As a student of aerodynamics everything you say makes perfect sense from an airflow standpoint. I really enjoy your videos and I learn a great deal. It's rare that you get free race winning knowledge from the pros. So every Vizard the Wizard video is like Christmas to me.
@@NotSure723 Neither is correct. Both are aspects of a more complicated series of phenomena that ultimately generate an aerodynamic force. Bernouli's principle explains why the pressure drops over a wing, but does nothing to predict or describe the vortex flow. Lifting line theory of Ludwig Prandtl(which in essence describes flow deflection) is also incomplete, along with the Kutta-Jukowski theorem, which was derived in part from the Biot-Savart law. Like I said, all are attempts to describe, and predict the forces involved in lift, all are just pieces of the overall puzzle. The real world is more complex that these frameworks would have you believe, regardless of how well they can approximate actual forces.
@@rolandotillit2867 That's great, but those ports aren't flowing just air - they are flowing atomized fuel. And an understanding of fluid dynamics would be far more useful.
@@CarsandCats Direct injection ports don't, cylinder wall wetting becomes the biggest issue you design around. Plus, don't you think I know that that fuel is involved? There's also much more air than there is fuel, around 12x as much air as there is fuel. When fuel combusts, the flue gas raises in temperature and has roughly the same density as the air going into the cylinder. Part of the reason why a flow bench can only tell you so much is because you can't replicate CC temperature and density by just flow benching.
The RPM head is basically what we have to run in NHRA Super Stock. 172cc max port volume, 57-62cc chamber and 65cc exhaust. Two valve packages 1.94/1.500 or 2.02/1.600.. They are raised and welded. Flow a lot of air and make crazy power on legal engines.
Dave you`ve played a big part in my prifessional life for about 3 decades, I`ve sought out your books to educate myself and helped me a positive direction, thanks Dave
I'd never seen his flowchart before, but he takes into account, energy as it is extrapolated from nearly every aspect ratio you could possibly measure and the effects of same. That's why I like this guy, the accounts for Concepts that nobody else looks at, and almost invariably building a better product. I don't think he's ever missed, but never say never.
After all these years watching and reading DV..(late 70's)...I think that was the most understandable testing and initial porting of a cylinder head...that my brain could understand. Thanks DV.
My take-away knowledge from this video is the port biasing and valve deshrouding as a relationship to each other for a flow path. Thanks for taking the time to produce these videos David 👍
,,,,,,,,,,,,,His explanations reveal what port bias is and the facts , because the intake and exhaust valves share the cyl. each one in a semi circle position above the cylinder,,,,.......Luv canted valve chambers and full hemi chambers in drag racing......
I been reading Mr.Vizard articles way back when. Now I lucky enough to watch these videos. Great teaching tool for me . Thank you for your time and effort Sir
No such thing as the "perfect" head - application always brings its own demands & limitations, and so this is THE channel to get pointed in the right direction. Take good, and make it better.
I'm a 2-stroke guy and I still found this presentation most interesting. I especially appreciated the level of scientific imperical data, measuring equipment and software being used. Doing it right, very impressive! Keep up the great work!
David , I'm a complete novice but able to just comprehend what you are revealing ! Thank you for this incredible education in this video ! I've read your articles for yrs and am truly grateful for all of your knowledge that you have shared with us .
Excellent stuff David. Glad to see your subscriber numbers have finally reached about what you had on your old channel. What amazes me is that you don't have 500k or more subscribers, but as a racer, that's probably a good thing. Makes it easier to beat the others. Looking forward to the next instalment. Regards Greg
DV is the best.I have learned and made better decisions on how to go about my build.This guy is the best of the best.I built my motor of his diagrams and HOLY SHIT!!!!.I love TORQUE and that was my goal.I tried my best to copy DV’s build and by all means I am no were even close to that man’s skills.This 406sbc AFR 195 is a MOFO on the street geeez.I did not expect this motor to do what it’s doing but I am more then satisfied.Every person I take for A ride in this 68 Camaro starts to cry when I stomp the gas and they get planted in the seat and scream begging me to stop.THANKS DV you the Freaken man I love this motor.
