Thanks David! Your ability to explain complicated engine dynamics to the average person goes beyond what words can say. Thanks for your time and sharing!
David, the knowledge of parts and tuning you share with us is of great value, and since I dont have an extra lifetime to spend in obtaining it myself, receiving it from you for free is a huge blessing. Thank you sir. I will be buying a book or two soon as well.....people should understand that what is shared can prevent the waste of thousands of dollars in time and parts doing inferior modifications.
Thank you Mr Vizard for all you have done for all of us! I believe I sounded like a complete asshat on previous video! One of the first books 📚 I ever learned from was smokies stuff, & your how to build horsepower books! I actually dug them out! Most people get to envolved in stupid little things because they forgot their basics! I was the only teenager at the track that knew about timing & carburetors because of you! Thanks again sir!
David, This episode is the most informative video ever done. Your knowledge is paramount. Its a set of laws at place that you explain well, then back up with solid proof. Well done Sir.!!
Thank you so much David! Smokey Yunick has always been one of my heroes.....Now I have a new one!!! I just love the way you explain things. The advancing of the cam after a rocker swap totally makes sense. Love all your videos! Oh man what I would give to be in one of your classes.. The dedication of this video is very touching and I am very sorry for your loss....I was not aware.
Oops. I meant to add: at the faster rate the rocker opens the valve it makes sense that would advance the cam. SBC with adjustable rockers introduced in the mid 50s, why after all these years of development hasn't anyone else covered this phenomenon more in the mainstream? You sir are a true genius..
@@marvingvx1 Hi there. What are your thoughts on the scorpions 1.6. I installed them in my SBF 331 stroker. I had a set of early Sig Erson. 1.6 ratio also. I changed out to the scorpions I got them for free brand new in the box. Cool looking blue. I am running edelbrock Performer RPM top engine kit. I don’t know much about finding more performance. But I said I like how they look. What can you tell me about these scorpions. Did I waste my time. Swapping out 1 set for another. Thank you for your time. Sir 🏁
Is there a formula used in the rocker height at the push rod end, when the valve lift exceeds the desig ? Rocker bodies can be rotated around the push rod cup or ball to roll back the shearing effect. (?) What's your opinion on this as well as torque efforts in rotating the camshaft or crankshaft on varying push rod lengths. I may not be wording this the way I intend however, you may fill it in your way.
Wow !! Excellent video Mr. Vizard. Very practical information indeed. I'm planning on upgrading to a higher rocker ratio in the near future and will keep this in mind. Please keep the excellent content coming. 👍
Another concept I've never heard of or considered before! Tightening the lash advances the cam! So bone head simple, yet it is never mentioned... until David Vizard shares this important concept with us. Thanks again David!
Excellent work thank you for revealing “what’s going on” I always knew there was much more to the ratio, I had no idea it affected timing and lash. Love story time too
i only subscribed last week and just about watched all of your vids! i literally just bust out laughing at how smart you are and by tweaking timing and telling them to do so and pick up 18 hp lol! i could sit down fir days and talk about this stuff! i hope i some day get to meet you ! will be definitely watching your vids and hope to see some sbf stuff! wicked info david 👍
🔔👍 Thank YOU, DV. I have had this discussion several times in years past and everybody thinks I'm nuts. Also the pushrod length affects the valve accellaration. I am sure that you will cover that. 👍👍
David: Thanks for clearing the air about rocker ratios and some of the changes that are made to improve/disprove horsepower. I am working remotely at the moment, so I can't get out into the garage to work on some of the engine projects I would like. I do, however, still dabble in engineering, hence, learn from publications either on the internet or from books and such. I would also like to convey my condolences for the passing of Jacque Vizard. Was She your daughter or niece? God bless your family. Thanks for all the information you've presented. You have been a huge help in bringing theory to my mechanic's endeavors.
David, just finished a BBC engine and utililzed the PRW 1.8 rockers per your BBC book. THANKS for all your work and info. It is very much appreciated. By the way, I discussed this matter with their tech dept and they stood by the 1.8 ratio and were unaware of your findings.
