DV cam logic Vs totally pro originated BS
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- Опубликовано: 8 сен 2022
- In this, episode 70 - part 1, DV takes on what seem to be beliefs widely held by many professionals concerning 'cam profile dynamics Vs cam event timing'. When some grossly misleading info was put forward by a company that supposedly consults on the topic of cams and engines in particular DV decided it was time to do some serious BS bashing. So here, with little held back, is part 1 of the crushing evidence supporting DV's totally 'dyno developed' counter argument to the OPINIONS of a company whose owner should know better.
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Gotta love a good David Vizard rant! I can listen to him put those lets call them uninformed ones in their place all day. Keep those stories coming Mr. Vizard, we won't be able to hear them when you retire. Thanks for sharing your knowledge and memories.
Mr. Vizard,
I have been reading your publications for over twenty years. I consider you to be the engine guru when it comes to performance.
Your ability to teach in a relatively simple manner, easily understood, yet still able to instill into the reader a full understanding of the subject matter is truly a gift few TEACHERS have. ( so there, another cap you can wear! )
Exactly, and me to. Great stuff Dave.
IMO, you are an automative legend, along with Smokey Yunich and a handful of others. Your racing accomplishments, publications and willingness to share your knowledge are a legacy to be proud of.
Legend doesn't do justice.
Dave over here in Australia ( and in a sheltered part of here), I thought you were (are) an engine builder/machinist. I’ve been using your books over 30yrs, thank you.
Dave I’ve looked up to you for 35 years had a big shop in Denver Co used a lot of your ideas from your books and done real well in the dirt circle track scene as well as asphalt circle and drag racing . Thanks for all of your books and knowledge I’ve learned a lot from you!
Don't forget You're A RACER TOO!!
I LOVE THE RACING STORIES!
A good racer knows his machine inside and out and how it works!!
You don't have to explain yourself to any of us Mr Vizard! The ones that care and follow you KNOW what you are, and if ever I heard anyone say different I would most DEFINITELY stand up for you and correct them regardless how many people we're in front of or where we are. I have every book you've ever had published. Literally. Thank you for all the knowledge you've given me and others like me! THANK YOU!!
Way back in 1971 I built a Ford Y block with info from one of The professors books and that motor really made good power the trick was the right cam and heads that flowed well for a y block that's hard to do but if you follow DV s advice you'll find the power ,unshrowed the valves keep the velocity up prep the intake bowl correctly don't touch the intake floor ,contour the edge of the intake valve on the chamber side ,contour the quench side of the chamber going into the exhaust valve all these bits of the professors info are Paramount in the HP equation on any I.C.E engine thanks professor you taught me well God Bless ya man
The Y block has always fascinated me, what kind of power/ET were you able to get out of one?
I'm glad you're finally taking these a$$holes to task. They love to say how jacked up the way you spec cams is but can offer no way to do it themselves, ever, on any forum you can think of, and get pissed off when you corner them up about it. I've had quite a few heated discussions about it.
I can scrap the "wide lobe separation syndrome" cams out of my friends engines, spec one out of your "How to Build Horsepower" book (SA24), and they always go faster. It's always hell to get them to go along with it though, because the cam companies and their LS cam minded buddies tell them it will never work.
I'm your number 1 fan guaranteed and have all of your books from about 1990 on.
High LSA is a very "it depends" kind of deal. Especially for those of us that need to meet emission requirements.
If say the cylinder head layout makes it hard to prevent or reduce wet-flow fuel transfer at overlap, and the exhaust has good scavange, then the HC-values at emissions testing will be too high, and you have to sacrefice performance by increasing LSA. Even tho it reduces thermal efficiency, the earlier EVO aids in heating up the catalytic converter faster in combination with deliberate late ignition timing the first minute or so after engine is first started. High HC with high overlap is mostly an issue with port-injection (or carbs), where injector duration makes some fuel puddeling on the back of the intake valve nearly unavoidable. DI however does not have that problem to the same degree, as you (often, not allways) have enough injector headroom to start injection (directly in the chamber) after IVC, at low revs and load to combat HC values.
