Big Block air flow from small block heads
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- Опубликовано: 24 июл 2022
- Impossible though it may at first appear, here are the results of DV's efforts toward doing the finished porting on a set of UltrPro Machining 9 degree small block Chevy heads. Ultra Pro's CNC, 293 cc, 2.25 intake valve version goes to 440 cfm before 0.800 lift. Can DV match that. Guess you will have to watch this to find out!
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I would like to see you apply your magic to some gen 3 hemi heads. Love the information you give to automotive community. Keep up the good work .
I agree. Would be great to see what he could do to some apache heads.
Keep up the great videos and sharing the incredible knowledge man!! Ty
I loved the 1/4" ball around the valve head illustration 👌. Great stuff DV!!!!
👍😎 That's something you'll rarely see, but it's just good common sense.... Well, maybe not very common.
Always love your videos!
Love the work done to have the figures shown on screen and voiced over.
Hey David. Great to see your stuff.
Not a GM guy but I'm very interested in this build. It seems like a treasure trove of good information, don't leave any details out! We're all listening.
As always thanks for sharing your incredible experience. We are all better for it.
Mr David Vizard. Thank you for sharing all of your knowledge. Your books helped a lot in the begging of my career. I´m from Argentina. Looking forward to visit you when I travel to USA.
Thanks for sharing your experience and knowledge mr vizard. Peace
Thank you for this. Anxiously awaiting further...
Thank u David 4 shairing your wisdom....!
Fantastic Dr V
I have every confidence that you will achieve your goal.🤗
Hey David,
Tim here, miss my notifications of new vids, hope ur ok, you ARE one of the BEST wizards of internal combustion, and we still need you!!!!...REALLY hope all is ok......take care.....
Great vidja DV🤙🏼🤙🏼
Hello Sir, after 19 years in other work, I fell in love with machining and building small and big block bottom ends over the past 3 years. I have been recently moving into how to get the most out of the machine work I do in the bottom end, with top end modification, and I find myself having to learn more and more about thermodynamics (didn't even know the word until recently) and port flow characteristics from online college lectures and you. I read/research about 2 to 4 hours a day, before the machining day starts, but there is a limit to online resources after a while. I enjoy COPYING what you do with cylinder head porting, but would like to learn whatever I can from you, and gain a deeper understanding to translate it into a lifelong career across different platforms. Comprehension, not just mimicking. I have not seen any class listings on your personal site after checking a few months ago, but would be happy to watch any seminar you would put out. I will be turning this into an actual business soon as people enjoy my machine work, so it would be a worthwhile investment. Thank you for your time, from Florida.
where in Florida? i could use some work
good looking port, mild short turn radius, nice strait funnel over all shape. can't what to see what these do.
David. On the zoom classes, I myself find difficult and look forward to traveling to you for a sit down class room setting. Please don’t cancel the class room!
Thanks, Robert
I'd like to join the zoom seminar! Great work sir!
Holy Crap Mr. You are sharing proprietary information here! (adjusted 400 heads on an expanded 455 block does wonders on the hobby stock circuit).
Thank you DV! v/r wh
this is awesome shows the even if people say its not worth it some times u just gotta battle your way into the winning formula i will be watching closesly as im just starting my porting carrer that silicon trick will be used as thats awesome
Always amazed. You're a power tech videos. I like candy for me.
Thanks for video!
I made 7 mm air-intake on carburettor,for high pressure air.2 cm original.Used 0.35 nozzle,0.25 idle original.Started idle,went to 60km\h original variomatic gear.But didnt fire.Fuel-line melted on carburettor,extreme heat.But top heat-damaged,still in use,with f1 sound,become better,hardened.
Thanks!
Is the answer boost? Just kidding, I love your porting advice!
It's crazy that from the factory any port is Is inconsisted with the group.
... The Ford 302 EFI It's a good example I think it was almost 30 CFM difference from the intake Ports on the ends From the ones in the center and usually it's one of those cylinders that ends up going bad 1st.
The machining aspect of an engine is it's just as important as any kind of performance Upgrades.
