This is a video showing valve float in a running engine at high RPM.
Пікірлер: 745
@thehaap10 жыл бұрын
OK, engineer here. What you are seeing in the video is not valve float - the title is wrong. Valve float is when the RPM of the valve train is so high that the spring does not have time to extend fully before the cam comes down again. IF this was valve float, you would see a video of a compressed spring that never seems to move back to its uncompressed state. What you ARE seeing is valve bounce, where the inertia developed by the cam is so high that the valve unseats itself slightly every stroke. Valve and spring rotation is normal at these RPMS. Finally, AlixHAF is correct - the reason it looks like the image is 'frozen' is because of the sampling rate of the video relative to the RPM of the vehicle, in the same manner that car rims sometimes look they're not moving in a video. It is based upon a part of signals theory called Nyquists Theorem, which I won't detail here but you can look it up if you're interested. Hope this clarifies things.
@starshooter1010 жыл бұрын
Another internet engineer huh? you are 100% correct... but you should have mentioned that you'll never see severe valve float on a rocker!
@mon0railbredpig9 жыл бұрын
It is Nyquist if they have intentionally set the frame rate to be at least 2x the frequency of the information as Nyquist's theorem states that is how information can be recovered from a signal. In this case it's aliasing or intentional undersampling to recover the information. I won't detail it here but you can look it up.
@CemArmutcu9 жыл бұрын
Eric H You are absolutely right my friend. It is not valve floating, just spring bounce.
@capt2519789 жыл бұрын
Correct sir.
@250gtskyline59 жыл бұрын
So, a Honda engine isn't really designed for what they advertised, 8500rpm (JDM), 7800-8000RPM (USDM), right? Don't push your Honda past 5000rpm perhaps?
@tcmtech75153 жыл бұрын
8000 RPM 4 Stroke: Shits getting real! 2 Stroke: I call this 'high idle'.
@jamppa46933 жыл бұрын
I have seen this one 2 stroke racing bike where the tacho started at 8k rpm lol
@conortobin61802 жыл бұрын
@@jamppa4693 What size engine was it?
@jamppa46932 жыл бұрын
@@conortobin6180 50cc :D
@pinkhead68578902 жыл бұрын
Why arnt F1 cars 2-stroke?
@pinkhead68578902 жыл бұрын
Why arnt F1 cars 2-stroke?
@Joolian.r9 жыл бұрын
this video makes me feel like im watching a nuclear explosion about to take out a whole city the all the noise and music and flashes
@WELLINGTON203 жыл бұрын
There’s no music you idiot
@Joolian.r3 жыл бұрын
@@WELLINGTON20 I wrote this comment 5 years ago and have absolutely no idea why I said any of it 😂
@tino82963 жыл бұрын
@@Joolian.r Legend 😂
@milojanis49013 жыл бұрын
There's gonna be an explosion alright, and real soon! Pistons are antisocial, and don't like meeting others, especially Mr. and Mrs. Valve!!!
@megaman992 Жыл бұрын
@@milojanis4901 they’re not very good neighbors when brought together. They like to stay separate.
@davidrobert20079 жыл бұрын
That valve at the end is rotating so much it could almost lap itself in - just add grinding paste.
@mbrewer579 жыл бұрын
davidrobert2007 You just made me spit coffee all over my keyboard!
@NoSmileification6 жыл бұрын
Buelligan what are you even replying to? Like the guy said nothing about ignition LOL.
@65sgboogieman86 жыл бұрын
Lol
@theravedaddy6 жыл бұрын
Wow! That was a random thread!
@tonyelliott41535 жыл бұрын
Buelligan88 Two live down the street here. Unfortunately.
@TheFordraptor1610 жыл бұрын
god i feel like im watching a very old horror movie.
@Peron1-MC3 жыл бұрын
yeah at 1:23 XD
@Ottodyn13 жыл бұрын
Great video, love the shot of the valve! In addition to spring pressure, cam profile plays a large part to minimize valve bounce too. Nice job!
