I did the exact same thing on my SBF TW170 heads years ago and flowed them - found a gain of 15-17 cfm on the intakes. Definitely worth doing. Easiest flow you can pick up.

Awesome video Eric, truly shocking and super valuable info... Thank you.🍻

Your video is full of hidden and interesting tricks that only experienced builders can se. In this case I can see it and it is about laminated flowing gas and It would be interesting to see a dyno run with a set of heads not modified verses s a set that are downsized and grinded with 60 grit and flow-matched to the unmodified ones. Great video !!!

This is a great video!! This is the kind of things I always wonder about!! I've got my 781's, and have been thinking about smoothing them out like this, but had no idea if it would even be worth the effort. Looks like it might be worth a few hours of work to me!! Thanks for sharing this, great stuff!!

Great video Eric and yes I'd like to see dyno comparisons be very interesting.

Hey, thank you, this was a very interesting and informative episode.

Great video. I once removed a pair of cylinder heads, just cleaned the ports with abrasive rolls and that’s all I’d did. The difference I felt in acceleration was actually astonishing.

Great video Eric! I can imagine this would greatly improve even a set of stock cast iron heads as well.

I love the analogy and it's so so true anywhere and everywhere. I don't know where I got it from but for as long as I could remember I always wanted to be the best and no matter what I was doing I wanted to do it better than anyone around even the person I was learning from. I always found the hardest working most knowledgeable person and work right next to them. You put the work in then when it's recognized you get the raise or if it's not recognized and you think you're valuable, you go get that raise yourself. It's your responsibility no one else's. 🇺🇸💪🏻👊🏻🤙🏼

Very addictive gear head content,, thanks for sharing

this is the cleanup i was talking about on the ports and bowls on my blueprint 190 cc afr knock off heads when i called you on prices. which i believe should help my lower lift #'s more for my torquer 350 vortec hydraulic roller cam engine for my old 84 gmc truck. tks for talking about the ferrea valves i will want those to. when i bring my heads in. i am taking notes so when i bring them in you will have a idea of direction in am headed with my heads.

Unbelievable! I wish I had done this on my PRC 225 heads for my LS6!

Eric Cool stuff 😎👌thanks

Quite the surprise! I was expecting 5 cfm TOPS! I now know to do it.

All about the boundary condition and the dynamics CSA of the port. 👌

Thanx for all the great Vids. Really helped me understand porting.

Nice work my friend!!

Attention to detail pays off. Thanks

Great video Eric

Tyvm great info...with fact testing. Loved it

Really glad to see this, I've been wondering what just smoothing them out would do, if anything. Hope you get the chance to do a different set and see if a similar change happens.

Thank you, thank you. woW oh woW ! ! ! eric did a test of these heads and it is great to see the afr along side the brodix st1 227cc CNC head and the dragonslayer. This has to be one of the most iconic cylinder head flow tests of the internet. Richard holdener and David Vizard ought to have some insight on this also maybe some dynotesting these heads on 383 and 406 plus 420 ci Super magic begins on 420 cubic inch =O=mazing things happen in a small block :o) this is totally the sweet spot for max streetables for me because the cam lifts won't be insane versus springs in a daily driver. 550-600 inch lift for me probably max thank you on the street daily driver pro tourer i would think. Hope i am correct. Just need better than great springs and lighter weight valve train. What would you recommend on a max daily driver/ track car including rocker ratio that holds on to springs for a hydraulic roller like XR300HR10 or even as small as an XR288hr10? i know track car and daily driver are two realms that don't mix and crash like astronomicaL flying blue and red skullz when met, although i believe it is where true street is supposed to exist.

The blue cartridge rolls are Zirconia. and they are awesome. last several times longer than standard Alum oxide.

Great video !!!

Really interesting vid, thanks

That is kind of shocking. Good video!

Wow! I would expect some serious reshaping to get increases like that! OTOH, my stock 823s with your valve job we’re a bit better…on the intake, anyway. Still, if I had a SBC, I’d be looking hard at these heads!

