18 cj bro vs 18 fbo ss vs 18 mani ported bro
11-14-2018, 08:56 PM
#181
TECH Enthusiast
My heads gain throughout the entire lift curve. Especially on the exhaust side. I also only remover 13cc's from the runner without increasing cross section at all. It is all from valve guide reshaping and short turn work. The rest of the port remains basically unchanged in my STG 1 head minus ditching the trash in the way around the rocker boss and what not. With the smaller 2.130" intake valve of the LT1 I am outflowing my LS3 head with the 2.165 valve from top to bottom back to back on my bench. But I am much more into velocity, flow distribution around the valve, swirl and runner sizing for the cam and motor. But I have since developed a STG 2 head that fixed the rest of the runner issues for my larger cam/higher rpm motors. There is obviously a ton more to it that I will explain when I have some time. There are some major flaws I see with all the other ported heads on the market. But I won't give out all those secrets. For a 3,530lb car to trap mid 109/136mph with all the issues I have I must be doing something right. LOL.
i agree that you are, and i figured that your approach was for minimal material removal. i would personally want the smallest port volume possible for the application. i use B heads for my turbo, which are legendary for ZERO low lift flow and tragic velocity at all lifts. the only thing my heads can do is flow a number and only make power under boost. which is why i like them.
im willing to bet there are fixable defects on the LT1 port without laying an eye on them. there always are. are your heads listed on stan weiss' database? i have debated him from time to time.
11-14-2018, 09:03 PM
#182
i agree that you are, and i figured that your approach was for minimal material removal. i would personally want the smallest port volume possible for the application. i use B heads for my turbo, which are legendary for ZERO low lift flow and tragic velocity at all lifts. the only thing my heads can do is flow a number and only make power under boost. which is why i like them.
im willing to bet there are fixable defects on the LT1 port without laying an eye on them. there always are. are your heads listed on stan weiss' database? i have debated him from time to time.
im willing to bet there are fixable defects on the LT1 port without laying an eye on them. there always are. are your heads listed on stan weiss' database? i have debated him from time to time.
I am also a weirdo and prefer perfecting ports on my SF110 flow bench before I put them on the SF600. Any clown can make a head flow at 28". The low flow of the 110 let's you know exactly when you messed up. With no real force or volume you have to get the details correct in every portion of the runner, valve and valve seat to make it work. Giving it a bigger runner does nothing. I have never, ever not had a head pick up a substantial amount on a SF600 after developing the port on a SF 110.
11-14-2018, 09:18 PM
#183
TECH Enthusiast
Don't know who Stan Weiss is so no. Not in his data base.
I am also a weirdo and prefer perfecting ports on my SF110 flow bench before I put them on the SF600. Any clown can make a head flow at 28". The low flow of the 110 let's you know exactly when you messed up. With no real force or volume you have to get the details correct in every portion of the runner, valve and valve seat to make it work. Giving it a bigger runner does nothing. I have never, ever not had a head pick up a substantial amount on a SF600 after developing the port on a SF 110.
I am also a weirdo and prefer perfecting ports on my SF110 flow bench before I put them on the SF600. Any clown can make a head flow at 28". The low flow of the 110 let's you know exactly when you messed up. With no real force or volume you have to get the details correct in every portion of the runner, valve and valve seat to make it work. Giving it a bigger runner does nothing. I have never, ever not had a head pick up a substantial amount on a SF600 after developing the port on a SF 110.
are you dimpling your top end porting job? and welding and runner changes? epoxy?do you have to add material to liven dead areas? for example the floor of modular 4v exhaust ports get left alone. opening them only kills the port.
edit: i guess there is no fuel there, so i bet no dimpling.
11-15-2018, 04:22 AM
#184
are you dimpling your top end porting job? and welding and runner changes? epoxy?do you have to add material to liven dead areas? for example the floor of modular 4v exhaust ports get left alone. opening them only kills the port.
edit: i guess there is no fuel there, so i bet no dimpling.
edit: i guess there is no fuel there, so i bet no dimpling.
11-15-2018, 05:51 AM
#185
I quit cartridge rolling years ago. I only use carbides now. So I end up with a carbide finish that I have found to make the most power. Even though it is a dry port the air still needs something to stick to. Both STG 1 and 2 get the same finish. I also don't have any redundant flow areas. I leave some extra material in certain places and remove it in others to ensure that. No welding required. With what I actually leave in the intake port allows me to remove some more in the exhaust to correct the factory deficiencies.
11-15-2018, 06:14 AM
#186
Absolutely. But it is a finer bit that I use for final smoothing and shaping. On the port injection cars I leave a rougher surface from the carbide to help atomize the fuel as well.
