67 years old here, been working on engines for 50 years. When you said “find it fascinating but most of the time it makes my head hurt “I couldn’t agree more!! Seems the more I learn the more I realize how much more I need to learn
You have made it very clear in this video, that any high end engine build has to start with information. There are a dozen items that the customer has to know to provide you in order to get a camshaft that may produce what they are wanting. I find this to be “Best Practices” for anyone wanting a cam, or trying to get results they want. Ironically, none of the info required is LSA or Duration. Thanks Daniel as you have helped possible thousands write down what they are trying to achieve, rather than give you information about how it should look! I hope that makes sense because I can have a better discussion about all of the variables that make a bump stick work in favor, or just work ok! Thanks kindly for sharing your valuable time! I appreciate your explanation’s & delivery.
Thanks a lot for sharing your experience and knowledge. I don't build "race" V8s, but was taught to build "strong" and reliable engines based off dynamic compression ratio desired and LSA is a component of that formula. LSA got me in the ballpark, but when I started measuring at the valve things weren't what I was expecting. Fast forward 10 years and I had gotten my head around what was working, but not until I got a chance to get one of my VW type 4s spun on a Spintron was I really able to begin to grasp what you're describing here. Exhaust valves were opening too slowly and closing too quickly. Called up my friends at Web-Cam and had them alter my favorite Type4 cam they produce slightly (86B/C). Picked up 800 usable RPM and flywheel HP went up by almost 30. Area under the curve also increased 10%.
I used to think that I knew a little bit about cams. After watching your videos and the cam challenge I realized that I've been riding the short bus this entire time.
Wow! This has been a great wake call for me in realising I was going the wrong rabbit hole with my cam for my next build. Thanks putting this all in perspective too! :)
@@mathewboyd3746 I was not making a cam comment it was a letting customers shit sit on the floor til I'm done doin bull shit like said dedicate to machine work or custom I don't care which machine shops in general take in work say I'll get it and 8 freaking months later it's not done and it's not done they made six videos they went to the races they went to the customers shop to see what that racer problem was hell they went on vacation all while saying next couple of weeks that's the rabbit whole they would have made. More money fixing the shit in the floor and not bought near the fuel they want that instant gratification so as far as I can see the next expert trust me I need more machine work than most old school Machinist are hard to find they aren't hungry
Dan, love all the great content. I learn something or many things in every video. Although, no matter how much you teach me, you're still gonna be the one choosing my cam specs! Good stuff!
Great explanation of valve events, thanks. I live in the street world, with hydraulic roller cams. I started trying to understand the mysteries of cams when I built a 4-cam Harley (Sportster) from 883 to 1250. I was successful in that I drastically improved torque and literally doubled the horsepower at the rear wheel (not just cams, but more displacement, better heads, exhaust, etc) but I just picked a cam (set) from the middle of the page, so to speak. Later I had a twin cam and picked a cam for it with higher lift and much shorter intake closing (34°@0.050 on the cam card). In the 103 just the cam bumped rear wheel torque from 80-ish to 104 and horsepower from 75 to 93. A two-into-one exhaust might have made those numbers better, but the bike was a joy to ride on the street. Valve events for a long stroke hemi-headed engine are very different than for an LS, but the bottom line is the valve events themselves make the engine work in a specific way. Thanks for a very educational channel.
Well said. That is the beauty of DOHC, you can change your LSA, but I don't care about LSA, what you really want to know at what moment the valve opens and closes and how fast and much in reference of your piston speed and position, plus exhaust scavenging.
I always appreciate the time you take to explain the intricate details. Great work Daniel. How's the new grinder working out? Maybe a video on it's workings and how it's different to your other machine. Tim Australia 🇦🇺.
What engine/vehicle information is required to get close to optimal valve event timing? What determines when you would want to increase exhaust duration in an engine head flow ,rpm ,displacement bore, vehicle weight etc? There is still a black art or trial and error to arrive at the best cam for any combination/use as the flow dynamics in a working engine are so complex😊.