@ryanfisher64026 жыл бұрын
So amazing it stays together even for a minute or two!
@superdave24033 жыл бұрын
Amazing video!! Great job! I never thought there was that much flex in the valve stem itself! And the rotation is interesting also!! Thanks I really learned something and I will remember what I learned and apply it toward my next engine build!!!!!!!
@Neo482 жыл бұрын
sloppy valve guide clearance
@noekiyu15 жыл бұрын
WOW!!! I've never seen an inside view of a running engine like that! Very informative!!
@1989GTADRIVER16 жыл бұрын
Amazing Video!!!!! This should help many people understand what's going on with their Valvetrain. The use of fast ramp rates just exacerbate the valve float problem. Better springs and lighter parts ie Valves, Retainers, Locks etc should alleviate the problem Thanks for the great Video!!!!
@smactek16 жыл бұрын
Great Video. Its nice to see that of those that understand common performmance issues and have learnt how to fix these issues, still take the time to help the general public with excellent illustrations such as this. Well Done. another anomoly in the high revving valve train arena. Is the virtual elimination of the hi frequency resonance by balancing camshafts. It works so well every engine running in the NASCAR Cup Series uses the technique. an 60% reduction in valvetrain death.
@johns8183 жыл бұрын
Valve float happens when the cam profile is too aggressive for the valve spring rate. The higher the lift, the stiffer the spring you have to use. Some people have the misconception that roller lifters add power.. but in reality it's just to alleviate friction from running super stiff valve springs.
@dentonthomas56222 жыл бұрын
Worn out valves are awesome! I just love the pop and crackle sound when I let off the gas at high RPM.
@BAYAREAMX8 жыл бұрын
Sweet, now I'm having a seizure.
@godfreypoon51487 жыл бұрын
You got triggered.
@kg4boj4 жыл бұрын
@@godfreypoon5148 LOL
@FiestaKing363 жыл бұрын
lol
@superwout3 жыл бұрын
Great, just after commenting somewhere that my drink went out through my nose you catch me off guard with this laconic remark
@ericdecker29143 жыл бұрын
I love little Cesar’s!
@getoffmyinternet15 жыл бұрын
Agreed. To see it all in action, such as in cutaway, is always interesting.
@lupuszzz14 жыл бұрын
Extremly good Video!!! I've never seen suh a dynamic process before and it helps me to understand what happens in the motor.
@sambarros15 жыл бұрын
Congratulations on a FANTASTIC video!
@sergioduenas15337 жыл бұрын
good vid. I have a better understanding now of valve train components valve springs in particular. thanks
@vart56923 жыл бұрын
That was fantastic! Thank you for uploading this
@TheKutia7 жыл бұрын
Wow. iv been in those engines. those valve stems are pritty stiff... and they just wiggle. amazing
@UncaDave4 ай бұрын
As I think I remember it, the Volvo P1800, according to a Car and Driver test article in the early 1960’s, was capable of valve float. The engine was incredibly strong with an actual five main crankshaft bearings. One 1966 P1800S holds the record for the highest mileage car of an original owner of non-commercial use at 3.2 million miles. Comments from any fellow old timers??? Interesting video!
@Docv4005 жыл бұрын
I'm guessing this was done with a Strobe Light? Would explain the non-continuous movement.
@Patrick.Weightman4 жыл бұрын
0:53 when the acid hits
@CarLoverPhotography3 жыл бұрын
Wow imagine seeing this in 2020 with modern cameras
@Mebob200111 жыл бұрын
Ouch, you can see the valve dancing back and forth, possably needs a set of guide's and obviously new springs xD sweet video!!!
@juancarlosRou6 жыл бұрын
Excellent video! Thanks
@dee_rz49529 жыл бұрын
Amazing video!
@Xeyph7 жыл бұрын
This video reminds me of VHS...