With the same concept I made my 3.8 hp Sears Eager One edger engine Good enough to pass up my friend's 5.5 horsepower Honda Powered Mini bike.
It's all about the flow.
I've said it before and I'll say it again, I'm interested in your porting seminar. Regards Greg
YES! Zoom seminar. Please.
Here is a $2 tip for you David. Smooth on offers a expanding foam small cell silicone. 2 tea spoons of material will expand a port up to 360 cc. Once curred, just trim flush with fave of head. It's self skinning so the walls will come out smooth. Yet collapse easier for removal. It cost half as much as molding silicone and only requires a 10th of material to mold a port.
1" into the chamber is equal to .300 of lift, after .300 the valve tulip profile takes over until its completely clear of the incoming charge. At about .650+/-.
Some heads like the Cleveland head need less for the valve to completely clear the intake charge.
Let Andy know....that's his fuel mileage loss that will keep him from ever achieving 20mpg. Hemi heads tumble, don't swirl for larger droplets of fuel. = less fuel economy then his previous Windsor!
Those heads are semi hemi heads. They have angle and cant unlike a true hemi head. Because of that, I think that it can't help but have swirl and lots of it.
Which product is that, Smooth-On offers many products. I have an intake I want to map out.
Link plz - - I was gonna use RTV and package peanuts !!
Great information, I wish I knew half of what you knew about this stuff, I have a basic understanding on it and would love to join one of your seminars but my schedule conflicts with your zoom 1 to 9 schedule unfortunately, Do you have a website where you have thing's for sale like your books or ported heads etc.
Remember Road & Track magazine reported the cylinder heads of a VW Beetle back in the early 1960's. Appeared as an article in Road & Track on Volkswagen 1954 to 1972.
David, since I left racing (pro stock 86 then road racing 88) I have not see any trace of research or testing done to learn about the differences between accelerating airflow in the intake during the first part of the stroke and the decelerating airflow during the last part of the stroke vs the steady state provided by the flow bench. It was clear to me then that research in that direction was the way to go. At that time large dynos (800hp+) , in car data acquisition systems and computer engine simulation programs were just beginning to be available. I was sure someone would push into those transient areas and find some gains. NO ONE did as far as I can tell. WHY?
Since you are the only one I have seen, besides myself, that built and researched an isolated valve port and the only one I have ever seen mention pressure recovery leading to a CD >1, I decided you might be the only one to ask about this.
It seems everyone else is utterly unaware of the radical difference between accelerating flow in the first part of the intake stroke vs the decelerating flow in the last part.
Bill, That looks like a good subject for a video. Remind me in about 2 months and lets talk on the phone.
DV
@@marvingvx1 Dave OK, there is a lot of ground work to covey about it.
maximum low lift flow is good for low end/part throttle torque, and maximum power to 5500 rpm, but the problem with big numbers at low lift is, the ports also flow backwards. meaning more reversion, dirty intake tract and carbon buildup on the valve stems. the ultimate port would flow zero flow, no flow at all until .100" lift and then start flowing, that would be better. less reversion. on the exhaust side, if you could design an exhaust port that flowed twice the intake, you could then greatly reduce exhaust valve lift and duration, and use less spring pressure, that would free up horsepower. that would cut down on exhaust reversion of exhaust gases back into the cylinder. what most don't realize is ports don't flow only one way, they're always flowing both ways, and a lot of power is lost when they flow BACKWARDS, as side effect of efforts to get ports to flow better FORWARD. the problem with static testing on a flow bench is it's only testing in one direction. this is why Smokey Yunick invented, patented the SMOKETRON, a flow testing machine that would spin a complete engine using a huge electric motor, to simulate the engine dynamics as if it was running. That device is now in the hands of none other than BIG DADDY Don Garlits, in storage at his drag racing museum. Don and Smokey were friends. You can look it up on youtube, Don did a video. Reversion reduction is another reason why a boosted blown or turbo engine makes so much more HP, the highly pressurized intake tract eliminates reversion using sheer pressure differential, and the extreme cylinder pressure forces the exhaust out the headers with authority- which is also why they use a much wider LSA on the cam.
