voice, and nothing against them, but it's too weird to listen while watching your face and your beautiful whiteboard 2) It's still pretty robotic, and the natural feel of hearing someone explain something I think has so much value in the process of learning 3) I'm not disturbed in reading subtitles ahahaha So yeah, it's a only matter of time, IA will copy perfectly your voice very soon... Up to now, I loved your content, so I'm really glad you now have a tool to further expand your channel in territories which people don't speak english!

[@leumel900]

I agree, but it shouldn't be set to start with the AI track automatically. For the user, there is (currently) no setting to change which track is selected by default.

[@saddle8bag]

Engines make power. Horsepower is a unit of power.

[@EngineeringExplained]

👆this is true

[@curbyourshi1056]

Horsepower is an expression of the power of an actual Horse. Just need a Ferrari designed coach pulled by about 750 Horses now.... Torque would be great, top speed and handling, not so. 😂😂😂😂😂

[@OxBlitzkriegxO]

engines produce torque. how quickly they can produce torque over time is measured as horsepower.

[@ShawnKitchen]

Torque is the power. Horsepower is a mathematical construct of the ability to produce torque at various engine speeds.

[@CarlosGutierrez-qw6pr]

🤓☝️

[@casey8836]

2:25 gold 😂

[@valentinuiliqnow6198]

Please can someone explain to me , why All American call , OHV push rods engine whit only 2 valve per cylinder Small block , because is obviously that you have cam shaft and push rods in the block, and this make bigger, on the other hand the head is small because it does not have cam shaft in it , is have to called, Small Head , not Small block because the head is smaller,the block is actually bigger

[@Amy-dq2lg]

@@valentinuiliqnow6198 Small Block is used as a counterpart to Big Block, as seen in chevrolet v8s, while both were OHV, the big block has a taller deck height and wider bore spacing making it a physically larger block

[@peterchang7646]

sounds like a good oil for my early 2000's outdoor power equipment.... snowblower and riding mower...

[@jeffgriffith7003]

I literally converted my Ford 2.3 turbo to a roller cam. Added bonus is that the oiling holes in the camshaft are much smaller since less lubrication is needed and it helped increase my oil pressure.

[@Cloud30000]

Ask Hemi owners about rollers eliminating wear…

[@MDAdams72668]

still need SOME oil (which those hemis do not get at idle)

[@theskullyhippiedude3719]

Uncle Tony's Garage did a breakdown on the new Hemi cam problem. He determined it was due to the lifter bores set at a flatter angle leading to low cam and lifter lubrication at idle.

[@dan725]

I learned sooo much about engines from this short video!! Thank you!!!!!!!

[@Daniel-OConnell]

One thing that all manufacturers have Managed to achieve is to make Petrol (Gasoline) engines that are unreliable, burn oil, suffer from chain stretch or chew wet belts. Not one of the latest generation of engines is immune. I have yet to see a FIAT OHC engine (Lampredi) with bucket tappets with a worn camshaft. These tappets have flat shims and a camshaft made with good quality steel. They will far outlive any roller tappet.

[@Cloud30000]

This isn’t due to the engine design, but the need to compete for the highest power ratings for marketing and highest in class reasons. The FIAT lasts because it is not being stressed to the limits of what the materials can handle; take one of the new engines marketed to hit 450 hp and tune it to max out at 200 hp instead and it will outlive the FIAT.

[@meedak3449]

@Cloud30000 This is also due to mass production reasons. They want a vehicle that they want to last just long enough to fulfill its warranty. After that, if it costs a ton to repair thats on you. A lot of modern engines have issues here and there, but you will find most of them have been in use for 10-15 years anyway. Peripheral technology might change or maybe the size or oil squirters or journals, or the shape of the intake to improve airflow, etc but a ton of modern engines go through multiple generations of change.