Well, that’s HUGE gains from smoothing up a port but you have so much experience in porting that you know where to concentrate when you do the rough grinding to get the best shape around in the bowl area. A typical person with 0 experience may not know where to concentrate on UNLESS they go back and check out some of your older videos (which would be smart). Thanks for showing the process and gains. I agree this is the best bang for your money.

Great video thanks

It would be interesting to see what flow numbers change with your rough in porting and then polished.

I'd say I've seen results on anything from a moped to a big block. You can always find something to clean up. Depending on "how bad" it is to begin with is proportional to the gains you'll see.

Erica thoroughly enjoyed your video on the dragon slayers I had a set I had done like them myself agenda don't put them on my 421 and I was going to put in my 65 Chevrolet pickup but some crackheads broke in my garage and sold them for scrap aluminum speaking about trucks when you'll carry your truck back to the drag strip would love to see it run again oh by the way PS they stole the transmission and the radio radiator also and a 1,250 dollar converter

Nice work

On naturally aspirated engines absolutely, it's well worth doing 👌

Eric, after watching this video and the one you did on LS heads. I'm curious. Do you think doing this to a 862 head since its a rougher casting than the 706, will bring the 862 to the 706 flow numbers?

🤔 interesting. Great information once again. Could we see anymore flow with a mirror finish, for a gasoline direct injected engine?

Same thing with the high flowing Ls heads. You need cnc and the hand work if you want the best. I have been watching Billy the Kid on TSC(youtube). He has been beating every body with his AFR headed S-10 after upgrading old electronics spark wise with a very basic blow through meth carb.

I have an older set of Brodix Track 1 sbc heads. I think they are 225 or 230cc intakes. What kind of numbers would you expect with a similar cleanup and polish? They are going on a 434 sbc with motown block and 260/264 degree at 050 solid roller cam.

What would you recommend for a Gen-6 Big Block. I was really liking the AFR's selection but this has me wondering!

sorry fer silly questions were or are these heads gasket matched or does that mtter in this test or would gasket match only show up on dyno thanks

Seen on Justin’s channel where he had you look at some old heads that were on his little red vette. How long has that engine been together, seems close to 20 years old. Crazy.

Id like to see if that makes any difference on a stock ls3 head and with your valve job .

Quality stuff, subscribed.

Nice, ❤ video

I'm not a "qualified" aerodynamasist but have been fascinated by aerodynamics all my life with aero modelling.. & to understand that.. an aircraft can be made to not fly with the right (or wrong) placement of a simple length of string.. span wise turbulator.. then to look at your CNC ports with numerous axial ribs that would work exactly as an aerofoil turbulator Influencing vortexes within the port flow.. then it's logical to understand how the CNC rough port at times flows more than the smoothed port.. it's to do with the size of vortexes as they converge into the valve/valve seat Venturi at critical flow rates.. AT THE SEAT Venturi.. harmonics create a hammer effect

What you think, how this go as wet port? Because since early 90 heard, port has to be rought to atomize fuel etc...

On a EFI head the intake port should be 'rumbled' to prevent a wetted surface from the injector fuel.

Great content ! 🇺🇲🇵🇷🦊👍

Sir, what bargain head, cast in the USA if possible, would you recommend to replace the 2X hump cast iron heads on my 307 SBC? Thank You.

Sir I'm curious on you take on the Brodix 5.0 series 171cc heads with 55cc 2.02 intake and 1.60 exhaust. On a 331 SBF?

Eric, where are you getting your long shank stones????? I've used a set given to me for almost a year now and it's time for new ones. Stones are a necessary step in my opinion.

Great video. Have you done Hemi Hellcat heads yet? It would be interesting to see the flow you could get.

@13:46ish,, what's the dark line around the valve guide at the 3 o clock position? just how the light is or what?

Wow, 8 think what 8s happening, is that getting rid of any objects that reduce laminar flow is helping to have more of the port area move. A better valve job would help the low lifts almost to .200.lift. and then obviously port. shape.takes place the shape of the throat will also come into play as the flow of the port takes over.

What do you think it would be worth on a cast iron small block head?

Interesting. Glad the 4 hours I spent doing this wasn't a complete waste.

Yeah that’s a really impressive gains especially since you didn’t make the port any larger It just increased the efficiency so that should work damn good!! Awesome content sir!

