Man this I right up my ally. Thanks for the detailed information. Freshing up a good running 76 350 my 17yr kid just got. Probably put these on it but not before some work. I still look at your books I bought years and years ago at a speed shop but these videos now are so great.Thanks
I have a few of his books and learned to port years ago. His older sbc books helped tremendously and my 355 sbc na made just shy of 500hp at 7rpm. Ported a set of old 292 turbo cast iron heads comp cam 306s vic jr intake also ported plenum 750db carb.
Thank you, thank you, thank you... l have restored cars my entire adulthood, and have recently built a 355 using these heads and running the local 1/8 th mile track . Gonna freshen up this off season and these porting tips are a God sent.... peace to you
Another great job of course!!!! I just watched your 2 hour video from the 80’s or early 99’s and thought it was fanatic! Can I just say the music in the background is a little interrupting. I’m not by any means trying to be a jerk lol. I love all your videos and built my small block chevys in the early 90’s with your book. I still have it amongst many others. I am about to start working on my old school Dart Pro1 215’s. Thank you very much!!
Thank you David for your expertise. I've been a mechanic and rebuilt engine's. But i never got deep into high hp and torque engine's. The engine's i built ran ok for me at the time. So i thank you
Gents, first I sincerely appreciate the channel. I find it hard to pick up all the words that David speaks. I would recommend no music in those areas where David is "teaching." Save the music for any fast forward, or time lapse sequences. I think it will improve our ability to understand David. All the best!
@@DavidVizard Thank you for understand the spirit of my recommendation David. You are such a gentlemen sharing these life long, and hard earned experiences. I bet the young men are so grateful for these "classes." Wishing your new channel great success. I would also recommend putting something in the "About" part of the old channel, and in the "dublidoo" of the last videos on the old channel, pointing to your new channel if you can.
Mr. Vizard @ 24:52 does that knife edge on the spark plug port cause a hot spot on the head or make you think about using colder colder plugs after the modification? Thank you for these video you do, they are priceless to people like us who build one or two motors in our lifetime, we’d never know any of this unless we had a profession in this industry.
You just answered my question does a turbo charge need the port work to perform maybe a stupid question but under pressure versus vacuum does the gains multiply
@@harrymiller3986 Well kind of Richard Holdener has shown that how an engine runs NA it does the same under boost so if an engine makes 500hp NA and you run 15psi to it which is double atmospheric it doubles the HP so it would make 1000hp. So the more power an engine will make NA the more power it will make under boost.
Thanks for the reply watching the work you did on your daily driver is amazing I am sure when you’re done with the dyno room we will see you coming home with a flowbench
Great video, thank you for making this series, I really like running Vortec heads for the street and with a little more flow even better. Is there any chance that you will do a sbc 305 Vortec head porting series? The 305 Vortec with the smaller 58cc chambers is a whole lot different than the 350 Vortec heads, it would really be cool to see how to improve on those without messing them up. The smaller chambers in the 305 heads are closer to the older style chambers and there is a swirl ramp in the throat. The swirl ramp isn't as bad as the older swirl port heads, they actually flow very well for what they are, supposedly over 210 cfm from the intake side and it looks like they have better exhaust flow potential than its big brother when ported. Anyway thanks again for sharing your many years of experience and knowledge, looking forward to watching all the future videos you make, my favorite yt channel.
I have an an old article in a magazine done buy Hegelson on porting the Vortec heads. Can you give your opinion on that ? I miss him he did great work.