I had AFR 195 heads on my 407 sbc street ‘69 Chevelle and they were awesome. It had a TH400 trans, 3000 stall converter and a 12 bolt with 4.10 gears. I used to get home from work and drive sideways behind my house while nuking the tires. I’d get butterflies in my stomach from it beforehand because I knew how much fun I was going to have.
david, every time i watch your videos, you confirm thoughts and ideas ive come up with on my own and make me wonder if i might actualy have half a clue with porting heads.
Have the same set of heads on a 355sbc with an edelbrock 1551 blower way overdriven to make a little 7psi thanks to the flowing heads and a large cam. My heads are about 6yrs old, Intake ports on mine were the same, cnc first inch on itake and exhaust. Intakes on the larger 1206 intake gasket. Mine were not as smooth as those though had to do a bowl blend, and port matched the intake and exhaust a bit better, reshaped the chunky short sides and just general smoothing. Boy to they make power!!!
David, I'm so glad that I found you here on RUclips. I've read several of your books. I'll be watching a lot more of your videos. I have learned so much from you over the years. Thanks so much for sharing your knowledge!
Best explanations on porting I have seen. Thank you, David. I have a request; I have been told that Edelbrock and Holley use different methods to flow test their carbs and that Holley carbs actually flow better or more than Edelbrock carbs based on CFM ratings, is it possible to set up a flow test and test them both using the same method to have a side-by-side comparison.
I loved this one!!! It was awesome seeing WHY you do what you do. Seemed like you weren't even gonna touch the bowls until the flow dictated an adjustment. Hope to see that rebound on the curve on the next vid.
My first exposure to DV was in I think 1977. He did a series of hop up's on a Yellow 76-77 V8 Monza. I think it was in Popular Hot Rodding or Super Chevy. I had just purchased my 75 Monza 2+2...which I still have, I have been a fan ever since.
In my personal experience with the SBC Performer RPM heads, the original version with smaller ports ran well enough on 327-350 inch engines. When the heads were revised, the ports grew, and typically torque dropped some on those engines. But the revised chamber did improve combustion over the original chamber shape. While I realize the revisions over time were meant to accommodate larger displacement street engines that are typical, I found most customers at the price point of these heads could not afford the extra work outlined in this video. These days, pocket porting a pair of these with chamber mods and clean up could be another $900-1200 by my shop on top of the cost of the heads, depending on how far we go. At that price I would probably move upmarket, and look at AFR or Dart heads. Maybe I am over estimating the cost to do these mods, figuring around $125 per cylinder. Maybe I move too slow, and others could do it for much less. I don't dislike the Edelbrock heads, I just think they are at an odd price point for my customers.
AFR is hands down best bang for the buck Dart are good castings but their out the door machine work is shit and the valves in their assembled heads aren't anything I'd trust a build to Qauntico bare castings are a decent clone of the AFR heads but I wouldn't trust the valves in their assembled heads or their valve seat finish they usually have cutter chatter and need the seats touched up like Darts stuff
@@79huddy You missed the part about the cross sectional area and volume of the port. The Enforcer is the imported head, essentially a copy of a 200 cc Dart. The smallest Eliminator (made by AFR) checks in around 185 cc. The 327 really needs a head around 160 to 170 cc. It sounds like a small difference, but the affect on the engines character is significant. So really, the low priced imported AFR isn't the best bang for the buck here, because it's the wrong head for the application. I usually only get bare heads from Dart, not sure why anyone would do otherwise. The machine work on the bare castings is rarely a problem, getting the castings and the price is the tricky part.
Hello David, thanks for this great tutorial. Although I do not expect to start porting heads, you have given me an understanding of what to look for when buying them. One aside and a suggestion: Near the end of your video, in the up-close inspection of the exhaust port, you lost focus on the actual port, in favor of the back of your hand. Auto focus can be a problem at times. My suggestion would be to set your camera focus manually on the area of interest to maintain focus where you want it. Love your videos!