Very interesting findings and theory. Another case of not just looking at the peak measurement (max lift) but what's going on as you transition from the base circle to the ramps. I would think this is very important if you are running heads with good low-lift flow numbers.
I miss getting that big PAW book, I never ordered from them but was interested to look at what they had, I know there book just quit coming one year.. never really heard anything good out of there internal parts
An old flathead Ford builder once said" never wash a reused camshaft as the impregnated oil will be washed away and the cam will require another break-in". If this logic is sound, would it be wise to soak a new cam and lifters in hot oil before assembly? Thanks DV, your contributions are appreciated.
Is there no upper limit to valve acceleration? Years ago at weber state we had this discussion and it was said that you could open the valves too fast. That's why things like slide vavles and rotary valves weren't pursued, they just offered no real advantage over what was available with poppet valves. The discussion included the hypothesis that rocketing the valve open on some ports could make the flow stall and require time to recover, which in turn reduced horsepower. In stock eliminator we've always been acutely aware of variation on ratio among rockers this is why I built a fixture for mapping lift and acceleration and set about profiling 2 five gallon buckets of 440 rockers to get just 1 set. If you were creative you could mod them to a degree and it was an area that at the time the never checked on tear downs
We must have crossed paths at some point David. Because i was called upon by GM on the 454 and 502 crate motors back in the 1990s. We found the harland sharps to add a bit more horse power then the gm rockers. Comp cams had not yet aquired their technical data gurus. So basically everything in those crate engines came from the guys doing work for indy and the B1 programs. I shared those results with GM and later it was used on the crate engines with the smaller GM cam and rockers. Those cam and rocker specks are now owned by trick flow in thier engine power combos.
Next we can get into shoe rockers and lash caps so you can have a rocker that actually stays close to maintaining its peak ratio as it approaches full lift rather than dropping off which is a big drawback to rollers for my part because generally you have to be setup to start beyond valve center and come in as lift increases to stay correctly over the valve stem so you tend to always loose ratio as lift increases.
Hi David. How can we tell whose rockers are actually what is advertised. I know we can do it installed on the head but most of us can’t afford to buy multiple sets. Thank you so much for your time and knowledge.
Mr. Vizard i am curious as to what you would have to say on the subject of the chevrolet 60 degree v6 as far as what all can be done to them for performance gains?
I have had some issues with induced valve float & hyd lifter collapse after swapping to increased ratio rockers on SBC1 engine. I believe the cam lobes on the off-shelf Comp Cam was already near the limit of intensity, and the added ratio pushed it over. When upgrading to stronger valve springs the lifter collapse only got worse, so no improvement until swapping back to a 1.5 ratio. I wish they would offer cams with a lower intensity closing ramp.
G,day David thankyou for producing these videos. This one I have found most interesting, it has shown that without fitting various rockers and testing them we can't really know the true ratio. You have mentioned a few times now the findings of Smokey Yunick, he like yourself contributed to my engine building knowledege way back in the 1980's. So safe to say I am a student of both of your teachings. Have you any dyno knowledge of his con rod length therories? Smokey talks of 2 and 3 to one rod ratios, and I have always wanted to build a long rod v8 for those reasons. At this point in time with a custom rod and an off the shelf stroker piston a ratio of 2.05 to 1 can be achieved in a Holden 308. I would be interested to hear your thoughts on such a build. At this stage it is all theoretical, and I am yet to look at the physical possibillities. It is very simple to cut and weld a rod to fit to a block to check clearances etc. Cheers Rob Teale.
It's going into a 74 Comaro. My first time going this way I like to go twin turbo and the Holly Terminerator X. Stock intake and good injectors. I'm a carb guy but this way seems more practical because Holly terminator x has trams controller for the 4l80e and I can run stock intake for cheap. And a turbo set up not so cheap
Thanks for sharing the info.Mr.Vizard,would I benefit from a higher ratio rocker/quick off the seat on a 396 Chev. big block with a 230 dur. Hyd.cam .526 lift, 110 lobe sep.I am running the comp cams 1.7 steel with roller tip rockers as we speak.Thank you.
