Dave Crower explained all of this to me regarding letting the solid roller down SLOW on the base circle so the seats are not pounded into the heads and also so the valves don't bounce off the seats. 302 SBC 11.5:1 - solid roller with .636 gross lift on intake 272dur and exhaust 284dur . Made 350ft# by 3000RPM

Cam design & ramps = Brain surgery + rocket science. Thanks again for the informative videos. Great job !😊

I had the good fortune to talk with of the great minds in cam design several years back. Harold Brookshire (RIP), formerly of Ultradyne and later Lunati was responsible for many of the grinds we all bought and used in the 80's, 90's and beyond. Most of what he said went well over my head but, he was patient with me and most likely "dumbed down" the technical stuff so that I might have some idea of what he was saying. LoL. Many of his cam profiles are still being sold and stuffed into hot rods around the world. Amazing guy who left his mark on the automotive performance industry.

Great explanation and video Daniel. A good video to see is from the Sorceress engine testing. They have the engine on a spintron and some high speed cameras showing valves and springs in motion. When they started testing it they were at 8500 rpm and the uncontrolled movement was really something to see. They did some changes to the design and could spin over 10,000 rpm with much better control of the valves. The difference in the sounds was very surprising to. Joe

Great information! Thanks for taking the time to educate me.

Really good stuff. One of the few things I miss from when I had Facebook, was listening to some of the cam / lobe design stuff that Billy Godbold and a couple other guys shared there. Thanks for taking the time to share this stuff.

Excellent video explaining a very complicated subject. I really like the end where you stated that in X amount of years, what we're doing will be completely different. Materials change, parts get stiffer, ports are better, etc. It's a constantly changing target. Keep up the great videos. I look forward to watching more videos.

Good video Brother, You know whats funny? Lol, I used that exact graph you used for your thumbnail in my cam video 8 months ago as an example of cam lobe profile dynamics, the polynomials & coefficients of lobe profile design and the complexity of lobe design like area under the curve, intake valve open & closing rates & velocity, exhaust opening & closing rates & velocity, ramp rates, jerk rates, deflection rates, etc... I gave a short explanation that polynomials & coefficients of lobe design are about taking into account all constants & variables to achive & maintain a proper balance of kinetic & potential energy with the objective being controlling kenitic & dynamic energy to achieve and maintain the best balance of dynamic to static motion possable and the fact that doing so typically requires a spintron to test which is extremely expensive... My last video wasnt nessasarily about lobe profiles, it was a long video and the begining was sort of an introduction of myself but there was a story line to it all and it lead up to the fact that optimal LSA exists and how to produce max tq & hp across the entire power curve in any given ci v8 engine combination via camshaft selection starting with optimal LSA which is based off an empirical equation and empirical equations dont lie, i had data to back it all up... Cam selection starting with Optimal LSA will produce ideal IVOP, IVCP and overlap placement in corelation to IVOP, which in tern allows the IVCP to take advantage of a optimaly filled cylinder, starting with LSA will always produce the best gas dynamics and result in optimal trapped volumetric efficiency across the entire curve... I explained this with data, all the while disproving Brian Tooleys incorrect "theory" he was spreading about LSA... Cam selection starting with LSA dont require guess work for Valve opening & closing points being as its based off an empirical equation... That video was approved by David Vizard who gave me a complement on that video in the form of a comment (its pinned at the top) that video influenced DV to follow my lead and use Brian Tooley as an example of a camshaft professional making videos & camshafts with an incorrect theory about LSA... Brian didnt think optimal LSA existed until he seen my video then i personality had to explain to him further in the comments that he was incorrect dynamicly about valve event placment and the effects of LSA, ultimately he had no rebuttal so he couldnt deny it at all... I then told Brian that DV had followed my suit and also made a video about him being wrong, so he scrambled over to DV and DV told him the same thing i did, Brian then invited DV to his facility/shop, im sure it will lead to Brian consulting DV for info... I had given Brian suggestions for improvment in aftermarket camshafts for stock engines and a line of camshafts specificly for aftermarket based engine builds for displacments common in LS engines... So im sure thats why he will consult DV... Anyway Back to lobe profiles, Being as i did give a lil credit to Brian on his ability to produce dynamicly stable lobe profiles, that had influenced Brian Tooley to make a video showing he can create a dynamicly stable lobe that is stable up to 10,000 rpm, he even had a nice amount of loft over the nose if i remember correctly... i bealive that was the last video he put out, you should check it out... Sorry for the long comment i know the long comments can be a pain in the arse... I just had to say something initially cuz i thought it was really funny that your thumbnail was in my cam video 8 months ago😆... Take Care Buddy👊🏻 ~ Adam ~