I always give the big 👍up's and I been subscribed already. You have so much knowledge and love your teaching. I really hope your channel grows very big and very quickly....Good luck!
Best Christmas I can remember for many years. For some reason RUclips cancelled my subscription👾 Binge watching the past 3 months of videos. Might have to have an extra day off work. Start the new year with a girlfriend and job, along with a load more information when it comes to building the new motor for next season😁
Always informative, I look forward to the results of your careful and thoughtful mods. Same heads in the hands of the average porter chasing flow numbers would probably be worse for the application they were intended for
Also those RPM performer heads on an FE Ford engine comes with huge holes to lube the upper end of the engine rockers stuff like that and at about 3,500 RPM you're pulling the oil out of the oil pan so fast that it doesn't even read on the stick. So you have to install restrictors to stop that so you don't burn your engine down. Also on the FE engine using those heads and the Edelbrock intake manifold there's not enough squish on the intake gaskets to stay put at the lower part of the port causing the gaskets to suck into the ports on de- acceleration with a manual transmission. The gasket issue is not a problem with an automatic transmission that problem goes away because there is a lot less manifold vacuum pulling at those gaskets on de- acceleration.That sucks literally. Those particular issues bother me more than a air restriction problem.
Mr. Vizard: The problem with you making decisions based upon your flow bench is that it doesn't wet flow. Dry air does not enter the intake port, atomized fuel does. And yes, that changes everything.
David, Can you evaluate the big block Chevy version, please? We use it in NHRA Stock and Super Stock. I'd like to hear what you think of the newest version of that cylinder head.
Nice. The one thing that I think GM engineers missed with where the ports are on peanut port big blocks. The ports are big enough to flow 300cfm theyre just in the wrong spot
Gm engineers didn't miss anything, all out wot maximum power was not their goal when designing them. Low rpm torque, broad usable power at part throttle with some amount of fuel economy, emissions compliance, and surviving warranty period were their primary goals.
I never did much with stock heads, but I always heard the larger chamber heads would flow better the the same basic head with small chamber, I can kinda see why they may think so, seems to me shrouding could become an issue, being less with small chambers, depending on the chamber design, and this was SBC heads I believe, because what else is there! 😆. Happy New year!!
If this is beyond your abilities and just want to bolt on some heads and make some decent power, of course AFR is a good choice! I've also found (and am currently running) are the Pro-Filer heads! You can pay a bit more and get the Pro-Filer cnc ported then they make awesome power! But their "as cast" heads are really a good head! This man has a lifetime of knowledge and is now sharing it with us!!! So cool to see, wish I could meet him in person and pick his brain a little bit!!!
Awesome vido and lots of good information, I like how you talk about price levels on heads, as not every one has unlimited funds for street engines, I build motors for mud play,snow plowed, towing, and always read about cylinder heads/ price/ and trying to find performance levels,is this the good choice of heads for truck/ play build but still street drive
Very interesting and informative, I'm reminded of Dr. Olds. Is it better to have large valves with low lift/duration or the opposite like Buick's nailheads?
DV THERE'S A SET OF SPORTSMAN II HEADS FOR 600.00 ARE THEY PRONE TO CRACK ANYWHERE? You have made big power with them does that sound like a good deal for my sbc 406?
An engine builder on RUclips has a couple of videos showing why you cant bolt aftermarket aluminum heads on the engine without first checking and cutting the seats so the valves seal. This was on a set of afr heads for a bbc. What are your thoughts on this?
Thank you for this video David. You lost me on the first half. I'll revisit it. Your flow test workup sheet (time 7:51) was out of focus and I was trying to make sense of what I couldn't see. BUT the second half of the video, how you measure the shroud area using the different size balls was fantastic.
I'm a bit confused is that's an e street head and not an rpm performer ? Edelbrock advertises more rpm capability with the rpm performers. Cost more too.