Same goes for squish/quench area. A very tight squish area may be good for performance (good TDC turbulence), and done correctly aid in end-gas detontaion resistance (due to later squish-open, when the temp and pressure has reduced some), but the downside is the very rich mixture trapped in there burning late, which increases CO emissions alot. Thus you are presented with choice of running a very large gap, that also prevents detonation, but gives less TDC turbulence due to little squish action at all, that reduces performance, but reduces CO, or a Medium squish, which reduces CO aswell, but will nearly almost open up the squish gap to a combustible distance at peak temp and pressure, giving detonation issues.
There are alot of variables at play, and sometimes maximizing VE and performace at WOT is not the only consideration, emissions and part load is also a huge part of consideration.
At least outside the US.
@@flyfaen1 - - agree with pretty much all you have said here but emission is far more dependent on overlap than LCA. Found that when I was having to meet emission standards when doing a project for Chrysler.
@@marvingvx1
Your books helped me build a tire shredding 383 for my old C 10.
David, your book "how to rebuild your Small Block Chevy" (HP books) helped give me the know how to rebuild my first motor when I was in my early 20's. Fast forward 30 years later and I'm still learning from you, except now through your YT videos.
I REALLY WISH I COULD "LIKE" THIS VIDEO 100,000,000 TIMES!!!!
You tell 'em Mr. Vizard & DO NOT pull your "punches".
Those narcissist primadonnas have always been envious of you & jealous of your genius skills.
I CAN'T WAIT FOR PART 2!!!!
Best regards,
Ben
You're my engineering hero. You got me so involved when I was 20. I'm 37 now. I have all your books. Read them 3 times front to back.
You also have a very good way of explaining physics to people who didn't study it.
I am really excited to see what David has to show on this subject. I've been curious about the effects of valve events on power output and rpm ranges since I came across a chart of cam events on the website of a BMW tuner called Metric Mechanics. This tuner was using the chart to show how their sport and race cams different in their opening and closing events in relation to piston location. The text discussed how low speed street cams needed different events than the high speed race cams. Nowhere did it mention duration or lift. But the descriptions were to general and I've not been able to find very much more on this subject. Looking forward to this. Thank you, DV!
Ok , I'm an engine builder and have been doing it my hole life and I also started at a very young age with no money, but was always able to figure out how to make what I have better to the point that this little 7 Year old kid built a go cart with a Honda 80 cc 2 stroke engine and was out running the teenager's with store bought 125 cc cart's. My dad was a mechanic in Vietnam and work on just about everything and was a great mechanic.. which I believe was a great benefit for me..So anyways I eat, breath and work on engines and race machines every day and I'm really looking forward to hearing what you have to teach me ?!!!!!? Always willing to listen to the older gear head's. And I believe that's why I have always been one of the top guys in my line of work and that's not me bragging it's just the flat out truth!!!!! ..... Bob..... Take care and have a great day
David, you are by far, an amazing engine builder, and true racer, that I’ve been hearing about for over 35+ years. I’m only 56, and I’m sure that we’ll be sharing your knowledge for many years to come! Let the “haters” be haters. We know what works, and we all owe a lot to you for that! 👍
I was locked up as a teen. I bought your books from jegs.. I was in prison. Jegs sent the books to me. Jegs said we DO NOT ship to correctional facilities but I'm this case, since you ordered educational material. We made an exception. And those where your books. You changed my life and my love for motors and engineering. And I've changed a lot of peoples minds on the old hot rodders wives tails. Gotta have back pressure etc.
When people debate me. I ask first. What is the main source of induction of a nascar motor??? It's not the piston going down. It's the exhaust. Resonant tuning.
DV, thanks for the integrity, it is indeed in short supply these days.
I am now 72 years old and have followed you throughout your career. I have learned so much from you. People will only put you down when they are jealous. God Bless You and Thank You for teaching me so much.
Mark Twain - 'Anyone who can only think of one way to spell a word obviously lacks imagination.'
What you are mr vizard is a legend stuff they rest jealousy a curse.your a mentor and a teacher of knowledge a legend.peace
They don’t make them like this man anymore. We all need to thank David for sharing this stuff with us. We don’t know how much longer we are going to get these videos.
