More examples of poor lobe designs

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  • Опубліковано 19 січ 2025

КОМЕНТАРІ • 53

  • @merr6267
    @merr6267 17 днів тому +10

    If calculus class was based around designing a cam lobes I feel like a lot more people would like math.
    Thanks for showing this stuff.

    • @PowellCams
      @PowellCams  17 днів тому +5

      @merr6267 absolutely 💯, I would have paid attention....but I had no idea

  • @jmflournoy386
    @jmflournoy386 16 днів тому +2

    Like back in the 60s in southern california we had some camgrinders that were much easier on parts than others. No cam doc back then. We knew who was coping masters and who was grinding with worn out camgrinders and that's about it. WE knew who was doing their own lobes and what presicision they could possibly achieve when making masters. Now some of these grinders are gone but their masters live on 70 years later. I can remember designing lobes on an HP35 and thinking we were the cat's pajamas and hand smoothing by refracting the flats off the ceiling. Remember when Harvey Crane offered his competitors his computer smoothing program. Great marketing ploy as he pointed out the gorilla in the room. Your point about exhaust under boost is so true and even more so with nitrous or nitro. When we got the rambler up to 60 lbs boost on Methanol Ed Winfield did several exhaust lobes. At least we had the dyno time on the independent Champion Spark Plug dyno. I have my own opinion on who has the best lobes and design software. Keep at it Daniel. No BS from you.

    • @PowellCams
      @PowellCams  16 днів тому

      @@jmflournoy386 definitely! Ty

  • @bdugle1
    @bdugle1 10 днів тому +1

    More really interesting info! I imagine lobe design has to include target rpm, a 6000 rpm engine is not going to beat up parts like a 10,000 rpm one. And if you get stiffer parts (pushrods), they’ll be heavier and add to the problem. The equation for horsepower increases linearly with rpm, but the stress on parts is more like the square of the increase. Easing off on the jerk and acceleration has to be a design imperative. Thanks, Daniel!

  • @chrisallmond6867
    @chrisallmond6867 15 днів тому +1

    I enjoy hearing your thoughts on this stuff. I've designed some lobes that were 0.00043 in/deg^2 at the lifter, but those were probably for a very different customer than what you're talking about here.

    • @PowellCams
      @PowellCams  15 днів тому

      @chrisallmond6867 pushrod stuff is sensitive, hydraulic lifter pushrod stuff is even more sensitive, you can do alot more with DA ohc stuff, I looked back through my emails, didn't see anything so your email way have went to spam?

    • @chrisallmond6867
      @chrisallmond6867 14 днів тому

      ​@@PowellCamsthat acceleration was on a hydraulic pushrod system, but again, likely very different than what this engine is for.

  • @waltercarpenter2439
    @waltercarpenter2439 17 днів тому +3

    I like your videos the more i listen to you the more i realize that the less i know. thanks for sharing the knowledge.

    • @PowellCams
      @PowellCams  17 днів тому +2

      @@waltercarpenter2439 ty, we are just passing on what we learned as we go

  • @JamesBower-l9d
    @JamesBower-l9d 16 днів тому +1

    Thanks again for sharing your experience with us peons…

    • @PowellCams
      @PowellCams  16 днів тому +1

      Im one to! just learning as I go

  • @mre1984
    @mre1984 17 днів тому +4

    Cam love design is so simple, NOT!
    I’m impressed with your knowledge Daniel.

    • @PowellCams
      @PowellCams  17 днів тому +1

      @@mre1984 Ty!, it's definitely complicated

    • @alexhise968
      @alexhise968 17 днів тому

      ❤Love is allways complicated.

  • @Scubasteve22
    @Scubasteve22 17 днів тому +2

    THanks a bunch for sharing.. If I knew I could get in the ballpark of duration @ .050 , lift and LSA of my choosing, I would start ordering cams from you brother. I've learned alot from ya. The problem is, is that i grew up knowing what a certain duration @ .050 and LSA would do for a motor , just based on experience of alot of combinations... I kinda know where the events should be , depending on what the use is of the combination.. Dont shoot the messenger..lol . We all learned a different way.

    • @PowellCams
      @PowellCams  17 днів тому +1

      @@Scubasteve22 my pleasure

  • @jeffreyworthington7558
    @jeffreyworthington7558 17 днів тому +2

    Thanks for Lots of really good information in the explanation.

    • @PowellCams
      @PowellCams  17 днів тому +1

      @jeffreyworthington7558 absolutely, our pleasure

  • @RustyorBroken
    @RustyorBroken 17 днів тому +4

    Mechanical noise is 100% correct description for what you found in the profile. My brain is wondering if one way noise could be introduced would be when the cam master is made. It's been many moons since I lived in the cnc world but back in the day the cnc controllers didn't actually move in a true arc. They used interpolation to basically chop the curve into many points connected by straight line segments. Essentially, the machine cut a polygon with many many sides. The more points it uses the better the approximation of the arc. I would think cncs still do this today but maybe the interpolation has gotten better. So, if the master was cut on a machine with lower resolution it would produce more noise in the grind. Just a thought rolling around in my head.