Hello again, David. I am planning to do some mods to my Nissan x trail 2.2 diesel engine and recently watched your vid on conrod lightening. I noticed that you lightened and polished the casting marks on the sides of the rod but did nothing with the "cast in" numbers on the indented sides of the rod. Why is that, is it because to remove them is more trouble than any gains made or is there another reason? Thank you so much for the benefit of your experience David.. Kind regards, Paul.
Thank you very much David for your videos. I think I'm starting to pickup on your teaching methods. I've never did any head work. My deceased brother used to do the heads for me so I never bothered to learn about porting, flow bench testing, etc. My goal is to become proficient in this skill and hopefully in time with watching your videos and reading your books I'll get it. I've been looking at purchasing a flow bench kit that's around $1,000 . It's not as elaborate as your setup but someone like me working out of my garage on my own stuff appears it would get the job done or, better yet, give me a better understanding of what I'm getting for flow out of my heads when I build my engines. My intentions are to build my own motors myself with the exception of machine work that I will have to send out for. What's your opinion? Should I make the investment?
Sure...all the bench has to do is show before after percentage of improvement. Doesnt have to be a super expensive piece. Youll become joined at the hip once you have it lol. Could open doors for you though for a side income. Everyone has to have those numbers
Has there ever been a situation where air flow from the center of the chamber side blocks the side where you work port bias? I see heads with veins on the guides and geometry that seems to be there to introduce twist to the swirl like a double helix. I can't believe that could happen at the speeds the column of air is flowing.
Calll me crazy. But what's the maximum Hp I can make with a 421 SBC. all steel 69 camaro cruising at 2000-2200 RPM at 60 mph. Running A/C in the summer.
If you're an engine builder this channel is like striking gold... Thank you David.
As a student of aerodynamics everything you say makes perfect sense from an airflow standpoint. I really enjoy your videos and I learn a great deal. It's rare that you get free race winning knowledge from the pros. So every Vizard the Wizard video is like Christmas to me.
What did your aerodynamics studies tell you about how airplanes fly, that Bernoullis is the dominant force creating lift, or is it air deflection?
@@NotSure723 Neither is correct. Both are aspects of a more complicated series of phenomena that ultimately generate an aerodynamic force. Bernouli's principle explains why the pressure drops over a wing, but does nothing to predict or describe the vortex flow. Lifting line theory of Ludwig Prandtl(which in essence describes flow deflection) is also incomplete, along with the Kutta-Jukowski theorem, which was derived in part from the Biot-Savart law.
Like I said, all are attempts to describe, and predict the forces involved in lift, all are just pieces of the overall puzzle. The real world is more complex that these frameworks would have you believe, regardless of how well they can approximate actual forces.
@@rolandotillit2867 That's great, but those ports aren't flowing just air - they are flowing atomized fuel. And an understanding of fluid dynamics would be far more useful.
@@CarsandCats Direct injection ports don't, cylinder wall wetting becomes the biggest issue you design around. Plus, don't you think I know that that fuel is involved? There's also much more air than there is fuel, around 12x as much air as there is fuel. When fuel combusts, the flue gas raises in temperature and has roughly the same density as the air going into the cylinder. Part of the reason why a flow bench can only tell you so much is because you can't replicate CC temperature and density by just flow benching.
@@rolandotillit2867 nice beatdown, bro.
Knowledge vs grabbing at straws.
The RPM head is basically what we have to run in NHRA Super Stock. 172cc max port volume, 57-62cc chamber and 65cc exhaust. Two valve packages 1.94/1.500 or 2.02/1.600.. They are raised and welded. Flow a lot of air and make crazy power on legal engines.
We’ve seen your super stocker heads, them things are a work of art.
Curious if you start with a machined Performer RPM or a raw head casting
David "Wizard. " This was the most in-depth flow analysis I've ever seen.
Dave you`ve played a big part in my prifessional life for about 3 decades, I`ve sought out your books to educate myself and helped me a positive direction, thanks Dave
Thank-you for taking the time to do these videos. You pack so much into each episode, just the straight goods, without a bunch of flashy bs!
David Vizard's books are worth their weight in gold! Every single one of them!