Hi David, just wanted to thank you for posting this video again in your rebooted channel. May I make a suggestion? As this is the rebooted channel and you are looking to rebuild your subscriber base, may I suggest you add something a little extra to your old videos to draw people back in to this channel instead of watching your old video in your old/new channel-or just continuing to make new episodes from where you left off? One update or bonus that you could throw into this video (like you did at the beginning of the video by mentioning this was one of your most popular videos) was perhaps adding the expected output like you did in your ford or ultimate porting video in the IOP program or Torque Master Program. There has to be something new or something more you can say about your old videos otherwise people would just watch the old channel. Don't get me wrong, this is literally one of the best videos and one of the first with very accurate Vortec porting information and that is why this video was so popular at the time and still racks up views today. And your follow up with the exhaust and comparison to the LS head was also amazing. Or maybe mention how this information supercedes the information in the your old How to Build Max Chevy Horsepower book-because I have a first edition (and 2nd edition) of that book from when I was first working on these heads and there was nothing in your old book about leaving that corner unported in the old book. I look back at those old pictures and that was something you must have learned later after publishing. But the bias in airflow at the end where you showed the port was in the book. But I digress. Thank you for sharing your knowledge. Just trying to draw attention to the fact that if you just republish your old stuff, your new channel might not show it in the search bar because your old channel with the same videos has a larger subscriber base and longer history and will probably show up first before this newer channel with fewer subscribers (even though you started this channel before the other channel.) For example, if you search David Vizard Vortec you'll note your old PowerTec Channel comes up in all the search results and this channel is just buried because your subscriber count and probably a few other things that go into the algorithm aren't there yet.
@@DavidVizard well at least you're subscriber base is almost where it was previously and moving at a good pace in just a few weeks! Thank you again for sharing your knowledge David. I have always enjoyed your books (I have an entire shelf of just your books) but your videos really bring your knowledge to life!
That's the same head I got from my engine shop to practice porting. Its a junk head and it was free so nothing lost in case I hit water or grind it wrong. I was looking at the heads I will be porting after I get some experience but they're Pontiac heads and they're different on the exhaust bowl. Stock Pontiac exhaust bowls look like they've been machined perfectly straight and have narrow 45° seats and has a lump of metal inside the bowl next to the intake wall and that's puzzling me because Chevy heads don't have that and I'm wondering if I should grind that off. It also has a lot of sharp machined corners. I asked Mr. Winegarden and he said I would be better off getting performance aluminum heads. I think he's right. After looking at these stock iron Pontiac heads they look awful and would be only marginal at best for improvements. The valve sizes are good 2.11 intake 1.77 exhaust but the exhaust bowl and port size is too small. Maybe I should have bought a Camaro instead of a second generation firebird. Or do an LS swap but I like being different even if I get my doors blown off 😆
pete mccarthy is a super stock pontiac dragracer ,and has done research on porting Pontiac heads,, sells his books and DVD on head porting,,easy to find online..
that part about 227 where it drops off is the most powerful part thats where the extra 40 hp hits 227 was where vortec tumble was about your first upgrade did realy good but when you went to 260 you pushed the tumble so high in rpm That it wont hit so you turned it into normal race head . The reason I know this is my 97 Camaro came with 561 96-97 lt1 heads I uncorked it with k&n trick flow elbow and all of a sudden at 5000 rpm a realy big surge of power would hit and just blow the tires off so it would Blow the tires at 221 cfm where the flow dropped off so car would smoke tires grab go through rpms hit 5000 rpm and blow them off so hard I wouldnt be able to use the power I port matched the Exaust Runner the exaust manafolds because i had to replace 1 seemed normal with little more gusto i knew the TB was holding it back so I gave it upgrade from 732 cfm to 807 . the Vortec tumble came in on throttle about 350 horse to the 280 made super fast hole shot quick 1-2 shifts were blast What I didnt realize was I hadnt hit the cam power range lol 3-6000 rpm is about 400 horse 430 torq at wheels Its overpowering 295 race tires ratcheting all rpms breaking loose and grabbing . What you did is what Chevy Did at the first discovery of the vortec tumble with the cop car iron lt1 heads they moved the intake runners higher in the head so straighter shot at valves. when the engineers ported them bigger the vortec disappeared so they left them small what they realy did was push them into higher rpm I am headporter engine tuner so this thing has been blowing my mind If you would have dynoed it after fist upgrade and after second upgrade porting Im thinking the first made more power than the 40 cfm especially with a exaust port match with the lt1 exaust hole D port cut in that chevy race heads incorporated into every head including SB2 that make them .2race heads testing all this I raced at a grudge night in 2022 with About 125 cars the racers at the track got to compete for the 2000 dollar purse My stock Camaro cleaned their clocks for the purse thats unheard of. tere is also a newer corvette LT4 box engine that beats the heck out of 96 LT4 but because they gave the newer LT4 head smaller exaust ports I think ill take it too because I did the bigger exaust ports after Grudge night And Im still running stock rockers and cam That first upgrade is worthy for its own Dyno for sure
Hello David, love the videos and the tech. In looking through your videos I wasn't able to find some pertaining to the LS heads. Do you have any on those heads. I know what you teach about porting heads will work with those heads too. But I would like to see what you have been able to get out of those. Thanks for the tech, very helpful.
