Super porting factory castings for aftermarket power.
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- เผยแพร่เมื่อ 2 ธ.ค. 2022
- In this, PowerTec 10 episode 31 DV goes into great detail on how to apply current hi-tech porting to early Chevy heads such as the 186, 049, 882, 041, etc, .In this video we look at just how m,uch power can be had from an early 186 casting. yes the casting is old tech but you will be amazed at what can be done by applying the lasted head porting tech. The motor shown in the heading shot produced 562 hp and 468 lbs-ft on a 11/1 CR. What was saved by doing the porting on a factory casting bought the intake, carb and camshaft which in this case was a 300 degree solid flat tappet from Howards cams
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That you give THIS amount of expertise, for free…
Is astounding..
Thanks David-
My old man is a master machinist and mechanic and has been building sbc race engines along time my first memories are handing him wrenches and helping while he was building race engines for late model dirt cars. In late 80s early 90s he was making 700hp sbc engines. So I’m lucky to have someone a lot like yourself who’s forgot more then it seems I can consume😂
Clicked on this this video and I said to myself "Oh, an hour long power tech 10 (10 means 10 minutes long) video. I'll probably take a brake half way through and do something else." DV then proceeds to keep me riveted through the hole video and I'm not even a Chevy guy! Can't wait for DV to do a seminar! Sign me up!
I LIKE YOUR VIDEOS BECAUSE I'M OLD SCHOOL. THANK YOU VERY MUCH.
My skilled friend always asked if we had tried to port a "Trapezoidal" type intake port. I was embarrassed to ask him what he was talking about. Looking at your intake profile I now know what he was alluding to....Stupid idiot I was. He is a guy who is well know by some people for making high HP...ported the cylinder heads for the Factory Yamaha MotoX team for several years. Thanks for sharing your knowledge. I own most of your books.😃
This is a master class in head technology.
I love seeing factory heads do work.
Rock and roll : Mick Jagger
Basketball: Michael Jordan
Internal combustion engine: David Vizard
Thank DV ! Long may you rein sir !!
This video is awesome. David is definitely a master at his craft. Amazing how he made a 50 year old casting relevant!
Love your last name! You must get this all the time, but I’ll say it here again, it sounds like a wizard. Mr. Vizard, you are definitely a physics application wizard! ❤
Another GREAT example of what hundreds of hour's learning on the flow bench & dyno will teach ya.
It's funny how many are still tunnel visioned on BIGGER is Better. You have Majority in disbelief just due to the 1.94 valve. Port volecity too many never take into effect...
Thanks for sharing as always my friend!
Have you ever given thought to partnering with a foundry to make a David Vizard designed cylinder head?
He could scan the port and chamber and do a CNC program for that head.
An excellent idea,!
I LOVE that idea! I bet they wouldn't be able to keep them on the shelf.
Yeah! Well i heard BRODIX is one of or if not THE LAST true family owned american usa engine business, and i am cite that as one reason maybe DV could consider it.
Imagine a David Vizard cylinder head design to be small block and big blocks of all manufacturer with sbf and sbc bbf bbc , and mopar first, then buick, pontiac, etc. With a 4 valve per cylinder-single ohv cam design for street apps first and foremost witch shall in turn translate to racing apps. Staggered valve sizes to mate with the bias of ports. And unstaggered street version and race versions.
Industrial and boat industry shall also want in on it. Like ADVAN and MAHLE with their new boat engines that have solved the inline 4 secondary engine imbalance limitations and now 30% more power is available, now boats with 6 to 8 engines only need 4 big high revving inline 4 cylinders! check it out in florida boat industry unveiling in 2024! imagine them in camaros with a BRODIX DV cylinder head!
I had a set of those 186 heads on my 350 cu. in. Chevy in the 70's ported by Kay Sissel with 194 intakes , that engine was a power house, thank you David enjoyed the schooling.
im so glad i saw this video i have a set of 186 ,maybe time for porting school😃
So 2.02-1.6 valves in a set of double hump heads actually hurts flow, yet every machinist out there says to put them in. What David shown us here makes sense. I've also done every mistake he said not to do. Lol live an learn.
So I'm starting to think my 2.05-1.6 valves in my double hump heads might keep being a conversion pice.