Air is heavy and slow and wants to travel in a straight line, it is a lot like water. It needs two things to navigate corners. It needs grip and buffer. It needs a buffer of slow air clinging to the surfaces of the runner for the fast air to travel on. If you don't have that the air will "skip" or stay in a straight line. That is why CNC heads do relatively well. The lines left over by the CNC process provide grip and buffer.
I learned this first hand about 20 years ago when CNC was brand new. I had one of the first sets of AFR 210's. I took them to a very well know head porter for some light work. He cartridge rolled the ports and we lost 10-12cfm. It took a bit of work to get it back. Then if you read the Larry Meaux Pipe Max stuff he goes into detail about it.
That is why I laugh when I hear people talk about Port and Polished heads or TB's. I really laugh when someone posts a pick of their shiny TB or perfectly pretty rolled intake ports. SMDH.
Air is heavy and slow and wants to travel in a straight line, it is a lot like water. It needs two things to navigate corners. It needs grip and buffer. It needs a buffer of slow air clinging to the surfaces of the runner for the fast air to travel on. If you don't have that the air will "skip" or stay in a straight line. That is why CNC heads do relatively well. The lines left over by the CNC process provide grip and buffer.
I learned this first hand about 20 years ago when CNC was brand new. I had one of the first sets of AFR 210's. I took them to a very well know head porter for some light work. He cartridge rolled the ports and we lost 10-12cfm. It took a bit of work to get it back. Then if you read the Larry Meaux Pipe Max stuff he goes into detail about it.
That is why I laugh when I hear people talk about Port and Polished heads or TB's. I really laugh when someone posts a pick of their shiny TB or perfectly pretty rolled intake ports. SMDH.
11-15-2018, 06:51 AM
#187
Absolutely. But it is a finer bit that I use for final smoothing and shaping. On the port injection cars I leave a rougher surface from the carbide to help atomize the fuel as well.
Air is heavy and slow and wants to travel in a straight line, it is a lot like water. It needs two things to navigate corners. It needs grip and buffer. It needs a buffer of slow air clinging to the surfaces of the runner for the fast air to travel on. If you don't have that the air will "skip" or stay in a straight line. That is why CNC heads do relatively well. The lines left over by the CNC process provide grip and buffer.
I learned this first hand about 20 years ago when CNC was brand new. I had one of the first sets of AFR 210's. I took them to a very well know head porter for some light work. He cartridge rolled the ports and we lost 10-12cfm. It took a bit of work to get it back. Then if you read the Larry Meaux Pipe Max stuff he goes into detail about it.
That is why I laugh when I hear people talk about Port and Polished heads or TB's. I really laugh when someone posts a pick of their shiny TB or perfectly pretty rolled intake ports. SMDH.
Air is heavy and slow and wants to travel in a straight line, it is a lot like water. It needs two things to navigate corners. It needs grip and buffer. It needs a buffer of slow air clinging to the surfaces of the runner for the fast air to travel on. If you don't have that the air will "skip" or stay in a straight line. That is why CNC heads do relatively well. The lines left over by the CNC process provide grip and buffer.
I learned this first hand about 20 years ago when CNC was brand new. I had one of the first sets of AFR 210's. I took them to a very well know head porter for some light work. He cartridge rolled the ports and we lost 10-12cfm. It took a bit of work to get it back. Then if you read the Larry Meaux Pipe Max stuff he goes into detail about it.
That is why I laugh when I hear people talk about Port and Polished heads or TB's. I really laugh when someone posts a pick of their shiny TB or perfectly pretty rolled intake ports. SMDH.
11-15-2018, 08:17 AM
#188
Carbon is going to build up no matter what. Especially on these dirty *** DI motors. But the same principals apply. Possibly even more so on the exhaust. When the valve cracks the exhaust is moving around 2,000fps. It breaking the sound barrier is what we are hearing as exhaust noise. But very quickly after that the velocity takes a crap and piston speed drives the exhaust out. When you have polished ports the air skips and bangs back into itself shutting down it's available fillable space. So you essentially restrict flow since you can't use the entire port any more. These are things we can't duplicate on a flow bench. So the more exhaust gas you can evacuate down low the better and the more velocity you can maintain during the cam shaft overlap period will help you get over 100% VE when your intake valve cracks open. However, if you didn't evacuate all that exhaust gas for what ever reason you can cause reversion back into the intake port and and screw your self. The LT1 head of now has the most torturous exhaust port we have ever had to navigate. So anything you can do to help straighten it out into the header and utilize every sq mm of it is essential. We can't have air skipping around in there.
