Porting to reach high rpm breathing
- Thread starter Fahlin Racing
- Start date
In reference to the Wagler heads.... I was able to get a real good look at these during the PRI show in Indy last week. every thing about these is just BIG. just with a fully CNC'd and polished bare head on display at the Brodix booth, one can easily see just how big the valves and runners are. just by waking by the booth. Alot of work went into these; as to re-curve of all the runners on many angles, just in "stock out of the box" form.
It will be interesting to see who posts dyno numbers from these heads in a full comparison of CNC'd stock, Wagler box stock, to Wagler CNC'd. to have these numbers off a same bottom end, same cam, same turbo, same exhaust... thats when we all may be able to start saying....well maybe the $6500 isnt so bad for that much of a gain....
Kind of like when the Big Chief heads first came out and they were priced way above the market at that time..... then once the power number and time slips started rolling out people were all over 'em...
It will be interesting to see who posts dyno numbers from these heads in a full comparison of CNC'd stock, Wagler box stock, to Wagler CNC'd. to have these numbers off a same bottom end, same cam, same turbo, same exhaust... thats when we all may be able to start saying....well maybe the $6500 isnt so bad for that much of a gain....
Kind of like when the Big Chief heads first came out and they were priced way above the market at that time..... then once the power number and time slips started rolling out people were all over 'em...
So by the time you guys cut more out and go through 3 sets of heads tryin to do better. You have just bought brodix heads.
The technical discussion is intrigueing but from a practical sense even socal stage 2 crack some timez and you guys are going bigger?
The more people that buy brodix the cheaper they get.
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The technical discussion is intrigueing but from a practical sense even socal stage 2 crack some timez and you guys are going bigger?
The more people that buy brodix the cheaper they get.
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You know seeing a CFD would be pretty kool!
Perhaps the area after the exhaust valves is large enough for our high pressure to evacuate quickly upon blowdown,but change CSA smooth enough to drive the gas charge to the turbine wheel more efficient than a straight out port but support post blowdown flow too once our valve reaches certain lift.
I agree with you on the Wagler heads Lt, same with you Jk.
Jk, its not necessarily bigger that will always paint the picture of improvements, but, shape and size w/ other numerous attributes to form the passage. I am hoping to receive some pricing soon on mold making silicone we can look at these things outside of the head not relying on cutaway of side or top views of the runners.
We must remember to involve the valve too when thinking about the tuned venturi since its all a package deal.
Thought on the straight runner's convergent side, from what the view I took a shot of only shows a narrow area I referenced to the width of my pointer finger. I believe this was on purpose to restrict since its not utilizing the entire valve curtain area IMO without seeing any CFD or wetflow testing. Reason would probably be its initial purpose, low rpm work range. Even with low rpm we need to use all areas to make efficiency higher.
What I have recently learned from an article by Jim Mcfarland that the flow in regards to area and changing direction the surface area placement from rectangular to circle to trapezoid each show different concentrations of bulk flow as the turn progresses. Very interesting article to say the least!
What I have recently learned from an article by Jim Mcfarland that the flow in regards to area and changing direction the surface area placement from rectangular to circle to trapezoid each show different concentrations of bulk flow as the turn progresses. Very interesting article to say the least!
I think "charging the runner" to provide constant velocity will enhance mid range torque.
Obviously smooth transition and minimum restriction is ideal for top end.
If we are street driving the engine at some point we need to include cam timing/duration and the overall effect on gas flow to drive the turbine into the equation.
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Good thought. If we maintain a charged runner then would we be concerned on velocity more than the overall density (lbs) if we are trying to shorten the duration or lengthen it. Of course, the thought of maintaining a flow rate to supply a piston flow demand is still needed even with a forced induction situation. However, the window between velocity and density with flow rate IMO become closer but density overpowers the importance of velocity but the importance of flow quality is still paramount.
Would you say it enhances more than just the mid range Jk? I am still on the fence with shapes near the SSR.
Once we get the intake, heads and exhaust where it may need to be for whatever application it is we then go ahead and chose the camshaft. Important at either level of operation.