@flyboy363314 жыл бұрын
Valves are supposed to rotate in operation. Some stock 3-piece valve retainers have funky spring washers to ensure they spin. Valve float is when the valve's inertia overcomes the spring pressure and the follower comes off the valve stem tip. In fact the entire valve train goes loosy-goosy. The side play is loose stem clearance and/or a too thin valve stem. Hard to fix since you need clearance to oil the stem. Double springs are a must for high seat pressures and to kill harmonics.
@BlkFlagMotorsports13 жыл бұрын
very cool video of the valvetrain at high rpms
@wd100014 жыл бұрын
Another possible factor is a hydraulic lash adjuster, either in the lifter or bucket. A sad feature of e hyd adjuster is that when there is even a small amount of float (loft) the adjuster takes up the lash. The net result is that the valve does not seat when on base circle and you lose cylinder seal.
@Frostman18216 жыл бұрын
You are totally correct about the compression ratio dynamic vs. static. And to further add to 23607's total and utter failure to read what ever book he's been reading properly, dynamic cr. sure as hell does mean alot when you apply static cr. If you have a dynamic compression ratio of 11:1 and apply pressure even 0.5 bar/7.35 PSI, could be damaging on any engine, generally, don't get carried away trying to prove me wrong on this data.
@buzta438 жыл бұрын
Nice video. Very interesting.
@beluga42013 жыл бұрын
dude !!! this is totally awesome video very nice!!!
@kirilakmadjov83078 жыл бұрын
this clip could make a good dubstep video
@pallymeat15 жыл бұрын
thanks for this very informative video.
@michaelrzepka7522 Жыл бұрын
Great video
@petthekittyz14 жыл бұрын
the idea of rotary valves is a great one! while the seal does suck, it can be made to work, and the RPMs would be amazing, as are desmodesic valves
@MrHeadshot198210 жыл бұрын
Cool vid keep up the good work.
@flyboy363314 жыл бұрын
The type of vavletrain makes a big difference. Pushrod engines are the worst because the spring has to arrest the inertia of the lifter, pushrod, rocker, retainer and valve. Next best would be the overhead cam with a follower pushing on the valve. The best is an overhead cam pushing directly on the valve via a valve spring cap. But they are a royal pain to set the lash. You have to measure all of the lashes, remove the cam, insert shims under every cap, then put it all together.
@onazram19 жыл бұрын
I believe there are some very normal things going on here, and that it is an over dramatization using worn parts, to promote their cylinder head service, as well the delays caused by raped frame rate changes deceiving the eye
@PooManchoo28 жыл бұрын
I know this video is regarding valve float at high rpm, but.. Do the springs tend to still oscillate as much at say, half the rpm? Is oscillating only really an issue at very high rpms? I have an engine with ~.300" between full lift and bind. I'm seeing wear patterns on the lash caps that look like the stem is moving around like in this video. However, the engine is rarely at 7000. Spends most of it's time between 3000-4000.
@jonasgrumby10933 жыл бұрын
Looks like it’s working perfectly fine
@DJM44214 жыл бұрын
great video
@299special13 жыл бұрын
so correct me if im wrong cause i no nothing about how your able to watch the valve. but from what it looks like, your using some sort of strob in timing with the valve so you can take almost still shots of it to see the placment and unwanted rotation of the valve spring. its really amazing that the quick flashes trick your mind into seeing it almost still when really its moving 7000 times a min.
@madmax46107 жыл бұрын
Great video...
@yamahale6 жыл бұрын
its supposed to rotate along with the valve, to help keep the face seated. The rocker arm intentionally pushes on the valve tip at a slight angle to make it rotate. Float is uncontrolled up and down motion from spring resonance. Hi-perf engines have 2 springs per valve to raise the resonance higher than the engine can even go.
@bicylindrico6 жыл бұрын
The direction of the valve spring coils cause the rotation. The rocker should theoretically be centered on the valve tip
@yamahale6 жыл бұрын
they are offset, to keep the valve rotating and clean of carbon. Don't take my word for it, the truth is out there.