I’d Love to see some porting on a Plymouth 383 aluminum heads just a little bit too much Chevy heads but VERY important porting to know for vortex heads!!
I have a set of bowtie heads from the 80s unmolested, they are pre vortec. Have you had any experience with these heads and is there any porting tips you can pass on? Thankyou.
I want to design my own head rather than just porting an existing one. The head I want to replace doesn't have much left on the table from the factory. If I design my own head I can put the ports and combustion chambers where I want them. I also want to change from inline valves to canted and rotated valves. I want to make an as cast head that doesn't need much to optimize the port flow.
Cut down the rocker stud bosses for guide plates and regular studs, tap rocker stud bosses, cut down valve guides for adequate lift, port work, valve job, flow testing, pressure testing casting integrity, milling decks clean, true, combustion chamber work before you buy new springs. easily wrap up $750-$1000 to pay for quality workmanship. Out of the box afr enforcer, or comparable is a real bargain, not prone to cracking, usually setup for hydraulic roller when ordered. And room to be ported later. We don't all own a flow bench, serdi valve job machines, or the tooling to mill the guides, rocker bosses etc.
You can do all of that with hand tools if you are patient and are willing to learn how to do it you can build a flow bench that works great for like 100 bucks UA-cam it considering you can get a Dremel a bit kit drill and a couple other tools and make a stock looking vortec head flow as good as some name brand aluminum heads you can get at the junkyard for 100 dollars it's well worth it 300 bucks in a set heads capable of supporting 550-600hp which is about all you are going to reliably get out of a stock block anyways it's super worth it just have to not be lazy
This was done a 28" of H20 lift----643's lift 561's Intake Exhaust Intake Exhaust .100---67 ---47 --63 --46 .200--121 --90 --120 --93 .300--170 --120 --170 --121 .400--205 --139 --198 --142 .500--206 --147 --201 --150 .600--205 --150 --202 --154 lift---cfm .050-30.1 .100-59.6 .150-84.1 .200-115.9 .250-144.2 .300-170.8 .350-191.4 .400-213.5 .450-223.4 .500-221.0 .550-218.8 .600-218.5 you see 450 lift its like Brake came on thats the after Burner firing up its not slowing tumble is hitting valve like SB2 this was covered up and over shadowed by LS family but was incorporated into their race head line the 561 was a stock verson of the Fast Burn .2 lt1 head 177cc intake the first lt1s 92-95 were Fast Burn Vortecs to but had some thing different might be a smaller exaust port
Very interesting THANKS. One thing I like to let you know is, the music on background is loudly this makes it more difficult to understand the spoken words from the very interesting lesson. Greetings Johan D. BELGIUM
Should use blue dykem, spray on head,install head on empty block turn block over ,scribe lines on head, never use a gasket as a guide, gasket are Larger than bore and can cause overhang and cause turbulance if you port to gasket size.
is it worth playing with these heads,, they also need spring upgrades over 450 lift and viton seals while your at it.. i never buy rusty junk from wreckers and spend money on what could be cracked. a new set will need work and brodix or simmilar are only $1200
when you thought you slowed it down you made it faster at tumble swirl was what you you mistook for lazy staying on top of they runner increased the tumble theflow cant swirl and tumble at same time one cancels out the other
I would like to see David just do a positive video. One that doesn’t need to point out everyone’s flaws. Just make your points and leave negative comments feelings out. If David could do that his videos would be much more enjoyable.