Here is my current progress, finally had the time to put some work in after getting my wedding details arranged.
Step 1 for me.
Next step I have in mind.
Would you say it enhances more than just the mid range Jk? I am still on the fence with shapes near the SSR.
Once we get the intake, heads and exhaust where it may need to be for whatever application it is we then go ahead and chose the camshaft. Important at either level of operation.
Here is my current progress, finally had the time to put some work in after getting my wedding details arranged.
Step 1 for me.
Next step I have in mind.
Wow you really opened up the split. That is a bunch of material removed. I think with those heads retard inrake valve close by 12 degrees to allow air to pack in as piston dwells bdc. Then advance exhaust valve opening 15 degrees to relieve pressure and enhance spoolup.
I think good charge sir cooling and the iat is also very influintial. Density has to be our biggest concern imho.
Have you put the heads on the flow bench yet?
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I think good charge sir cooling and the iat is also very influintial. Density has to be our biggest concern imho.
Have you put the heads on the flow bench yet?
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Thanks for the timing info.
No flowbench yet, wont be for a while until I get both ports where I would like to be at. My reasoning on the shape and length of the partition that still exists, is if the cylinders in the central area (cylinders between the very front and very rear on each bank can grasp flow not from around the bend but straight out from the point of that 70 something degree turn to the valve making less distance, less distance to travel we have a higher chance of keeping a 'charged' runner for that particular cylinder inlet point from my point of view. The tricky thing is shaping the roof and floor to stay laminar or smooth or just plain quiet if you will. Same as thoughts needed to adhere to when the runner in the right of the picture when flowing due to its firing order position. The basic thing we just have to think is turbulence generation around the partition if it does or doesn't exist here during the valve operation. If you remove it completely like others have done, the concern is in other areas near and most likely lower in severity level. More on the surface of walls, roof, floor. My idea may produce a noisy ugly port or maybe less, I won't know until the bench is suckin air through it to give an example of what just may be happening to flow during operation.
Now with the cylinder head intake side towards you, the very right port, that is the runner for the most rear cylinder on the passenger side and the very front runner on the driverside cylinder bank. These are the two "dog leg runners" I will have the most cumbersome time with IMO because you can't make a hole in the side of your head, for street apps anyhow. That will be investigation for when the tiime arrives!
Once I get things cleaned up I will be using my telescoping gauges, micrometers and such to throw up some measurements.
No flowbench yet, wont be for a while until I get both ports where I would like to be at. My reasoning on the shape and length of the partition that still exists, is if the cylinders in the central area (cylinders between the very front and very rear on each bank can grasp flow not from around the bend but straight out from the point of that 70 something degree turn to the valve making less distance, less distance to travel we have a higher chance of keeping a 'charged' runner for that particular cylinder inlet point from my point of view. The tricky thing is shaping the roof and floor to stay laminar or smooth or just plain quiet if you will. Same as thoughts needed to adhere to when the runner in the right of the picture when flowing due to its firing order position. The basic thing we just have to think is turbulence generation around the partition if it does or doesn't exist here during the valve operation. If you remove it completely like others have done, the concern is in other areas near and most likely lower in severity level. More on the surface of walls, roof, floor. My idea may produce a noisy ugly port or maybe less, I won't know until the bench is suckin air through it to give an example of what just may be happening to flow during operation.
Now with the cylinder head intake side towards you, the very right port, that is the runner for the most rear cylinder on the passenger side and the very front runner on the driverside cylinder bank. These are the two "dog leg runners" I will have the most cumbersome time with IMO because you can't make a hole in the side of your head, for street apps anyhow. That will be investigation for when the tiime arrives!
Once I get things cleaned up I will be using my telescoping gauges, micrometers and such to throw up some measurements.
6.42" center to center on the rods.
In those cylinders that dog leg....be careful where the head bolt passage area is. Its thinner than you may guess. Ask me how I know .
I really like the 6.7 ford heads. Talked to wade the other day and I might get a cam reground to use the intakes for exhaust and exhaust as an intake.
The exhaust is straight in and we could put larger valves in.
Maybe look into heat treating the intake side of the head.
