Great video I can tell this man has been working heads for a long time. There is a lot to learn from the old school. That said, can somebody get this man a laser pointer? We have moved past broomstick technology.
Greetings from Australia,Great insight Mark, thank you. Very few engine builders would share 'secrets' as you do. You're impressive on all fronts. I'm Currently building 496 with full CNC AFR heads 300CC ,with 260@50 solid roller.
Great video series. I'm an old guy. And still remember that at one time a 3 angle valve job. Was the height of what we knew about head flow. Me personally. I'm shooting for efficiency. Since smog big block Ford's. Have a major hump to deal with.
It’s time to grind. Thank you for the videos. You do a great job. I e hand ported a lot of sbc, but no bbc. My last set was a pair of darts. I had Todd Goodwin CNC port those. I’m going back old school again, so this is fantastic.
I put in a soaker tub once and was frustrated at how slow it filled. I took the faucet off and ported it like an engine. It flowed like a beast after I was done!!!
I mean, technically air is a liquid by definition. That's why the word aerodynamics is defined as the study of fluid motion and is still used to explain how planes fly.
Thanks Mark. This is knowledge that only comes with years of R&D work. Thanks for sharing your knowledge with us. The porting takes a special hand and eye to get it right. Can’t wait to see the port work!!!
What does a sonic thickness checker cost? And where to find one?? Great video, I'm debating on should I port my 94 7.4 Chevy heads, the engine is from a rv. I have a ovalport pergormer rpm I take and full length headers. A very similar engine made 330-340hp and about 450ft lbsTq. At a fairly low rpm. I'd like to get it to about 400hp. and 550 in the TQ! I'm curious about the truck heads, if they are worth porting? I know they are probably thin , of should I look in to some older model Heads. Maybe 70's heads I don't want to raise the compression much. I want it under 10:1, all though a 10.5:1 454 would be awesome on the street! But I want to run mid gtade gas. , and decent mileage, that is new to me. I'm used to getting by all the power and measure in gallons per mile!! I'm rambling , great video
I did get bench numbers from my 781's that I ported (first time porting anything). I'm curious what your opinion is on my numbers Mark. I'm using Ferrea 2.19" 1.88" back cut/swirl polished. The guy that ran the bench only flowed on port, and I'm not entirely sure which port. But here goes.... .200=151.5 ex 114.2 .300=283.2. 147.1 .350=266.1...???? 158 .400=287.5. 169 .450=297.9. 178.1 .500=306.9. 186.2 .550=307.8. 193.4 .600=310.1. 201.9 .650=311.3. 210.3 .700=311.3. 211.6
Awesome video. I understood that the 2.19" valve port would flow poorly but I don't know why. It makes sense by looking at it but I don't understand why it make sense. I have often had this issue where I understand why or how something works but couldn't explain why I know it if my life depended on it. Perhaps someone could explain precisely why or recommend a book that would help me to understand the basics better. I would very much appreciate it. Thanks
Pretty sure it's momentum and direction of the airflow. Air intakes rely heavily on momentum to "ram" more air into the cylinder. Larger openings means a reduction in that ram effect but a potential increase in flow capacity if shaped correctly. Its always a trade off between air intake speed and flow capacity.
4" is pretty much perfect. The longer the shank the less control you have over the tool. I have done hundreds of motorcycle heads and they are generally more challenging as the ports are much, much smaller so control is everything. I use Foredom foot speed control units...great torque to run at slow speeds to enhance control as well.
@@trailerparkcryptoking5213 Youre probably correct with the enhanced valve size that he used and other tricks, he is a VERY smart guy with that complete build, from crank and balancer updates to everything else. The rect. port VS the oval from back in the day had bigger valves, i had a 427/425 in a 67 Camaro so it was a Yenko clone and had the 2.19 intakes like the 396/375
You state that the modified port (as originally drawn) won't flow past .500 lift but fail to explain why. The statement at 9:28 lacks an explanation too. (I know why. Just pointing out the failure to offer explanations.)
ohhh ffs the greatest velocity of flow is at the center of the conveyance wether air or water change the damned valve so your air isn't running head long into it and the rest piles up behind it would you fit a large circular object to the front of your friggin cars to go faster and it would make a terrible spoiler. the valve is always the biggest problem no matter what shape you make it. the friggin slug in the intake is being slowed down by it