@@malglasspool9302 let’s say on the dyno the power falls off quicker past peak than you want. you could either: 1-increase both intake and exhaust duration 2-leave intake alone and increase exhaust duration well, option 1 will surely hurt torque in the bottom of the rpm range option 2 will help top end without losing hardly any low end but let me throw a caveat in here: what if the falloff in power was due to a poor header or exhaust system? what if you have some valve float at high rpm? what if the intake plenum is too small, or carb too small? gotta consider everything the things you mentioned would not be considerations as to whether you need more exhaust duration or not (imo)
@@malglasspool9302 I would start with application, street or track? If track, high lift, high rpm, late valve timing. For street is it a daily or weekend thrasher? If a weekend thrasher, just build it like a track car, which will be more baby sitting but that was your goal no? If a daily how many miles do you want out of your engine, a lot or dont care (this means are you planning on lots of rpm or short gearing) for your daily? If you want a lot of rpm and dont care about how long the engine lasts or fuel mileage, late closing valve timing for high rpm, like a track car. If you want it to last, keep rpms low but get a cam where the valve closes sooner to build torque asap and also get a taller gear for the highway. Still want more power for your daily with tall gears and a torquey cam, get a blower or start with the largest feasible displacement. Thats how i planned my setup and i got what i wanted without changing out parts and avoid reliability issues. Just my 2 cents, not gospel.
Engine analyzer pro can actually model everything you talked about. Import the cam doctor file of the lobe profile and watch the valve motion change with the variables you discussed, and spring pressure, and rocker stiffness etc…. I think you would find EAP very useful when you get the dyno running. Also, the book high performance cams and valve trains by Billy godbold talks about using lash circles and advancing/retarding the cam to predict what to grind next when optimizing a combination on the dyno.
Got a couple paIrs of dohc cams i plan on comparing. Gonna mockem up in a spare head with dial indicator on the valve to read the lift along with a degree wheel on the cam gear. Then i can get a good comparison of how they sctually open/close the valve.👍
This is probably apples to oranges but when I was racing in stock eliminator I had 2 cams ground with the same intake and exhaust lobes and had one ground on 109 and the other 106. The 106lc picked up over a tenth at the track on a car that was already running .7 under it’s index
@@PowellCamsTightening LSA simultaneously increases dynamic compression ratio and scavenging/overlap which will gain average and peak torque, up until it doesn’t… Tight LSA events are very effective in the low/mid RPM range, pushing past 6k starts needing more duration but not much more overlap, so the LSA will spread. In my opinion LSA rules of thumb work very well on street-duration single pattern cams, dual pattern cams start throwing a wrench into things and valve events are an easier way of thinking about things.
i could say “i have to have 108 lobe sep” well, that could mean huge differences in overlap depending on the duration! but what if i want 10* overlap at .050 ? i can accomplish that with either 108 or 112 lobe sep, again, depending on the duration. the better question is “how much overlap do i want, or need?” or… what if i want to close intake at 45* at .050 and open exhaust at 50*? i could have that with vastly different intake opening and exhaust closing, and thus different overlap. with all this said, we see the real question keeps coming back to: how much overlap do i need or want? need, for best average power in the desired range…or want, for reasonable driveability if it is a street application? if for race only, what is a reasonable pocket depth in the piston i am willing to run? i could keep increasing overlap and the peak tq would go higher, but lose on each side of the peak. or, reduce overlap and lose peak tq but gain at each end of the curve conceivably, i could have the same average tq, but less performance if the ends of the tq curve are too weak. ie…power falls off too fast up high.
@@PowellCams thanks. I am still working through the videos. There's just so much information out there! I will be looking for them and watching them. Thanks for your time.
Mr. Powell, how is valve lash determined? Valve Lash is the 'clearance' between the valve train (rocker tip) and the valve. Lash is required on solid roller/lifter cams to allow for expansion of the cam, valve train and the valve-no lash and the valve remains open. Any advantage experimenting with the minimum lash an engine needs, so that the valve sees the max lift of the cam, and minimizes the 'hammering' of the rocker on the valve tip? Thank you.
@18:00 you are showing a graph of the motion, then you show the graph of the first derivative, which is the rate of change of velocity. That graph was a little bit ugly, right? The second derivative, the rate of change of the rate of change, would demonstrate the inherent harmonic of the cam profile, and show where forces are at their maximum.