11-15-2018, 12:15 PM
#193
I am small time and can only do so many heads. I am also not giving up much real information on port designing or other stuff. Just some general principles moving forward for the guys that care. I am sure there are a hundred head porters out there that will dispute everything I saw. It is what it is.
11-15-2018, 06:29 PM
#194
TECH Enthusiast
I am small time and can only do so many heads. I am also not giving up much real information on port designing or other stuff. Just some general principles moving forward for the guys that care. I am sure there are a hundred head porters out there that will dispute everything I saw. It is what it is.
i don't have your tools. what i do have is information for my selected heads and gifted friends on the flowbench to flow mine and give me pitot velocities in critical areas, as well as their expertise performing valve jobs. one of my buddies is craig clack.
he is a bad ************. he builds a lot of big chief pro mod and pro stock motors. his machine shop is not advertised. he did the valves and surfaces on the heads. he specializes in 409s. of course he is published.
i haven't dimpled my heads. my maximum grit is 80 grit 1" flapper wheel. my secondary port is exactly like a DI port. no injector boss and decent cross section with minimal taper. imo from your info , it is better than a lt1 di runner. (proportionally)
you have answered my questions about the weaknesses of STOCK LT1 ports. nutswingers take questioning weaknesses in a design personally. as good and near perfect for street applications as the LT1 intake port is, it's astounding that the port can be modified to flow enough for a killer peak power number WITHOUT ruining the laminar flow and cylinder filling the stock port does so well.
if the rumor of a 6.6 DI engine turns out to be true, its scary how much torque and power that cylinder head holds in modified form.
11-15-2018, 06:39 PM
#195
i don't have your tools. what i do have is information for my selected heads and gifted friends on the flowbench to flow mine and give me pitot velocities in critical areas, as well as their expertise performing valve jobs. one of my buddies is craig clack.
he is a bad ************. he builds a lot of big chief pro mod and pro stock motors. his machine shop is not advertised. he did the valves and surfaces on the heads. he specializes in 409s. of course he is published.
i haven't dimpled my heads. my maximum grit is 80 grit 1" flapper wheel. my secondary port is exactly like a DI port. no injector boss and decent cross section with minimal taper. imo from your info , it is better than a lt1 di runner. (proportionally)
you have answered my questions about the weaknesses of STOCK LT1 ports. nutswingers take questioning weaknesses in a design personally. as good and near perfect for street applications as the LT1 intake port is, it's astounding that the port can be modified to flow enough for a killer peak power number WITHOUT ruining the laminar flow and cylinder filling the stock port does so well.
if the rumor of a 6.6 DI engine turns out to be true, its scary how much torque and power that cylinder head holds in modified form.
he is a bad ************. he builds a lot of big chief pro mod and pro stock motors. his machine shop is not advertised. he did the valves and surfaces on the heads. he specializes in 409s. of course he is published.
i haven't dimpled my heads. my maximum grit is 80 grit 1" flapper wheel. my secondary port is exactly like a DI port. no injector boss and decent cross section with minimal taper. imo from your info , it is better than a lt1 di runner. (proportionally)
you have answered my questions about the weaknesses of STOCK LT1 ports. nutswingers take questioning weaknesses in a design personally. as good and near perfect for street applications as the LT1 intake port is, it's astounding that the port can be modified to flow enough for a killer peak power number WITHOUT ruining the laminar flow and cylinder filling the stock port does so well.
if the rumor of a 6.6 DI engine turns out to be true, its scary how much torque and power that cylinder head holds in modified form.
Next up for me is I am putting LS3 valve seats in the LT head and cutting down some LS7 Ti intake valves to 2.165" for the stock bore. I am also going to cut an inch out of the runners in my MSD. I should be able to clip 400cfm that way and be able to spin the SBE to 7,500 like the cam was designed for.
Shortly following that I am going to do an all bore 440 with 2.200" LS7 intake valves and a sheet metal intake with lots of compression. I think I can do 700-720rw that way.
11-15-2018, 06:48 PM
#196
TECH Enthusiast
I love my pitot tube. It has thought me so much. I also do some funky stuff with my flow bench to test stuff. But any way.
Next up for me is I am putting LS3 valve seats in the LT head and cutting down some LS7 Ti intake valves to 2.165" for the stock bore. I am also going to cut an inch out of the runners in my MSD. I should be able to clip 400cfm that way and be able to spin the SBE to 7,500 like the cam was designed for.