Cattledog Garage sent me 😎🤘

You are so self effacing. Nobody knows the relationship between velocity, acceleration and what you’re calling ‘jerk’, that it’s calculus. I’m impressed and I learn from your videos. Thanks.

I asked a cam manufacturer about the difference between their standard and aggressive ls lobes and they basically told me that they wouldn’t sell anything that would beat the valve train to death. They asked if I had any problems with my lobes on my current cam and I couldn’t say yes or no cause I hadn’t pulled it out.

Damn Daniel, you got smoke comin out my ears, Great stuff man keep it comin!!👍👍

Thank you, sir. I, appreciate you and your information!

This has to be one of the most enjoyable/in depth vids on cams i've ever seen......you explain quite well!!....i'm a Vizard nut, and love his tech, but even HE has not explained anything about the jerk curve, and i didnt know, i didnt know....haha....EXCELLENT content, and i'm a PROUD sub'r!!!...TY sir!!!

I enjoy your videos. Keep ‘em coming!

This is a very interesting subject. I for one Daniel, am into reliability and endurance. I do not like wearing parts out. I have fixed alot of heads that had to much spring pressure and and the possibility of to aggressive of a camshaft. While camshaft company X says their fast ramps are worth as much as 50 to 70 horsepower over the slower Y companies. It is easy to make false and unverifiable claims. Reliability and long-term Performance is my goals. I find that there are less problems in the long run. Thanks again, great video. Have a great day.

Great video, took me back to an hr long phone call I had year's ago with a cam designer (Harold Brookshire) who took his time trying to explain how it all works, lotta math involved.

This is amazing. I’m into bikes. I had a Honda 600RR in 2003. It would do 17,500 RPM. So the valves were opening and closing 125 times a second. I still can’t understand how it would do that without leaving me on the side on the road.

Great info! Never heard of valve jerk before, but it makes sense as you explain it. TYVM Daniel!

I wanted to run this by you due to this video and your others about hydraulic flat tappet/cam failures. My thought is that the aggressive acceleration angle profiles are probably causing a lot of the failures, by making the tappet "dig in" to the lobe. I don't know if you are familiar with the old "rule of 47.5%", which is an over simplified method of gauging cam lobe/tappet angle for longevity. It states that the cam duration AT 0.050, divided by the TOTAL lift at the valve, ( i.e. 202° / .425 = 47.5%) must meet or exceed 47.5%. Most cams produced today are a lot more aggressive than that, then you add in someone that is not aware of the angle issues, who adds 1.6 or greater rockers and compounds the problem, even with proper break-in procedures. I know you have been checking for hardness, lifter and lobe face machining accuracy, and lately metal compatibility (which I think you have a great idea there). I'd love to see a video break-in test that compared the old school lobe vs new lobe style. Same lifters, same grind on cam, with only the lobe acceleration being different. Heck, you could probably have a third contestant being an old school lobe angle/lifters being broken-in using only oil (with the similar amount of zinc used back then. No break-in lube etc. ). I bet it would survive. I thank you for your diligence in trying to solve this problem. I hate to see people lose loads of money and time due to these problems. Most are probably on tight budgets and some cannot afford the roller lifter route. Most of all, I hate to see younger gear heads give up the hobby after one of these disasters. Let's see if we can bring back the fun and love of automotive DIY. Thahks

Great advice ❤

Thank you for your knowledge and video's USA 🇺🇸 USA 🇺🇸

Really good and informative content.