Man this I right up my ally. Thanks for the detailed information. Freshing up a good running 76 350 my 17yr kid just got. Probably put these on it but not before some work. I still look at your books I bought years and years ago at a speed shop but these videos now are so great.Thanks
David, when you mention any of the products you are using or any of the books you have written you should consider having a link for them.
I have a few of his books and learned to port years ago. His older sbc books helped tremendously and my 355 sbc na made just shy of 500hp at 7rpm. Ported a set of old 292 turbo cast iron heads comp cam 306s vic jr intake also ported plenum 750db carb.
What is the center line on that cam ?
@@darrellsomers5427 cam specs on the comp 306s is 110lsa 260/260@0.50 555/555 lift. Intake center line 106. I used 1.6 crane roller rockers.
@@cappy_skateboarding7920 You built a powerfully engine, right parts, right know how. 🤠💥
The master and commander of engine tech!!!
SO happy he’s teaching Andy Wood all of his wisdom!!!
You left out guide work short turn bowl work and area ruling in chamber your original series was much-needed info thanks again
The best information on cylinder heads. The entertainment is always great! Keep making these great programs.
Thank you, thank you, thank you... l have restored cars my entire adulthood, and have recently built a 355 using these heads and running the local 1/8 th mile track . Gonna freshen up this off season and these porting tips are a God sent.... peace to you
Another great job of course!!!! I just watched your 2 hour video from the 80’s or early 99’s and thought it was fanatic! Can I just say the music in the background is a little interrupting. I’m not by any means trying to be a jerk lol. I love all your videos and built my small block chevys in the early 90’s with your book. I still have it amongst many others. I am about to start working on my old school Dart Pro1 215’s. Thank you very much!!
Thank you David for your expertise. I've been a mechanic and rebuilt engine's. But i never got deep into high hp and torque engine's. The engine's i built ran ok for me at the time. So i thank you
Gents, first I sincerely appreciate the channel. I find it hard to pick up all the words that David speaks. I would recommend no music in those areas where David is "teaching." Save the music for any fast forward, or time lapse sequences. I think it will improve our ability to understand David. All the best!
Hey Mr. Big Moose, We are now doing exactly as you recommended but keep those comments coming anyway.
@@DavidVizard Thank you for understand the spirit of my recommendation David. You are such a gentlemen sharing these life long, and hard earned experiences. I bet the young men are so grateful for these "classes." Wishing your new channel great success. I would also recommend putting something in the "About" part of the old channel, and in the "dublidoo" of the last videos on the old channel, pointing to your new channel if you can.
Can't wait for you to get started on the LA!
Best teacher. Logical work. Make one change see what the effect was. I love it
Great information. Need to watch all the head flow vids again.
Love your channel so much information . Thank you for sharing all your wisdom ,passing it along to the younger generation .
Mr. Vizard @ 24:52 does that knife edge on the spark plug port cause a hot spot on the head or make you think about using colder colder plugs after the modification?
Thank you for these video you do, they are priceless to people like us who build one or two motors in our lifetime, we’d never know any of this unless we had a profession in this industry.
Your welcome
I Like How He Put It In Easy To Comprehend By Keeping it Simple !!!
I so need to build a flow bench!
You just answered my question does a turbo charge need the port work to perform maybe a stupid question but under pressure versus vacuum does the gains multiply
@@harrymiller3986 Well kind of Richard Holdener has shown that how an engine runs NA it does the same under boost so if an engine makes 500hp NA and you run 15psi to it which is double atmospheric it doubles the HP so it would make 1000hp. So the more power an engine will make NA the more power it will make under boost.
Thanks for the reply watching the work you did on your daily driver is amazing I am sure when you’re done with the dyno room we will see you coming home with a flowbench
Great video, thank you for making this series, I really like running Vortec heads for the street and with a little more flow even better.
Is there any chance that you will do a sbc 305 Vortec head porting series? The 305 Vortec with the smaller 58cc chambers is a whole lot different than the 350 Vortec heads, it would really be cool to see how to improve on those without messing them up.