I wish they would take that exact port and chamber and put it in a head to fit the big block MOPAR.
Awesome information but since I'm into the small block ford cleveland luckily I can just use the factory 4V 351 Cleveland heads they already flow like big block heads.
David, I'd be interested in the zoom seminar.
Been a mechanic and racer since the mid 70s... Have had literally dozens of customers ask for porting work. How hard could it be? Well I inform them that if it was really as easy as it looked? there would be a lot more really fast engines.. I will blend bowls, open up pockets and that is about it.. Simply way too much time to do something that in the end has no value or worse, causes a loss of performance.. Today? you can buy CNC ported heads for less than the cost of a set of fully ported heads 20 years ago ($3500+).... I love that I can take a set of plain jane every day heads, toss them aside and bolt on either as cast or cnc ported heads and pickup pretty impressive gains... And then there are the internet guys today... everyone can port a head..... Yea you can but lets see it work when you are done.. Flow aint everything....
Great stuff. I’m interested in a zoom seminar. Would this be more targeted to enthusiast rather than pro level?
What would be a good filler in the passages on a cast iron head both intake and exhaust for street use? I've been thinking about the second scale on your degree wheel, so far ? I haven't come up with any more ideas. can't weight for your input on this. Thanks Fred
Got caught off guard and wound up 4th on the likes. Looking for the right phrase to acknowledge the Prussian Blue on your fingers.
Busy.
Prussian blue on fingers. Literally 'HANDS ON' work
👍💪
Are those valve seats contacting each other?
Do a video on how long it takes for reciprocating and rotating assemblies take to rev from idle to max rpm. Compare speeds by time.
Bloodviking
Hello Mr Vizard, I have been watching you channel since the beginning and Ford and Chevy have been the primary focus but wanted to know if you have ever played around with any of the 3rd generation Hemi heads? As you know they have a true straight line cross-flow design instead of the more common Ford and Chevy designs. Is the more complex valve train geometry worth the flow gains and if so why are they the only big manufacture doing it. Thanks Jon
what is the name of this port molding compound? where can I buy it?
Por que é gravado em mono? Se escuta a voz dele no canal esquerdo e o chiado do vinil no canal direito...
A bit off topic; my sbc 427 dart block AFR heads with AFR eliminator intake sucks oil from bottom edge of intake runners. I measured the intake to head gap and the two are perfectly parallel.
Should there be less gap at bottom edge than the top?
I’ve tried numerous different intake gaskets but all suck oil.
There isn’t any information about this on the internet that I could find and I know if anyone can tell me it would be you.
Hey David, What are you thoughts on a stock set of World Sportsman 2 heads for SBC?
I wonder what your wizard mind would think about DARPAs rotating detonation engine. new type of rocket.
I'm a small small block guy, I would put those heads on a 327 with 230 duration .5 lift cam range and I no that would make a lot of power.
Sluggish velocity it would be a low rpm dog.
Too much head for a 327. Minimum 400 cubic inch.
There are formulas for determining the cross section area of a port versus cubic inch and rpm range. Order an engine math book and crunch the numbers.
how does all the extra flow work with port energy that you talk about? at some point the air must stop flowing and just stagnate onto a big swamp of air?
watch part 3!
Boys, for those that don't know, you're watching a man, at the top of his field, and whose name could be mentioned in the same way as the likes of Harry Ricardo, Smokey Yunick, Bob Glidden, Don Losito, Don Garlits, Michael Schumacher, Igor Sikorsky and Hans Pabst von Ohain. Check out his books. I have been since I was a boy in the 80s. They helped me become a man. My wife even agrees.
Roy - I sure love your comparisons but I think I might just find it hard to live up to them - but gracious thanks anyway.
DV
@@marvingvx1 You're already there in your own way, so no need in trying, you'll always be a legend with them all.
what does that have to do with Bruce Lee?
lol!
