Camshaft - High Lift and Duration - Increase Horsepower
Вставка
- Опубліковано 10 лют 2025
- Can you increase horsepower with a better camshaft? How can camshafts be optimized for maximum horsepower? What techniques do engineers use to design a camshaft? What is high lift and duration? This video explains several methods to keep in mind when purchasing or designing an aftermarket camshaft.
Be sure to check out:
Engines: • Car Engines - Explained
Dohc vs Sohc vs Ohv: • DOHC vs SOHC vs OHV - ...
HP vs. TQ: • Horsepower vs Torque -...
Please feel free to rate, comment, and subscribe!
And don't forget to check out my Facebook page:
/ engineeringexplained
Also check out my official website: Make suggestions, participate in forums, enter for Car of the Month, learn through logically ordered lessons, read FAQs, and plan your future!
www.howdoesacar...
NEW VIDEO EVERY WEDNESDAY!
I don't understand why most of his videos have dislikes. They're informative, well structured and well made. I'm guessing it's just the people who are too slow to understand basic mechanics.
i agree
haters bro, haters..
At the time I'm viewing this, he has 50 times more likes. He's doing just fine.
A few car enthusiast's think they know everything about how engines work, so when they hear something that conflicts with their "knowledge" they get upset. Just like everything, it's ego.
Cause he's exposing the secretssss hahah
It's possible to increase your max hp and still get better fuel economy, but that doesn't necessarily mean that the two will happen simultaneously. For example, more hp typically means you'll need more air, and consequentially more fuel. But if your engine operates more efficiently at lower RPM, and creates higher power at higher RPM, you can have a combination of good fuel economy and HP. This is basically the principle behind VTEC/VVT/valve timing.
Don't forget, changing a camshaft can change your cars sound!
Awesome explaining as usual sir!
So THIS is how you started! Great video, clear presentation. No CGI, no sponsors, just the facts!
As a car fanatic and a soon-to-be mechanical engineer, I gotta say u know ur stuff and ur really good at explaining it! Keep it up!
Hey buddy. Im planning to study motorsport engineer. Just a question. Do you think its a good career?
@@mrangulo0 is it a good career brother ?
One of the major limitations of stock engines, if you're trying to get higher revs is valve float. With stock valve springs, there is a designed limit to how quickly the valve can open and close. At higher rpms, the valve can't snap shut before the cam is opening it again, so the valve just "floats" there in a semi-open position.
Just putting in a more aggressive cam does not solve this problem. You must use stronger valve springs, so that the valve can snap shut more quickly than stock. Of course, stronger valve springs bring considerations of their own and cannot reliably be done in isolation. So, just a camshaft swap cannot produce magical results, and you'll invariably notice compromises like reduced fuel economy, rougher idle, worse emissions, and poorer power at lower rpms.
The moral of the story is that a camshaft swap in isolation doesn't produce a dramatic effect for the better, and there are invariably compromises for the worse. An engine is a very fine-tuned collection of parts that have been selected for their particular properties that contribute to a gigantic pile of chosen compromises. To "increase horsepower," in a reliable way, you generally have to swap out entire "sub-systems," so that, say, the entire valve train and timing set will cope with increased loads, etc.
But then you get into questions like, "Were your 6000 rpm wrist pins and rod bearings designed for 8000 rpms and 25% greater horsepower over stock? Your main bearings? Are you going to get adequate oil flow to critical components at the higher rpms?" Etc. There is no free lunch. You can't get something for nothing. Swap out certain parts, and you're just making other sorts of compromises, usually at the expense of reliability. At the outer end of the spectrum of compromises are top fuel dragsters that typically get an engine rebuild after every run (and an entire replacement clutch set)! That's "maximizing performance," but you do not get something for nothing!
My best friend, who built racing engines for living, used to say to wannabes, "Speed costs money. How fast do you want to go?" A camshaft swap-out in isolation is pretty cheap and easy, and it doesn't net you very much at all.
^Absolutely true
On a side note, I also have a friend who runs a grassroots racing team focused on endurance race and the likes.
He actually tries to cram in OEM stock parts as much as possible since they're the most robust and reliable.
Maybe you should make a youtube video
Someone finally explained how a camshaft works where the person can understand. You have a gift of making things easier to get. Thanks for that. Love your channel by the way
The video isn't a recommendation; it's a basic overview of *how* altering the cams can alter horsepower. The comments are for discussion of course, so add any knowledge you may have, or feel free to leave a video response.