I'd never seen his flowchart before, but he takes into account, energy as it is extrapolated from nearly every aspect ratio you could possibly measure and the effects of same. That's why I like this guy, the accounts for Concepts that nobody else looks at, and almost invariably building a better product. I don't think he's ever missed, but never say never.
After all these years watching and reading DV..(late 70's)...I think that was the most understandable testing and initial porting of a cylinder head...that my brain could understand.
Thanks DV.
My take-away knowledge from this video is the port biasing and valve deshrouding as a relationship to each other for a flow path. Thanks for taking the time to produce these videos David 👍
,,,,,,,,,,,,,His explanations reveal what port bias is and the facts , because the intake and exhaust valves share the cyl. each one in a semi circle position above the cylinder,,,,.......Luv canted valve chambers and full hemi chambers in drag racing......
I been reading Mr.Vizard articles way back when. Now I lucky enough to watch these videos. Great teaching tool for me . Thank you for your time and effort Sir
David your books are what got me started in making horsepower many years ago. Great content you are producing these days.
No such thing as the "perfect" head - application always brings its own demands & limitations, and so this is THE channel to get pointed in the right direction. Take good, and make it better.
I'm a 2-stroke guy and I still found this presentation most interesting. I especially appreciated the level of scientific imperical data, measuring equipment and software being used. Doing it right, very impressive! Keep up the great work!
Thank you for the video,
best wishes for 2023
Always something to learn here ..
David , I'm a complete novice but able to just comprehend what you are revealing ! Thank you for this incredible education in this video ! I've read your articles for yrs and am truly grateful for all of your knowledge that you have shared with us .
Excellent stuff David. Glad to see your subscriber numbers have finally reached about what you had on your old channel. What amazes me is that you don't have 500k or more subscribers, but as a racer, that's probably a good thing. Makes it easier to beat the others. Looking forward to the next instalment. Regards Greg
Great explanation! I built my first small block Chevy with his book back in 1992 I’ve been hooked ever since.
Thank you David for this video perfect timing for my 385 stroker ! Your knowledge is amazing.
This man is a living legend
DV is the best.I have learned and made better decisions on how to go about my build.This guy is the best of the best.I built my motor of his diagrams and HOLY SHIT!!!!.I love TORQUE and that was my goal.I tried my best to copy DV’s build and by all means I am no were even close to that man’s skills.This 406sbc AFR 195 is a MOFO on the street geeez.I did not expect this motor to do what it’s doing but I am more then satisfied.Every person I take for A ride in this 68 Camaro starts to cry when I stomp the gas and they get planted in the seat and scream begging me to stop.THANKS DV you the Freaken man I love this motor.
I had AFR 195 heads on my 407 sbc street ‘69 Chevelle and they were awesome. It had a TH400 trans, 3000 stall converter and a 12 bolt with 4.10 gears. I used to get home from work and drive sideways behind my house while nuking the tires. I’d get butterflies in my stomach from it beforehand because I knew how much fun I was going to have.
Just re-watched. currently using these heads with some of your suggestions. Works for me
david, every time i watch your videos, you confirm thoughts and ideas ive come up with on my own and make me wonder if i might actualy have half a clue with porting heads.
Thank You David, your knowledge in engine building & AirFlow Research is not only Race Proven but Truely Unmatched.
,,,,,,,,,,,,,well said.................thanks....I got most of his books.....still learning....at 73....here....
Have the same set of heads on a 355sbc with an edelbrock 1551 blower way overdriven to make a little 7psi thanks to the flowing heads and a large cam. My heads are about 6yrs old, Intake ports on mine were the same, cnc first inch on itake and exhaust. Intakes on the larger 1206 intake gasket. Mine were not as smooth as those though had to do a bowl blend, and port matched the intake and exhaust a bit better, reshaped the chunky short sides and just general smoothing. Boy to they make power!!!
A very interesting combination that I had been contemplating.
Can you reveal what type of power you are talking about?
