GN1 R or TA aluminum ported head flow numbers

No, why you ask?
I discovered excessive exhaust seat wear when I disassembled my TA SI heads. The exhaust valves were just as badly worn. I searched all of 15 minutes on the web and discovered the cure that was more than 40 years old. Martin Wells Well-Tite exhaust seats.They were bought out by someone and that someone was bought out by SB Internatioal or SBI. SBI now offers the same mixture of alloys that Martin wells used to use in their Well-Tite exhaust seats.When you order from them,you simply add a N suffix to the part number and you will get this tried and true exhaust valve seat material. It was discovered by them that this particular blend of alloys created a chromium oxide layer in this high heat/low oxygen environment that both lubricated and cushioned the contact between the exhaust valve and seat just like lead. There is no substitute for this material in an exhaust seat application.

I found out from TA that the exhaust seats in my heads were made from a high end ductile iron.It took me 2 minutes of searching to find out that this is the cheapest valve seat material on the market.

http://www.sbintl.com/valveseatinserts.html
 
Thanks for the information however i have had iron heads, stage2 heads, GN1 heads and now GNR heads and never had an issue with the exhaust valves. That is very good info and something worth looking into for future purchases.
 
Another point to consider when looking a flow numbers and the end use of the heads. How the valve jog is cut.....A valve job with steeper angle grind will pick up flow and give higher numbers and is fine for race but is NOT good for a street car/longevity.....Its a trade off
 
This should be made a sticky! Great information!!


Sent from my iPhone using Tapatalk
 
You want to use berrilium seats and inconel ex valves and you'll be golden, also using flow numbers from different benches around the country are useless unless you use a weather station and then use a correction factor, but even then the benche's can still vary by as much as 10 cfm because of bench variat ions or operator, might get some disagreements on this but that's ok
 
You want to use berrilium seats and inconel ex valves and you'll be golden, also using flow numbers from different benches around the country are useless unless you use a weather station and then use a correction factor, but even then the benche's can still vary by as much as 10 cfm because of bench variat ions or operator, might get some disagreements on this but that's ok
I have seen even higher bench to bench variations.
 
Problem is everybody thinks of cfm and flowbench numbers like they do dyno numbers if it's more your the winner, NOT,then they get to the track or the street like me:eek:and get that ass kicked and wonder how, then I just smile :)and go about my business
 
Me too matter of fact I don't even pay that much attention to flow numbers the real deal is airspeed not cfm, boy did I just open myself up for a crap storm of comments

flow numbers are a good thing to know and for the most part they do give you somewhat of an idea on how the heads will perform. A cylinder head that flows more has the ability to make and support more horsepower . Now flow numbers really do make a bigger difference in naturally asperated motors more then power adder motors . Airspeed defiantly plays a role on the performance of the head as well but it isn't the only thing its about the mixture of both the airspeed and cfm combined . When I look at flow data I not only look at the max cfm at the higher lifts I am more focused on the mid lift numbers as your cylinder sees those cfm numbers twice during the intake stroke. if someone has a better flowing head then you and gets there ass kicked by you at the track that isn't just the heads fault its the guys entire combo. flow numbers will give you data on what kinda cam you should run and from there what turbo and converter .
Now here is the flow numbers from my hand ported set of TA SE heads
IN / Ex
100 59.9 / 42.7
200 86.1 / 95.4
300 142.1 / 133.5
400 203.4 / 178.8
500 231.6 / 193.9
600 234.6 / 203.5
700 234.4 / 205.1
cylinder head.jpg
 
Guy's,
I am a Novice/home garage head ported and I have been watching this post since it started and the information is outstanding/very helpful. I thought I would throw our numbers into the mix. These are just the first round of a basic clean up on the SE head with no throat area modifications, push rod pinch area, and a valve job as delivered. They will be going back to the flow bench in a few weeks for a multi angle valve job and final check on the bench.
Thanks,
Bob
 