Thank you so much David for sharing all this knowledge. I read most of your books and am very happy with my 406. I used every trick I could do from your books. Ported and polished the oil pump and passages and even streamlined the butterfly shafts and screw heads on my hp950. All paid off. I ran a 7.13 NA in the 8th mile spinning on street tires.
My buddy works at an aftermarket manufacturer that specializes in engine oiling systems, he was interviewed by one of the largest magazines about engine oiling, they wrote the story almost verbatim from what he said and never credited him, passed it all off as his own knowledge, that was the last interview he ever gave
Hi David,
I bought your books some 30 years ago and read them while cheekily grinning at the thought and (what I saw as) just plain common sense behind them.
I still tune today based on what I learnt from you back then and have an ever-increasing list of satisfied customers who drive away smiling and amazed at the apparent simplicity with which I solve their problems.
It's so great to finally see you in video form!
Cheers from Australia! 🇦🇺 👍
Rob @ The Hilltop Workshop.
Dear Mr Vizard, I am sitting at my table with one of my favorite books
This book is HOW TO BUILD CHEVY SMALL BLOCKS ON A BUDGET
This is a book that YOU wrote back in 1995 when we were young handsome devils. This book has
10 BEST ENGINE COMBOS that are still used today! Thank You for your
accomplishments and teaching me so much.
Aww omg. The tribute at the end. Makes my heart break for you. But makes me proud for you too. So much respect for you. You're a strong man. You've helped a lot of people. I was 18. Got caught up being a punk. Got let out when I was 24. I read your books. Engineering books. All while serving my time . And I keep learning. You've changed my life. Really you have.
When I was 18 I thought I knew it all about engines. Hanging with car guys. You broke me free of my dunning Kruger mentality.
Physics doesn't give a fuck about your feelings.
I'm not a fan. I'm just so greatful for you. You opened my eyes. And made me have to admit to myself. That I don't know shit. So shut up listen and try and see.
Thanks, and for anything great or small that I have been able to do for you let me say 'you are very welcome'.
DV
Probably more than a few opinions but a very good subject. Growing up, DeLong Cams was nearby and hand massaged cam lobes would be developed and refined. His masters are still out there as are copies of his cams. Much later in life I took on dealing with the extra unknowns in smoothing a 9-term polynomial for a cam (college senior project). During this time I sent off to Florida, got the book, and wanted to show some of my work. The comment back that I should start at half my peak jerk opening the valve and not start at zero was very helpful. The question I got asked made me feel like a school child asking the nice man if he liked the picture I drew in class. He asked if I was using the polynomial to describe the cam lobe shape or the motion of the valve to the seat.
All the fancy math of motion gets you a little more area under the curve, a little more durability, a little less friction, and more rpm with the valves still under control. The power is coming from air and fuel getting in and the combustion products pushing the piston then leaving the engine. The cam timing deals with the when of those events starting and stopping relative to the rest of the engine dynamics. I've still much to learn from Mr Vizard about the "when" of things (especially with engines very over-square that rev up to the silly high rpm range - F1).
Great stuff as usual, I love the history lessons!
This episode does remind me of one thing I would like to see more of on this channel. That is how to set up or build a good suspension system for a road race car. I have a cobra kit car that handles like ass and I'd like to improve it while I've got it apart (it's getting a big block and top loader). I put new OEM shocks and Ebock sway bars on my dad's 97 Lincoln Towncar. Now, that 2 ton Lincoln can take corners at the same speed as my 2500 lb Cobra can before beginning to oversteer! Now that's embarrassing!
I know the tires are old on the Cobra and the springs are not ideal, those are getting replaced when I get the engine back. I'm just trying see if there's something fundamentally wrong with the car's suspension that I should address.
DV, did you write a book on the subject or can you recommend one?
I first came across your writing/views in Cars and Car Conversions ( a UK car mag now long gone ) probably 50yrs ago! and have read and used a few of you books, so glad to find you on here.
Your knowledge is much appreciated in my book! I was one of the kids that sat up front in math class! LOL!!
When I discovered you (your book and articles) my vision about build power subbenly change. Finally a really competent man. From dark to the light.