David this video reminded me of the articles you wrote in Popular Hot Rodding in the early to mid ‘80s on porting these head castings (and prepping the block) for a budget bracket racing engine. I used this article for a friends 355 with the 291 head castings back then. I see that as expected over the last 30+ years you have made new refinements to get the most from these heads but the main modifications are still very similar
It is amazing the amount of time you have put in grinding iron heads. It is really cool that you are old school enough you had to port iron. I have done some sets myself and stopped years ago due to the amount of time it takes versus doing an aluminum set.
Thanks for the content David l'm looking forward to see what you do with the 318 Mopar. 🇺🇸
Uncle Tony's garage Tony is a old school Mopar guy.
You know what no channel talks about heat
Thank you for the teaching Mr vizard you are the best
I can’t wait to see what you do to the 318 heads. I keep trying to see if you post anything yet. I think it will be big with a pro like you chopping at the heads getting the big numbers out of the motor. Thank you D V .
Straightforward explanation of complex subject material. 👍Thanks DV
David, there was a lot of work and time in what you have accomplished, thank you...
Excellent video Mr Vizard! Everything in this video pertains to every SBC I own😉
550 hp on a 302 is impressive. Surprising potential in those old castings, definitely improved upon with years of R&D.
Back in mid 80s NHRA Super Stock 302ci 11.5 to 1 compression 2.02 461 head match port intake into the head runner .250 max ,3angle valve rob, cleaned up combustion chamber factory cc. The heads CAN NOT be ported. 3250lbs 10.70 125mph. Same cast iron head 2022 full porting is allowed 10.00 130mph Z28 302ci Camero stock body. Got to be around 600hp.
@@jeroldlafferty54interesting. Thanks for info 👍
These were being built to 600 horse within a few years of coming out.
Awesome video. Thanks for sharing your knowledge. I've got a set of these 3927186 . I'll be 70 in couple months I'm having as much fun with these heads now as I did 50 years ago. Back then most people didn't have a clue when I'd talk about porting.. Anyway keep bringing it David 👍 gotta love old iron. Keep em on the road.
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,most go in and open shit up,,,,,not thinking about potential crack generations.......................I got DV's books........and I'm still learning......
There is so much that I can apply to my 50yo cast iron 4-banger with known exhaust port problems, similar to the old Pontiac and Chev 6-pot port issues. Time to get a practice head, some flow balls and start from there. Thanks David.
Best video I've ever seen on porting and flow. 👍👍
I concur!
Very cool - cause it’s factory heads:)
Thank you Sir David Vizard…
I'm happy that you made the Chevy 302 the subject around those 186 casting numbers those engines came with those castings anyway I'm a big fan of the 302 Chevy and many think that it's a waist of time building them but in reality they can run circles around a lot of engines in the quarter mile drag strip if properly built and in a good chassis car. Those engines were quite common in modified production and in the alphabetical lower classes which had even smaller engines, generally they all were capable of turning 9,000 to 11,000 rpms . If you could find some of those 90s videos from Rockingham with Brett Kepner the tower announcer at one of those super rod events, super rod is IHRAs modified production like NHRAs modified production you will see the times those cars ran some had to carry weight depending on the cubic inches and many were running high 9s to low 10s and I'm very familiar with those Lola T-70s and they came equipped with the 302 engine for the five litre class and that's pretty Ironic, because they couldn't sell a lot of those 302s in the Camaro in 69, 70, 71 and so on so those engines had to go somewhere and many ended up in the Lola's and in the South African CanAm muscle cars so they are still out there just somewhere else, I'd like to see you do more work with a 302 engine we all know that the 383 is trending today and anyone can build one even GM markets a crate engine, Jegs, Summit, Competition products and everyone else let's see you build a small cube Chevy or even a Clever or Windsor 289, or 302 and twist them on the Dyno and let's see what they can put out in today's era in performance parts
Wow, I can now improve my porting technique. Thanks for sharing.
Those were the heads to have back in the 70s but my first real set of good performance heads was a cast iron set of Lee Shepard 202 angel plug heads I had a solid lift high winding small block in a 67 camaro that picked up 4 tenths in the quarter mile in 1977 I payed $500 for them from a guy I knew who had a pair on his dragster. That was the most expensive part on my car and I pulled the heads off when I sold the car and put them on my 331 I had in my nova. I love street racing back then.... your friend from Louisiana Rick 427
I'm surprised there is no mention of the 462 heads. they have a similar chamber to the 186.
Good to know thx!
thanks dave another great porting show
Great content David, very helpful stuff
This was an excellent session ,thank you David from all us poor boy hotrodders,,,!!!
Excellent content, looking forward to Richard Holdeners Omni 4 banger and UTG’s / Unity Motorsports Garage 318 build as well . Keep up the good work.