Thanks, they do go hand in hand, really. Increasing the amount of air/fuel etc means a greater pressure rise in the cylinder, meaning a greater torque, meaning greater power. You may want to check out my video "Horsepower vs torque."
I suppose it would yes. Especially if you're actually allowing in significantly more air/fuel. Hence when VTEC "kicks in" it is noticeably louder, from the change in cam lift.
i hate how youtube broke comments on old videos
Correct. If it was designed specifically for the stock engine, the stock cam is probably best. But if you have additional upgrades and need better airflow, this can help.
I do not.. haven't gotten much into engine building, though I do plan on it eventually. Best of luck!
I love the videos that this guy uploads, they're so useful and everything's just clearly explained. These videos are good for beginners and people who want to know about how each components function in cars.
I really learn a lot in a short period of time from watching your vids! thank you. I cant wait to get my gsc s2 cams installed in my 2007 sti
WHEN I FIRST OPENED THIS VIDEO I THOUGHT THIS WAS GOING TO BE SOMETHING FUNNY TO WATCH, LIKE A KID THAT DIDN'T KNOW WHAT HE WAS TALKING ABOUT. AND EVEN THOUGH HE DIDN'T GO IN DEPTH WITH MORE ASPECTS SUCH AS ICL AND LSA, FOR A BASIC EXPLANATION HE WAS VERY GOOD AT DESCRIBING THE MECHANICS OF A CAMSHAFT AND HOW IT OPERATES. MOST PEOPLE DO NOT FULLY UNDERSTAND DURATION AND LIFT AND HOW THEY AFFECT THE OPERATION OF THE VALVE, BUT MOST THAT ARE TRYING TO DO CAM SWAPS JUST LOOK AT LIFT AND DURATION BLINDLY OR LISTEN TO WHAT PEOPLE SAY HAS WORKED ON THEIR BUILDS NOT UNDERSTANDING THAT IT MAY NOT WORK ON OTHER BUILDS.
VERY GOOD BASIC INFORMATIVE VIDEO. THERE NEEDS TO BE MORE OUT THERE LIKE THIS FOR THE PEOPLE WANTING TO LEARN.
Great video as always, however this is not at all the whole story. Improving the breathing at higher revs will give you more power at those rpms but also lower the power at low rpms and often narrow the power band considerably. The more of a "race cam" you put in your engine the bigger the problem gets. Overdoing this can make the car almost unusable at low rpms. Great for a race car where you want full power most of the time, but bad for a street car where you also want to be able to cruise without reving the hell out of the engine at all time.
Who wants to have 200hp at 7000rpm but only 50hp at 6000rpm and below? I would much rather have only 150hp at 7000rpm but 100hp all the way down to 4000rpm. Would make for a greater street car and also a better race car.
So please do not go out an buy the most extreme cam you can find. Camshafts are a black art in itself and on top of that the camshaft need to match every other part of the engine and bigger is not always better.
With that said most engines, that are not already high performance engines, can almost always benefit from replacing the camshaft. You should easily be able to increase hp with 20% without loosing driveability. However depending on the engine you might need to replace other parts of the engine to take advantage of the new cam.
Could you explain the science behind that please? Its just that everyone says it and I'm not 100% certain if it's true.
@@MrAndrius12 you lose manifold vacuum at low rpm, the more overlap the cam has (intake open and exhaust open at the same time) the worse it performs at low rpm
@@averyfilbert1596 yeah the intake and exhaust being open at the same time makes full sense. May I ask, how would turbo/supercharging would affect all this?
My Name Is Hello they got specific cams for forced induction, they’re pretty similar, people used to run more lobe separation on them to increase back pressure on the exhaust but now they’re running similar specs to the n/a cams... im not 100% sure on turbo cams but the bigger they are the less drivable the car is, they have trouble with idle and depending on boost your power band would be higher but youd make more power
@@averyfilbert1596 so even if the turbo boost is 30 psi (2 bars) the cam is going to be similar?
"So simple and have nothing fun about them." Relax dude... I bought my Integra in high school because I wanted something reliable (VW/Audi don't shine as bright as Honda in this category), light weight, with decent gas mileage. To each their own - I did my research and picked out a car that's met my needs, and it's done well over the past 6 years. But if you want to tell me why you built a VW feel free to PM. You can try your hardest to convince me :)
More airflow nice!
Those drawings make easier to understand
This man has the same great style and informative explanations eleven years back… nice
I couldn't tell you the direct relationship, and of course it would depend on the engine, but larger valves will promote better airflow, and likely will affect high RPM power a good amount (assuming the cylinder head is expanded accordingly).