@PCMenten the first derivative is velocity., velocity is the rate of change of lift per degree of rotation, acceleration is the rate of change of velocity per degree., it's not really "ugly " some designs are "visually " smoother than others as some move faster than others. Some ne the manipulate the acceleration to keep the main event from going inverse ect.
@@PowellCams That's fair enough as it turns out I can't type, that should have read. "Would it be fair to say you care about LSA if what you are worried about is how the engine SOUNDS?" Sorry about that.
I think it can be good in some situations where you are just trying to make what you have better and not starting from scratch. In my application they regrind the base circle smaller to get more lift. I think both of these mods can change duration as well as lift.
If you want to add ex. Opening you add the duration and spread the lobe separation one quarter of the amount of dur. That you added. That will get you close.
@@powellmachineinc Think again one quarter. When you add dur it puts half on opening and half on closing . Lsa is determined by cam degrees not crank degrees so like I said, one quarter.
Hi Daniel, I watch your Videos for some time now and this is my first comment: I honestly don't understand why the duration gets bigger with valvelash (e. g. 12:55 ) in comparison to no lash, but with a bigger valvelash the duration gets smaller again. That is physically impossible, so I must have misunderstood something.
@dschordschee lash doesn't make it bigger, rocker ratio does.... you're confusing lifter motion and valve motion, that's the point of this video, maybe it isn't clear enough 🤔
@@PowellCams ok, so if I understand your answer correctly: - the first sheet shows cam/lifter motion, (starting point) - the second sheet shows valve motion with 1.6 rocker ratio and lash (longer duration because of the rocker ratio) - the third sheet shows valve motion with 1.6 rocker ration and bigger lash (duration getting smaller again because of the bigger lash) Correct?
so, as rocker ratio increases, more lash is required on the same lobe? (if i am understanding that correctly) however, the increased ratio has the effect of making the valve motion more aggressive? so, we are increasing lash AND increasing ratio which are both making valve motion faster and more aggressive? this must be why a lobe like a Comp TK is not to be paired with say, a 1.8 or 1.9 ratio?
I watch two videos on utube that race. Old Man’s Garage, and Street Racing channel. They have trouble always breaking rockers and or bending pushrods in BBC engines. Just thinking.
@@PowellCamsWhen I place an order on a "custom" cam that has 110 LSA & I specify that I want it on 112LSA, that is a direct input which has moved the centers of the lobes farther apart reducing overlap, closing the intake valve later and opening the exhaust valve sooner. Please explain how that is not an input please.
@@bigboreracing356 Not every situation is egg turns into chick, chick being LSA. I already have the perfect 110 LSA cam & now I want another one with same specs with 112°LSA. The lobes stay identical, they are only spread apart more. How is that Not an input? I think selective wording may be the disconnect here.
@@bigboreracing356 It's extremely clear that there is a disconnect with language & terminology here. The language & terminology that I have always used with everyone & vise versa does not register with yours. There's nothing wrong with that, we simply speak different languages. Good day sir.
@RA31A simple, you are just using "common " language because u don't know even timing, it's still a product of events, know where the events need to be is much more effective than just saying I want "x" Lsa....
This, as soon as you use a calculator and move cam events around, you realize centerlines just add up to the LSA. Not the other way around. Others like to use fancy words like seat velocity, which is just proper event timing.
When David. Posted his 128 formula, it was just to get us unlearned people in the ball park on a 10 to 11 to one compression pump gas motors, not race motors ! In later videos he says, if you have a better flowing valve open lsa by one deg. 12 to1 open lsa by one more etc. A lot of people criticize him not knowing where he is coming from ! Instead why not call him and discuss it !? Its rude not too ,right ?
#1 I have no clue what ur talking about # 2 widening the Lsa doesn't work, the Lsa method doesn't work for anything, #3 this video is general knowledge and directed at people who call me and say "I need a cam on x Lsa..which is absolutely nonsense
lol, set the mill up, all ready to start machining some custom cams for a little project of mine... dont even ask, its hard to explain the intention. stop and have a rethink, somethings niggling at me... oh. the flat faced cam followers mean that with the base circle diameter i have, and the planned duration... i end up with virtually no lift. sigh... now i have to rethink these followers... its easy to complain about various design aspects... until you design something yourself and have to figure these things out the hard way...
@@lykinsmotorsports Well Clearly you just don't understand the ordering process of a custom grind camshaft. Keep learning Too the back of the class mate.