The smaller chambers in the 305 heads are closer to the older style chambers and there is a swirl ramp in the throat. The swirl ramp isn't as bad as the older swirl port heads, they actually flow very well for what they are, supposedly over 210 cfm from the intake side and it looks like they have better exhaust flow potential than its big brother when ported.
Anyway thanks again for sharing your many years of experience and knowledge, looking forward to watching all the future videos you make, my favorite yt channel.
I have an an old article in a magazine done buy Hegelson on porting the Vortec heads. Can you give your opinion on that ? I miss him he did great work.
Unfortunaly Roger has passed, He was truly a great friend and never to be forgotten!
Hi DV. Thanks for all your videos. I have seen there always is a red or blue vertical line in the flow program. What is it for?
Is the original vortec head series still available? They had tons of good information.
Thank you so much this content you give is very useful just the best in the business❤️👍🙏
Hi David, just wanted to thank you for posting this video again in your rebooted channel. May I make a suggestion? As this is the rebooted channel and you are looking to rebuild your subscriber base, may I suggest you add something a little extra to your old videos to draw people back in to this channel instead of watching your old video in your old/new channel-or just continuing to make new episodes from where you left off? One update or bonus that you could throw into this video (like you did at the beginning of the video by mentioning this was one of your most popular videos) was perhaps adding the expected output like you did in your ford or ultimate porting video in the IOP program or Torque Master Program. There has to be something new or something more you can say about your old videos otherwise people would just watch the old channel. Don't get me wrong, this is literally one of the best videos and one of the first with very accurate Vortec porting information and that is why this video was so popular at the time and still racks up views today. And your follow up with the exhaust and comparison to the LS head was also amazing. Or maybe mention how this information supercedes the information in the your old How to Build Max Chevy Horsepower book-because I have a first edition (and 2nd edition) of that book from when I was first working on these heads and there was nothing in your old book about leaving that corner unported in the old book. I look back at those old pictures and that was something you must have learned later after publishing. But the bias in airflow at the end where you showed the port was in the book. But I digress. Thank you for sharing your knowledge. Just trying to draw attention to the fact that if you just republish your old stuff, your new channel might not show it in the search bar because your old channel with the same videos has a larger subscriber base and longer history and will probably show up first before this newer channel with fewer subscribers (even though you started this channel before the other channel.) For example, if you search David Vizard Vortec you'll note your old PowerTec Channel comes up in all the search results and this channel is just buried because your subscriber count and probably a few other things that go into the algorithm aren't there yet.
I would like to but I cannot acces the video's only the comment section.
@@DavidVizard well at least you're subscriber base is almost where it was previously and moving at a good pace in just a few weeks! Thank you again for sharing your knowledge David. I have always enjoyed your books (I have an entire shelf of just your books) but your videos really bring your knowledge to life!
Also looking for a good head for a 383 towing application
That's the same head I got from my engine shop to practice porting. Its a junk head and it was free so nothing lost in case I hit water or grind it wrong. I was looking at the heads I will be porting after I get some experience but they're Pontiac heads and they're different on the exhaust bowl. Stock Pontiac exhaust bowls look like they've been machined perfectly straight and have narrow 45° seats and has a lump of metal inside the bowl next to the intake wall and that's puzzling me because Chevy heads don't have that and I'm wondering if I should grind that off. It also has a lot of sharp machined corners. I asked Mr. Winegarden and he said I would be better off getting performance aluminum heads. I think he's right. After looking at these stock iron Pontiac heads they look awful and would be only marginal at best for improvements. The valve sizes are good 2.11 intake 1.77 exhaust but the exhaust bowl and port size is too small. Maybe I should have bought a Camaro instead of a second generation firebird. Or do an LS swap but I like being different even if I get my doors blown off 😆
pete mccarthy is a super stock pontiac dragracer ,and has done research on porting Pontiac heads,, sells his books and DVD on head porting,,easy to find online..