Engineering Explained is completely amazing. Not only is he very smart, He also has that unique ability to teach. He has that mentors grace. Not every smart person has that. He has an amazing talent, skill, gift, whatever you wanna call it. Just wanna say thank you EE for all the help. You have done wonders for me in helping me understand my car's engine, transmission and its engine components. This understanding has helped propel me on what I could do. Thank you.
Very kind works, thank you, and thanks for watching my channel!
Thank you sir. The pleasure is mine. Thanks to you I have a better understanding of what I have in my car and what else I can do with it. More power to you and Wish you the best in all you do. Especially in teaching folks about engines & transmissions etc etc.
Cams shouldn't affect the brakes in any way, unless your power gain is very significant, in which case you may want larger/better cooling brakes to compensate.
What is it with people not liking these videos, there the best out there and have a lot of science and math involved and a lot of info.
This channel is still the top recommendation I get for my search preferences. Thank you EE!
Other people usually unintentionally make this a very complex discussion enabling the it to be very difficult to understand, BUT with him, He makes understanding or knowing any of his topics simple.
I've watched most of your stuff .It is as good as any class lab at tech school . thamks
Thanks!
I think you should also have mentioned the disadvantages, like low performance at low RPM :)
Robin K. Wouldn’t a tune for more power at the bottom end fix that?
@@wey12341 no, given what can you would decide to go with most benefit upper rpm for peak hp not tq, so you sacrifice low end tq for top end hp. Has nothing to do with a tune, more or less just the design of the camshaft. To my knowledge lol
So, the low end torque will decrease for sure if I use a performance camshaft that boosts the power on the higher rpms?
Alfa Kenny Juan you spend a majority of time at 1500-3100 rpm
@@getsuccessfulwithandito1550 yes. a larger lift cam will typically yield more torque at the low end compared to high end hp gain, a high lift cam usually doesnt need an increased rev limiter. high duration, high seperation cams are for high rpm, top end hp gains but sometimes a loss of power in the bottom end
Some geometry I suppose, and faith in your valve springs. Good valve springs are critical for higher RPM.
Always enjoy the videos. I think you should clarify that in addition to going to a higher duration/lift camshaft it is often required that a stronger spring and retainer be used to compliment the additional stress from opening the valve further and at a higher rate of speed and to make sure valve float does not occur at higher rpms than what the stock valvetrain was designed for. Could you do a future video explaining what lobe separation angle is and how adjusting it changes torque peak?
Man these schematics you drew are perfect. Just wanted to know what a high lift cam shaft does and just by looking at the whiteboard, I immediately got it
I can't decide if you're 19 or 40 years old
+Master of None Why not both?
Master of None came here to write this
He's a 19 40 year old
Agreed
2 years later this is still the best comment
Yes, a better lobe for high rpm power production. It has higher lift and I think it also has higher duration. Engineering Explained may have done a video on VTEC. Also, Eric the Car Guy did a great video on VTEC in which he actually shows your the camshaft of a car with the system and does a very nice job of explaining it. Oil pressure is used to select the new lobe in a VTEC system.
Great video, made that super simple to understand why a cam shaft upgrade is worth it.
An interesting video and very appropriate for me today as I've been looking at swapping out the cams on my Caterham Roadsport for either the Supersport spec cams, or piper 633's. Both have greater lift and greater duration than the standard cams, and deliver this power at much higher RPM. So instead of having say 120hp at 6500rpm, i'll have more like 140hp but probably nearer 7500rpm! Obviously to get these kinds of gains, you need to remap your car to take account of the new cams and rev limit, and also ensure that your intake manifold and exhaust system can supply and remove enough air quickly to make the most of the hotter cams.
It's a hugely interesting subject and shows just how much can be done to alter the nature of a car.
I wouldn't look to swapping cams, as it's probably pretty good as is. There are of course many other routes to increasing airflow.
Seriousness ehh?? Not bad. A subscriber made it for me, something like "fs13" I like to think of it as a manual gearbox pattern. Very cool.
Absolutely.
Nice video!! For a future video I think a good topic to talk about would be the torque and horsepower curves.
I took a few classes in college including internal combustion engines, and automotive engineering (yes, the titles were this basic). Mostly researched on my own, I have a bit more detail on my FAQ's, you can find the link on the "about" page of my channel.
i believe eli Martinez is referring to a change in vacuum. camshafts can affect vacuum pressures, and in turn affect how the brake booster operates.