Im guessing the wheel has two scales, because you always have to split the difference in either direction when you zero a normal wheel before degreeing. So i guess it would be to technically zero, and give you exact degrees, rather than the 1,2 or 3 degrees you normally are off in either direction.
David, can I conclude that the increase in rocker ratio does increase duration? Or..., duration remains the same but because the valve is opening faster it is "effective" of a cam that has increased duration? I come to these questions based on the cam retard you specified and the positive results that occurred. Also, if I may ask, I have a Corvair with lowly 80HP engine. The cam spec I'll give sound like they are at the lobe but, yes, are actually at the valve. They are Intake .314 lift and exhaust .344 lift. The stated Corvair rocker ratio is 1.56. The GM factory 348/409 rockers are said to be 1.76. My math says the effective lift change would be: Intake .314 to .368, a .054 lift increase and Exhaust .344 to .403, a .059 increase. Given the cost of splitting the engine case, cam purchase (a new gear is always required) new lifters etc. a swap to the 1.76 rockers seems a budget friendly exercise for an old fool who likes to tinker. These lift specs increase results similar to that of the Corvair 95HP engine. Your thoughts.
Hi David, you said the BBC is under valve. I read the intake valve to bore ratio should be: 52-52.5% - 454, 4.25 bore = 2.23 intake valve. I would like to know your thoughts on that formula? Thanks.
I've run valves as big as 2.32 even sacrificing exhaust valve size and always made more power. You cannot stick an intake too big in a bbc. Oh and you don't need 1.88 ex 1.84 are plenty and I've had good results with as small as 1.78.
Mr. Vizard.. Can you cover for the beginners and/or people on an extremely low budget.. or even if just replacing broken parts with the easiest upgrade.. Replacing a stock 1.5 rocker with increasingly higher quality & performing rockers that are still 1.5? .. This, hopefully, would give an improvement without having to change any other parts.
If you are super low budget then you are probably better off looking elsewhere for dollar per hp than the rockers. The factory rockers are reliable on mild builds.
What about if the intake AND exhaust ratios are both changed, what happens? Usually the exhaust side would be the side enhanced with extra ratio. This is the first time I have seen the intake only being enhanced. Good to know the cam needs retarded if the intake ratio is enhanced. Would changing both make even more power without changing the degreeing of the cam?
I am building a Chevy 383 stroker with a CompCams 305H .525/525 lift and am using 1.5 rockers. Should I go to a higher ratio rocker? Will it run OK with the 1.5's or will it make more power with lets say 1.6? Thank you for the videos I am learning sooo much. I am from Windsor, Ontario, Canada.
I would junk that cam in 1983 it was good but the newer designs are quite a bit ahead try the Lunati voodoo series or Comps extreme energy series. I'm a big fan of the voodoo they were designed by Harold Brookshire. If you have the mind Google him and read up on his advice and accolades.
I'm no David Vizard, but I'm of the impression that the lash speced by the cam manufacturer is done so in accordance with the profile shape of the lobe opening and closing ramps in mind. Different cams ground by different manufacturers require different lash values based on the camshafts intended purpose. There is no industry standard in terms of valve lash specs that I've ever seen.
@@CharlieBrown-pb9xn The manufacturer would not spec those values if it increased potential for failure. The last thing they want is tons of warranty claims.
Yeah, for some reason he insists on adding that distracting spooky music. It adds nothing but distraction and technical audio problems over an otherwise outstanding video. I'd literally pay him to stop adding music.
Again problem with audio, the music is in one ear and the voice is in the other. For viewers: if you're using earphones or headphones with a cable, you can slightly pull out the connector, this should turn stereo into mono and the audio will be much better.