David, I'm so glad that I found you here on RUclips. I've read several of your books. I'll be watching a lot more of your videos. I have learned so much from you over the years. Thanks so much for sharing your knowledge!
Enjoyed the diagnostic approach to creating quality airflow, thanks DV!
Thanks
Great detail in this video. Appreciate you taking more time to talk about the program and where the numbers come from.
Best explanations on porting I have seen. Thank you, David. I have a request; I have been told that Edelbrock and Holley use different methods to flow test their carbs and that Holley carbs actually flow better or more than Edelbrock carbs based on CFM ratings, is it possible to set up a flow test and test them both using the same method to have a side-by-side comparison.
I loved this one!!! It was awesome seeing WHY you do what you do. Seemed like you weren't even gonna touch the bowls until the flow dictated an adjustment. Hope to see that rebound on the curve on the next vid.
My first exposure to DV was in I think 1977. He did a series of hop up's on a Yellow 76-77 V8 Monza. I think it was in Popular Hot Rodding or Super Chevy. I had just purchased my 75 Monza 2+2...which I still have, I have been a fan ever since.
In my personal experience with the SBC Performer RPM heads, the original version with smaller ports ran well enough on 327-350 inch engines. When the heads were revised, the ports grew, and typically torque dropped some on those engines. But the revised chamber did improve combustion over the original chamber shape. While I realize the revisions over time were meant to accommodate larger displacement street engines that are typical, I found most customers at the price point of these heads could not afford the extra work outlined in this video. These days, pocket porting a pair of these with chamber mods and clean up could be another $900-1200 by my shop on top of the cost of the heads, depending on how far we go. At that price I would probably move upmarket, and look at AFR or Dart heads.
Maybe I am over estimating the cost to do these mods, figuring around $125 per cylinder. Maybe I move too slow, and others could do it for much less. I don't dislike the Edelbrock heads, I just think they are at an odd price point for my customers.
Maybe that why I am broke... I dont charge anywhere near enough🙈
@@sniperpronerfmods9811 You are not alone my friend
AFR is hands down best bang for the buck Dart are good castings but their out the door machine work is shit and the valves in their assembled heads aren't anything I'd trust a build to Qauntico bare castings are a decent clone of the AFR heads but I wouldn't trust the valves in their assembled heads or their valve seat finish they usually have cutter chatter and need the seats touched up like Darts stuff
@@79huddy You missed the part about the cross sectional area and volume of the port. The Enforcer is the imported head, essentially a copy of a 200 cc Dart. The smallest Eliminator (made by AFR) checks in around 185 cc. The 327 really needs a head around 160 to 170 cc. It sounds like a small difference, but the affect on the engines character is significant.
So really, the low priced imported AFR isn't the best bang for the buck here, because it's the wrong head for the application.
I usually only get bare heads from Dart, not sure why anyone would do otherwise. The machine work on the bare castings is rarely a problem, getting the castings and the price is the tricky part.
This video was the perfect Christmas present!
Thank you
Thanks!
Terrific wealth of info here- can't wait for part 2!
Hello David, thanks for this great tutorial. Although I do not expect to start porting heads, you have given me an understanding of what to look for when buying them.
One aside and a suggestion: Near the end of your video, in the up-close inspection of the exhaust port, you lost focus on the actual port, in favor of the back of your hand. Auto focus can be a problem at times. My suggestion would be to set your camera focus manually on the area of interest to maintain focus where you want it. Love your videos!
Anyone who wears a button down shirt with 5 buttons open you know he’s a bad ass and knows what he’s doing
Been waiting on this he read my mind I just built a 383 from a L31 with these heads but 64cc chambers
DV, looking forward to part two! Right now I’m wondering if purchasing a better flowing head would be a better starting point.
I bought these heads back when they first came out in the 80s
I always give the big 👍up's and I been subscribed already. You have so much knowledge and love your teaching. I really hope your channel grows very big and very quickly....Good luck!
Best Christmas I can remember for many years. For some reason RUclips cancelled my subscription👾 Binge watching the past 3 months of videos. Might have to have an extra day off work.