Great video as always Jason. Thanks for taking the time to make this.
To increase revs you also have to have in mind do the components of the engine are strong enough to be revved more. Most important component that will stop a engine revving safely is valve springs, if any valve float caused by weak springs will cause problems if a collision with piston occurs at higher revs. Also rod /stroke ratios that is detrimental to the strength of piston as it approaches and passes it's design speed has to be thought about also. Making a engine rev past it's designed strength of components can be a failure of a component waiting to happen. To make a engine safe to rev more than it was designed too is a tricky and expensive undertaking.
Short ram intake vs cold air intake
I think that'd be a great one
And thank you for these videos there very helpful
Matthew Iwanka short ram pulls hot engine bay air = les air in same space but cold air from outside engine bay means more air molecules in same space = more power
thanks, that was very easy to understand, now I understand why Vtec creates more hp at high RPMs
Plus a bit of overlap at high RPMs is a good thing, because the inert gases in the burnt air lower the reactivity of the mixture therefore lowering the temperature below the level of NOx formation. Plus the amount of Oxigen available is also lowered further reducing NOx formation.
Very good informative video. Higher rpm improves the horsepower potential of an engine not automatically add hp.
Well you don't want any load other than directly down, a cam may put a sideways load on it, but probably can/has been done.
Overlap is actually quite desirable (to an extent). It creates scavenging (exhaust pulls the intake charge in). Huge gains in efficiency were gained when we figured this out. Before flathead v8s only made 100hp. Now we have smaller stock v6s that make 325.
As long as the valve spring is strong enough, the timing depends on the degrees of rotation, not the amount of lift.
Hope so!
This guy literally has an amazing channel!
Perhaps, but it really shouldn't be affected too much since both valves will be closed during the compression stroke, which is when the spark will fire.
haha I know, I do need to get into diesels a bit more. Though I think electric/hybrids will be next.
Still a very informative video. Thank you for your hardwork and passion🙏💪🏼💪🏼
I completely agree with every thing in this video... But one thing that does help make a vehicle faster- a RWD vehicle, changing out your rear end gears to a higher ratio.
I like your content bro, thank you for taking the time to instruct and help further understand one of my favorite subjects, keep doing the amazing job!
This guy deserves more views! Awesome vids, explains better than most teachers out there!
Your videos are fantastic and have cleared up so many things that confused me before. Please keep posting!
You've come a long way... Great video!
if I wanna know something I don't know. this guy needs to do it. thanks AGAIN bruh.
Great video I understood the basic concept before but now it actually makes sense.
You'll reduce the rotational inertia, yes, which is a good thing, but doesn't mean you can increase the RPM limit. Just how quickly you get there.
Yes. Higher lift means more exhaust is being release from the chamber which would be louder since more exhaust is being expelled than before.
This dude is awesome. I didn't know he was this good when he was younger. Reminds me of Mexican boxers.
I think you should re do this one, Most of your stuff is that next level of information I look for mate, but this was basic and addressed none of my questions, and felt rushed.
1 how can a new came increase efficiency and power?
2 what makes lower torqueier cam vs high rev came
3 what makes a show cam like the thumper, probably a bit like the Harley timing huh?
4 why wouldn't the original manufacture take advantage of this wear?
I am researching for the classic small block, better example I think.
Yep
thanks for the video. Its simple enough so anybody can understand the idea behind so called performance cams. What I can't work out is why this isn't already optimized on the stock gear. Why not have the bets air filter and best possible cam already from factory. It surely would not be that much more expensive if at all.
Thanks
One for intake valves, one dedicated to exhaust valves.
Ring gaps should be very small, and shouldn't cause too much influence on the engine. When the ring is compressed into the cylinder, the gap itself can be incredibly tiny (thousandths of an inch). That said, I do hope to have video on the topic eventually.
Variable cam timing and or cranking timing is the way to go and keep everything as close to optimum as techknowledge will allow for. If you have the bucks.
You could, but all the extra spring force that isn't needed is just wasted energy. So you want to balance it in order for maximum efficiency.
I like the Way PTP players Cry when the game brings actual balance. As a Returning players I Love this new Change. There is a Sense of order during gameplay and nobody is too strong or weak. I know the cost of these new Currency will be expensive in the future... But with players investing thousands of Dollars per hanger there was absolutely no room for low paying or free to play players. THIS NEW CHANGE WAS A GODSEND.