It seems like a lot of machine shops have a good grasp and then they turn expert builder I see machines for real work what a person does lsa lca mean the most to me I don't care any other opinion back to the other part what you want is important to you every machine shop I could depend on is toast to me because they all builders now their is none where I can drop of parts for repair and 3 to six months before I see it and I give a lot of work never used you because I don't think you can service my end of things it's dangerous rabbit whole work turn out makes money not thoughts of work just can't find anyone there's business to run and I need equipment working not waiting
@bigboreracing356 here's what I'm saying every machine shop thinks it's an expert builder and that leads to work pile up and back up the works for people that relie on getting parts back
@bigboreracing356 by the way you put a lot of stock in someone who has no dyno lsa and lca are peak events so I guess it matters not the only parts you can't change on regrind of course it don't matter you don't know what it does you must follow your compression and flow and don't mean the compression ratio either so yes the first things you need does involve lca lobe center crank angle intake center exhaust center angle to crank angle then that gets you lsa but when is not up to you it's up to what the motor wants not someone's opinions I'll say it once more compression not ratio dynamic compression real compression and if you don't think lsa can make it or kill it the you are foolish a few cam swaps will tell you
Watch Pete Harrells last video! Where fake Pete sticks an engine together! Just the first 4 or 5mins (for his music!) is good enough 😝😝😝😝! Intelligent conversation 😳😳😳😳! 66million voted for Camel 🐫 A 🤣🤣🤣🤣! How’s that new grinder working? Most people don’t have a clue what lash loops are! Most professionals do it, so the next camshaft will be better! If they don’t know the right one to start with!
67 years old here, been working on engines for 50 years. When you said “find it fascinating but most of the time it makes my head hurt “I couldn’t agree more!! Seems the more I learn the more I realize how much more I need to learn
Absolutely
You have made it very clear in this video, that any high end engine build has to start with information. There are a dozen items that the customer has to know to provide you in order to get a camshaft that may produce what they are wanting. I find this to be “Best Practices” for anyone wanting a cam, or trying to get results they want. Ironically, none of the info required is LSA or Duration. Thanks Daniel as you have helped possible thousands write down what they are trying to achieve, rather than give you information about how it should look!
I hope that makes sense because I can have a better discussion about all of the variables that make a bump stick work in favor, or just work ok!
Thanks kindly for sharing your valuable time! I appreciate your explanation’s & delivery.
Absolutely, spot on!!
Thanks a lot for sharing your experience and knowledge. I don't build "race" V8s, but was taught to build "strong" and reliable engines based off dynamic compression ratio desired and LSA is a component of that formula. LSA got me in the ballpark, but when I started measuring at the valve things weren't what I was expecting. Fast forward 10 years and I had gotten my head around what was working, but not until I got a chance to get one of my VW type 4s spun on a Spintron was I really able to begin to grasp what you're describing here. Exhaust valves were opening too slowly and closing too quickly. Called up my friends at Web-Cam and had them alter my favorite Type4 cam they produce slightly (86B/C). Picked up 800 usable RPM and flywheel HP went up by almost 30. Area under the curve also increased 10%.
I used to think that I knew a little bit about cams. After watching your videos and the cam challenge I realized that I've been riding the short bus this entire time.
@@RustyorBroken lol, ain't we all...
Wow! This has been a great wake call for me in realising I was going the wrong rabbit hole with my cam for my next build. Thanks putting this all in perspective too! :)
@@mathewboyd3746 I was not making a cam comment it was a letting customers shit sit on the floor til I'm done doin bull shit like said dedicate to machine work or custom I don't care which machine shops in general take in work say I'll get it and 8 freaking months later it's not done and it's not done they made six videos they went to the races they went to the customers shop to see what that racer problem was hell they went on vacation all while saying next couple of weeks that's the rabbit whole they would have made. More money fixing the shit in the floor and not bought near the fuel they want that instant gratification so as far as I can see the next expert trust me I need more machine work than most old school Machinist are hard to find they aren't hungry
@paulpruitt2776 what in the world are u talking about and what does it have to do with me????
@mathewboyd3746 glad it's helpful!