I can vouch for everything that you have said. You’re giving people good information. So many times I have heard people say things that I knew just wasn’t true. I have read everything that Bill grumpy Jenkins ever wrote. I named my son William Tyler Smith. William Tyler Jenkins is Bill grumpy Jenkins‘s real name. when I built my first engine I had done thousands of hours of research. I have read several articles in hot rod, super Chevy, popular hot rodding magazines that were BS. The things that you talk about I know you have experience with. There will always be haters!
I have a 400 small block chevy built to specifications from you. Just need to purchase a cam. I am anxiously waiting on more information to finalize my selection. Was going to call Lunati about one of the cams recommended in one of your small block chevy books but now I am going to hold off for the upcoming videos. I really value everything you have written. Thank you.
Debra, it is coming soon so keep watching
I've always enjoyed your frank, honest and accurate advice. You are a hero of mine and have been for nearly 30 years.
One of my favorite rivalries was between Bob Glidden,the innovative mechanic, versus. Warren Johnson the engineer.
I'm to young and to Danish to know who David Vizard was. But stumbled upon your video"s and like the contents. Showed it to my coworker for verification of the contents. Hes original from American and have a big engineering education from the Danish DTU and have worked with Engine Design for 17years. Beside that he has always works on cars. He approved your content so I trust it.
Love you DV!I´ve build my first sbc383 from your book,and it HAULS!And I preciate these videos,thank you!!
I have wondered how wide LCAs are so popular with cam grinders. I am currently working on a 438 windser it will have a 108 LCA with a intake center line of 104. When i told my engine builder this he thinks i am crazy. We will soon see.
Mr Vizard, I discovered your books and articles oh so many years ago! I quickly learned that you had the knowledge and experience that I wanted to apply to my automotive endeavors. Now for a potential suggestion for a video...if you take suggestions. Could you please look into why flat tappet camshafts and lifters are experiencing catastrophic failure from premature wear. Is it a metallurgy issue, heat treat issue, lubricant? I recently incurred instant lobe failure while using name brand assembly lube and the typical break in procedure of 2000 RPM for the splash oiling on a sbc. Also used break in oil. Lobe was wiped in 5 minutes. Thanks for sharing your time and knowledge with us!
G’day David, the difference between you & Smokey, and ordinary journalists, is that you both did the thought experiments, did the research, and you did the development, then you presented the FACTS. Practically all other journalists, whether they like it or not, are trying to sell something - sometimes it is their ego that they are trying to sell to us!
Glad to hear your recognition from Smokey.
Dv, I truly did not know that you were pushing 80. Good for you man. And I'm sure i speak for many many others when I say don't worry about some fruitloops dishing dirt on you. I watch you, read you and follow you because you SHOW me regularly how things work and why. Im no race engine builder,, just an engine enthusiast that can always take away information from your show or articles.. That is why you have the following that you do. And thats not to say that there aren't others in your field that do the same. But your legacy? As a teacher and a mentor, it is assured. Keep doing your thing and God bless.
You are the man David 💪👍💯
You're a really good man Mr David Vizard. I appreciate all your videos you're so informative. Bless you. However I was wondering of one of your topics of Cam picking, I was praying you would make a video of picking a cam duration an overlap for cylinder bore or cubic inch that you have in your books. I would and a lot of people probably would appreciate it. I've read the books and tried it myself I hope I'm doing it right but a video on it would be excellent for one big block and one small block to give us the idea the run through I would so graciously appreciate it. I have all your books, and respect your work you're a very great man. God bless you
Keep watching my friend and all will be revealed!
@@marvingvx1 yes please please thank you thank you. I would appreciate it very much. Take care
Hey Liberty - just hang in there - it's in the works right now!
Hey! I was 12 mins in before I realized I've got both channels of sound!
To answer the cam argument, two cylinder heads with identical port/valve configerations, one with super cam profile 101 operating the valves, the other with solenoid control. I know exactly which my money would be on.
I recently found your video's and find them highly educational and can't wait for your chevy cam selector! Try to stay away from videos without a demonstration of some kind. Great videos!