Excellent video. Please make more videos about your camshaft knowledge.

outside of duration being how long the valve stays open & lift being how much the valve open's( in thousands of an inch) & your center line being were the cam maker wants(or recomends) the cam to be timed 4 your application...ie. 4 degrees advanced /4 degrees retarted) most people dont know more than that...! or understand more than that...!..in 40+ years with cars I have never herd the term "jerk cerves" used...even by engine builders...?..the cam can make or break the build.....i would like to understand it "better" but dont know if i have enough of the gray matter needed...?..to designe a cam/lobe profile that "works"...is true talent...!..!..IMO....thanks for a good video...wouldent mind see'n more...thanks again...

You're right, I guess I really don't know squat about cam design. Great video by the way 👍

Good discussion, cams are way more complicated than most people realize. Thanks for the video :)

Damn, there’s just so much to know! Thanks for sharing!

Modern cam manufacturers are betting on stupid acceleration rates, hoping better valve springs will control them. They are hoping for the last 10hp to be advertise on the internet with no repercussions from the valvetrain/lifter damage

I like your explanation👍🏻. Adam from Cattledog Garage sent me over here. He shared your video and he said you provide good information so I gave you a sub. I see with Adam sharing your video you hit your 3000 subscribers mark, congratulations sir. 👊🏻😎🤘🏻 I look forward to more videos.

smooth is power. well done

It's easy to see from the jerk curve that your grind took a little out and softened the motion over the nose. It makes perfect sense, especially if the cam was originally grpund in a high production environment. Off the base circle might be a little more surprising, but when you consider too many people design cams that close too quickly these days, often just reducing an opening velocity rather than producing a proper closing, your jerk curve makes sense all around.

Excellent information

Awsome!

Polynomial equations are the ticket. There’s a lot of factors to consider. Some things that you think will work, don’t and some that shouldn’t work well, do. There are maximum levels of velocity, acceleration, jerk, and others in increasing order. It’s how those factors are manipulated that make up the lobe curve. The thing you have to remember is that the rocker ratio amplifies the factors like acceleration and jerk. The compressibility/deflection of the components reduces the impact. Then there’s the vibration component where you don’t want to excite the natural frequencies of the system. Every component has a natural frequency and the combination has nodes due beating that need to be considered.

GREAT VIDEO I think from what i've read conical springs sound good , they're supposed to snap shut quicker and help with loft and maybe that jerk curve. and this with less spring rate. the only ones i've found with a low rate are elgins rv 9937. what do you think?

I read a Harvey Crane article years ago where he referred to .020 .050. and .200 as Snap Crackle and Pop. 😊 Great video....thanks for taking time to help explain whats going on. Just wondering......would the jerk curve be related at all to the stone condition? As small as those bumps looked I was curious if it was maybe stone "chatter"?

Did I hear you say you had a cam doctor? Here’s a question for you. I have an old General kinetics cam that I ran years ago would it be possible to use the cam doctor to get all the info off the cam? The cam has a wiped lobe but I’ve held onto it for years hoping to find a way to get the specs off it and have a new cam made. Might be a flat tappet but made more power than anything I’ve ran across since.

So what is a custom cam grind? Can a set of custom cams be made for my 3.6 pentastar? With a little more power.

Is it true that in most cams they always have a certain amount of loft in them. I would also venture to say that rpm and valve train has a factor in that. I was told that all cams have loft in them there is no way around it by a engine builder.

I had talked you before about grinding a cam for a pulling tractor. OUr tractor is running well and we won the points for the year but we are having problems with valves. We run solid roller lifters but I found out they ground hydraulic roller lobes on the cam. Could this cause the valves to tulip?

I don't know if you watch Engine Masters but, they just had a similar explanation of what you just did. On a white board ! Lol Season 8 ep7

Set on kill = killed camshaft and killed wallet