It doesn't matter how many times I watch one of DV's videos I learn something. You are doing the entire performance community a huge service by putting your knowledge and experience on this kind of format. Love the books but this is just a step from taking a hands on class. In a lot of ways its even better. Thank you Kindly Sir!
Showing the cut away sections of the head was a good way to show what you accomplished and where not to remove too much material on the floor of the port.
Excellent job explaining the information. Very good video but I could do without the music when I'm trying to listen to you. It would be fine at the end during your credits but not during the video. Keep up the good work.
Thank you! I have graduated from watching Summit Racing parts videos to watching David Vizard performance videos before I ever place the first bolt back in my first dismantled block. I know I have thousands of miles to cross in this educational journey but this channel is the much-needed boost to a naturally aspirated learning curve. I'm grateful for your legacy and your generosity to make and share these videos.
I probably would never be doing this , but it’s fascinating to watch a craftsman share a lifetime of knowledge, it inspires one to try their own , but like Clint has said “ a man has got to know his limitations “ Great video gentleman . It would be nice if high school, school classes could delve into these topics and prep kids for careers as engineers or race mechanics and broaden their horizons
Thank you David. Ill be looking for your live session with Tony. I have a suggestion to show how anyone can find the flow through a port with exspensive equipment. Recently ive hooked up a wood shop vacuum system to a 4" polycarbonate cylinder. When i turn it on with a adjustable dial for the valve lift. I then spray diluted marking dye from a spray bottle into the cylinder. It leaves a very clear marking on where the liquid flows inside the ports. Darker areas are where the mass of flow is making contact on the walls. Its amazing how much the valve boss area directs flow in the port. It literally becomes a ramp for most of the flow coming in from the intake side of the exhaust port.
What an incredible port design! Absolutely genius. Too much port hogging with no velocity happening. That's the difference between adding 25-30hp and 60hp. Awesomeness!
Great info and very well made but just so the young guys are aware, gen 3 hemi heads and the higher end LS stuff all flow 300+ CFM (426 hemi flow numbers and better than any big block chevy), you're starting at a much higher level just by using one of those engines, if you have the means. I believe the 392 flows 340 cfm bone stock and the 2009+ 5.7L eagle isn't far off, an engine you can find in any junkyard. If I was a kid on a budget I'd be going 09+ eagle and Holley EFI, it'll cost the same as a set of aluminum heads for a chevy. mopar or ford small block - and absolutely destroy any of them
Thank you so much, I have a set of Iron Impala LT1 heads that im porting out and machining for bigger valves. Im following your advice as much as possible with these because i know your right. Your books showed me Behive springs, how much valvelift i need, timing advance, lash on roller lifters etc. My first cam swap was a success over all because of your guidance and I know im still in good hands with these heads.
Been a long time fan ever since I first became aware of your talents and knowledge Mr Vizard "the Wizard" , Which was in the late 80's or the early 90's. Keep the content coming !
thank you dave,i followed your advice and did this to my vortec heads...i didnt go quite as far as you but definitely cleaned up the exhaust ports nicely and my sbc is alive and angry now.
I read one of your books before I started my aprenticeship. I'm now watching you while teaching the younger ones than me. My current apprentice is a lovely lady who seems to have a very food skill.
I give David VIzard A+ for theory & promoting his performance tech innovations. But quite often when it comes to live demonstration of what he is referring too & how do we get there I give David a D . Most of the time part 2 fallow up of whatever , never appears, Is RU-vid limiting him , or is the reason part 2 is seldom presented is because David wants the viewers of part One to be thirsty & purchase one of his how too books or sign up for one of his classes
David i have looked up to you since a teen. I went to work for a family friend who owned a automotive machine shop and was the engine builder /fabricator that built my dads two show cars.. I already had a passion for motorcycle 🏍 and motorsports off road racing got introduced to a dragster..got the horsepower bug bite on my own time that summer I between learning how to cut valve seats resurface heads ,guides,valves,I learned very quick the heart to performance was heads and cam centered . My uncle taught me how to work over a set of camel hump heads once he showed me the carbide cutting bits/sand paper rolls and a old 600series flow bench I spent all my money buying heads and sandpaper rolls carbide cutters long short and exotic lol bought a used flowbench and went to town made some serious big block power on stock casting for 1994
David: This is some of your best videos I've seen to date....I have a question: The quench area below the spark plug and above the valves should not be touched to a grand extent because the fuel will not be atomized. What are your thoughts on this?