David,
You would have to go a long way back to remember me. My name is James Worsham and used to run the machine shop in the back of The Riverside NAPA store. The guy who turned Gilbert Mink loose with a die grinder. 😉
I have recently acquired a 1966 MG Midget and would love the opportunity to pick you brain. I remember that you used to be quite the “Hot Foot” way back and I have followed you on the web.
OK, you don't like to be called a writer. But before I finish trying to get my point said t must tell you how much I appreciate that you do what you do so well. Thank you. And by the way, for a 2bit writer.. your 3 1/2 bits of all right.
Make sure to add “ring the bell” to the like share and subscribe at the end. This has become very important to get videos out there on yt lately.
Great tutorial on honesty David unfortunately the world is full people with one intention MONEY. Australia.
Give em hell..
I knew a lot of people who I thought knew it all. Cam duration and lift. After you I know about jerk values ramp speed area under the curve. Overlap lsa and why they are important
could you possibly reccomend the best hydraulic roller cam to use in a 445cu.in. small block ford ? 10.8 static comp 3000lb car with a manual transmission 3.73 rear gears? AFR 220 heads 2.10/1.6valves 1500-7000rpm?
I would much rather read about all the stuff that he says and actually have to listen to him I find it very hard to listen to him that's not a put-down he's obviously a smart man
Caution, you piss David off, he will not just tell you you're wrong, but will visually prove it, gotta love him!
Thank You David for spending your money for all of us to learn from your help is priceless.
God bless you and I hope that you continue to flourish and I hope to someday be a third of the person that you are.
Ur a blessing to the passionate gearheads DV
Mr. Vizard, my dad was an artist. Incredible handwriting and painting. Could not spell!
Mr V is salty today! I love it! You know, sir, the Motor Trend scribes (Hot Rod, et al) always go to Billy Godbold at Comp for their cam recommendations. I suspect Comp COMPS them the cams, lol. What do you think of Billy as a cam engineer?
DV has commented about BG on these videos.... Very favorably actually.
Never forget CC company is selling cams for many computer and boosted engines that make the catalog look .... 🤔 Strange.
Billy's profile designs are top notch and I really admire Billy. Great guy in my book.
I first bought one of your books originally published back in the 70s, and what you said then about poorly designed cams heads, exhausts, etc from major component companies is unfortunately still valid today, yet too many people still buy their crap.
Hi, To You , THANKYOU !!! for your knowledge , Teaching All Of US ! The "BS S - - - - " Comes from those
People Who Can Not Even Know How / Hold A Wrench !!!!! Thank YOU !!!!! 👍👍👍👍👍👍👍
Does cam timing change for long rod vs short rod big block chevy that are same displancement
Your the best, anyone who has the balls to tell the truth and say that is a great person in my book. You are so correct about the, you did it and have patients and they are quoting things that they are told. I will be quiet now and enjoy your video. Great day to you!
If I don't learn something new everyday, I have failed myself and my comrades at work.
,,,,,,,,,,,,,thanks again David...............I have many of your books [even got one for a friend] , and got smokey yunick's book among all other great legends...........jenkins,,,lingenfelter,,,etc etc ...
Like I said to you on Speedtalk about 3 years ago when some of those guys were treating you the same as these guys- ignore them. They are beneath you and I totally understand were you would feel this way, but ignore them.
Troy - let's not forget they are providing me with writing material!!
@@marvingvx1 true enough, lol
Ive read alot of your books back in the day...and ive learnd alot. Your blunt and.to the point..and.you rub some people the wrong way....what i have found ouy in 55yrs of life is that most people ive run across are a$$holes thats just my opinion....you sir..keep up the great work and thank you for shareing your knowledge...
Should I bring my spotlights to see through all the upcoming shade
Spell a door three different ways Lol !Wow, you’re good. I can only do it in two different ways. That was a good one David thank you ! I enjoy your videos.👍
Lol David engineers are never wrong.
I'm a millwright. I keep tire curing presses running. PLC ladder logic Hydraulics steam. Valves etc. Lvdt sensors. It's amazing to me how many engineers don't listen to us mechanics who keep these machines going.