And if I stopped pointing out where I, as a bonified research engineer with dozens of patents, am coming from I would have guys LIKE YOU criticizing this writer (ME) who has all these wild ideas but YOU SEE AS HAVING no experience or proof of what he is talking about. Also I bet you were the one responsible for the single 'dislike'. I think you need to do a little ( on second thoughts maybe more than just a little) self analysis. before criticizing others. DV
Thanks David! Your ability to explain complicated engine dynamics to the average person goes beyond what words can say. Thanks for your time and sharing!
So sorry about your daughter David. Life is fleeting
Love your videos David, keep them coming
David, the knowledge of parts and tuning you share with us is of great value, and since I dont have an extra lifetime to spend in obtaining it myself, receiving it from you for free is a huge blessing. Thank you sir. I will be buying a book or two soon as well.....people should understand that what is shared can prevent the waste of thousands of dollars in time and parts doing inferior modifications.
Once again, thanks for involving us in an excellent experiment that shows the full need for a dyno tuner that knows what their doing
Thank you Mr Vizard for all you have done for all of us! I believe I sounded like a complete asshat on previous video! One of the first books 📚 I ever learned from was smokies stuff, & your how to build horsepower books! I actually dug them out! Most people get to envolved in stupid little things because they forgot their basics! I was the only teenager at the track that knew about timing & carburetors because of you! Thanks again sir!
Once again we learn how important cam timing is. Great lesson, thanks Mr. Vizard
Thanks David. Excellent information as usual. I’m really enjoying all the new content that you have been releasing.
As usual Mr. Vizard your videos leave me asking for more and more. Thank you for your time and knowledge sir.
Well, I started learning with the August 1954 Hot Rod, and today I'm sure I'm still learning .
David, This episode is the most informative video ever done. Your knowledge is paramount. Its a set of laws at place that you explain well, then back up with solid proof. Well done Sir.!!
Thank you so much David! Smokey Yunick has always been one of my heroes.....Now I have a new one!!! I just love the way you explain things. The advancing of the cam after a rocker swap totally makes sense. Love all your videos! Oh man what I would give to be in one of your classes..
The dedication of this video is very touching and I am very sorry for your loss....I was not aware.
Oops. I meant to add: at the faster rate the rocker opens the valve it makes sense that would advance the cam. SBC with adjustable rockers introduced in the mid 50s, why after all these years of development hasn't anyone else covered this phenomenon more in the mainstream? You sir are a true genius..
Smokey --- you picked a great hero here!
@@marvingvx1 Hi there. What are your thoughts on the scorpions 1.6. I installed them in my SBF 331 stroker. I had a set of early Sig Erson. 1.6 ratio also. I changed out to the scorpions I got them for free brand new in the box. Cool looking blue. I am running edelbrock Performer RPM top engine kit. I don’t know much about finding more performance. But I said I like how they look. What can you tell me about these scorpions. Did I waste my time. Swapping out 1 set for another.
Thank you for your time. Sir 🏁
The intro. "Oh crap my rockers off it's rocker!" Thanks so much for sharing your knowledge.
Is there a formula used in the rocker height at the push rod end, when the valve lift exceeds the desig ? Rocker bodies can be rotated around the push rod cup or ball to roll back the shearing effect. (?)
What's your opinion on this as well as torque efforts in rotating the camshaft or crankshaft on varying push rod lengths.
I may not be wording this the way I intend however, you may fill it in your way.
Wow !! Excellent video Mr. Vizard. Very practical information indeed. I'm planning on upgrading to a higher rocker ratio in the near future and will keep this in mind. Please keep the excellent content coming. 👍
Another concept I've never heard of or considered before! Tightening the lash advances the cam! So bone head simple, yet it is never mentioned... until David Vizard shares this important concept with us. Thanks again David!
And hydraulic cams bleed oil due to spring compression lessening the lift/accelleration. Another variable, 😨
Excellent work thank you for revealing “what’s going on” I always knew there was much more to the ratio, I had no idea it affected timing and lash. Love story time too
Thank you so much my Grandmaster, every time I see your videos I learn a lot from you.
i only subscribed last week and just about watched all of your vids! i literally just bust out laughing at how smart you are and by tweaking timing and telling them to do so and pick up 18 hp lol! i could sit down fir days and talk about this stuff! i hope i some day get to meet you ! will be definitely watching your vids and hope to see some sbf stuff! wicked info david 👍
🔔👍 Thank YOU, DV.