Spectacular demonstration and explanation.
I'd like to see the comparison of the factory port vs the one you ported . Thanks for all the knowledge of porting .
The charts are pretty, question is, what cam specs are needed to take advantage of them.
Thanks once again David!!
You are the man David, thanks for sharing your knowledge 💯👍
...still learning....
Thank you very much 👍🏻👍🏻
I mean if the old casting has the ability to match the new geometry there is no reason it can't make the same power. the engine doesn't care when it was made.
Awesome content
Great job very good information.keep up the good work. Thank you 😊
Great information. Wish I had time for porting
I'm blown away that you achieved those results! Fantastic job!!
I love these videos, makes me want to scrounge up some old heads and get the die grinder out.
I have everyone of your books Dave, Great work is never done, Thanks a MILLION>
Great content I have a set of those heads did something like what you just showed on porting and had them on a sbc 383 with a 1107 summit cam pickup half a second on the quarter mile. Was very pleased with the results.
Thank you for sharing your knowledge!
thank you sir. you are a master of your skills and have blown my mind with info... I'll be processing this for a while... Thanks again...
Love the content. Will admitted I just getting up to speed. I'm building a mopar 5.9 for a 98 Zj limited. Want to keep it iron and get all I can out of it. Lots to learn from your shows
Thank you for this.
Wow, I have heard the name Vizard but now I know why! Such a clear and concise explanation and really made me feel confident about some of my guesswork which has been somewhat clued in by the late David Ijams in regards to port velocity and shrouding. I’m only building mild street truck engines and I have questioned running a smaller intake valve on a 1093 open chamber head and this is just enlightening to say the least. I’m probably not going to do that $$ but where I thought I was only going to focus on exhaust ports and valve face may be revised. Total noob machinist here 🥳🤣
great video thank you david
David Hobbs the bad ass road racing master!
Thank you Mr. Vizard!
Hey DV, so good to see another video!
One thing I didn't see you mention however, I thought I'd bring up...
...whenever I am going to work on any old engine part, I am a firm believer in chasing EVERY threaded hole before any other machine work is done, and before cleaning.
Learned behavior... I found that if I didn't do it first, it got left until the very last. After everything was done, and I was going to assemble it. Which means, I had to take a lot of care to not get any chips in anything (and not infrequently had to take things back apart for cleaning afterwards)
You probably already know this (and probably do it and just didn't document it on video), since you've been doing this stuff since before I was born - but mention it in hopes it will save somebody else a little bit of hair pulling on some project...
What product do you use for the port molding?
Professor David 'the humiliator' Vizard. Specialty; machining stock production passenger car cylinder heads & using them to outperform the best cylinder heads the aftermarket high performance boys can design & build. The David Vizard motto; "If you can design & build it I can better it!"
I truly appreciate this video. I’m building a 55 Chevy 2 dr post. I have been thinking about which of my blocks and heads I want to run. I have a 350/010 block with TRW .30 over. I have a 327 large journal in an 010 block I was thinking about building a 331 from. I also have a 283 setting under a shelf I’ve been waiting to build. I have a slew of heads including a couple sets of power pack heads (896s). I have several other sbc heads I am going to go through tomorrow and see what’s in there. Now your video really has me rethinking things. I’m disassembling the 327 right now and inspecting it. The heads that are on it are 032s. I’m not going to the drag strip in the 55 but I want it to haul tail if I can say it that way. Thank you sir for the great information!
Huge Hobbs fan!!! F1 isn't the same without him.
David is the man
If I had the cash and the time I'd like to drop a 4 inch crank in a 318 and build a long runner crossram intake to see how much low rpm torque I could get.
Got it 👍thanks again
Just imagine if Mr. David Vizard forged/casted his own line of cylinder heads and intake manifolds?
The performance/racing world would be a better place.
,,,,,,,,,,,,,,,,,,,,,,,,,,He is a master with the flow bench and comparing the data received.....No one in the industry has his experience........
Okay? @@ThomasELeClair
,,,,,,,,,,,,,,,,,,,,,,The man has been in front of corporation cyl development,,,,,,and they.........................do what they do,,,, ....
@@ThomasELeClairDavid is good. He's not the only one.
Was glued to the tv watching this one! Thank you again David for such a brilliant comprehensive review
With all the chamber cutting, how much has the volume increased, hence the compression ratio dropped?
Thank You .