I just know the exhaust in valley makes turbo spool and plumbing wonderful.
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In those cylinders that dog leg....be careful where the head bolt passage area is. Its thinner than you may guess. Ask me how I know .
I really like the 6.7 ford heads. Talked to wade the other day and I might get a cam reground to use the intakes for exhaust and exhaust as an intake.
The exhaust is straight in and we could put larger valves in.
Maybe look into heat treating the intake side of the head.
I just know the exhaust in valley makes turbo spool and plumbing wonderful.
from mobile
you may have just F'd those heads up pretty good there with removing the divider between the ports.
Was thinking of doing the same to heads I just finished and while talking to the guys that were helping me along we had a lengthy discussion about this. Apparently back in the late '70's early '80's he had done some work on quite a few sets of twin cam heads with the oversight of Detroit engineers and they did all kinds of port combinations on flow benches and the on the engines themselves. The combo port of 2 separate cylinders; like what is represented in a D-max head actually LOST FLOW and TORQUE when on the flow bench and once installed on the engine. They way it was explained to me is that the air hits the bottom "wall" and the tries to bounce back up the port. Once the valve for the opposite cylinder starts to open, it is trying to pull the air from the adjacent port/valve area at a not so nice flow angle which causes A LOT of turbulence and starts to choke down the overall flow.
once the divider wall was re-installed, even at just a thickness of 0.030", the flow numbers came back up as did the torque numbers. so by having that wall in between the ports is needed to keep things balanced.
we talked for quite a while about how that if these 2 SEPARATE ports were for the SAME cylinder, then removing the divider wall up to about 1/2 the valve diameter in length above the top most curve of the valve seat, is DEFINITELY BENEFICIAL!!
in our case thou, the 2 SEPARATE ports are for 2 SEPARATE cylinders and the pulse flow into each cylinder hurts the adjacent cylinder when they are that close together.
Was thinking of doing the same to heads I just finished and while talking to the guys that were helping me along we had a lengthy discussion about this. Apparently back in the late '70's early '80's he had done some work on quite a few sets of twin cam heads with the oversight of Detroit engineers and they did all kinds of port combinations on flow benches and the on the engines themselves. The combo port of 2 separate cylinders; like what is represented in a D-max head actually LOST FLOW and TORQUE when on the flow bench and once installed on the engine. They way it was explained to me is that the air hits the bottom "wall" and the tries to bounce back up the port. Once the valve for the opposite cylinder starts to open, it is trying to pull the air from the adjacent port/valve area at a not so nice flow angle which causes A LOT of turbulence and starts to choke down the overall flow.
once the divider wall was re-installed, even at just a thickness of 0.030", the flow numbers came back up as did the torque numbers. so by having that wall in between the ports is needed to keep things balanced.
we talked for quite a while about how that if these 2 SEPARATE ports were for the SAME cylinder, then removing the divider wall up to about 1/2 the valve diameter in length above the top most curve of the valve seat, is DEFINITELY BENEFICIAL!!
in our case thou, the 2 SEPARATE ports are for 2 SEPARATE cylinders and the pulse flow into each cylinder hurts the adjacent cylinder when they are that close together.
That is the theory behind the charged runner concept we discussed a few posts ago.
The guy titled this thread high rpm breathing so I am assuming he is looking for hp not torque.
But no doubt you are right on the longer runner by not cutting divider out
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The guy titled this thread high rpm breathing so I am assuming he is looking for hp not torque.
But no doubt you are right on the longer runner by not cutting divider out
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Only advantage is that you can completely port the intake ports and the whole bowl area much better with the bridge taken out. this helps in the dog leg area of the factory casting. and overall CFM gained slightly but velocity fell off a cliff. NGM Diesel explained it to me this way and said flow bench numbers prooved it as well, as for track testing he didnt say. But indicated that High boost situations would like this head, like 100+PSI , but normal 40+ would hate it, because of the lack of velocity and swirl.
6.42" center to center on the rods.
In those cylinders that dog leg....be careful where the head bolt passage area is. Its thinner than you may guess. Ask me how I know .