@yamahale6 жыл бұрын
hmm thats weird thats not what I have been taught since high school. In fact its simply wrong..."Depending on valve train design, the valve rotation might be obtained by using the cam or rocker offset position or by using angled cam"
@yamahale6 жыл бұрын
I see what you are saying, some designs don't have it, but to say NO designs have it is false. Honda tech school explained how they do it. In fact the last year CB750F suffered valve guide wear when they put the latest camshaft in it, the side load was beyond the original parameters.
@josepeixoto33846 жыл бұрын
Duke Nukem, makes a lot of sense,i never thought of it! After all,the spring is a torsion bar;
@andyharman30222 жыл бұрын
Seat load of the spring is only part of the reason for valve bounce. Under extreme dynamic conditions, coil surge changes the seat load. If the valve seats when the coil surge is heading up the stem, it can unseat the valve if the acceleration and amplitude of coil vibration are high enough to overcome the static seat load.
@wheelmenroadracedirector880811 жыл бұрын
Yes, The frequency of the valve was at or close to the resonant frequency of the spring. This condition is know as spring surge and can cause spring failure ie snap the spring.
@chuckthebull3 жыл бұрын
I'm wondering if these tests are really done by just spinning up the valve train or actually running the engine,,especially with the underside of the valve view.. cylinder pressure also pushes valves closed but granted during intake and exhaust pressures are lower, but during the compression stroke would valves seat faster or more efficiently? I see no flame front on the compression chamber during these tests. and I'm actually surprised the float is not worse.. but this was still fascinating to see.
@TestECull14 жыл бұрын
Also, they replaced the springs when I had the head decked and cleaned up. They used the OEM part. Still floats around 4100RPM, which coincidentally is Ford's recommended max RPM for my engine.
@ChickenStripsRacing11 жыл бұрын
valves spinning is a regular occurance. bmw did tons of testing on their s1000 motor before going into production. valves spin regularly. and when harmonics come into play, manufacturers put in inner valve springs, which also raises overall spring pressure.
@maleco26144 жыл бұрын
one of the best videos i seen great job!
@iliasmetalworks3 жыл бұрын
Apart from the correct spring pressures, what you have to say about the installed seat pressures?Is it so important?
@olivier0123413 жыл бұрын
@novaracer1963 at the end the valve seems to go faster but in fact it goes almost the same speed. It's just because the strobe-light is not timed perfectly with the rpm... you can see the same thing with a timing light and a fan.
@KapteinOpel13 жыл бұрын
@FLSHBK1 The valves are supposed to rotate ok, one of the spring holders contain a "roto-cap" and causes the valve to rotate slightly each time it is pushed. A friend of mine once had a Ford V6 that sounded like it had a bad valve lash on one valve. Removed the valve covers and found that one of the valves didnt rotate. Gave it a squirt of 5-56 and knocked it with a hammer(yes it was running), and the sound disappeared.
@SarraPiyopiyo13 жыл бұрын
@FLSHBK1 The rotation isn't bad, the jackhammer effect is... It's basically pounding on the valve seat. Excellent video!
@downback58227 жыл бұрын
Curious as to valve seat run out/ valve run out. Concentric to one another? Looks like a bowl wobbling on a table. Cool old vid
@trumpnut13 жыл бұрын
What did you do to correct the side to side valve movement, I know how important the spring pressure is but did you tighten up the stem clearance? Was this an actual running engine or electric motor driven?
@CrisURace13 жыл бұрын
How is this filmed? Its awesome!
@CreditMunch15 жыл бұрын
Good video - cheers.
@produKtNZ15 жыл бұрын
Hmm so what is it we are seeing here exactly, or rather more, how is it done? Is that a strobe light used in order to capture the motion? (assuming that at 8000 rpm the valve assembly couldn't been seen by the camera, letalone the naked eye)?
@KirkTheGod14 жыл бұрын
@mikem75 How do you think they adjust timing belts? A computer is used with a strobe light hooked to it and the computer is hooked up to the engine to calculate the engine's RPM. Then uses this RPM and tells the strobe light what frequency to flash with.