[@DeputatKaktus]

If you squeeze more and more horsepower out of any given amount of displacement and engine mass while reducing weight as well as material cost, something has got to give eventually. No surprises there. The fact of the matter is that the pencil pushers in accounting tend to make the engineering decisions these days. In other words: people who have never touched a wrench or got their hands dirty and who have zero interest in engineering. Manufacturers therefore have no interest anymore in building engines that last. Because “make more sales and more faster please”.

[@vinicius9670]

This is the industry trying to do more power with less (or cheaper) material. Everything is on the limit. The wet belts on the other hand were just plain stupidity.

[@xxwookey]

@@vinicius9670 Yeah, why did they switch to wet belts - did they really think it would work better? It clearly doesn't in practice. In general engines have been getting more reliable since the 1970s but this seems to be a major step backwards.

[@dannyjdonovan]

"Wow! I'm really good at this." Got me lol

[@philnolan7193]

Classic Jason, seems a lot of people missed it?!

[@ronblack7870]

fun fact briggs and stratten style engines on lawn mowers and snow blowers and riding mowers are still flatheads . honda engines are overhead valves.

[@eDoc2020]

I thought they stopped doing flatheads over 15 years ago.

[@thewhitecarrot]

I hope Mobil creates an oil that helps keep Dodge/Jeep/Ram/Chrysler needles inside their lifter/follower bearings. That would be a feat in engineering.

[@cardo1111]

Class is in session 👍🏽

[@Capt-awesome]

Great to see this new product from Mobil. I have a 1970 el Camino with 396 that needs the additional zinc. I use to buy the QUAKER STATE DEFY back when its was available with 1200 ppm of zinc to support the older solid lifters cannot wait to try this product.

[@Taras-Nabad]

Thats when you know you have made it on KZbin, when Mobil One sponsors you. Well done.

[@DustinSilva]

Replacing flat tappets with rollers single handedly contributed to more blown cummins engines than ever before! Nice job engineers

[@kailuagarage]

How are the needle bearings in the rollers protected?

[@krusher74]

oil

[@Mayamax3]

@@krusher74 word.

[@arauchfuss]

Static vs kinetic friction. Roller and ball bearings do not slide so there is no need for a sacrificial layer of zinc.

[@PSA78]

It depends, it can be by hydro dynamic oil film or by circulating additives like moly.

[@adiamondforever7890]

Oil is the coolant

[@alanpilibosian1979]

Roller lifters made such a dramatic power improvement in the mid to late 1980's. What I don't get is how many modern engines have failing roller lifters....Ford 7.3 V8 gas, Hemi V8's, GM V8's and even Cummins recently added them to the I6 diesel and they're failing too!

[@davidpowell3347]

I think quality problems with the lifters themselves or contaminated with manufacturing scurff from the factory. Do the car engine manufacturers make their roller lifters in house or do they buy them from outside suppliers? Low bid ?

[@NBSV1]

Over time the cost gets reduced and the design gets changed. They don’t want something that lasts forever because then you don’t need to buy a new one. If the corporate overlords could have their way the vehicle would make it 1 mile or 1 day outside of the warranty and completely fail.

[@AlienLivesMatter]

Inbuilt obsolescence and penny pinching by the accounting department.

[@DAT240Z72]

NOT ALL OHC engines! SOHC engines are limited on timing optimization and air flow. DOHC engines are the only OHC engines see improved air flow and timing optimization. Roller lifters really aren’t that impressive. Sure they eliminate the need for ZDDP. But that’s about it! Rollers are NOT going to reduce friction or improve power enough to overcome the wear and reliability of the roller lifter. Sometimes engineering looks great on paper……

About 50% accurate.

[@Amy-dq2lg]

SOHC sees improved airflow over OHV, even if it isn't as large an improvement as DOHC, 4 valve SOHC engines do exist, and VVT can be more easily implemented to SOHC than OHV

[@2006gtobob]

My wife and I have had excellent service from our LG washer and dryer units between two homes. One home uses natural gas, the other is electric. Both sets have been flawless. Our LG refrigerators...well the first one in our 2nd home lasted about 3 months. Big box store couldn't find a direct replacement because, well, they were junk and none were available. LG and big box store replaced the refrigerator with one that was 2x more expensive, and bigger. Over 7 years now and no issues, at all. I have no qualms recommending LG.

