FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: plovett on January 15, 2021, 12:52:14 PM
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Has anybody ported the TFS heads yet? If so, any results?
thanks,
pl
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Yep. My guy is working on a pair right now and has them up 25 cfm past advertised right now. Close to 360 cfm.
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Yep. My guy is working on a pair right now and has them up 25 cfm past advertised right now. Close to 360 cfm.
Neato! Thanks!
That's a lot of flow. Valve sizes the same?
pl
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Yes.
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I am guessing the ported heads still have the vane in the floor?
Thanks,
pl
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Looking forward to what Brent comes up with, but after having a few sets in my hands, I'd bet the gains will be on the roof and sides, not much on the floor. I bet he doesn't take much away from the bottom.
However, just because the vane worked for their initial port, doesn't mean it's right for big flow numbers. Heck it could even be there for marketing LOL not like the chamber and floor will behave the same way in every bore and piston combo
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Looking forward to what Brent comes up with, but after having a few sets in my hands, I'd bet the gains will be on the roof and sides, not much on the floor. I bet he doesn't take much away from the bottom.
However, just because the vane worked for their initial port, doesn't mean it's right for big flow numbers. Heck it could even be there for marketing LOL not like the chamber and floor will behave the same way in every bore and piston combo
What is the purpose of the vane, what does it "do" ?
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Looking forward to what Brent comes up with, but after having a few sets in my hands, I'd bet the gains will be on the roof and sides, not much on the floor. I bet he doesn't take much away from the bottom.
However, just because the vane worked for their initial port, doesn't mean it's right for big flow numbers. Heck it could even be there for marketing LOL not like the chamber and floor will behave the same way in every bore and piston combo
What is the purpose of the vane, what does it "do" ?
I am not sure, but there was skepticism about these heads and that vane in the intake port, when they first came out. Not so much anymore.
pl
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Look at the nice short side turn, it’s not just the vane, it’s the whole small efficient port
Whether that vane helps after porting, who knows, I sure don’t see a reason to take it away unless port volume is too small for the size and rpm
My guess on the vane is a flow director around the valve for cleaner low lift flow, but I am not a head porter
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Some Nascar teams many years ago used to use a vane in the floor on cleveland 4V heads to re-direct flow. Some porters feel it is a crutch to fix something not right about the port and if the port is right should not need it.
Brent how is the ported exhaust look? If the exhaust can keep up with the intake Id say this is good news for this head since it is basically a cnc ported TFS could easily offer it in a "ported" form. I guess they have yet to see a market demand to do so, but if guys are going to use this on 500ci engines I can see a need. Ports on the current version really look small when you see them in real life.
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It would be interesting to dyno test stock TFS heads and then pull the heads, shave the vane and dyno again. I remember reading about the vane in one of Vizard's books. It does make a difference in some port shapes.
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Could it be to induce swirl? Or, direct the flow away from the cylinder wall? Either could help overall efficiency.
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The shortest distance between two points is what? A straight line. Airflow wants to take the shortest path from point "A" to point "B", and if you look at the FE intake port, what is the shortest point from the gasket to valve seat? The air wants to go to the short turn next to the exhaust valve . That reduces flow, creates turbulence, and loss of power. A porter should try to direct the airflow so that it stays up in the port, and exits over the whole valve face, not shear across the short turn side of the valve. Those vanes in the TFS heads do that quite well. If you take the intake valve out of the TFS head, you will see the bowl is not round like other heads, but has a huge directional wall that helps with directing the airflow into the combustion chamber. Reminiscent of the first LS heads with their swirl channel built into the port. By keeping the ports small, it forces the airflow to stay in suspension, and not shear like most FE heads do when the airflow gets very fast in the ports. Short turn work is critical in keeping a FE head airflow increasing with valve lift. Joe-JDC
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Not sure if these pics' are similar size.......Here's an Edelbrock intake port next to a TFS port. Note the big ramp and longer radius to the valve, in the TFS head, like Joe mentioned. I guess the floor does matter.
pl
edit: looking for a better Edelbrock pic.....
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To me it looks like the vane keeps a lot of the air on the longer path with the bigger radius, rather than taking the shortest path to the combustion chamber? I don't know. Just asking.
pl
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Not sure if these pics' are similar size.......Here's an Edelbrock intake port next to a TFS port. Note the big ramp and longer radius to the valve, in the TFS head, like Joe mentioned. I guess the floor does matter.
pl
edit: looking for a better Edelbrock pic.....
The radius on the flow is referred to as the short side radius (ssr) and is one of the most important parts of the port, air doesn’t like to turn sharp corners
Time to just buy a set and let that next motor breathe!
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The radius on the flow is referred to as the short side radius (ssr) and is one of the most important parts of the port, air doesn’t like to turn sharp corners
Time to just buy a set and let that next motor breathe!
One of the most common mistakes novice porters make is to grind down the "ski jump" on the port floor on bowl approach. This feature is very common on all heads that I've seen. I know you know this, but when you're evaluating a port, you have to understand that air is a fluid and has mass. I've heard people using a garden hose in the port to understand how the port is working. I think that's pretty reasonable if you can read the flow. I haven't tried it, but there's probably a technique to it. But the point is, you have to take time to study the port and think about that air moving in the port, and how inertia is going to influence that turn. I find it helps me if I think of how the port would flow in both directions. In other words, the intake also flowing as an exhaust. At least it forces me to slow down.
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And I think gasoline has about four times the mass of air, if it is "atomized". So it tends to go straight even more so.
pl