Start the new year with a girlfriend and job, along with a load more information when it comes to building the new motor for next season😁
Another video chock full of usable information. Thanks, David.
Always informative, I look forward to the results of your careful and thoughtful mods. Same heads in the hands of the average porter chasing flow numbers would probably be worse for the application they were intended for
👍Thank you for the review and information
We used a pair of these heads on a 377 ci sbc that we drag raced a few years back. They move some air.
Loved this video. I'm thinking of using these on my next build.
Also those RPM performer heads on an FE Ford engine comes with huge holes to lube the upper end of the engine rockers stuff like that and at about 3,500 RPM you're pulling the oil out of the oil pan so fast that it doesn't even read on the stick. So you have to install restrictors to stop that so you don't burn your engine down. Also on the FE engine using those heads and the Edelbrock intake manifold there's not enough squish on the intake gaskets to stay put at the lower part of the port causing the gaskets to suck into the ports on de- acceleration with a manual transmission. The gasket issue is not a problem with an automatic transmission that problem goes away because there is a lot less manifold vacuum pulling at those gaskets on de- acceleration.That sucks literally. Those particular issues bother me more than a air restriction problem.
Mr. Vizard: The problem with you making decisions based upon your flow bench is that it doesn't wet flow. Dry air does not enter the intake port, atomized fuel does. And yes, that changes everything.
Thanks for sharing your knowledge DV
David,
Can you evaluate the big block Chevy version, please? We use it in NHRA Stock and Super Stock. I'd like to hear what you think of the newest version of that cylinder head.
Nice. The one thing that I think GM engineers missed with where the ports are on peanut port big blocks. The ports are big enough to flow 300cfm theyre just in the wrong spot
Gm engineers didn't miss anything, all out wot maximum power was not their goal when designing them. Low rpm torque, broad usable power at part throttle with some amount of fuel economy, emissions compliance, and surviving warranty period were their primary goals.
This was great info. Thanks David!
I never did much with stock heads, but I always heard the larger chamber heads would flow better the the same basic head with small chamber, I can kinda see why they may think so, seems to me shrouding could become an issue, being less with small chambers, depending on the chamber design, and this was SBC heads I believe, because what else is there! 😆. Happy New year!!
Thanks always great content
Thanks DV for the review. Have you or would review the big block ford 460 rpm heads ?
Thank you for all this valuable information.
Thanks 😊
David
If this is beyond your abilities and just want to bolt on some heads and make some decent power, of course AFR is a good choice! I've also found (and am currently running) are the Pro-Filer heads! You can pay a bit more and get the Pro-Filer cnc ported then they make awesome power! But their "as cast" heads are really a good head! This man has a lifetime of knowledge and is now sharing it with us!!! So cool to see, wish I could meet him in person and pick his brain a little bit!!!
great viedeo to see how to prepare a stock aftermarket part to better results
Awesome vido and lots of good information, I like how you talk about price levels on heads, as not every one has unlimited funds for street engines, I build motors for mud play,snow plowed, towing, and always read about cylinder heads/ price/ and trying to find performance levels,is this the good choice of heads for truck/ play build but still street drive
Awsome, can't wait for part 2
David have you done or would you be interested in looking into some ecotec 2.0/2.2 cylinder heads with porting?
Very interesting and informative, I'm reminded of Dr. Olds. Is it better to have large valves with low lift/duration or the opposite like Buick's nailheads?
DV THERE'S A SET OF SPORTSMAN II HEADS FOR 600.00 ARE THEY PRONE TO CRACK ANYWHERE? You have made big power with them does that sound like a good deal for my sbc 406?
I know I am not DV but those are decent heads and would be a good deal, can you take them to a machine shop and have them checked before buying?
They can crack but they are very tough, thick casting. I did a few videos on them and got them to about 300 cfm.
I have a set of these heads on a LA 360, new heads and motor never been fired yet; been sitting for a couple of years.
Small block Dodge exhaust ports are a superior design.