[@TCPUDPATM]

@7:42 Says every mechanic when screwing in an oil filter…

[@u563rick6]

Haha, I remember on my car forum everyone speculating that High Milage Mobile 1 was better because of greater zinc content but it’s more complicated than that. Thank you.

[@andrepatacchini]

I've installed hydraulic valve lifters in my 1971 VW beetle. It became another car. Silent engine and no adjustments.

[@leftcoaster67]

@@andrepatacchini A silent Beetle?? Witchcraft???? 😁

[@RingingResonance]

Are these drop-in replacements or do you need to do anything different with the oiling system? Asking for an older generator I have that uses solid lifters.

[@gary3074]

If only Hilter had specified hydraulic lifters from the start huh…

[@theblackhand6485]

The Mexican air cooled Beetle had hydraulic valve adjustment and used a cat. too. These parts are still available.

[@sealteamsix1784]

not an car/engine expert, but i figured something like this existed already. it is probably not possible to retrofit, but what about "gas piston" timing?... like where the exhaust pressure from one cylinder opens another intake valve for the next cylinder? (similar to how an AK-47 works).

[@LovSven2011]

Excelent vido. Concise and no empty space. Big like.

[@EngineeringExplained]

Awesome, happy to hear it!

[@golfbravowhiskey8669]

@54 sec. I just love it when there's something that is unexplainable and the term is so simple like flathead you just kinda give that nod as there's no other better way to explain it. That made me bust out laughing.

[@RealDeanWinchester]

The issue with push rods is column buckling which is more related to the force required to compress the valve spring than the force required to accelerate the added mass of the push rod.

[@TucsonDude]

Really?

[@RealDeanWinchester]

@TucsonDude No, nothing could be further from the truth. It's probably related to ethanol fuel.

[@drfisheye]

Don't classic cars often need 15W40? My 1965 Renault certainly does. Mobile Classic doesn't come in that thickness.

[@adiamondforever7890]

Delo 400, Motorcraft 15-40 for powerstrokes, there are several good alternatives. Have fun

[@GoFastGator]

Most often 10W30 or 10W40. AMSOIL’s Z-Rod line has offered both (and a 20W50) for older engines. Higher ZDDP formulations in 15W40 are very common in oils labeled/marketed for diesel applications too.

[@alexjenner1108]

The owners manual for my old Alfa Romeo said 10W50 which we couldn't get where I lived, so we used 20W50 or 15W50 when that became available.

[@njsongwriter]

Incredibly cool indeed and you sir are incredibly knowledgeable. That's why I watch your videos. 😊

[@EngineeringExplained]

Happy to hear it, thanks for watching!

[@yootoobvyooer]

Old motorcycles even with DOHC required valve clearance check every 5000 miles, roughly oil change interval. By the way, check out 1983 Honda Nighthawk, automatic oil pressure adjusted valve lifters, self adjusting cam chain tensioners, shaft drive, it was practically maintenance free (relatively speaking)

[@rightwingsafetysquad9872]

Most new motorcycles still require valve clearance checks and adjustments. Though most have pushed it to ~12,000 miles.

[@zeke2566]

26k and more,were have you been?

[@michaelguerin56]

Thank you, Jason. That was an exemplary explication and explanation of the subject matter. Cheers from NZ🇳🇿.

[@r4dios1lence92]

"More horsepower is always better" Pedestrians: *sweating profusely looking both ways when crossing a street on a crosswalk that is open for them*

[@djkjthe3rd185]

Corny

[@dbblues.9168]

"Lubrication" doesn't always = "Slippery". Great video as always.

[@lebojay]

Finally. It is so hard to find synthetic high-zinc oils for our old engines.