I really like the 6.7 ford heads. Talked to wade the other day and I might get a cam reground to use the intakes for exhaust and exhaust as an intake.
The exhaust is straight in and we could put larger valves in.
Maybe look into heat treating the intake side of the head.
I just know the exhaust in valley makes turbo spool and plumbing wonderful.
from mobile
That would be smart because then you could centralize things as a normal engine, an utilize a true twin set up.
Correct to the t sir.
Just look at thread title. I had to go back to that a few times myself before it sank in
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Using reverse flow would be a little more tricky with these heads, for one your induction route that is currently use is too long and awkward and areas are too thin IMO to handle the flowing gases with temperatures we see throughout the runner's length to drive the turbo efficiently, you want short and to the point exhuast evacuation. Quicker it is removed, less we have a concern of about heat soaking the engine.
I haven't seen the 6.7 Scorpion heads before so I can not say. Thank you for the rod length.
Lt wrote
What are these twin cam heads and does their configuration come close to the Duramax setup?
If we talk about wave tuning, removal of the wall does kill a tuned harmonic wave. As far as the turbulence due to an obtuse angled corner, you can't bluff what a flowbench shows you. However, was there any discussion on the vortex coverage? Interesting posts! Not to negelect, we can always add material when needed. For now its just modeling clay to find the area contour.
Firing order
1 – 2 – 7 – 8 – 4 – 5 – 6 – 3
Passenger side
1,3,5,7
Driver side
2,4,6,8
While cyl. 1 is open, we have cyl 3 right next to it, 3 doesn't fire until the last, or directly before. Cyl 2 is open, we have cylinder four next on the DS bank to fire at which is 3 sequences away from this point which the charge will be replaced by then for cyl 4 opening point. Cyl. 7 is open, we have cyl. 5 next to it which also doesn't fire until 3 sequences after. Cyl. 8 we have next to cyl. 6 which doesn't fire until 3 sequences as well. Cyl. 4 is open now with cyl. 2 next to it which has already fired. Cyl. 5 is open, cyl. 7 has already fired but cyl. 3 hasn't so both cylinders next to have full runners. Cyl 6 is open with cyl. 4 has been closed for 2 sequnces now. Last cyl 3 is now open with cylinders 1 and 5 on either side, cyl 5 already has fired, however cylinder number 1 is going to need to fire. With that dog-leg the charge may be less dense in that runner and not fill soon enough.
Again thought like Lt mentions the turbulence generation due to extreme angle coming from the straight runner, but, the remainging area finishing that dog-leg is still there. Granted we know forced induction only amplifies or vortex areas. The long straight runner will experience some turbulence due to the sharp change coming from the dog-leg, I hope to shape, and yes add some, but not much material to produce a contour better than what is. Hopefully minimize the occurrance.
Great thoughts rolling around for sure.
Dave, I would like to see NGM's view after since you mention 'would' in what you heard from them. You say the velocity fell off, that only reinforces my belief on the importance of flow rate even in forced induction engines. However, flowbenches they only tell us CFM and unless you have other tools to view flow rates listening to the bench in terms of more if better in CFM alone is a misleading viewpoint from what I have learned. Are we after CFM or are we after OVERALL WEIGHT. My view is overall weight of air ingested.
I will be making some radius gauges of card board using one of my drawing stencils to help shape areas and use a stick than can fasten to these pieces. Well, back to thinking on what you guys have presented, interesting things around!
:thumb: Happy New Year
On the ford head they are designed so the exhaust is close to the edge. So you have a good point which is clear by the physical differences of the heads.
I own a 6.7 ford and a dmax.
I have some extra 6.7 heads and was going to cut 1 in half.
They did 230 on a flow bench so I am happy for now. But maybe we can work on those.
Not here obviously this Is an izuzu site!!
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I own a 6.7 ford and a dmax.
I have some extra 6.7 heads and was going to cut 1 in half.
They did 230 on a flow bench so I am happy for now. But maybe we can work on those.
Not here obviously this Is an izuzu site!!
from mobile
I bet those suckers are double the weight of the Dmax heads. How much if I were to be interested in a junker to port?