I have had this discussion several times in years past and everybody thinks I'm nuts.
Also the pushrod length affects the valve accellaration. I am sure that you will cover that. 👍👍
David: Thanks for clearing the air about rocker ratios and some of the changes that are made to improve/disprove horsepower. I am working remotely at the moment, so I can't get out into the garage to work on some of the engine projects I would like. I do, however, still dabble in engineering, hence, learn from publications either on the internet or from books and such.
I would also like to convey my condolences for the passing of Jacque Vizard. Was She your daughter or niece? God bless your family.
Thanks for all the information you've presented. You have been a huge help in bringing theory to my mechanic's endeavors.
Thank you so much master, sorry about your loss, cheers from Chile!!
This is great info. The way you explain it makes perfect sense. Thanks!!
David, just finished a BBC engine and utililzed the PRW 1.8 rockers per your BBC book. THANKS for all your work and info. It is very much appreciated.
By the way, I discussed this matter with their tech dept and they stood by the 1.8 ratio and were unaware of your findings.
Thanks Dave....
Great content
Very interesting findings and theory. Another case of not just looking at the peak measurement (max lift) but what's going on as you transition from the base circle to the ramps. I would think this is very important if you are running heads with good low-lift flow numbers.
Good video sir
I miss getting that big PAW book, I never ordered from them but was interested to look at what they had, I know there book just quit coming one year.. never really heard anything good out of there internal parts
2nd on that
They had a complete long block 392 hemi kit....I sure wish that was still available
An old flathead Ford builder once said" never wash a reused camshaft as the impregnated oil will be washed away and the cam will require another break-in". If this logic is sound, would it be wise to soak a new cam and lifters in hot oil before assembly? Thanks DV, your contributions are appreciated.
Is there no upper limit to valve acceleration? Years ago at weber state we had this discussion and it was said that you could open the valves too fast. That's why things like slide vavles and rotary valves weren't pursued, they just offered no real advantage over what was available with poppet valves. The discussion included the hypothesis that rocketing the valve open on some ports could make the flow stall and require time to recover, which in turn reduced horsepower. In stock eliminator we've always been acutely aware of variation on ratio among rockers this is why I built a fixture for mapping lift and acceleration and set about profiling 2 five gallon buckets of 440 rockers to get just 1 set. If you were creative you could mod them to a degree and it was an area that at the time the never checked on tear downs
We must have crossed paths at some point David. Because i was called upon by GM on the 454 and 502 crate motors back in the 1990s. We found the harland sharps to add a bit more horse power then the gm rockers. Comp cams had not yet aquired their technical data gurus. So basically everything in those crate engines came from the guys doing work for indy and the B1 programs. I shared those results with GM and later it was used on the crate engines with the smaller GM cam and rockers. Those cam and rocker specks are now owned by trick flow in thier engine power combos.
Very good video.
Great content David.
Thanks, EM.
Very good video very telling thank you!
Wow, I never knew rocker arm geometry was so nuanced.
Thank you
Next we can get into shoe rockers and lash caps so you can have a rocker that actually stays close to maintaining its peak ratio as it approaches full lift rather than dropping off which is a big drawback to rollers for my part because generally you have to be setup to start beyond valve center and come in as lift increases to stay correctly over the valve stem so you tend to always loose ratio as lift increases.
Wow...... just wow.
Hi David. How can we tell whose rockers are actually what is advertised. I know we can do it installed on the head but most of us can’t afford to buy multiple sets. Thank you so much for your time and knowledge.
Mr. Vizard i am curious as to what you would have to say on the subject of the chevrolet 60 degree v6 as far as what all can be done to them for performance gains?