@@louisrichards3702 thanks for the advice that's wonderful news. Finally found some good info I appreciate it 👍
Would this apply for the lt1 head of the 90s please let me know I'm your but im willing to learn whatever I can
I would like to see someone do a port job on a cylinder head just 1 cylinder intake and exhaust
that part about 227 where it drops off is the most powerful part thats where the extra 40 hp hits
227 was where vortec tumble was about your first upgrade did realy good
but when you went to 260 you pushed the tumble so high in rpm That it wont hit
so you turned it into normal race head .
The reason I know this is my 97 Camaro came with 561 96-97 lt1 heads
I uncorked it with k&n trick flow elbow and all of a sudden at 5000 rpm a realy big surge of power would hit and just blow the tires off
so it would Blow the tires at 221 cfm where the flow dropped off
so car would smoke tires grab go through rpms hit 5000 rpm and blow them off so hard I wouldnt be able to use the power
I port matched the Exaust Runner the exaust manafolds because i had to replace 1 seemed normal with little more gusto
i knew the TB was holding it back so I gave it upgrade from 732 cfm to 807 .
the Vortec tumble came in on throttle about 350 horse to the 280 made super fast hole shot quick 1-2 shifts were blast
What I didnt realize was I hadnt hit the cam power range lol 3-6000 rpm is about 400 horse 430 torq at wheels
Its overpowering 295 race tires ratcheting all rpms breaking loose and grabbing .
What you did is what Chevy Did at the first discovery of the vortec tumble
with the cop car iron lt1 heads they moved the intake runners higher in the head so straighter shot at valves.
when the engineers ported them bigger the vortec disappeared so they left them small
what they realy did was push them into higher rpm I am headporter engine tuner
so this thing has been blowing my mind
If you would have dynoed it after fist upgrade and after second upgrade porting
Im thinking the first made more power than the 40 cfm
especially with a exaust port match with the lt1 exaust hole D port cut in
that chevy race heads incorporated into every head including SB2 that make them .2race heads
testing all this I raced at a grudge night in 2022 with About 125 cars the racers at the track got to compete for the 2000 dollar purse
My stock Camaro cleaned their clocks for the purse thats unheard of.
tere is also a newer corvette LT4 box engine that beats the heck out of 96 LT4
but because they gave the newer LT4 head smaller exaust ports I think ill take it too because I did the bigger exaust ports after
Grudge night And Im still running stock rockers and cam
That first upgrade is worthy for its own Dyno for sure
Hello David, love the videos and the tech. In looking through your videos I wasn't able to find some pertaining to the LS heads. Do you have any on those heads. I know what you teach about porting heads will work with those heads too. But I would like to see what you have been able to get out of those. Thanks for the tech, very helpful.
I’d Love to see some porting on a Plymouth 383 aluminum heads just a little bit too much Chevy heads but VERY important porting to know for vortex heads!!
I have a set of bowtie heads from the 80s unmolested, they are pre vortec. Have you had any experience with these heads and is there any porting tips you can pass on? Thankyou.
Sell them an get a set of vortecs , their good but can't compete with the vortecs
What happens if you open the port by removing the majority or all of the vortex just b4 the seat? Will it kill flow?
What was the size of the throat?
What a fantastic video! Thanks so much.
I want to design my own head rather than just porting an existing one. The head I want to replace doesn't have much left on the table from the factory. If I design my own head I can put the ports and combustion chambers where I want them. I also want to change from inline valves to canted and rotated valves. I want to make an as cast head that doesn't need much to optimize the port flow.
The Vortec head can be made into a Super Sleeper head! As DV has shown
Sure, if you have the equipment and skill to modify them. For us mere mortals it's cheaper to begin with an as cast aluminum head now days.
Cut down the rocker stud bosses for guide plates and regular studs, tap rocker stud bosses, cut down valve guides for adequate lift, port work, valve job, flow testing, pressure testing casting integrity, milling decks clean, true, combustion chamber work before you buy new springs. easily wrap up $750-$1000 to pay for quality workmanship. Out of the box afr enforcer, or comparable is a real bargain, not prone to cracking, usually setup for hydraulic roller when ordered. And room to be ported later. We don't all own a flow bench, serdi valve job machines, or the tooling to mill the guides, rocker bosses etc.
