Interesting flow results on the exhaust valve. Personally I look a lot at the lower lift flow because the valve spends more time in that area. It only reaches peak lift once, but goes through every other lift point twice. Getting a lot of air moving earlier increases the inertia of the air as the valve is closing, giving more cylinder filling. Well that's the way that I think of it anyway. But you undoubtedly have more experience than I do. Another great video Charlie. Hope you get better quickly. Regards Greg
My opinion, midrange lift (and low lift) does not equate to low and midrange rpm results. Low lift in those areas can drop horsepower. Depends on if the better valve and back cut improvement increases reverse flow especially from .05-.250". If reverse flow still is under check the low lift flow can allow a shorter duration cam to work equal to a longer cam.
Once that exhaust valve opens blowdown its important the valve head backside shape directing exhaust gasses out. Mind blowing what I have seen 1st hand.
You normally lap the valves to the seat to create a witness mark for placing the initial back cut. As you know you shouldn’t do a back cut blind. Good videos! 👍
Gooday A ! I use the back cut on valves after lapping them in to just reduce the seat width to the width I want the seat to be . . . It works for me . Thanks Motor Mouse
Been told by a World Infamous Pontiac V8 engie builder here in Illinois I have known since 1999 the biggest secret he uses is the exhaust valve shape backside of the valve or Tulip. Seen what Rick does. A Huge Radius Tulip that takes up all volume area with the valve closed. You would think nothing would flow out hardly on Exhaust slowdown stroke. But he did make 920 Hp True with a Pontiac V8 stroker 427 ci Old Wenzler heads 1 st generation 1992 year issue casted. Just 330 cfm intake flow. Something the Flow bench can not duplicate any True Exhaust gas velocity air speeds running and then turning 7000-9000 rpms. I swear the exhaust valves look like Smog Era Pontiac 455 exhaust valves but are Titanium.
Remember years ago during an engine master challenge a fella used bow tie vortecs with a 50 degree valve angle flowing 290cfm and made 606hp. Why isn’t the 50 utilized more…..
Interesting video and documentarie. I think Wet Flow comes into play in a running engine and has to be tested in the real world driving on the street and Racing at the track. On a Water Brake engine Dyno you can look at B.S.F.C. Numbers calculated printed off.
The 421 15 degree Chevy intake I did for D.V. got my texture and he did mention how good the brake specifics were while making 743hp. Too bad he forgot I did the work.
@@servediocylinderheads I like D.V. Staying out of. Cylinder heads and intake Porting is highly competitive. I have been at it almost 2 years now. I have building Street Performance and Racing engines since 1987. I am 52 now. I am a Corvette and Classic car Mechanic in Chicago Burbs now. Head Corvette Mechanic. Worked hard for decades fixing daily drivers and Diesel semi trucks to make ends meet feed the family 1st. Cylinder Head Porting and intake Porting a fairly new Hobby for me.
Nice, you mention the exhaust back cut increasing reversion. I know there are ways to get around that in certain applications with a 2 seperate or a “split” valve job? I was wondering is there legit testing that shows it to affect reversion around the entire valve or mainly on the short or long side? Could some type of pattern be machined somewhat like a 1 way parking lot barrier on the throat? Drive over one direction, the reverse causes flat tires. Or maybe a few rows of like a metal file pattern?
Charles thank you for going over this in so much detail. I watch all of your videos as I am starting to get into some head work in some engines that I am rebuilding for a couple old cars I'm fixing up. In a few of your videos you discuss the flow at high lift being improved, and I believe you correlated that to improved high rpm flow. Am I interpreting that correctly? Is it a specific correlation, or does a good low lift flow also contribute equally to a successful flowing port at high rpm? I appreciate any insight you can give. Thanks so much
Good question! Depends on who you ask and application. I don't work for low lift flow, it is what it is. I usually have an idea what I think the application needs high lift wise and shoot for that. Lots of low lift flow can increase reversion and lower the low rpm torque. It flows better in both directions.