Dan, love all the great content. I learn something or many things in every video. Although, no matter how much you teach me, you're still gonna be the one choosing my cam specs! Good stuff!
I'm learning right along with u
Thanks for your efforts and input. Hopefully people can use this and others people input to comprehend how things actually work in real time events.
@@hankclingingsmith8707 that is our goal!
@@hankclingingsmith8707 ty, hope so
Another great video, the more i learn the more I realize I don't know much in the grand scheme of things!
@@DavidSmith-eu4lq facts!
Glad you enjoyed it!
So interesting watching this video.I am still learning after 30 years.I need to watch this over again.Thanks a bunch.👍
Glad you enjoyed it
Great explanation of valve events, thanks. I live in the street world, with hydraulic roller cams. I started trying to understand the mysteries of cams when I built a 4-cam Harley (Sportster) from 883 to 1250. I was successful in that I drastically improved torque and literally doubled the horsepower at the rear wheel (not just cams, but more displacement, better heads, exhaust, etc) but I just picked a cam (set) from the middle of the page, so to speak. Later I had a twin cam and picked a cam for it with higher lift and much shorter intake closing (34°@0.050 on the cam card). In the 103 just the cam bumped rear wheel torque from 80-ish to 104 and horsepower from 75 to 93. A two-into-one exhaust might have made those numbers better, but the bike was a joy to ride on the street. Valve events for a long stroke hemi-headed engine are very different than for an LS, but the bottom line is the valve events themselves make the engine work in a specific way. Thanks for a very educational channel.
Glad it was helpful!
Well said.
That is the beauty of DOHC, you can change your LSA, but I don't care about LSA, what you really want to know at what moment the valve opens and closes and how fast and much in reference of your piston speed and position, plus exhaust scavenging.
Absolutely 💯
I always appreciate the time you take to explain the intricate details. Great work Daniel. How's the new grinder working out? Maybe a video on it's workings and how it's different to your other machine. Tim Australia 🇦🇺.
@timh6977 absolutely, will do
What engine/vehicle information is required to get close to optimal valve event timing? What determines when you would want to increase exhaust duration in an engine head flow ,rpm ,displacement bore, vehicle weight etc? There is still a black art or trial and error to arrive at the best cam for any combination/use as the flow dynamics in a working engine are so complex😊.
@@malglasspool9302 I fully agree
@@malglasspool9302 let’s say on the dyno the power falls off quicker past peak than you want. you could either:
1-increase both intake and exhaust duration
2-leave intake alone and increase exhaust duration
well, option 1 will surely hurt torque in the bottom of the rpm range
option 2 will help top end without losing hardly any low end
but let me throw a caveat in here:
what if the falloff in power was due to a poor header or exhaust system? what if you have some valve float at high rpm? what if the intake plenum is too small, or carb too small?
gotta consider everything
the things you mentioned would not be considerations as to whether you need more exhaust duration or not (imo)
@@duanebusch72 So if a new combination no dyno time only engine specs and components how do you narrow down valve event timing?
@@malglasspool9302 if you only have access to the drag strip, do lash loops and advance/retard the cam.
@@malglasspool9302 I would start with application, street or track? If track, high lift, high rpm, late valve timing. For street is it a daily or weekend thrasher? If a weekend thrasher, just build it like a track car, which will be more baby sitting but that was your goal no? If a daily how many miles do you want out of your engine, a lot or dont care (this means are you planning on lots of rpm or short gearing) for your daily? If you want a lot of rpm and dont care about how long the engine lasts or fuel mileage, late closing valve timing for high rpm, like a track car. If you want it to last, keep rpms low but get a cam where the valve closes sooner to build torque asap and also get a taller gear for the highway. Still want more power for your daily with tall gears and a torquey cam, get a blower or start with the largest feasible displacement. Thats how i planned my setup and i got what i wanted without changing out parts and avoid reliability issues. Just my 2 cents, not gospel.
Engine analyzer pro can actually model everything you talked about. Import the cam doctor file of the lobe profile and watch the valve motion change with the variables you discussed, and spring pressure, and rocker stiffness etc…. I think you would find EAP very useful when you get the dyno running.
Also, the book high performance cams and valve trains by Billy godbold talks about using lash circles and advancing/retarding the cam to predict what to grind next when optimizing a combination on the dyno.