Shortly following that I am going to do an all bore 440 with 2.200" LS7 intake valves and a sheet metal intake with lots of compression. I think I can do 700-720rw that way.
Next up for me is I am putting LS3 valve seats in the LT head and cutting down some LS7 Ti intake valves to 2.165" for the stock bore. I am also going to cut an inch out of the runners in my MSD. I should be able to clip 400cfm that way and be able to spin the SBE to 7,500 like the cam was designed for.
Shortly following that I am going to do an all bore 440 with 2.200" LS7 intake valves and a sheet metal intake with lots of compression. I think I can do 700-720rw that way.
i'm not kidding when i say i wish i had some LT1s to cut up and look at.
how small can ls7 Ti valve stems be cut with a rpm limit in mind? if they have a substantial undercut number, and the cylinder wall doesnt shroud them at 2.2", then why waste time with SS ls3 valves?
also .. seriously..... if there is material for cutting the cylinder wall to unshroud 2.2" Ti valves, are you considering that approach. if the top ring has clearance, there should be no penalty in sealing.
BTW hio you ****.
i googled all of these approaches you have never heard of in your 4' 6" life.
11-15-2018, 07:07 PM
#197
i'm not kidding when i say i wish i had some LT1s to cut up and look at.
how small can ls7 Ti valve stems be cut with a rpm limit in mind? if they have a substantial undercut number, and the cylinder wall doesnt shroud them at 2.2", then why waste time with SS ls3 valves?
also .. seriously..... if there is material for cutting the cylinder wall to unshroud 2.2" Ti valves, are you considering that approach. if the top ring has clearance, there should be no penalty in sealing.
BTW hio you ****.
i googled all of these approaches you have never heard of in your 4' 6" life.
how small can ls7 Ti valve stems be cut with a rpm limit in mind? if they have a substantial undercut number, and the cylinder wall doesnt shroud them at 2.2", then why waste time with SS ls3 valves?
also .. seriously..... if there is material for cutting the cylinder wall to unshroud 2.2" Ti valves, are you considering that approach. if the top ring has clearance, there should be no penalty in sealing.
BTW hio you ****.
i googled all of these approaches you have never heard of in your 4' 6" life.
the 440 will be 4.185×4 so I will have plenty or room for a full 2.200 valve. The LT1 chamber is already at my size for the 4.065 bore.
11-15-2018, 07:18 PM
#198
TECH Enthusiast
the 2.200 would be a bit shrouded on a 4.065" bore. The splayed valves would help a bit though. The 2.165" will be just fine. The LS3 stems are to long so that valve is out. There are a couple companies that cut down the LS7's already. But the valve stems are all 8mm for LS and LT so no worries there. I am looking to spin my SBE to 7,500 or so.
the 440 will be 4.185×4 so I will have plenty or room for a full 2.200 valve. The LT1 chamber is already at my size for the 4.065 bore.
the 440 will be 4.185×4 so I will have plenty or room for a full 2.200 valve. The LT1 chamber is already at my size for the 4.065 bore.
nice man. im looking forward to your results. all of my buddies are chevy guys. that's ok, ive had to build them for a living, and there are just more of them, so i'm good. chevys paid the bills. and besides i got results. see ya man.
11-15-2018, 09:19 PM
#199
10 Second Club
iTrader: (8)
i'm not kidding when i say i wish i had some LT1s to cut up and look at.
how small can ls7 Ti valve stems be cut with a rpm limit in mind? if they have a substantial undercut number, and the cylinder wall doesnt shroud them at 2.2", then why waste time with SS ls3 valves?
also .. seriously..... if there is material for cutting the cylinder wall to unshroud 2.2" Ti valves, are you considering that approach. if the top ring has clearance, there should be no penalty in sealing.
BTW hio you ****.
i googled all of these approaches you have never heard of in your 4' 6" life.
how small can ls7 Ti valve stems be cut with a rpm limit in mind? if they have a substantial undercut number, and the cylinder wall doesnt shroud them at 2.2", then why waste time with SS ls3 valves?
also .. seriously..... if there is material for cutting the cylinder wall to unshroud 2.2" Ti valves, are you considering that approach. if the top ring has clearance, there should be no penalty in sealing.
BTW hio you ****.
i googled all of these approaches you have never heard of in your 4' 6" life.
11-15-2018, 11:35 PM
#200
Just wanted to say I appreciate the guys like pray on here who make posts that you can learn a little from good stuff 👌 I ported my 5.3l heads and probably hurt them more than helped lol but didn't know that about the grinding marks. Pray do you leave the marks parallel to air flow or put some perpendicular to increase turbulence? Or is that to small to matter