Enjoy your content so very much. Would love to know what you'd do to a Alloy LS1 5.7L head
also, one of my late friends had an "open wheeled" "winged modified dirt track car and with a destroked 302, he won the feature and you could hear his motor on the track no matter where it was, over the others.... his tattle tail tachometer read 9,200 rpms!!!
Great Informationen next time i will work for better radius on fast flow side to the Chamber
First time subscriber I think this is a wonderful learning channel appreciate your advice and insight on cylinder heads that I am very interested in do you have anything on LS heads that I can learn
I loved your video and your explanations. I'm from Quebec and I want to modify a 283 SB CHEVY with a crank of 350, 6.125 rods and original heads # 520 of 283. Make a video on these heads and their possibility of modification would be very appreciated. I want to keep the look of the 283 even if I'm going to have 340 cubic inches.
Did you polish the water jacket side of the crack-prone area to stress relieve it?
I learned from this
Hi David,I appreciate the hands on knowledge you share with us on TH-cam, I am grateful.One question for you:Would exhaust flow better if the valve face had a convex shape to assist in directing the exhaust flow directly to the circumference of the valve?Just thinking.Thx David and looking forward to your reply
So if the plan is a racing engine that will be pushed hard, would it be worth it to get a set of 186 castings? Or would it be more economical to clean up an aftermarket set?
With low comp and .475" lift rule we made 580ish hp in ihra class 360 Mopar in the late 90's. Gezz with all this info we would have made 1000hp. 😆
WOW! That's a lot to think on. Nicely done. Any quick thoughts on roots blown head work? These would be 2V 351C heads we're working with. Where do you spend time and money? Thank you David. All the best!
David, if you were to put that head on an empty, upside down block, and look down the cylinder, would it be advantageous to have absolutely no overhang of the chamber over the cylinder edge adjacent to the exhaust valve?
Hi David ive got a set of BBC 702 castings. these are closed chamber bathtub style chambers (96cc ) If i do the same mods to the exh side quench area, blend and clean up the bowls , do a 3 angle valve job and some port work on the roof side, i should see atleast a 30-50 ft lb of improvement in the low end?
Very informative and interesting when porting cylinder heads do you ever change the way you port a head, for instance, Cam Duration lift lobe separation RPMs what you're using it for etc... Just Curious about that GODSPEED and Thank You for your wisdom
Thank you for. your great videos. But something goes not my brain, why do you leave the dog leg in. the exhaust port? Doesnt it hurt the flow? Marco
One thing I noticed is that a lot of the older sbc heads have alot more meat in them to hog out , like vortec heads flow better than double hump heads out of the box but when ported you get better flow out of double humps
I believe when I weighed them the vortecs were 10 pounds lighter .
Early 70s heads and blocks were that way
Love this kind of content! I would like to know how my IOP program can tell me if an exhaust port needs more bias as in the case shown here? Thanks for another great job!
Muy bueno los videos no inglés. Pero me lo traduce el celular y trato de aprender muchas gracias. DAVID
WOW 😳!!!!
He ant no sissy. Most premodonas will not work on cast iron heads.😩
The 426 ci engine flowed 302@ .600 with the iron 65 heads and 224@.600 The cam was .600 with the 1.76 rockers
Would love to see the results with the same head treatment on a 400 cubic in Chevy.060 over 10:1 compression with 770 cfm holley on Performer intake. Hydraulic flat tappet limit approx 6000 rpm.
How much chamber Cc will you lose when unshording the valves?
I am goone port like you Show hear Tanks four yor tricks hear👍👏⛄️🎄👍
You could have learned more about porting with this information then buying a set of after market heads...yes. Realizing modern day heads have these modifications done in the original sand cast. So good heads already have these mods (as cast)! From a business aspect. Man hours cost considerably more then buying the next size up cylinder head. This info is for guys on exstream budgets. Or restricted racers looking for maximum performance from a limited head.
When you can't lower the ramp of the short turn. Raising the floor of the port before the short side improves flow everywhere!!!!
I want to share an experience I have had with my small block ford.i put a 2 inch spacer under my carb,oh man what a difference. My problem is I can't run one cause I have no hood clearance. My car is a 1974 tvr I've installed a 347 ford.supossidly it runs 503 hp the car weights 1800 without me in it.Small block ford for ever
I have a set of 040 head are they similar to 186 heads they have no accessory holes
May i ask if these same pricipals apply to big block chrysler 915 closed chamber heads since they are very simular ?
What do you use to mold a port ??