An engine builder on RUclips has a couple of videos showing why you cant bolt aftermarket aluminum heads on the engine without first checking and cutting the seats so the valves seal. This was on a set of afr heads for a bbc. What are your thoughts on this?
Great vid as always! Really enjoying your book.(How to build Max Perf sbc on a budget)Wish I would have read it before I had my engine built.
Great detail DV thanks!
Thank you for this video David. You lost me on the first half. I'll revisit it. Your flow test workup sheet (time 7:51) was out of focus and I was trying to make sense of what I couldn't see. BUT the second half of the video, how you measure the shroud area using the different size balls was fantastic.
I'm a bit confused is that's an e street head and not an rpm performer ? Edelbrock advertises more rpm capability with the rpm performers. Cost more too.
Great information as always mr Vizard
wouldn’t Edelbrock use an LS chamber by now on this latest
Edition?
This is invaluable information. An African saying is " When an Elder dies, you lose a library of knowledge".
Excellent content
i just bought 2 of your books. is there anyway you would look at my parts list for my 347 stroker engine i want to put in my 1990 ford bronco?
Hello again, David. I am planning to do some mods to my Nissan x trail 2.2 diesel engine and recently watched your vid on conrod lightening. I noticed that you lightened and polished the casting marks on the sides of the rod but did nothing with the "cast in" numbers on the indented sides of the rod. Why is that, is it because to remove them is more trouble than any gains made or is there another reason? Thank you so much for the benefit of your experience David.. Kind regards, Paul.
Thank you very much David for your videos. I think I'm starting to pickup on your teaching methods. I've never did any head work. My deceased brother used to do the heads for me so I never bothered to learn about porting, flow bench testing, etc. My goal is to become proficient in this skill and hopefully in time with watching your videos and reading your books I'll get it. I've been looking at purchasing a flow bench kit that's around $1,000 . It's not as elaborate as your setup but someone like me working out of my garage on my own stuff appears it would get the job done or, better yet, give me a better understanding of what I'm getting for flow out of my heads when I build my engines. My intentions are to build my own motors myself with the exception of machine work that I will have to send out for. What's your opinion? Should I make the investment?
Sure...all the bench has to do is show before after percentage of improvement. Doesnt have to be a super expensive piece. Youll become joined at the hip once you have it lol. Could open doors for you though for a side income. Everyone has to have those numbers
I would love to see you compare super Cobra jet and Cobra jet 385 series heads
Has there ever been a situation where air flow from the center of the chamber side blocks the side where you work port bias? I see heads with veins on the guides and geometry that seems to be there to introduce twist to the swirl like a double helix. I can't believe that could happen at the speeds the column of air is flowing.
Would like to see you do this with Pontiac cylinder heads.
Guy's give King David a like it helps a lot for the channel!!!👌👌👌👌👌
What would it cost me to have my heads evaluated in this manner and how do I go about it
How are the sbc Victor Jr 215 heads? 2.08 int valves. 64 chamber. 215 runners. They Only claim 284 cfm?
Thank you, DV! v/r wh
Calll me crazy. But what's the maximum Hp I can make with a 421 SBC. all steel 69 camaro cruising at 2000-2200 RPM at 60 mph. Running A/C in the summer.
I hear that you have an extensive camshaft selection program how could I contact you for a camshaft for an engine thanks.
Edelbrock ❤
Was part 2 made?
What brand spring compressor is that
Goodson
Heavy Duty Manual Valve Spring Compressor
model: CF-1500
Where can I obtain that flow bench program?
Looks like the indicator tip needs to be tightened up.
👍🤴Mr HP Wizard
You still havent told us how you did the ignition hack yet!
great stuff .
Could you please analyze a head of 1970s Mercedes Benz V8 6.3 or 6,9 ?
isn't it better to increase the lift so you get the flow and keep the chambers small than to grind the chambers and decrease compression?
I would think piston to valve clearance plays a factor in valve lift vs flow vs whatever other engine factors im not smart enough to think of. Lol.
Excellent, thanks
Amazing man
Vizard is a wizard