@MrBoolyman12 жыл бұрын
@JasonMann8 normal speed with a strobe light cycling just slightly less or more than the rpm of the engine. eg: 8000 rpm engine with a 7999 or 8001 flash per minute strobe. Very cool effect
@ltp973516 жыл бұрын
Nicely done friend,no wonder my machine shop keep telling me ,vavle guide can wear quicks on Honda motor and Mitsubishi motor,but also they should have some way of making diff. kind of valves guide instead of brass material,prevent fro wear on valves and valve guide,wonder if double valves spring also cause the damage on valves and valves guide also.
@ufarkingicehole4 жыл бұрын
Wow... Cool video
@jesvans8 ай бұрын
very cool vid
@Rotard12a15 жыл бұрын
Yeah, most have two rotors though, so generally people just cite the number as 3. Engines with 3 rotors are fairly rare and engines with 1 or 4 rotors are extremely rare (though in the case of 4, extremely cool, too!) Water/oil pumps, distributors, carburation/fuel injectors, etc. are all accessories of course, so they don't really count. Though as fun as it is to tote the simplicity of the engine, the sealing system is actually much much more complex than that of a piston engine, so...
@wizardofx11 жыл бұрын
Did those springs reach a resonant frequency? Is that why they began to wobble?
@ganithajanitha11 жыл бұрын
Please help me to understand because I'm yet a student in this field. 10000 rpm means about 83 valve openings per second. How comes the rocker arm seems to rock very slowly. is it some optical illusion like "wagon wheel effect". Thanks in advance.
@authmaax13 жыл бұрын
have you tried tubular valve stems? 1.2 mm in diameter holes?
@1971SuperLead13 жыл бұрын
@FLSHBK1 I think the problem with valve float is that the valve doesn't make good contact with the valve seat and so not only causes a loss in engine power but the valve does not cool properly and the valve "burns" causing permanent power loss and valve cooling problems.
@jr54012311 жыл бұрын
just today i saw about 6 of them pass me by on a 12 mile long road, and all of them looked about as good as the day they rolled of the Assembly line.
@fastcars11738 жыл бұрын
I can't believe it's been 9 years already that he's gone!
@BigEsGarage9 жыл бұрын
That's pretty cool.
@nepzski2 жыл бұрын
imagine if someone had an epileptic seizure watching a valve float video
@peteacher527 жыл бұрын
Most helpful.
@bisnonnocanapa13 жыл бұрын
@299special yeah it is correct,strobe lights was used for super slow motion before the invention of high fps cameras
@yelyab13 жыл бұрын
Eric is correct. Valve float is when spring can’t keep up with the mechanical motion of the camshaft. This is from a 2nd engineer, BSME.
@AWDfreak13 жыл бұрын
I think I might want to consider upgrading my valve springs and cams after seeing this O.O I redline my Subaru pretty much every day I drive it, and I have no idea if the stock valve springs would like it...
@roflex213 жыл бұрын
I couldn't really see any valve float, the spring always looked connected to the rocker to me?
@JITProductions9 жыл бұрын
This video reminded me of how my wife and I conceived children our children for some odd reason. LOL! Seriously this video gives some really good insight to what might be taking place in some engines.
@g2dashizal8 жыл бұрын
*1:15** SEIZURE WARNING*
@mr.sandman53117 жыл бұрын
or is it at 1:35? yes I see the time stamp
@shimaafrazmanesh1306 жыл бұрын
G Smith *AND IT CONTINUES TO **4:21**!?*
@vinster10000024 жыл бұрын
This should be in the title.
@maximuswedgie51492 жыл бұрын
Is the roller on the rocker spinning like crazy?
@gravey0713 жыл бұрын
Im not arguing it. But wanted to know how valve spring rotation can be a good thing? And what is valve bounce exactly? Whwn the valve isnt quick enough to return to its position or whwn it wobbles? Or...? Thanks.
@ClanOfSteel16 жыл бұрын
nice to see, how valves works...