There has been other Chatter talk by Famous Builders and Racers here on You Tube lately getting the exhaust out. Need that flow bench to test. But it's not fully accurate what is going on exhaust side any engine running. The old Timers talking You Tube. Develop a theory. Build it. Tune it. Test it. Then Race Hard.
@@servediocylinderheads Cylinder Head Porting is Awesome I am still learning from all the Pros online and You Tube, from small Independent home Porters also. I Surmise head Porting to pure physics and science along with Race math applied. Your able to create what you want exactly to meet your goals, budget, engine life expectancy. Often exceed your personal goals set, I did myself. Everyone has great ideas. Is anyone incorrect ? Perhaps Yes. Test. Build it. Drive. Race away. Try and Win !
Interesting flow results on the exhaust valve. Personally I look a lot at the lower lift flow because the valve spends more time in that area. It only reaches peak lift once, but goes through every other lift point twice. Getting a lot of air moving earlier increases the inertia of the air as the valve is closing, giving more cylinder filling. Well that's the way that I think of it anyway. But you undoubtedly have more experience than I do. Another great video Charlie. Hope you get better quickly. Regards Greg
My opinion, midrange lift (and low lift) does not equate to low and midrange rpm results. Low lift in those areas can drop horsepower. Depends on if the better valve and back cut improvement increases reverse flow especially from .05-.250". If reverse flow still is under check the low lift flow can allow a shorter duration cam to work equal to a longer cam.
Great information!!
Darin Morgan also said that it tunes air but really helps with wet flow...
Seem like a back cut valve flows better till they get to around .500 then it starts to fall off
Yep. I could knock the ssr down and pick up high lift flow but that would be expense of the rest of the flow curve.
Once that exhaust valve opens blowdown its important the valve head backside shape directing exhaust gasses out. Mind blowing what I have seen 1st hand.
So, I need to retest at a higher depression. Good idea. I should have thought of that. The radius should be helping. Thanks
You normally lap the valves to the seat to create a witness mark for placing the initial back cut. As you know you shouldn’t do a back cut blind. Good videos! 👍
I only lap before valve install. But I definately goofed on this backcut while designing this port. A little blue shows where you need to be.
Gooday A ! I use the back cut on valves after lapping them in to just reduce the seat width to the width I want the seat to be . . . It works for me . Thanks Motor Mouse
Been told by a World Infamous Pontiac V8 engie builder here in Illinois I have known since 1999 the biggest secret he uses is the exhaust valve shape backside of the valve or Tulip. Seen what Rick does.
A Huge Radius Tulip that takes up all volume area with the valve closed.
You would think nothing would flow out hardly on Exhaust slowdown stroke.
But he did make 920 Hp True with a Pontiac V8 stroker 427 ci Old Wenzler heads 1 st generation 1992 year issue casted. Just 330 cfm intake flow.
Something the Flow bench can not duplicate any True Exhaust gas velocity air speeds running and then turning 7000-9000 rpms.
I swear the exhaust valves look like Smog Era Pontiac 455 exhaust valves but are Titanium.
I shopped for tulip valves for this project. I like them. Yes, they weigh more.
This is true. That is killer hp at that flow.
With enough compression and rpm you can get hp to 2.7 or 2.8 x cfm. Of course a better head will make even more power.
Remember years ago during an engine master challenge a fella used bow tie vortecs with a 50 degree valve angle flowing 290cfm and made 606hp. Why isn’t the 50 utilized more…..
I have a set of gt40's coming with a special 50 degree vj for an 1/8 mile racer.
I thought a 50 degree seat was more for the purpose of sealing a really radical engine. Can there be
a high lift flow advantage as well?
@@andysteele4056Eric Weingartner likes 50 and 55 degree seats, nothing but flow improvement
It comes at the cost of longevity.
Harleys racing dept in the 70s (if I'm right) found that back cuts don't work in every valve/port configuration.
I agree. Thanks
Interesting video and documentarie.
I think Wet Flow comes into play in a running engine and has to be tested in the real world driving on the street and Racing at the track.
On a Water Brake engine Dyno you can look at B.S.F.C. Numbers calculated printed off.