    • @PowellCams
      @PowellCams  17 днів тому +2

      @RustyorBroken this is accurate, but most modern cncs will produce a quality master with low noise, but anything is possible as I don't know the facts and we are just guessing

    • @seancollins9745
      @seancollins9745 17 днів тому +2

      Yes, they still use interpolation, really well tuned servos will create incredible arcs however. Tangency in arc intersections as well as arc shape is critical at design time. Garbage in garbage out

    • @PowellCams
      @PowellCams  17 днів тому +3

      @seancollins9745 once we get a design done, there is a smoothing feature to take care of that, , our masters are cnc ground in a Landis so we don't have that issue

  • @69L88
    @69L88 17 днів тому +1

    Daniel, thanks for your latest video, I forwarded it to friend. One thing though, your machine is an Audie Cam Pro Plus, it is much better and more capable, than the old Cam Doctor. Inexperienced people should know their is a difference. Again thanks, always

    • @PowellCams
      @PowellCams  16 днів тому

      @69L88 yes it's pretty much the best besides a Adcole

  • @alexhise968
    @alexhise968 17 днів тому +1

    On my DOHC stuff we can open stuff so fast in comparison to pushrod stuff. Just have to slow down at the top of the lobe and for the RPMs we turn we have to shut the valves as soft as possible.

    • @PowellCams
      @PowellCams  16 днів тому

      @@alexhise968 definitely, almost no weight or deflection!

  • @williamv3134
    @williamv3134 17 днів тому +3

    Keep up the great content

    • @PowellCams
      @PowellCams  17 днів тому +2

      @@williamv3134 absolutely 💯, ty

  • @christophercullen1236
    @christophercullen1236 17 днів тому +2

    Do you believe that the main stream cam grinders over spec , there spring rates ?
    Kit from down under

    • @PowellCams
      @PowellCams  17 днів тому +3

      @@christophercullen1236 most yes

  • @tracycurtright2671
    @tracycurtright2671 16 днів тому +1

    The problem isn't always the other cam grinder when the customer says Damn the torpedoes, give me the most aggressive cam you can make. Then when it beats itself apart the think the cam grinder was the bad guy.

    • @PowellCams
      @PowellCams  16 днів тому

      definitely disagree, nobody should be selling lobes that don't work in a given application, the customer didnt ask for that and ... its our job to educate, so your scenario is just not the case.

  • @jeffreydurham5342
    @jeffreydurham5342 17 днів тому +1

    Can you vary the speed of the grinding wheel? Maybe reduce some of that?

    • @PowellCams
      @PowellCams  16 днів тому

      @jeffreydurham5342 yes we can, not sure about other companies

  • @martin-vv9lf
    @martin-vv9lf 17 днів тому +2

    Do you think that auto manufacturers who are prone to destroying cams at low mileage have bad lobe designs. could they alleviate the issue by specifically reducing the power of the engine, and taking the stress off the cam by using variable valve timing.

    • @PowellCams
      @PowellCams  17 днів тому +7

      All the oem designs I've seen are very gentle

    • @yurimodin7333
      @yurimodin7333 17 днів тому +1

      its the afm and dod eating oem cams

    • @johnsalvaterra3116
      @johnsalvaterra3116 15 днів тому

      Most of the problems that occurred, That I've been privy too, are either machining problems, or material and process problems, ie. Poor heat treat, and/ or material not up too specification.

  • @100amps
    @100amps 17 днів тому +2

    Well this one is bit over my head in terms of being able to imagine what caused it. Was the lobe lumpy or something? I guess that's what the first part of the video was about, the grinding machine smoothness.

    • @PowellCams
      @PowellCams  17 днів тому +1

      @100amps no, it's probably a bad master plate, or, just had poor machining when the master was made

  • @edpetrocelli2633
    @edpetrocelli2633 17 днів тому +1

    What are the units for the numbers you are referring to. For example velocity is distance over elapsed time and acceleration is distance over time squared. I`m assuming the distance is the verticle movement of the valve and the time unit is in some sort of degrees of rotation? I haven`t been able to expand the numbers on the side of the graph enough too read them to try and answer my own question (not that it would) due to my lack of expierience in your field of expertice but I`m damn curious.

    • @PowellCams
      @PowellCams  17 днів тому +2

      @edpetrocelli2633 velocity is the rate of change for lift, acceleration is the rate of change for acceleration and jerk is the rate of change for acc.

    • @chrisallmond6867
      @chrisallmond6867 15 днів тому

      @edpetrocelli2633 the english units for velocity are inches per cam degree. The units for acceleration are inches per cam degree squared.

  • @GhostSniper67
    @GhostSniper67 17 днів тому +1

    This is the "Mike Tyson Cam" because it destroys everything....😂

    • @PowellCams
      @PowellCams  17 днів тому +1

      @@GhostSniper67 lol, except elapsed time!🤣

  • @DavidSmith-eu4lq
    @DavidSmith-eu4lq 17 днів тому +1

    SEG Racer??

    • @PowellCams
      @PowellCams  17 днів тому +2

      @@DavidSmith-eu4lq I can't give out any more information than I did in the video

  • @brianholcomb6499
    @brianholcomb6499 16 днів тому +1

    Did he also send you the camshaft that worked? My old boss always said, you are only as good as your last camshaft! He would only use certain grinders where the guy grinding, never changed! (The old guys used to say they could hear it, if it wasn’t ground right 🤷🤷🤷🤷?) He also knew his grinder, inside & out! Because we went through a big rash of knocking lobes off, & breaking parts! Except very few had Camdoctors to figure out the issues! Now most of the big names are using CNC grinders 🤷🤷🤷🤷!

    • @PowellCams
      @PowellCams  16 днів тому +1

      @brianholcomb6499 it's all about QC, can u qualify the part u made, if u can't it's all guess work.