Attachments

  • photo.jpg
    photo.jpg
    607.3 KB · Views: 88
flow numbers are a good thing to know and for the most part they do give you somewhat of an idea on how the heads will perform. A cylinder head that flows more has the ability to make and support more horsepower . Now flow numbers really do make a bigger difference in naturally asperated motors more then power adder motors . Airspeed defiantly plays a role on the performance of the head as well but it isn't the only thing its about the mixture of both the airspeed and cfm combined . When I look at flow data I not only look at the max cfm at the higher lifts I am more focused on the mid lift numbers as your cylinder sees those cfm numbers twice during the intake stroke. if someone has a better flowing head then you and gets there ass kicked by you at the track that isn't just the heads fault its the guys entire combo. flow numbers will give you data on what kinda cam you should run and from there what turbo and converter .
Now here is the flow numbers from my hand ported set of TA SE heads
IN / Ex
100 59.9 / 42.7
200 86.1 / 95.4
300 142.1 / 133.5
400 203.4 / 178.8
500 231.6 / 193.9
600 234.6 / 203.5
700 234.4 / 205.1
View attachment 336754
You are misinformed as cfm will NOT determine the power of the engine it is the mean port velocity (airspeed )through port, but go ahead and stick with that theory
 
Last edited:
flow numbers are a good thing to know and for the most part they do give you somewhat of an idea on how the heads will perform. A cylinder head that flows more has the ability to make and support more horsepower . Now flow numbers really do make a bigger difference in naturally asperated motors more then power adder motors . Airspeed defiantly plays a role on the performance of the head as well but it isn't the only thing its about the mixture of both the airspeed and cfm combined . When I look at flow data I not only look at the max cfm at the higher lifts I am more focused on the mid lift numbers as your cylinder sees those cfm numbers twice during the intake stroke. if someone has a better flowing head then you and gets there ass kicked by you at the track that isn't just the heads fault its the guys entire combo. flow numbers will give you data on what kinda cam you should run and from there what turbo and converter .
Now here is the flow numbers from my hand ported set of TA SE heads
IN / Ex
100 59.9 / 42.7
200 86.1 / 95.4
300 142.1 / 133.5
400 203.4 / 178.8
500 231.6 / 193.9
600 234.6 / 203.5
700 234.4 / 205.1
View attachment 336754
By the way here's some more food for thought boosted application engines are going to use the exact same cylinder heads as n/a engines
 
You are misinformed as cfm will NOT determine the power of the engine it is the mean port velocity (airspeed )through port, but go ahead and stick with that theory
CFM is a measurement of a quantity of something over a period of time. We need more oxygen to burn more fuel. According to you,if we modify a port to increase the amount of air moving through it in a given amount of time,it might not make more power. You should see how much the speed of the water,exiting my water hose,increases when I put my thumb over the end of the hose.
 
CFM is a measurement of a quantity of something over a period of time. We need more oxygen to burn more fuel. According to you,if we modify a port to increase the amount of air moving through it in a given amount of time,it might not make more power. You should see how much the speed of the water,exiting my water hose,increases when I put my thumb over the end of the hose.
It WILL make more power, the difference between your theory of water hose and water coming out of it does not have a valve that is controlling the amount of time that the air has to fill the cylinder, so according to you if everything is equal using the same port and I have air that is traveling faster you trying to tell me that I won't have more air in the cylinder by the time the valve closes compared to the air that is moving slower in the same amount of time need to do your homework
 
By the way that being said I'm not saying that CFM should be thrown out the window but what I am saying is that CFM will not determine the power and engine makes you can have two identical cylinder heads that flow the exact same CFM but one will make more power because the port has more mean Port velocity and was designed better, it's like he's like having two slides at the water park with different turns and Curves in them but are the same length one will be faster than the other down to the bottom every time CFM is just another tool in the toolbox and it is useful problem is people get hung up too much on it like Dyno numbers
 
Top