[@GoFastGator]

AMSOIL Z-Rod has been around for years and they make multiple viscosities.

[@RealJimSkinner]

6:23 The ZDDP is still very helpful with wear in roller applications in increasing longevity. Just maybe not “as critical” as in flat tappet lifters.

[@rubikfan1]

2:45 i do wonder we cars dont have electric valves. Where a computer open them. They are fast enough. And it would be much easyer for valve diactivate. And far less friction.

[@hoonaticbloggs5402]

Konigsegg free valve

[@berto1014]

Cost + patents is why.

[@randomnerd112]

Chevrolet engines with cylinder deactivation use solenoids to raise or lower the oil pressure of the hydraulic lifters to deactivate and reactivate cylinders. It causes more problems and pollution than it saves

[@AbbeyRoad69147]

Reliability

[@olivermikolajuk4631]

Konigsegg had the same idea, it’s called Freevalve, it uses solenoids to open and close valves. It should improve efficiency and power. But it still isn’t used to much, I couldn’t tell you why.

[@drunkenhobo8020]

What sort of bearing is in the roller? Does it rely on an oil film or how does it work? To me it seems you've just transferred the load from the tappet to the axle of the roller.

[@adiamondforever7890]

Depending on manufacturer, bronze bushing, pressure fed; or needle bearings with ‘a metered amount of oil’ or not for cooling. Some of the poorer applications only use splash lubrication. Have fun

[@EinChris75]

I am very impressed, how well you explained "flat hat" and "overhead". I never would have guessed it's meaning ;-) Jokes aside. Great video. It shows so many design choices and the technical evolution. And the models are awesome.

[@nickd.7267]

Until these inventions come into production, I'll keep this channel in the back of my memory.

[@donovanwilliams5424]

"Without sacrificing any reliability" .....Ford 4.6 and Chrysler 3.7,4.7, and 5.7 cam followers would like a word.

[@fjoco1]

Don’t for GM 6.2 5.3 they have something to say.

[@justplanecrazy5575]

Ford 4.6s are amazing what

[@123cp8]

Dude, your whiteboard graphics are immaculate!

[@GorhamWorks]

Love roller lifters. The cam profiles can be tailor to the application and really work well. Cool video!

[@richardseelye9938]

WOW, WOW, WOW. Thank you for that presentation. I really appreciate the way you explain all topics that you bring forward in each teaching session. Again thank you

[@wade-potato6200]

Engineers discover the wheel lmao. My friend wore the lobes off his cam because it didn’t have roller lifters, if only mopar had discovered the wheel in 1997 when they made the engine

[@EngineeringExplained]

1997?! What vehicle??

[@wade-potato6200]

@ jeep Cherokee XJ with the 4.0. He measured the lobes and they were half the lift of the factory ones, no wonder he was making so little power!

[@OxBlitzkriegxO]

@@wade-potato6200 there are ohv drag engines that turn in excess of 10,000rpm. there are endurance ohv engines that turn 9,000rpm for hours on end without problem and make tons of power. your friends 4.0 is a very reliable engine. if it failed, it was either due to neglect, abuse, or high mileage.

[@soaringvulture]

Mopar ain't doing so good with rollers either.

[@D2O2]

Ironically, todays engines with roller lifters/followers seem to randomly become flat tappets when the roller bearings fail.

[@j...bro.]

thank you for using scientific temperature measurements.( metric) keep it up!

[@BangerFleet]

Did a roller lifter conversion in a 1953 Arnolt-MG. For the MG XPAG engine, aftermarket flat lifters tend to not rotate properly and wear ridiculously fast, even with proper oil. Changing to roller lifters, as video said, enabled me to use a cam with far less pointy lobes and eliminate a wear risk. This cam swap was part of a full engine rebuild, so I can’t say what performance improvement came from the more modern cam profile alone, but overall the new engine is much much stronger and happier on hills. These MG engines are usually in the 50-60 horsepower range so picking up a few HP is a larger percentage gain!