You can do all of that with hand tools if you are patient and are willing to learn how to do it you can build a flow bench that works great for like 100 bucks UA-cam it considering you can get a Dremel a bit kit drill and a couple other tools and make a stock looking vortec head flow as good as some name brand aluminum heads you can get at the junkyard for 100 dollars it's well worth it 300 bucks in a set heads capable of supporting 550-600hp which is about all you are going to reliably get out of a stock block anyways it's super worth it just have to not be lazy
Hello Mr. Vizard , where Is possible to buy your IOP program?
he was 80 when he started this channel He's likely passed on. his books are affordable pick a few up they should answer any questions you may have.
Cutting into the chamber is going to hurt the compression right??
Yes whenever you take cc's out of a chamber you will reduce the C/R. However picking up flow offsets that in spades. Heads make or break your power.
If u use forced induction that removal of the pinch port may gain power.
Bloodviking
This was done a 28" of H20
lift----643's lift 561's
Intake Exhaust Intake Exhaust
.100---67 ---47 --63 --46
.200--121 --90 --120 --93
.300--170 --120 --170 --121
.400--205 --139 --198 --142
.500--206 --147 --201 --150
.600--205 --150 --202 --154
lift---cfm
.050-30.1
.100-59.6
.150-84.1
.200-115.9
.250-144.2
.300-170.8
.350-191.4
.400-213.5
.450-223.4
.500-221.0
.550-218.8
.600-218.5
you see 450 lift its like Brake came on thats the after Burner firing up its not slowing tumble is hitting valve like SB2
this was covered up and over shadowed by LS family
but was incorporated into their race head line
the 561 was a stock verson of the Fast Burn .2 lt1 head 177cc intake
the first lt1s 92-95 were Fast Burn Vortecs to but had some thing different might be a smaller exaust port
Great tip 's Thanks as allways
Thanks David
What's the ideal port velocity for 4-valve ports?
Might be worth reading the info on here, grandprixengines.co.uk/, and this article grandprixengines.co.uk/How_many_valves_per_cylinder.pdf
320-350 fps
Very interesting THANKS.
One thing I like to let you know is, the music on background is loudly this makes it more difficult to understand the spoken words from the very interesting lesson.
Greetings Johan D. BELGIUM
Amazing! Thanks
another good way to take the chamfer off the valve is put it in the drill press an use a file on it
🥝✔️
Checking Powermax poyec x185cc
Thanks for this video.. i have vortec heads and after this talk theres no reason to Port.
Should use blue dykem, spray on head,install head on empty block turn block over ,scribe lines on head, never use a gasket as a guide, gasket are
Larger than bore and can cause overhang and cause turbulance if you port to gasket size.
is it worth playing with these heads,, they also need spring upgrades over 450 lift and viton seals while your at it.. i never buy rusty junk from wreckers and spend money on what could be cracked. a new set will need work and brodix or simmilar are only $1200
when you thought you slowed it down you made it faster at tumble swirl was what you you mistook for lazy
staying on top of they runner increased the tumble theflow cant swirl and tumble at same time one cancels out the other
Why not unshroud the valves at the back of the comb chamber. It's badly shrouded.
I hear a bit of an accent. But I can't tell if it's Aussie or Irish.
I don't have an accent - I'm speaking the King's English!
@@DavidVizard Well I suppose you don't then 😁
I certainly enjoy hearing you share your knowledge with us.
I have the second book but not the first😊.
10 days 🤔
I would like to see David just do a positive video. One that doesn’t need to point out everyone’s flaws. Just make your points and leave negative comments feelings out. If David could do that his videos would be much more enjoyable.
Bye Karen.
Very helpful video that would have been better without the repetitious back ground music
They are surperb
Does anyone else think that David Vizard looks like Michael Cain?
Devin off knight rider
Not at all
trun down the jam sozz a body can hear ya
Background music is annoying
Fantasic information. Thank you.