What would happen if you tapered the guides?

Wonder what would happen if you just polished just the short turn after the 60 grit

Good video and one im glad to see i do just that to any as cast heads that come my way and i figure it would have to help ive smoothed some pretty boogerey stuff. Now you didnt mention the chamber i got some dart 230 sbc heads that had a boogered up chamber and i smoothed that out cause im running nitrous and dont want hot spots wondering if i gain power from it i know its safer. But these questions are just why i watch your channel keep it up i cant wait for you to get a dyno. Things will get real interesting then. Questions will be answered.

Back in the 70's and before. The hype to get better flow was involved in c.c. the heads and port and polish chambers to allow smoother flow of the combination of gas and air mixture to combust better. Well would you just throw mixing of a cake mix directly into the pan. No: Mix, first must be mixed thoroughly prior to cooking, correct?

I wonder how much this might help on an OEM iron head... I've got a set of Pontiac 6X4 heads on my bench I've been wanting to do something with.

Ask Richard Holdener to help you set up running both Brodixheads cause I’m sure he would love to help you out in this one. He seems like a really good guy.

I believe that some of these tricks that add a very few horseponies is like me picking up pennies Off Wally World ground today. Lot's of wishes but when the thing makes more than they can put to the glue they use on strips now, does it make the difference? I believe it is the skill of the driver plus many hrs. Of work that does so.

What will happen if you extrude hone those heads ?

Hello Eric, great Chanel, I need to flow some Studebaker 289 heads. Would like to go to a bigger intake valve, stem is .3437 @ 1.6562 Dia. , exhaust is 1.5312 I cleaned up the lip around the valves. Intake valve of a 1.875 will fit.. Any thoughts or input, thanks

But what happens to the fuel vaporization with the different surfaces?

Excellent video. I have a Falconer V-12 head going on a Chevy inline 292 with a 6-71, NOS. It's cast aluminum. Would you be willing to port it for me and flow test it if I sent it to you? The only flow numbers I have are 340I and 220E. Thank you for your time.

Improves idle and partial throttle response

It helps flow but does it help Fuel mixture and puddling I’d like to see dino numbers

Rough surface ie 60 grit made more power not always more cfm over polished. This was because it promotes swirl and lamanar air flow. Fuel atomized better.A friend who built drag motors and ported for a nascar team years ago did similar tests and then dyno aftwards. He was friends with warren Johnson. I was amazed at the in-depth research they did.

Is it possible to smooth a casting (and not do anything crazy) and LOSE flow?

impressive !!!

But what that work on a Chevy cast iron stock head that could be done at home versus the high-end store-bought aluminum race head

2v 4.6L Ford engine, port match the exhaust and clean up the bowls... WOW... huge difference. I am sure that is the basis for their 3V engine.

Dang... I should have done some work on my ports when I had my heads off during my build. I didn't do it because I was worried I'd screw it up and make flow worse. Oh well. There's always next build!

Thanks man

I Like your bench. I built a PTS and love it

Do I smell a dyno room in the future??? That would be a sure fire way to see what's up!

Before we get too excited, let's see the end results on the dyno?

Most flowing to what RPM ?

I think your intake needs to be a bit rougher for laminar flow and exhaust smooth so it doesn’t hold on to carbon

Though I don’t play with v8s for last 10 years every 4g63 head I touch I at least do this and polish the chambers to help with det. Seems to show nice gains as these heads flow good already.

For direct injection smooth ports are the way to go, the smoother the better. Switch that to a carb and a rougher finish is preferable, any would be power gain in flow are often lost to lack of atomization of fule.

Where are you located

Those results 100% fall in line with golf ball dinple porting. When you have a rough surface, it gravs air and causes a turbulent pocket of stagnent air. This pocket of stagnant turbulent air displaces moving air making the port smaller. This is the same thing that dimple porting did. In fact it's argued that you can use dimple porting as a way to avoid epoxying the floor if you need to raise it a bit. But that gets into a bunch of unknown variables. Anyways, i kinda expected this. On a GDI engine, i bet you could even get away with polishing the ports (almost to a reflective shine) since the ports dont atomize fuel in a gdi engine, and you'd likely see even more gainz, albeit minimal. So really, you're makijg the port bigger as far as the air is concerned even though you really didnt move any material.