[@rekire___]

**see description** Damn don't know if Jason was AI all along

[@raymondjackson6069]

To track the corrosion of the catalytic converter to...... the oil ingredient that is used to paste a hardened surface on a cam, took some incredible engineering detective work and tracking. Wow! Who'd a' thunk it. Great video, like straight to the point without "music" and razzle-dazzle.

[@BojanKvakic-j6d]

I recommend everyone to find the book titled The Hidden Path to Manifesting Financial Power, It changed my life.

[@1a1u0g9t4s2u]

Thanks for the background information about the changes in engine design has on oil requirements. This helps me understand why the owners manual specified certain oils when doing an oil change. I will certainly pay more attention I get the correct oil. BTW I appreciate your video on fuel type i.e. unleaded, unleaded premium and the ethanol blend as the manufacture recommends unleaded premium for the vehicle I drive. Thanks for sharing.

[@sheerwillsurvival2064]

I use pennzoil platinum ultra synthetic. Love it

[@MrJohnBos]

KZbin helps me learn something new every day.

[@kc7ekk]

Amazing how complicated these modern Rube Goldberg engines are. Makes me love my EV even more. I don't miss the days of limping home from work in a malfunctioning gas car, do 5 hours of unplanned engine work so I can have it working by the time I need to go back to work the next day. Still it's fun to see the evolution and incremental improvements of ICE engines. Thanks for sharing.

[@yestfmf]

ROFL Have fun with your EV when it breaks down or you want to travel more than 100 miles. Or….during an extended power outage. I will wave at you as I drive by you stuck on the side of the road. There are multitudes of ICE owners who regularly drive theirs 200,000 miles or more. Yes, you have to maintain and repair them from time to time. Any reasonably mechanically inclined guy can successfully fix most breakdowns on their older car (not so much the newer ones). I’ll take my cheap car over a $40000+ rolling thermite bomb any day.

[@soaringvulture]

Yes, I believe that an important factor in increasing the adoption of EV's will be the reduced performance and reliability of IC engines as they try to meet increasingly stringent fuel economy and emission requirements. And besides that, EV's go like hell.

[@bobjackson4287]

@@soaringvulture Tesla has not proven that EV are a more reliable solution, if anything they are on par or even less reliable than some of the better ice examples. EV adoption is a multi faceted thing that will take decades if at all. They will need to be equal to an ICE solution on reliability, cost of repair, recharge vs fillup rate, range, and weight. Where EV's win is instant torque and speed vs normal cars (Purpose built race ICE cars still win) Right now they fail on the range, cost of repair and have some really bad downsides that are unique to them that ICE don't have. The other problem is they really only make sense as cars right now. Truck / large EV's are a joke because they are not only insanely expensive but have poor performance to go with it. EV adoption is trying to be forced, the market is not choosing it because of said negatives. If it was truly better the leap over would of been done a decade ago naturally. Batteries are not quite there yet, a better design will be needed for the switch over.

[@kylearmstrong5533]

Your videos are fantastic. Thank you for explaining it to all of the rest of us.

[@thejbcrazy]

The Carbon build up on the intake values on modern direct injection engine really needs to be addressed, I don’t know why they just put an injector in the intake to open up at W.O.F. To clean the backside of the intake values … Sometimes I feel like I could build A better motor than these Big Corporations…

[@falxonPSN]

Many modern designs do exactly this and have a hybrid injection system. The Japanese makers were some of the early adopters

[@jamesengland7461]

That additional injector costs money they're not often willing to spend.

[@ryanci2689]

It does exist, it's called port injection. Some cars still use it today and some direct injection engines have direct injection and port injection.

[@AY-xd9rk]

Toyota has both direct and port injection in one engine, which solves that. In most cars like BMW a catch can can somewhat solve this issue. So, get yourself a proper catchcan setup

[@davidpowell3347]

"Direct injection" without port injection is defective injection. (Unless talking Diesel).