'Boys, big man here"!🤣
meanwhile ...a turbo Civic leaves him at the pump🤪🤣
'Boys!'🤣
@@marvingvx1 good thing? he probobly smelled them!🤣🤪
@Evgeny Hulkanon F the so called FORUM. This man has made his own WAY
cant hear you talking can hear everything but David audio this is true on several of DVs vidios
David Vizard, did you use a formula to come up with the 1.312 radius for scalloping the combustion chamber around the exhaust valve? If so, was this formula the same as what you showed us on the 2.2 head?
I'm interested in doing the 10 porting seminar in person. Perhaps I'd do an online seminar, if the price was _drastically_ reduced. Would you be interested in doing 1 on 1 zoom chat, for perhaps maybe an hour for $100 or so, or something along those lines?
I'd pay a fee just to listen and have no input at all.
Only sound on left channel. Can we have stereo???
pull your audio plug out a bit, you will see.
We do that by turboing
What do you know about multi valve heads?
Lots!
@@marvingvx1 somebody already ported the heads on my trinity engine (5.8L), but I'd like to hear more about it.
David, 99% of your content concerns 2valve V8 motors. Why do you neglect 4 valve heads? These are what most of the world uses. 2valve V8 motors are used in just a small percentage of worldwide performance applications. You say you know lots about 4 valve heads..... Then show us what you know.
Could you possibly find a way, to do a recording, and a Pay Per View to access that recording. That way we still have access, and you get funding. You wouldn't have to release it right away. I think there are many people who would pay just to watch for information like myself.
Might just do that but not right now.
@@marvingvx1 that's okay, I was just suggesting as an idea, I understand it would be quite an undertaking just to set up such a system. But I am glad you saw my comment. Thank you for all of the great information.
What's Zoom?
David's talking only comes through left audio channel...
pull your audio plug out a bit, you will see.
Veary well done videos good detail work . But the music 🎶 chamber maid got to GO. 🥺
Love your work but alot of your videos have bad sound or none. Would love hear what your saying. Thanks
I have told him he has a problem ...
today I pulled my audio plug out a bit and could hear very well.
@@ralphhbernstein6798 Ok thanks will try that.
Its simple to get big block flow numbers from a small block head. Step 1 just get some 4v Cleveland heads. Step 2 put them on and go spank all the chevy boys butts.
Alright,I know this is probobly not t right time or video for this, but my question is not somthing that I have seen before about porting/ exghaust, manifolds vs headers. It may be that expensíve headers can be had with square or rectangular gasket- to- head tubes, but Ive only got t round type myself. So while port matching the heads, what does one do? I'm in California where headers are no longer legal on cars after1975. I have a 1986 chevy g10 w/305. The only way to get anything out of it, is to get t exghaust open wide, then work on what will pass t smog inspection. So I will not be able to put t headers on until after that. But I can port match the stock cast iron... and then 'customize' them to a close fit with t tubular gaskets, making a square chunk of iron round on t inside shouldnt be to hard, within limets. But how to do the heads? I can only use a pre aproved RV cam, afterwards using 1.6 rockerarms when I swich too t headers & Holly. And thats about it. I will go to a 1.60 exghaust valve, and if t xtra lift is still alright, maybe sneak in a 1.98 intake, but thats it. I think. ?!?&%#@?
Please get a Stereo Mic. especially if doing paid for seminar's. Having only Mono-Left sound is not acceptable.
Stop complaining. I can hear him just fine
pull your audio plug out a bit, you will see.
440cfm? You must be on DRUGS! Even the best flowing, ported Hemi heads don't flow even 100 cfm less than that!
Stock? Let’s skip to the Edelbrock head that at .700 delivers 429 cfm.
Address the valves and the valve job, I think we can get where we need to be…. 440 cfm.
Grant - you have every right to be a sceptic here - if I did not know better I would be also. And thanks for a civilized statement of opinion.
@@marvingvx1 I want to apologize for my toxic comment. I should have been more tactful. In all honesty, I have never seen any flow tests that show a head getting anywhere near 400cfm.
@@GrantOakes look at some gen 3 hemi heads from livernois, or thitec. They get flow numbers in the 400s.
@@GrantOakes I have seen heads flow in the 400s. Big flow numbers are not a guarantee of the most horsepower
Thanks!
Thanks!
Thanks!
Thanks!
Thanks!