I did a test run with it, wasn't impressed, it said hyd lifters would "pump up" at like 5800 rpm... we know that's nonsense
Got a couple paIrs of dohc cams i plan on comparing. Gonna mockem up in a spare head with dial indicator on the valve to read the lift along with a degree wheel on the cam gear. Then i can get a good comparison of how they sctually open/close the valve.👍
Definitely
Back in the early flathead V8 days, Karl Orr ran 21 different grinds in 21 weekends, running out at the dry lakes. Because they didn't know....
@@rickmachale8646 I could see that
If you could get the specs on the winning cam from the contest, I would enjoy you explaining why that design outperformed the others.
@@MrTravis789 definitely
I've learned a lot from you. Believe it or not
@@EsmondPerformanceEngines that makes me feel better!
This is probably apples to oranges but when I was racing in stock eliminator I had 2 cams ground with the same intake and exhaust lobes and had one ground on 109 and the other 106. The 106lc picked up over a tenth at the track on a car that was already running .7 under it’s index
@@Patrick-xd8jv u realize the engine had no clue of the Lsa of either cam.... but it it did know the events changed.
@ and by changing the lsa, you change the events, correct?
@@Patrick-xd8jv correct
@@PowellCamsTightening LSA simultaneously increases dynamic compression ratio and scavenging/overlap which will gain average and peak torque, up until it doesn’t…
Tight LSA events are very effective in the low/mid RPM range, pushing past 6k starts needing more duration but not much more overlap, so the LSA will spread.
In my opinion LSA rules of thumb work very well on street-duration single pattern cams, dual pattern cams start throwing a wrench into things and valve events are an easier way of thinking about things.
@ probably not because I never ran faster than .95 under the index with that exact combination and only held the national record for a few days 🤷🏼♂️
I appreciate this alot.👍
@@Shademax4273 you're welcome
i could say “i have to have 108 lobe sep”
well, that could mean huge differences in overlap depending on the duration!
but what if i want 10* overlap at .050 ? i can accomplish that with either 108 or 112 lobe sep, again, depending on the duration.
the better question is “how much overlap do i want, or need?”
or…
what if i want to close intake at 45* at .050 and open exhaust at 50*? i could have that with vastly different intake opening and exhaust closing, and thus different overlap.
with all this said, we see the real question keeps coming back to: how much overlap do i need or want?
need, for best average power in the desired range…or want, for reasonable driveability if it is a street application? if for race only, what is a reasonable pocket depth in the piston i am willing to run?
i could keep increasing overlap and the peak tq would go higher, but lose on each side of the peak.
or, reduce overlap and lose peak tq but gain at each end of the curve
conceivably, i could have the same average tq, but less performance if the ends of the tq curve are too weak. ie…power falls off too fast up high.
I have a video explaining that
I'd like to see exactly how the process of grinding a cam is done and how the machine works.
We have plenty of videos on that
@@PowellCams thanks. I am still working through the videos. There's just so much information out there! I will be looking for them and watching them. Thanks for your time.
Thanks..How did your cam place in the challenge?
9th, I did a video on the results
Startin to understand this 😊
@@Anthony-nw5zv AWSOME
Mr. Powell, how is valve lash determined? Valve Lash is the 'clearance' between the valve train (rocker tip) and the valve. Lash is required on solid roller/lifter cams to allow for expansion of the cam, valve train and the valve-no lash and the valve remains open. Any advantage experimenting with the minimum lash an engine needs, so that the valve sees the max lift of the cam, and minimizes the 'hammering' of the rocker on the valve tip? Thank you.
@ts302 all this is in the video
@18:00 you are showing a graph of the motion, then you show the graph of the first derivative, which is the rate of change of velocity. That graph was a little bit ugly, right? The second derivative, the rate of change of the rate of change, would demonstrate the inherent harmonic of the cam profile, and show where forces are at their maximum.
@PCMenten the first derivative is velocity., velocity is the rate of change of lift per degree of rotation, acceleration is the rate of change of velocity per degree., it's not really "ugly " some designs are "visually " smoother than others as some move faster than others. Some ne the manipulate the acceleration to keep the main event from going inverse ect.
I will look right now but does anyone know whether AI is being used to recommend cam specifications?