I started out in aviation in the burr shop, picked up very good metal fabrication skills from then on out. I did this to my G 35 heads, using what I call a cobra profile and some Formula One heads that I've seen in the past. Everyone in the G 35 and 350 Z community says that porting your heads is a complete waste of time. They say that only porting the intake Plenum upper and lower is all you should do. I don't know if they have poor quality because of how they did their own, But after I dynode

question, if you do this on per say only exhaust side, (been thinking of an old 350 chevy engine wanting to just gain trq) would that actualy help in trq? engine is daily driver dont want to increase fuel use.

i see know how polishing the ports works >>> the valve guide seem to interfere to can they be shortened to ???? or is it set n stone you carnet cut them down

Did you 60 grit the exhaust ports all the way? Looked like it was just done to the cnc blending. Wonder how they would compare to the cnc ported heads if the whole port was smoothed.

VOLUME AIR FLOW is one thing, great if you've a fuel injected motor BUT, it's not all about getting in more air or fuel !!!.....It's about getting the MIXTURE better vaporised so that it burns better and produces more power.. Why do we dope 2 stroke fuels with IPN ? well it's to increase the flame speed so that the oil that slows the flame speed that is preventing optimum power , can be coated in molecules of ISO PROPYL NITRATE (only a tiny amount is required for a big increase in performance), this increase the flame speed across the fuel oil mixture in the cylinder and helps the combustion burn completley by setting it all on fire faster. thats why twin spark plug heads work better than single spark plugs... 2% mix will give 20% more power in a two stroke engine, then it trades off so don't go running 50% IPN.. been there done that. so why am i talking about two strokes ? well as just explained, by using a chemical in this case to get a more complete and faster combustion you get more power..for the same amount of fuel... so by having a turbulent ( not restricted) airflow, the swirling effect can help mix the droplets of fuel even further than the carburettor has done so far.. way back in the 70's you could buy a disk with cupped fingers pointing into the center, to fit on the inlet ports.. the air fuel mixture that passes over the fingers redirects the condensed fuel into the main air flow but more importantly the wet fuel running along the walls of the inlet are also collected on the outer ring and fed down the fingers and remixed with air to produce a better vaporisation of the fuel.... The smaller the droplets of fuel, the faster the flame speed, and more complete the combustion of the fuel.. this applies to 2 stroke and 4 stroke engines alike.. This is why fuel injection workes better than a carburettor..The high pressure used to blast the fuel through the injector causes the fuel to be very finely vaporised into smaller droplets. resulting in a more efficient burn, bigger droplets of fuel take more time to burn and are still being consumed as the exhaust stroke kicks them out !!! I would suggest that the real reason a partial DIMPLING works better than complete dimpling, is that the mixing effect of wet fuel running down the inlets is achieved better with this disturbance area and not enough to start slowing the main air flow. There has been a lot of other methods tested to sucessfully create smaller fuel particles that result in a better combustion producing more power and even less pollution.. Robin XXXX did this and got paid millions for his "invention" to keep quiet about it.. because the car manufacturers didn't want it to replace their investments in catalisers, to get cleaner emissions, and reduce fuel consumption at the same time... Perhaps if you did two areas , one at the start and another further along to create two areas where wet fuel can get thrown into the mix a bit better...This of course won't show an increase by taking flow measurements !!! but in DYNO TESTS that will show more power when the fuel mix is actually finer particles caused by the dimpling.. colin .

As a engineer you need a rough surface to create a pocket of air for the fast moving air to move freely with less resistance

🙏🏻

Do you happen to port LS Heads? What would the pricing be for a Stage 2 or 3 port job on them. They are stock casting LS6 243 heads.

So would this cleanup be like a stage 1 port program? I had them do stage 2 on mine wonder how they flow compared

That's all part of your Porting, yes

Those are some big ass ports.

As professional porter ...sometimes you go sit down, start from 0....and then wonder: ???? This is soooo familiar !!!!

My auto shop teacher did this to his heads in 1985. Some "new" ideas are not so new. 😊

Is extrude honing any better for heads as it gets places bits cannot?