Dude i know how you feel, I could ramble on about why and what I do to my motor all day. Its hard keeping track of everything sometimes. You have lots of good info to share and your very good at explaining, although, Id probably have a hard time understanding some if i wasnt using HP tuners for my LT1.
You can certainly match core shift with a cnc if you know what you’re doing and have a probing system in the machine. You could plot an entire port with probing, apply a macro shift program and end up with the same result. Just takes a decent bit of front end work and a high level programmer.
Unfortunately nobody wants to take advantage of features almost every machine comes with now a days. Couple of days of front end work and 5min extra cycle time would make all the difference.
I believe the term you were looking for when it comes to surface finish is "Boundary Layer". I usually use a 60-80 grit finish in aluminum and leave the last .080-.100" of the bowl (right next to the seat) burr finished. Remember, you can slow the velocity down over the short turn by widening it as well as raising the roof. Several heads out there don't have that much (if any) room to raise the roof over the short turn without running into cracking issues because of the spring pockets. L92/LS3 heads come to mind. Casting consistency can be an issue with any casting but most CNC programs leave a pretty safe margin as to not get into trouble......but that's also why there's more to be had out of those CNC'd heads. Cool Video BTW.
Does anyone have a contact or a link I'm wanting to do a cylinder head ports on 2 that have been welded up but I only have a 3 axis mill the head can move but it's on a quil so It can't be programmed on rotation.
Okay going to just make my point so clear somehow it's getting lost! I deal with "core shift" all the time on every type of casted part I cnc cut for all kinds of things for years! Heads of all kinds and other parts for all kinds of applications! Too say like it does in the video you can't cnc mill a head cause of core shift is silly! The machines use Gcode with sets of codes to use probes that sense every surface they cut and program in. Core shift means zero when a CNC machine detects the surface variations and makes corrections to the cut patterns to realign the tool path to make up for the core shift. I normally split the core shift in half to find center unless the part needs tlc because it's so one sided to again you input commands to set the machine up to correct for the variations or it needs to be aligned perfectly with the mating parts. Dealing with core shift is one of the first things every machinist leaners for adapt for that will mill casted items. Never nocked hand polished ports. Never said they are bad. What I said is I done over 5,000 heads on a cnc mill over the years of all kinds core shift has never been an issue unless it's a super badly casted item which even hand ports wont fix. Most modern cnc programs even have built in features to deal with it now so you don't even have to think about it except for some situations
I get what you are saying. Clark Trost also posted in here saying the same thing. Clark runs CNC machines for his business and him and I talk extensively. What I am saying is that even though the ability exists the heads I see do not have it done. You can tell the head is jigged up and the program is run regardless of where the valve seat and port location actually are. When you look in any of these ports it is explicitly simple to see that the CNC did not track at all where the valve seat was placed. When that happens you end up with very mismatched ports. If I said it can't be done then I misspoke. I mean in my 30 years I have not seen it done. I can track every head port left to right and top to bottom and NONE of them are the same. And that is just from the port entrance. Not even getting into where the seat and guide were drilled and placed. I hope that clears up my point.
As a machinist I’d say you’re not fixturing your heads right and you may not have very good programs the guides and seats are CNC machined from the factory
I don't CNC. But I have seen CNC ports from at least ten different companies and the results are always the same. Core shift kills them. The heads ar NEVER uniform. Also, GM usually gets their seat angle and second cut properly aligned. But if you machine in a third cut to the valve seat you will see how wonky they are. This is just my experience though. 🤷♂️
it's not just what the piston draws. how else would you get 120% VE? you do cram air. your philosophy on port shape and texture is off. make air turn corners? lol
As professional head porter I can agree with him on this specific head. Chances are that tricks he did on this type of head dont work as well as on other type of head. I have seen on different types of sbc heads the need for complete opposite texture and shapes. Sometimes a mirror polished intake with radius shaped seats worked best ( back to back tested) and sometimes aluminium carbide cutter textured port walls with 5 angle seats working best..... There is no rule which works for all.....
Dude i know how you feel, I could ramble on about why and what I do to my motor all day. Its hard keeping track of everything sometimes. You have lots of good info to share and your very good at explaining, although, Id probably have a hard time understanding some if i wasnt using HP tuners for my LT1.
You can certainly match core shift with a cnc if you know what you’re doing and have a probing system in the machine.
You could plot an entire port with probing, apply a macro shift program and end up with the same result. Just takes a decent bit of front end work and a high level programmer.
Which you and I both know never happens. No one mass producing ported heads does it. I see that in every single CNC head I get my hands on.
Unfortunately nobody wants to take advantage of features almost every machine comes with now a days. Couple of days of front end work and 5min extra cycle time would make all the difference.
@@clarktrost6271 so the point and content of the video stands. 😘
Never said the point didn’t 😁
@@prayperformance5137 chill bro
These are the best videos thank you for sharing some of your knowledge Brett🇺🇸👍
Thanks for the info! Dig the flags on the bottom side of TS’s heads
Doing a 416 stroker build n/a 2018 ss camero convertible....wanted to ask if your able to port factory heads within the next couple months
Fantastic video. Fyi, me personally, I enjoy long videos.