Well some engineers are never wrong - it's just the theory they are pushing doesn't apply to the project they are doing!
Another great video, I love it.
Keep on doing what you are doing ! Dont worry about those that dont know what they are doing !
I could listen to this guy all day and enjoy the broadcast regardless of what it is. You're going to be around for a good time yet and I will have to say that you are more of the engineer than a journalist. Calling you a journalist is a great insult because they are telling what the establishment tells them to and you say it the way it is and how you see it. I grew up right after you and I didn't have any of that stuff or equipment that the well off had. All my 400 to 500 HP engines were made from insurance company totaled wrecks and assembled on a home made stand made from pallets, a tire, and scrap steel that we got from the local railroad yard that a family owned and was still using old school Unit cable magnetic cranes to load and unload the rail cars and trucks until his death at almost 90 at home in his recliner after a hard summer days work. His name was Horowitz and he owned a whole city block and in the 70's this was a great feat for a small town guy who started with a brother, a cousin, and one employee. He had two rail lines and had a good business with the Bessemer and Lake Erie Railroad. Felt bad but later I realized that his longevity was due to doing what he was happy doing and loved to do. Great day to you Mr. V and God bless you and your family plus your honesty and bluntness will be there in history of the sport and the business for decades to come unless we allow them to outlaw it. Thanks again for your dedication to your work and dedication to keeping this honest and straight forward with facts.
Sincerely, Mr John Elliott.
Go on David! Get these fools exposed!!
Me also I was in the middle of the road in spelling in school and they're changing the meaning and spelling of words the past 30 years now that it is hard to keep up with the changing of the language that we were taught in school.
Those magazines talked me into buying this new part or that. Took me a while to figure out they are glorified sales brochures.
If you're getting accolades from Smokey🤔......You're doing it right😉
Love the vids!
🔔😎
DV
St. Jude #1 since 1978 👍👍👍
God bless youz Sir.
Hope to see you y'all in 3 weeks.
YeeeeeHaaaaaw!!!! 👍😎😎
My father in law is an engineer. He met zora duntov. Well was at he's lecture while he was in school for mechanical engineering. I've told him all about you. He's also a fan.
I don't have an opinion, I have a Dyno
Right on brother!!
Hi David…can you post a link to the cam debate on speedtalk? Was going to ask on your ST section but Looks like they locked the thread.
UNCLE Vizard needs a word with you! Your Mother tells me your homework is waning!
??????
"Old engine builders never die, they just become tutors"!
Unfortunately people do this today even if they know they’re wrong!!… as it keeps their name in circulation think of how much publicity he’s name is going to get now that old saying “no such thing as bad publicity”.
I got all my faith in you David
speaking of Cams, I believe Ed Iskendarian's Birthday is near, I believe he will be 101!
So whom do we contact for a cam recommendation?
James - - coming soon - just watch this channel.
Love this guy.
David did you have anything to do with a bunch of Mini`s in So. Cal. in the early 70`s called the purple people eaters? They were whooping everybody`s butt at Riverside Race track for a while.
Brain fade here - can't remember.
Shills are everywhere. I'd consider it the journalistc standard. It's appreciated that you stand above.
Mr Vizard puts the orse in horse and the ower in power....the man must have got sucked in one of his motors and spit out the exhaust cuz he knows what goes on inside an engine. Kinda like that jet airplane mechanic did on that replay everyone shows.
Go get em David!
This is an argument over which is worse feels like the old argument over taste great or less filling. I am usually trying to get the best profile and event timing so good luck in the pissing contest hope you win.
Thanks for your support Don. Just be sure to see the concrete proof in part 2
Get him David , He's only poking the big bear because he's jealous of the big bear because he knows the big bear is better than him and secretly wants to be as good as the big bear 🤣 . Dont take no B.S. from anyone. You have done more in half of a lifetime than than most will do in a full lifetime. Very smart guy you are.
🙏
People copy and repeat BS...People are amazing. 95% of people that assemble engines disagree with me when it comes to cams, heads, etc. When it comes to N2O engines, the way I see it Ray Charles and Helen Keller could build a nitrous engine. Keep the information coming.