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the head sat all winter.. now i am finishing it up, had to add a little jb weld on the combustion side, to fill some gaps,, this will allow a steeper curve/drop off than the stock inlet, alfa 2 liter head weak design, this will allow better mixing and a steeper downward drop into the cly..like a steepness of the twinn spark inlet..
 

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most of the jb weld will be filed/sanded away to get the shape that i want
 

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more work done.... the floor of the intake port has a bigger radius now, not week and shallow. but not finished yet.. the best part about the twinn spark motor, i belive is the steepness of the intake port, quick dump and good mixing.on the intake mounting flange on the head. it looks out of shape,, just camera effect..i have not touched that part.
 

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a template of new ports, floor side

did not disturbe the port cealings( top of the port) notice the floor behind the valve seat is much steeper now.. jim k. noted that the floor of the ports are way to shallow for best mixing( less power), oh yes,, the top of the paper template is not the roof of the intake port.. not filled in all that much..and the floor of the port is much smoother than my paper cut out.. but you get the idea?
 

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168 views? no commets? humm.. too far out there?
 

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I love what you're doing.
But the final results (power and torque figures) will tell the complete story.
Well, they won't tell the part throttle characteristics story, but they will tell plenty.
 

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Looking at the drawing. Will there be anything left to hold the valve guide?

I can't believe there is that much dead metal to change the intake angle that much.
But if you can pull it off I would think it will flow very well.
 

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slyalfa..i did not thoch the valve guide area.. i took it to a local engine builder, that has some alfa exp... he owned one.. he said it should increase speed of the intake charge, with better mixing..with a smile he said ' more power '
 

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slyalfa, the drawing below the last photo, i just that a drawing.. the template is a truer value of my new port desing, sorry for the mix up. maybe this might help...so you see a vertical dump of fuel-air,, sort of like the twinn saprk head.. they have a more vertical dump of air-fuel.. i don't think the extra spark plugs helps that much in a central located spark plug.. from what i have read here, from jim k. and the twinn spark folks, that's were the twinn spark makes more power than the nord head.. the vertical dump of fuel-air..and the flat floor of the intake port adds speed.. this accrd. to the chevy, ford guys..
 

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OK makes more scene now. Some time back I saw a head port post on the bb that was using some hi/low PSI to redirect the air. I saw it and knew what was going on. but a lot thought it must be some bad port. I do not know if the guy ever used the head but I bet it would have performed.
It is hard to describe so I found a link that shows it on a truck.
link Reducing drag with Airtabs™ - Transformacomm


 

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interesting idea....
 

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slyalfa, the drawing below the last photo, i just that a drawing.. the template is a truer value of my new port desing, sorry for the mix up. maybe this might help...so you see a vertical dump of fuel-air,, sort of like the twinn saprk head.. they have a more vertical dump of air-fuel.. i don't think the extra spark plugs helps that much in a central located spark plug.. from what i have read here, from jim k. and the twinn spark folks, that's were the twinn spark makes more power than the nord head.. the vertical dump of fuel-air..and the flat floor of the intake port adds speed.. this accrd. to the chevy, ford guys..
i get the picture of the D-ports concept as practice on the ford and chevy guys and it would be interesting to see how it pans out on a nord head. i guess it would may even work even better on a nord head given the very shallow angle of the intake tract. Will you get flow numbers once you finish with the D-port?

Im thinking your drawings are throwing everyone off on your d-port project. they dont remotely even represent what a nord head really looks like. moving the intake port up is a good idea but you will soon bump into the water jacket if you port more than 5mms on the top surface. The earlier drawing depicts your modified intake track exiting through the cam.

In not so sure it’s the just the shape of the D-port that adds speed in the to the intake charge but the reduction in port size and better utilizing the outside “shrouded area of the valve. That would be closer to the advantages of the gtam heads and TS heads that have the steeper port geometry.

My 2cents

db
 

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davbert..at were the intake manifolds meets the head itself.. there is only a 8.8 mm addtion to the floor, this is to get a nice flat floor there sit is 44 mm on that port, at theradius of the floor the bad , shallow part , i added , after shaping only 3 mm of added epoxy.. so it is not as filled as you might think,, but the radius of the floor behind the valve is much steeper.. as to the top of the intake port,i did nothing, just cleaned the bumps of a bit.if you look at the photos, you will see that the intake is not as constricted as you might think. the first drawing, i got from wiki.. intake ports, sorry about that one.. the 2" drawing is close to what a nord intake port looks like.. shallow floor, shallow floor radius, very poor.
 

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Discussion Starter #15
i removed the first drawing to stop the confusion.. hope this helps
 

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davbert..at were the intake manifolds meets the head itself.. there is only a 8.8 mm addtion to the floor, this is to get a nice flat floor there sit is 44 mm on that port, at theradius of the floor the bad , shallow part , i added , after shaping only 3 mm of added epoxy.. so it is not as filled as you might think,, but the radius of the floor behind the valve is much steeper.. as to the top of the intake port,i did nothing, just cleaned the bumps of a bit.if you look at the photos, you will see that the intake is not as constricted as you might think. the first drawing, i got from wiki.. intake ports, sorry about that one.. the 2" drawing is close to what a nord intake port looks like.. shallow floor, shallow floor radius, very poor.
heres a head that i cut to accurately measure the dimensions when i ported my head. you can draw over this pic to get a better idea what the section would actually be or get some silicone and pull a mold of your intake trac to see what it really looks like in 3D.

yes the port geometry is awful by today's standards. its a pretty good bet that the airflow will separated and it runs across the lower portion of the valve seat as it enter the combustion chamber. im sure this what your D-port trying to improve on trying to keep the airflow attached longer. the good thing with the wide valve angle old style hemi head is huge valves with decent flow. the trade off is poor port geometry and large slow burning combustion camber not to mention the intake charge wanting to escape out of exhaust side during overlap period.
 

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..sorry. i think you forgot to post the photo...as for the exhaust.. i plan to use 38 mm valves..
 

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Im confused, what happens when all the epoxy falls off & goes through the engine?
If in the exhaust port it will burn away.
...............................................................
 

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Porting

Unless you remove the guides and open up the ports you are only wasteing your time. The bottom floor work is not going to result in any flow improvement..
 

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Discussion Starter #20
i plan to remove the valve guides.. just getting this started.. going to use 8 mm valves 45/38 mm
 
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