[@jeffrey1312]

A long time ago I helped rebuild small block Chevy engines. The lifters were always more dished that I could believe and the cylinder walls had a huge lip at the top because the bores were worn oversize. Back then an engine with 100,000 miles on it was worn out. The progress has been amazing.

[@jamesbosworth4191]

Most people didn't regularly change the oil. Engines in where it WAS changed regularly and frequently were in much better shape than that. What you are describing is engines with well over 100,000 miles. Oil back then was a far cry from today's synthetic oil, with one exception.

[@jeffrey1312]

@@jamesbosworth4191 What I'm describing was the norm for engines in the rebuild shop in the 1970's. Also there was usually huge paraffin buildup under the valve covers and in the lifter valley.

[@jamesbosworth4191]

@@jeffrey1312 That paraffin buildup was because of the use of paraffin-based motor oil, and not changing it enough, rather than any deficiency of the engines.

[@Vasquez-t9k]

it's really crazy how nobody is talking about the book the elite society's money manifestation, it changed my life

[@walterbates1654]

How cool is it that we have you to explain all of this to us. Thank you .

[@TheDoubleBee]

"Well, there's a solution that fixes both the wear problem and the emissions problem [...]" - and I said to myself: "Yeah, it's called electric motor."

[@TobiasHinz1992]

You don't understand how the world works.

[@riba2233]

@@TobiasHinz1992 neither do you

[@Epacman17]

That creates a new problem, they don't run on liquid fuel

[@OxBlitzkriegxO]

eletric motors are not better than ice, just different. nothing is free, pollutants are happening somewhere, just not at the EV. dont be so smug

[@TobiasHinz1992]

@@riba2233 what do you think how much energy a car needs to drive? How would we generate and distribute that? It's just impossible with our current infrastructure and it will stay that way for the foreseeable future.

[@timaz1066]

I love how the government wanted manufacturers to take zinc out of the oil and they have no problem sacrificing an engine over a catalytic converter. Thanks for the video. Nice job.

[@EngineeringExplained]

The goal is clean air; sometimes it’s a challenge to figure out but seems like a solid goal!

[@philh8829]

More rollers, more bearings, more complexity, more repair time, more money.

[@Benlucky13]

Longer lasting, less frequent repairs, better efficiency, less money spent on gas

[@KenLeonard]

More rollers, bearings, complexity yes. More repair time? Quite the opposite when done right. See the average Honda and Toyota engines going many hundreds of thousands of miles on average. 100,000 miles without a single part failure is very common. Dr. Deming can be thanked for that.

[@trobjon1130]

Excellent overview and explanation Jason- learned a lot.

[@Daniel_Anishchenko]

First

[@JSFGuy]

Doubt it

[@rjcd9183]

You are fantastic Jason, never stop this 👌

[@JSFGuy]

5G is very slow

[@gosalie]

The pauses are perfect!

[@pooyakhalili406]

I love to see how a part changes over time. Thanks Jason ❤❤❤

[@geniferteal4178]

As long as they get better, not cheaper😢

[@cameronturner7475]

Roller lifters were invented in the late 1800s and many manufacturers were using them in the early 1900s but they were expensive to produce, too expensive for Ford and GM so they produced flat heads with flat tappet lifters. Roller lifters are actually older than flat.

[@GoFastGator]

Awful lot of antique hit and miss gasoline engines out there with rollers in the valvetrains but no spark plugs or carburetors!

[@831Dre]

Wow! What an informative, visually explanatory, with some humor! Thank you!

[@chipper7711]

The internet’s best pitchman for Big Oil.

[@TTime685]

So does the modern common synthetic oil not have enough ZDP for OHV engines? Which ones are best for OHV besides this "classic" formula? Now I'm hesitant what to use for my OHV engines

[@ILoveTinfoilHats]

If you have rollers you're fine

[@TTime685]

@ILoveTinfoilHats Ah ok. Didn't realize modern OHV's had rollers. Thanks

[@tristanschaper281]

Best video I've ever seen on this subject!