I have had some issues with induced valve float & hyd lifter collapse after swapping to increased ratio rockers on SBC1 engine. I believe the cam lobes on the off-shelf Comp Cam was already near the limit of intensity, and the added ratio pushed it over. When upgrading to stronger valve springs the lifter collapse only got worse, so no improvement until swapping back to a 1.5 ratio. I wish they would offer cams with a lower intensity closing ramp.
G,day David thankyou for producing these videos. This one I have found most interesting, it has shown that without fitting various rockers and testing them we can't really know the true ratio. You have mentioned a few times now the findings of Smokey Yunick, he like yourself contributed to my engine building knowledege way back in the 1980's. So safe to say I am a student of both of your teachings. Have you any dyno knowledge of his con rod length therories? Smokey talks of 2 and 3 to one rod ratios, and I have always wanted to build a long rod v8 for those reasons. At this point in time with a custom rod and an off the shelf stroker piston a ratio of 2.05 to 1 can be achieved in a Holden 308. I would be interested to hear your thoughts on such a build. At this stage it is all theoretical, and I am yet to look at the physical possibillities. It is very simple to cut and weld a rod to fit to a block to check clearances etc. Cheers Rob Teale.
Would be so great if you can do away with music inserts and enhance audio before release. Contents are as always so valuable. Thank you Mr David
Have you done anything with Gen 3 hemi. I have all your books on small block Mopar wonderful books
so sorry to hear about your daughter Mr. Vizard
David, is there a high ratio PRW rocker with similar quality for the Chevy Small Block ?
So better to have adjustable pushrods than adjustable rockers so you have control over the ratio geometry.
The Ford rail rocker gave me nightmares of the past
How do you test rocker ratio we can run any rocker ( stock stamped) ( roller tip) (needle bearing) but can only run 1.5 ratio
I need a good cam for a 454 any suggestions. I'm thinking of going Isjy
And after watching this I'm going 1.8 Rickers.
It's going into a 74 Comaro. My first time going this way I like to go twin turbo and the Holly Terminerator X. Stock intake and good injectors.
I'm a carb guy but this way seems more practical because Holly terminator x has trams controller for the 4l80e and I can run stock intake for cheap. And a turbo set up not so cheap
Thanks for sharing the info.Mr.Vizard,would I benefit from a higher ratio rocker/quick off the seat on a 396 Chev. big block with a 230 dur. Hyd.cam .526 lift, 110 lobe sep.I am running the comp cams 1.7 steel with roller tip rockers as we speak.Thank you.
Thank you for the response.......common man.
Im guessing the wheel has two scales, because you always have to split the difference in either direction when you zero a normal wheel before degreeing. So i guess it would be to technically zero, and give you exact degrees, rather than the 1,2 or 3 degrees you normally are off in either direction.
David, can I conclude that the increase in rocker ratio does increase duration? Or..., duration remains the same but because the valve is opening faster it is "effective" of a cam that has increased duration? I come to these questions based on the cam retard you specified and the positive results that occurred.
Also, if I may ask, I have a Corvair with lowly 80HP engine. The cam spec I'll give sound like they are at the lobe but, yes, are actually at the valve. They are Intake .314 lift and exhaust .344 lift. The stated Corvair rocker ratio is 1.56. The GM factory 348/409 rockers are said to be 1.76. My math says the effective lift change would be: Intake .314 to .368, a .054 lift increase and Exhaust .344 to .403, a .059 increase. Given the cost of splitting the engine case, cam purchase (a new gear is always required) new lifters etc. a swap to the 1.76 rockers seems a budget friendly exercise for an old fool who likes to tinker. These lift specs increase results similar to that of the Corvair 95HP engine. Your thoughts.
Hi David, you said the BBC is under valve. I read the intake valve to bore ratio should be: 52-52.5% - 454, 4.25 bore = 2.23 intake valve.
I would like to know your thoughts on that formula? Thanks.
All 2 valve per cylinder engines are under valved no matter how big
I've run valves as big as 2.32 even sacrificing exhaust valve size and always made more power. You cannot stick an intake too big in a bbc. Oh and you don't need 1.88 ex 1.84 are plenty and I've had good results with as small as 1.78.