No idea
Would it be fair to say you care about LSA if what you are worried about is how the engine shows?
@stusue9733 I have no idea what that means, but no I don't care about Lsa anytime
@@PowellCams That's fair enough as it turns out I can't type, that should have read.
"Would it be fair to say you care about LSA if what you are worried about is how the engine SOUNDS?"
Sorry about that.
Is ever a good idea to add ratio to your rockers to gain valve lift without adding duration at the bump stick?
If you design for valve motion rocker ratio is irrelevant
I think it can be good in some situations where you are just trying to make what you have better and not starting from scratch. In my application they regrind the base circle smaller to get more lift. I think both of these mods can change duration as well as lift.
That’s what I’ve noticed about a cam calculator. It’s not taking into account for rocker ratio.
@@JeremyFrazelle-or1mt no event Calc looks at valve motion it's all at the lobe, so no rocker would be assumed or relevant
Right on.
I'm guessing that NK performance tested alot of headers on LS engines?
They tested 20 cams before the competition, idk how many headers
If you want to add ex. Opening you add the duration and spread the lobe separation one quarter of the amount of dur. That you added. That will get you close.
1/2, not 1/4
@@powellmachineinc Think again one quarter. When you add dur it puts half on opening and half on closing . Lsa is determined by cam degrees not crank degrees so like I said, one quarter.
Hi Daniel, I watch your Videos for some time now and this is my first comment: I honestly don't understand why the duration gets bigger with valvelash (e. g. 12:55 ) in comparison to no lash, but with a bigger valvelash the duration gets smaller again.
That is physically impossible, so I must have misunderstood something.
@dschordschee lash doesn't make it bigger, rocker ratio does.... you're confusing lifter motion and valve motion, that's the point of this video, maybe it isn't clear enough 🤔
@@PowellCams ok, so if I understand your answer correctly:
- the first sheet shows cam/lifter motion, (starting point)
- the second sheet shows valve motion with 1.6 rocker ratio and lash (longer duration because of the rocker ratio)
- the third sheet shows valve motion with 1.6 rocker ration and bigger lash (duration getting smaller again because of the bigger lash)
Correct?
@@dschordschee correct
so, as rocker ratio increases, more lash is required on the same lobe?
(if i am understanding that correctly)
however, the increased ratio has the effect of making the valve motion more aggressive?
so, we are increasing lash AND increasing ratio which are both making valve motion faster and more aggressive?
this must be why a lobe like a Comp TK is not to be paired with say, a 1.8 or 1.9 ratio?
@duanebusch72 correct
I watch two videos on utube that race. Old Man’s Garage, and Street Racing channel.
They have trouble always breaking rockers and or bending pushrods in BBC engines.
Just thinking.
We don't have that problem
Am im wrong of thinking that no matter what you do you want to make sure the engine needs to have the proper amount of overlap that the engine needs?
Overlap is important but it's just 1 piece of the puzzle
Yep, my head hurts. LOL
Lol😊
Exactly, valve motion matters, LSA it a tunning tool, but it's not going to make or break the engine.
Lsa is a result not a input
@@PowellCamsWhen I place an order on a "custom" cam that has 110 LSA & I specify that I want it on 112LSA, that is a direct input which has moved the centers of the lobes farther apart reducing overlap, closing the intake valve later and opening the exhaust valve sooner. Please explain how that is not an input please.
@@bigboreracing356 Not every situation is egg turns into chick, chick being LSA.
I already have the perfect 110 LSA cam & now I want another one with same specs with 112°LSA. The lobes stay identical, they are only spread apart more. How is that Not an input? I think selective wording may be the disconnect here.
@@bigboreracing356 It's extremely clear that there is a disconnect with language & terminology here. The language & terminology that I have always used with everyone & vise versa does not register with yours. There's nothing wrong with that, we simply speak different languages. Good day sir.
@RA31A simple, you are just using "common " language because u don't know even timing, it's still a product of events, know where the events need to be is much more effective than just saying I want "x" Lsa....
This, as soon as you use a calculator and move cam events around, you realize centerlines just add up to the LSA. Not the other way around. Others like to use fancy words like seat velocity, which is just proper event timing.
I'm not sure, when u say "seat velocity " can u define that?
@PowellCams Exactly.