Ive been seeing this dumpling thing on a few vids wondered what your thoughts on it might be, thanks for the vid
Not long winded. All good stuff.
I believe the term you were looking for when it comes to surface finish is "Boundary Layer".
I usually use a 60-80 grit finish in aluminum and leave the last .080-.100" of the bowl (right next to the seat) burr finished.
Remember, you can slow the velocity down over the short turn by widening it as well as raising the roof. Several heads out there don't have that much (if any) room to raise the roof over the short turn without running into cracking issues because of the spring pockets. L92/LS3 heads come to mind.
Casting consistency can be an issue with any casting but most CNC programs leave a pretty safe margin as to not get into trouble......but that's also why there's more to be had out of those CNC'd heads.
Cool Video BTW.
Yessur, Boundary Layer is exactly what I meant. Thank you. I don't rehearse my vids or make notes. So I get lost.
@@prayperformance5137 Ditto!!!! I think it's called "Sometimers" and it only gets worse with age....
Does anyone have a contact or a link I'm wanting to do a cylinder head ports on 2 that have been welded up but I only have a 3 axis mill the head can move but it's on a quil so It can't be programmed on rotation.
Could you probe the port? Or rough grind with the CNBC and touch up by hand at the end?
What about the Ls7 heads?
Esmejor rugoso que pulido
Have w website ?
The factory spent millions to develop, my dad said the same thing 40 years ago
If that is the case then y r that making so much more power duh
Okay going to just make my point so clear somehow it's getting lost! I deal with "core shift" all the time on every type of casted part I cnc cut for all kinds of things for years! Heads of all kinds and other parts for all kinds of applications! Too say like it does in the video you can't cnc mill a head cause of core shift is silly! The machines use Gcode with sets of codes to use probes that sense every surface they cut and program in. Core shift means zero when a CNC machine detects the surface variations and makes corrections to the cut patterns to realign the tool path to make up for the core shift. I normally split the core shift in half to find center unless the part needs tlc because it's so one sided to again you input commands to set the machine up to correct for the variations or it needs to be aligned perfectly with the mating parts. Dealing with core shift is one of the first things every machinist leaners for adapt for that will mill casted items. Never nocked hand polished ports. Never said they are bad. What I said is I done over 5,000 heads on a cnc mill over the years of all kinds core shift has never been an issue unless it's a super badly casted item which even hand ports wont fix. Most modern cnc programs even have built in features to deal with it now so you don't even have to think about it except for some situations
I get what you are saying. Clark Trost also posted in here saying the same thing. Clark runs CNC machines for his business and him and I talk extensively. What I am saying is that even though the ability exists the heads I see do not have it done. You can tell the head is jigged up and the program is run regardless of where the valve seat and port location actually are. When you look in any of these ports it is explicitly simple to see that the CNC did not track at all where the valve seat was placed. When that happens you end up with very mismatched ports. If I said it can't be done then I misspoke. I mean in my 30 years I have not seen it done. I can track every head port left to right and top to bottom and NONE of them are the same. And that is just from the port entrance. Not even getting into where the seat and guide were drilled and placed. I hope that clears up my point.
Do you only port gm heads? If not , do a video on 5.4 3v
The rest of the internet tells how good the factory ls3 heads are....yet you dont.
These are factory LT heads. Not LS3 heads.
@@prayperformance5137 Oh ok got ya.
Hey dood. You cant make a bad design engine like this run better or do anything better . Why not just use a windor
As a machinist I’d say you’re not fixturing your heads right and you may not have very good programs the guides and seats are CNC machined from the factory
I don't CNC. But I have seen CNC ports from at least ten different companies and the results are always the same. Core shift kills them. The heads ar NEVER uniform. Also, GM usually gets their seat angle and second cut properly aligned. But if you machine in a third cut to the valve seat you will see how wonky they are. This is just my experience though. 🤷♂️
Gee, I never met God Of Hand Porting over CNC porting. Try not to hurt your lips blowing your own super horn.
Sound like a huge waste of money.
Oh I don't know. I did just make 810rw in 5th gear with them and take the N/A 6yh Gen record back. So.....
And your name suits you perfectly. Was it on purpose?
Texas speed is way overrated and overpriced. You ant great cylinder heads you to a real head manufacturer like dart or CID
it's not just what the piston draws. how else would you get 120% VE? you do cram air. your philosophy on port shape and texture is off. make air turn corners? lol
Kinda funny that I make more power and run faster than anyone else with stock ported LT1 heads with my wrong philosophy. LMFAO.
How many heads have you ported? What gains did you get ?
@Crysmatic
As professional head porter I can agree with him on this specific head. Chances are that tricks he did on this type of head dont work as well as on other type of head.
I have seen on different types of sbc heads the need for complete opposite texture and shapes. Sometimes a mirror polished intake with radius shaped seats worked best ( back to back tested) and sometimes aluminium carbide cutter textured port walls with 5 angle seats working best.....
There is no rule which works for all.....
@@Baard2000 maybe due to it being a dry head because of DI?