Mr. Vizard.. Can you cover for the beginners and/or people on an extremely low budget.. or even if just replacing broken parts with the easiest upgrade.. Replacing a stock 1.5 rocker with increasingly higher quality & performing rockers that are still 1.5? .. This, hopefully, would give an improvement without having to change any other parts.
If you are super low budget then you are probably better off looking elsewhere for dollar per hp than the rockers. The factory rockers are reliable on mild builds.
What about if the intake AND exhaust ratios are both changed, what happens?
Usually the exhaust side would be the side enhanced with extra ratio. This is the first time I have seen the intake only being enhanced. Good to know the cam needs retarded if the intake ratio is enhanced.
Would changing both make even more power without changing the degreeing of the cam?
Interesting
I am building a Chevy 383 stroker with a CompCams 305H .525/525 lift and am using 1.5 rockers. Should I go to a higher ratio rocker? Will it run OK with the 1.5's or will it make more power with lets say 1.6? Thank you for the videos I am learning sooo much. I am from Windsor, Ontario, Canada.
I would junk that cam in 1983 it was good but the newer designs are quite a bit ahead try the Lunati voodoo series or Comps extreme energy series. I'm a big fan of the voodoo they were designed by Harold Brookshire. If you have the mind Google him and read up on his advice and accolades.
What is the LCA you are using? Give me that and I can answer your question.
Correct LCA is vital. 👍👍
David.
Why rely on custom rockers and sll the complications assiciated with this.
Wy not specify your lift from the camshaft manufacturer.
Great video. I was looking at an Isky cams .632 solid flat tappet for a 351w and it calls for .028 lash. I dont understand why so exsessive on lash?
I'm no David Vizard, but I'm of the impression that the lash speced by the cam manufacturer is done so in accordance with the profile shape of the lobe opening and closing ramps in mind. Different cams ground by different manufacturers require different lash values based on the camshafts intended purpose. There is no industry standard in terms of valve lash specs that I've ever seen.
@@Torquemonster440 yeah but 028 would beat parts up it seems
@@CharlieBrown-pb9xn The manufacturer would not spec those values if it increased potential for failure. The last thing they want is tons of warranty claims.
Duntov 30/30 🤔🤔
3:01 NO SOUND CAN THIS BE REMEDIED IT'S TOO VALUABLE TO MISS.
The rocker ratio in all my engines is 1:1. They're all cam-on-bucket DOHC...
👍💪
👍
I'll buy a whole engine with the money dave spends on a two piece timing chain cover.
If you have to change cam timing often, for R&D as they were doing here, the time savings are important.
And so you might but what will we learn about cam timing and rocker ratio characteristics - my guess here -- nothing.
Does anybody else hear weird distracting background music while DV is talking?
Yeah, for some reason he insists on adding that distracting spooky music. It adds nothing but distraction and technical audio problems over an otherwise outstanding video. I'd literally pay him to stop adding music.
Should be renaming these vids Power tech 23
Again problem with audio, the music is in one ear and the voice is in the other.
For viewers: if you're using earphones or headphones with a cable, you can slightly pull out the connector, this should turn stereo into mono and the audio will be much better.
Yeah, I don't get his insistence on including spooky music over really good content.
Dave's gotta quit bullshitting everyone. He's also gotta stop tooting his own horn.
OK ol'boy how about pointing out the BS so we all can see it!!!!
And if I stopped pointing out where I, as a bonified research engineer with dozens of patents, am coming from I would have guys LIKE YOU criticizing this writer (ME) who has all these wild ideas but YOU SEE AS HAVING no experience or proof of what he is talking about. Also I bet you were the one responsible for the single 'dislike'.
I think you need to do a little ( on second thoughts maybe more than just a little) self analysis. before criticizing others. DV
@@marvingvx1 "as I a bonified engineer" lol
Replace "bonified engineer" with 5hp part salesmen.
@@billbraski2175 Please let me know what 5 hp parts I 'sold' in the video!