It'd be an awesome and insightful video if you'd cover the efficiency and emissions aspect of valve timing. I kinda wonder how much better fuel efficiency one would be able to get with different cams and a more efficient tune.
Not bad for an explanation on how a bigger cam works. But there are a few key things missed. Overlap is good, and the cam lobe doesn't necessarily get taller/bigger. The base circle gets smaller. Otherwise on a OHV engine, the lobes would be bigger then the hole the cam goes into in the front of the block. If you go to radical, then you run into valve train geometry issues.
Looks a little like mine but yours is much nicer. Have you done a video on displacement and strokers yet?
It would be cool if you could do a video on tappets, how they work, whats their purpose, and different types.
omg youre so young , you deserve your views!
Also, I would love to see a video on twincharging!
You should have mentioned something about valve float in there when you started talking about higher rpm applications.
THANK YOU!!! well said, i can actually understand this now. Much appreciated!
This guy is great with explanations
Big like, I learned a lot from this simply explained video ✌🏼 you got a subscriber
Great points, thanks for sharing.
I just realized is better compromise to have a higher lift than a longer duration. Since if you have larger intake systems more air is flowing in general and it flows better if the valve has more lift. Having longer duration doesn't help as much since the lift is the same it would create a bottleneck at every instant so air flow is not maximized entirely. Is best to flow large amount of air more often then more time taking same air, this helps engine rev faster also.
Exactly I've seen where a smaller cam but better flowing heads did way better in the lower rpm range than a big cam and shitty flowing heads it falls on it's face the cam is made for high rpms but the heads are not conducive to that much air flow
Randomly browsing youtube for cam shaft size explanations....and of course Engineering Explained has a video on this....from SIX years ago! LOL!
Here's what you need to know. There's no such thing as too much cam. There's just not enough engine.
@EngineeringExplained: first of all thanks a lot for having this UA-cam channel in the first place. I have a question... How can you ensure when your using a high lift camshaft that at some point under some conditions that your valve wont be lifted too much off its seat that it actually hits the piston?
nice. i knew about the higher lift allowing more air into cyl's for extra power, but didnt know about high duration. thats why they reccomended s4 cams for my pocket rocket nx2000 with underdrive pulley kits and lighter flywheels etc and possibly cam gears adjustment set as well as the racing headers to get the heat out quick etc. then the chip and a tune. lol, im guessing the video you have about upgraded valve springs and kit is for the valves ability to get back to closed position asap.
You forgot to mention that if the head will flow a max lift of say .500, and you use a cam with a lift of .550, you get air reversal(back pressure), and the head may only flow .480(per Comp Cams).
Aw, this was a really nice post. In idea I would like to put in writing like this moreover - taking time and precise effort to make an excellent video but what can I say I procrastinate alot and in no way appear to get something done.
Isnt there a overlap stroke on everything 4 stroke?
Awesome video! All about raising compression or efficiency(not both, though?). Avoid too rich or lean and mind overlap. Also the clearances. Lot's of variables that's why cams are the hardest thing in my opinion; they aren't made tight sometimes too and you gotta degree them to verify
Might want to mention that you need to reflash the ecu if your putting really large cams.
Can you cover the free-valve actuators and how they might be better than the cam shafts?
Thanks!
i suppose you need to reprogram your ECU to adjust the air to fuel ratio
Depends on too many things like construction material, displacement, bore, stroke, etc.
So apart from the cost of good quality camshafts, what would be the negatives of installing them on lets say a small 1.8L or 2.0L engine? Would additional costs such as a new ECU or new adjustable cam gears be required to fully maximize the potential of the camshafts or just installing them on the stock cam gears and stock ECU be still okay to run with HP increase?
UA-cam stops the counter at 300 if a video receives a lot of views in a short period of time, to make sure the views are legitimate. The actual views should be accurate after a day or two.
Hello, i wish that you also explained one of the cam parts, which is a cam wheel. Could you please do a video about adjustable cam gears on SOHC/DOHC?
How advancing/retarding the timing of camshaft functions?
What does it do to SOHC/DOHC? I would love to hear that.
Great video as always, loved the explanation !!
yeah, good question. i always thought there was a direct connection with the lobe and the valve
Awesome videos man! I've been learning a ton!
Can you make one explaining the relationship between fuel efficiency and maximum horse power?
If I give my engine more horse power, does that automatically mean that I'll get worse gas mileage... or is it possible to increase both my max horse power AND my gas mileage at the same time?
Did you find out?