Hi David, I built the 447hp sledge hammer budget build you designed the cam shaft for. The cam does not have a lot of overlap. Would these port mods improve my build or hinder it. (I did a mild clean up port job on the vortecs) Thanks. Love your video. I built my 1st motor using your how to build a sbc back in 85 with no engine building experience at all. Have since built many more after that. I am especially impressed with the 447 sledgehammer build. Cheers
The spark plug area looks a lot like the chamber wall that is typical of an open chamber Big Block Chevy head. I wonder if this will reduce chamber swirl as the block that used to induce that has basically been removed, less swirl could affect ignition timing .. of course if intake port swirl is improved (by more biasing ?) it would negate that ..... After seeing this vid i can see i need to spend a bit more time recontouring the valve guide bosses.
Do you port match the coolant passage also? I have a #906 Vortec head and there is ALOT of material within my blued scribe mark. Intake gasket is out of a kit. "Problem solver gasket" i was told. Plain metal core with black rubberized molded gasket around port.
99 percent of us would have a hole punched in this lol. ive been trying to take a little bit from each video and then i chose to watch these last and wow the amount of time he must have in these heads that he just cut in half is probably more time then im gonna have in this entire engine. would be an honor having a set of heads done by this guy but for a street engine most of us will never move air over .500
Hello, I have the head off my Toyota 1zz engine at the moment. It is a typical modern 4 valve design with the usual rough casting marks etc in the inlet and exhaust ports. If I was to try to smooth these down, assuming I do a decent job of it, am I likely to get a noticeable power increase if the rest of the engine stays standard or will it just make minimal difference?
Certainly not enough information im sure but what would you say about a 6000 pound 4x4 automatic trans truck with a vortec 350 that has .010 milled heads and .020 gm performance head gaskets and gm performance dual plane aluminum 4 barrel intake and a 650cfm carb and hei distributor (1.60" ehaust valves and 33* seat angles). Stock exhaust manifolds but free flowing exhaust after the manifolds My question is with those things considered what would you say to putting in a hydraulic roller 208/208 (or 208/212) duration @.050 and .420/.440 lift with 107LSA since i want to keep this a reliable daily driver i can still do truck things with and still have the engine last 200k+ miles?
Ive seen ones made out of old bbq grills from a garage sale or found at the dump. Honestly it works. I made an adapter and filter box for my flowbench so I could just port on it instead of making something that takes up more space.
I have two sets of aluminum heads I'd like to port, a max street effort head, (if there is such a thing), for a lot of TQ, 3400lb vehicle, with 385cid, for one set, and the other possible 406cid , with high velocity ,high efficiency, in mind for 2400-6800 with 585" lift on the 385, I would like to flow match the ports, I can't see having them professionally ported, when I'm capable, with guidance, you inspire me, I want to get back at it, after being unable after a car accident, I have been laid up for years not being able to do as much as I'd like! Thank you!
Edelbrock heads always seem to pull a little lower numbers than everybody else, if that's what you have then you probably have some room for improvement.
I would like to see dodge la motor done . A pro like you would I bet make a killer head. Would like to see the difference between the two to. Thank you for your work you do for this.
Wouldn't you be better off starting with a Magnum head ? The Magnum was developed right round the same time as the Vortec, technology of the day was looking at what had been learned from the TBI swirl-ports and improved chamber designs, if i recall correctly the LA head is a non quench smog head that is actually a step down from chevys gas guzzling open chamber 883 casting, sorry ta rain on yur parade. Check out the Magnums, see what ya think of those.
It occurs to me that port energy density is easier to calculate than port energy. Is there some reason to use total energy that doesn't show up when you use energy density?
Whats up with the subliminal frames? Look at 4.21. I don't know if you meant for that to be there longer but yeah. The video editing may need to be checked out.
"All'uu'mini'uu'm" English not Al 'uh"mininim American heads now I've started it!.... a pronunciation debate between the great continents of the world... :-)...
Would be a big help if you use sharpie markers to mark the port so we can better see what you are describing. The scribe is sometimes a bit vague. Other that that my head porting capability has already gotten MUCH BETTER..