This is one reason I like a backcut on the intake. Also why I texture the ports and chambers.
The 421 15 degree Chevy intake I did for D.V. got my texture and he did mention how good the brake specifics were while making 743hp. Too bad he forgot I did the work.
@@servediocylinderheads I like D.V.
Staying out of. Cylinder heads and intake Porting is highly competitive.
I have been at it almost 2 years now.
I have building Street Performance and Racing engines since 1987.
I am 52 now.
I am a Corvette and Classic car Mechanic in Chicago Burbs now.
Head Corvette Mechanic.
Worked hard for decades fixing daily drivers and Diesel semi trucks to make ends meet feed the family 1st.
Cylinder Head Porting and intake Porting a fairly new Hobby for me.
Damn kids.
HOWdy C-S-C-H-P&F, ...
Thanks for the DETAILS,
COOP
the WiSeNhEiMeR from Richmond, INDIANA
...
N.p.
Have you ever added a third angle below the lap line and into the margin? Let's say you end up with 30, 46, and 55 degree angles.
I have use a double back cut on some applications. Not after the seat angle. Thanks
lol did ALL THE FERRA measurements on the Ferra valves meet the specs YOU CALLED for? If yes- that would be a first.
These were not custom valves. I have had no issues with Ferrea valves.
Nice, you mention the exhaust back cut increasing reversion. I know there are ways to get around that in certain applications with a 2 seperate or a “split” valve job? I was wondering is there legit testing that shows it to affect reversion around the entire valve or mainly on the short or long side? Could some type of pattern be machined somewhat like a 1 way parking lot barrier on the throat? Drive over one direction, the reverse causes flat tires. Or maybe a few rows of like a metal file pattern?
The exhaust valve can get a ditch cut on the tulip part above the seat. It does weaken the valve.
Charles thank you for going over this in so much detail. I watch all of your videos as I am starting to get into some head work in some engines that I am rebuilding for a couple old cars I'm fixing up.
In a few of your videos you discuss the flow at high lift being improved, and I believe you correlated that to improved high rpm flow. Am I interpreting that correctly? Is it a specific correlation, or does a good low lift flow also contribute equally to a successful flowing port at high rpm? I appreciate any insight you can give. Thanks so much
Good question! Depends on who you ask and application. I don't work for low lift flow, it is what it is. I usually have an idea what I think the application needs high lift wise and shoot for that. Lots of low lift flow can increase reversion and lower the low rpm torque. It flows better in both directions.
I think I understand your goal now that you say it again. Thank you for the awesome reply
What's up Chuck?😂
Never heard that one before, sheesh.
Thanks. What are the part numbers please ?
Part numbers for what? Thanks
There has been other Chatter talk by Famous Builders and Racers here on You Tube lately getting the exhaust out. Need that flow bench to test.
But it's not fully accurate what is going on exhaust side any engine running.
The old Timers talking You Tube.
Develop a theory. Build it. Tune it.
Test it. Then Race Hard.
Old timers like me call it R&D. Race em and destroy em.
@@servediocylinderheads Cylinder Head Porting is Awesome
I am still learning from all the Pros online and You Tube, from small Independent home Porters also.
I Surmise head Porting to pure physics and science along with Race math applied. Your able to create what you want exactly to meet your goals, budget, engine life expectancy.
Often exceed your personal goals set, I did myself.
Everyone has great ideas.
Is anyone incorrect ? Perhaps Yes.
Test. Build it. Drive. Race away. Try and Win !
@@brracing7861 It is awesome and it is a challenge. The learning will never stop. Never the same thing either.
hmm you should have been able to SPECIFY the margins when ordering the fine ferrar valves. lol whether you got what you ordered is another story.
Thanks for the video. I forget what head that is.
Eq vortec. I should be clearer.
@@servediocylinderheads thanks
you forgot to tell us the manly vales are fine chinese products.
They used to be made here. Are they made over there now?
@@servediocylinderheads at least 3? yrs
@@samstewart4807 That is good to know. Thanks
That's a 20% gain?
I am no math expert, so is it?