If you stop saying motors were built, honed or decked by a blind person, that will help greatly in your desire to never be derogatory.
Point taken
I wonder how the old guys did it in the day when there was no cam programs,no internet and nowhere to get information except the cam co?
Their cars were slow.
@V8Lenny yeah back then if your street car ran in the 10s in the quarter it was a bad machine. Now not so much.
They just kept stabbing cams in the motor and run it till they found the power they were looking for.
We appreciate you figuring this out for us. Thank you for the lesson.
@@Hillbillygarage1215 what has changed, that is still done today. No different.
When David. Posted his 128 formula, it was just to get us unlearned people in the ball park on a 10 to 11 to one compression pump gas motors, not race motors ! In later videos he says, if you have a better flowing valve open lsa by one deg. 12 to1 open lsa by one more etc. A lot of people criticize him not knowing where he is coming from ! Instead why not call him and discuss it !? Its rude not too ,right ?
#1 I have no clue what ur talking about # 2 widening the Lsa doesn't work, the Lsa method doesn't work for anything,
#3 this video is general knowledge and directed at people who call me and say "I need a cam on x Lsa..which is absolutely nonsense
Thank you for your knowledge and videos TRUMP USA 🇺🇸 MAGA 2024
@@patrickwendling6759 no problem
lol, set the mill up, all ready to start machining some custom cams for a little project of mine... dont even ask, its hard to explain the intention.
stop and have a rethink, somethings niggling at me...
oh. the flat faced cam followers mean that with the base circle diameter i have, and the planned duration... i end up with virtually no lift.
sigh... now i have to rethink these followers...
its easy to complain about various design aspects... until you design something yourself and have to figure these things out the hard way...
Good luck!
It's really frustrating when two reputable people tell you completely opposite information.
I didn't "tell " u, I showed u, there's a difference
It's not as simple as you think.
🤔 variations
Pfft..
If you think LSA or Lobe Seperation Angle is unimportant, and counter productive,
You Better go Back and Learn again Mate.😂
Daniel is 100% correct. LSA is just something to help adjust overlap. If you start out first by picking an LSA, you’ve clear missed the boat.
Why would the engine care where peak lift happens over where the valves open and close?
@@Mrshotshell True in a max effort situation lift is chosen based on the flow of the head,intake,exhaust and or piston design restrictions.
@@davenorman8251 yes?
How does that relate to valve events?
@@lykinsmotorsports
Well Clearly you just don't understand the ordering process of a custom grind camshaft.
Keep learning
Too the back of the class mate.
It seems like a lot of machine shops have a good grasp and then they turn expert builder I see machines for real work what a person does lsa lca mean the most to me I don't care any other opinion back to the other part what you want is important to you every machine shop I could depend on is toast to me because they all builders now their is none where I can drop of parts for repair and 3 to six months before I see it and I give a lot of work never used you because I don't think you can service my end of things it's dangerous rabbit whole work turn out makes money not thoughts of work just can't find anyone there's business to run and I need equipment working not waiting
Allrighty then.....
High speed chicken feed is a hell of a drug😆🤣😅
@bigboreracing356 here's what I'm saying every machine shop thinks it's an expert builder and that leads to work pile up and back up the works for people that relie on getting parts back
@@paulpruitt2776 You are wrong.
@bigboreracing356 by the way you put a lot of stock in someone who has no dyno lsa and lca are peak events so I guess it matters not the only parts you can't change on regrind of course it don't matter you don't know what it does you must follow your compression and flow and don't mean the compression ratio either so yes the first things you need does involve lca lobe center crank angle intake center exhaust center angle to crank angle then that gets you lsa but when is not up to you it's up to what the motor wants not someone's opinions I'll say it once more compression not ratio dynamic compression real compression and if you don't think lsa can make it or kill it the you are foolish a few cam swaps will tell you
Watch Pete Harrells last video! Where fake Pete sticks an engine together! Just the first 4 or 5mins (for his music!) is good enough 😝😝😝😝! Intelligent conversation 😳😳😳😳! 66million voted for Camel 🐫 A 🤣🤣🤣🤣! How’s that new grinder working? Most people don’t have a clue what lash loops are! Most professionals do it, so the next camshaft will be better! If they don’t know the right one to start with!