@JarcodeRover6 жыл бұрын
Wouldn't valve float mean that the valve spring can't co op with the rotation from the camshaft and by that way stays open? Here you can see it bouncing and thus closing on the seat. Never thought it rotated this much on a stroke.. Nice footage!
@leslie-tolman3 жыл бұрын
This just made me anxious and paranoid. I'm rebuilding my whole damn car from the ground up (seriously... in my garage, by myself) and I was already worried about bottom end bearings and piston rings. Looks like I'm just gonna replace all internals, go bigger, forged etc and hope my husband's at least kind enough to let me have a few blankets and a pillow in the doghouse. He's gonna have a damn canary and an aneurysm simultaneously when I spend what I'm bout to... he just got a new motorcycle tho so he'll be fine lol. Hopefully I will be too... hahaha
@grantjohnston58173 жыл бұрын
That will teach him...go get em Cha Cha Muldowny!
@TheCreedBratton13 жыл бұрын
sweet vid
@VaderisOne4 ай бұрын
I remember when I was young and just learning about fixing cars ‘( 87, ) some guys said valve float was accelerating as fast as you can and when you reached max rpm let off and hit the breaks….i always questioned that and where as I never became some super race tech ( I prefer cars all factory, and I do refrigeration ) I could never believe that. I have rebuilt a few engines in the VW air cooled area and more in the Honda 96-2012 line and consider myself a decent tech, the valve float thing is real but rare from my view point
@garypeatling79273 жыл бұрын
Amazing how long valve spring last wonder how many million time they operate in life time ?
@katrinan9429 жыл бұрын
dude you need to go back to class that isn't float .. float is when the spring hasn't expanded all the way before the rocker start coming down again.
@danielsanpesongco44956 жыл бұрын
gswy ohhki K. Thanks for explaining in the most easiest way possible. Thanks doood
@danielsanpesongco44956 жыл бұрын
fuzzy wuzzy hmm. I don't know. Should I?
@mechanicalking6 жыл бұрын
IKR waste of my time
@stephenr19993 жыл бұрын
ok 6 years reply in the making. in laymen terms float is when the valve cannot close completely ( or floats) because spring cannot overcome centrifugal force applied .
@paulstandaert57093 жыл бұрын
This depends, I guess. The way I learned it is that a valve is considered to be floating when the lifter loses contact with the back side of the cam lobe, contributing to the valve slamming closed and the bouncing that you see. The back side of the cam lobe is "supposed" to be designed to permit a gradual closing of the valve. When a valve stays open long enough for almost 720 degrees of crankshaft rotation, (where it is about to be pushed open again) a piston is liable to make contact with that valve in the mean time. I would expect engine power to drop off to nothing at that point, thus the only way for this to happen is to jam it into low gear on the highway.
@AlixHAF10 жыл бұрын
What you see there maybe it's not what really happens. Have you taken in mind Shannon's Sampling Theorem for this video capture? You may see frequencies that don't exist at all. Aliasing happens.
@godfreypoon51487 жыл бұрын
This video is more like "equivalent time sampling". ie deliberate aliasing.
@kingof20v16 жыл бұрын
you are right in that b/c only one company deals w/ rotaries, they are inherently expensive, but they is a reason why everyone is doing piston engines and no one bothers w/ rotaries
@0johnny0824 ай бұрын
The valves are supposed to rotate so the portion of the stem that the rocker arm contacts doesn't wear a a singular spot at the point of contact. The keepers and spring retainers and springs are all made to help induce this rotation.
@JosephArata11 жыл бұрын
I've seen push rods bend in diesels without the piston even contacting the valve. Due to harmonic weakening of the metal over time.
@robby84411 жыл бұрын
Does it physically move? All it does is connect the lifter to the rocker arm. If they are adjusted the don't move at all.
@rangerRZR112 жыл бұрын
howd you get the camera there?
@yak55x13 жыл бұрын
Fun with strobe lights ! :)
@getoffmyinternet15 жыл бұрын
I don't know which part I doubt more, the idea that you'd be in the movie, or that they'd let you use your accord in it too.