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  1. #1

    Default Porting on the toyota V6 3vz-fe.

    How to gain approx 20bhp (peak) via 3vzfe Cylinderhead modifications, a guide by 4v6.

    The disclaimer.

    You, yes you, are entirely responsible for any work you decide to perform on your engine or vehicle.
    The procedures described in this article can be accomplished by most anyone with common sense and a fair degree of patience, skill and time.
    It cannot be stressed highly enough that the three components above are ESSENTIAL to producing a quality job that performs as expected.
    If you do not posses the necessary qualities, or you doubt your ability to perform the following actions, then do not proceed to attempt them.
    In short, if you destroy your engine or hack your own head off with a grinder in the process of making modifications based on procedures described in this article, then its not my responsibility, no one made you do it!
    Use common sense and employ safe working methods when making any modifications.
    I have tried to ensure as much relevant detail as possible is included but this is a rather condensed account of what to do because the flowtesting part isnt included and errors and omissions can unfortunately creep in, so if in doubt at any point, re-read and if still unsure ask!

    Now thats out of the way, lets see what tools are needed.

    Youll need either a high speed air or electric die grinder (variable electric is best) although an electric drill can be used and at a pinch a dremel type tool- however theyre generally unsuitable because the tools are smaller and remove less material.
    Better to use that for detailing/cleaning up jobs later on.
    A supply of 80 and 120 grit abrasive cloth on a roll.
    A carbide “Oval” Burr.
    Sanding Rolls 80 to 120 grit.
    Some wd40.
    Engine degreaser.
    Paper towels ( lots of them)
    A vacuum cleaner would be useful also.
    A plastic storage box for washing purposes.
    A valve spring compressor to remove the valves.
    A piece of ¼ inch rod around 6 inches long with a slot hacksawed into one end.
    A dust mask and some eye protection.
    At this point ill assume you have enough knowledge to have removed the heads off the
    engine,
    removed and ordered the valves correctly.
    Read the engine manual if youre unsure how to do that and get familiar first!
    Clean the head in the plastic box with Jizer or some other engine cleaner that has a corrosion
    inhibiter in it otherwise the guides and seats will rust.
    Once done with the majority of cleaning, dry the head and blow it off with compressed air if available and use your can of WD40 to coat the guides both inside and out and the seats to further protect them along with the cam cap retaining studs.
    Unless you want your hands torn to shreds, its a good idea to deburr all sharp external edges
    with a carbide cutter or sanding roll, so do that next and save your fingers.
    Ok, if you look down the intake ports youll see all manner of interesting stuff.
    Casting marks, valve guides, the bosses and ridges left by machining ops at the factory etc.
    The first thing to note is this: Be guided by the fact that youre not going to be making these
    ports monstrously bigger so resist vigorously the urge to go bananas with your carbide cutter!
    If youve got a pile of chippings as deep as your armpits when youre finished, then you may
    have gone a little too far.....
    This first photo shows a view down the port as itd normally appear minus the valves of
    course.

    Things to note.
    Rough surface texture, guide bosses and guides, fairly wide splitter, machining ridges left by
    the factory.
    Incidentally, the reason theyre not removed ( on newer engines they are very much better
    finished) is because the engines built to meet a specific aim in terms of power and cost
    which, even in this state it does so, plus its a design thats over 15 years old and was never
    really intended to do what we’re asking of it.
    The next shot shows the chamber, the seat and bowl areas.
    Ive sprayed these with a welding product called flaw finder/developer, it highlights contours
    quite well.
    You can clearly see the ridges and changes in port cross section thats been left by the factory
    machining ops.
    At the other side of the port theres a sharp edge.

    Ive already taken port moulds of these heads on numerous occasions and you can clearly see
    how uneven and poorly finished the surface comes as stock.


    So where to start?
    First attach a vacuum cleaner to the port and use it to keep the dust and chippings down.
    If you cant use a vacuum cleaner, then wear a dust mask, aluminium dusts not supposedly
    good for your health ( alzheimers) so protect yourself just in case.
    I usually start at the port mouth and smooth the surface, just removing casting lines, flash etc.
    Its important to run the tool fast enough to cut the port material but not press on it as itll clog
    up rapidly and end up slowing you right down.
    Just let the tool cut steadily and keep it moving.
    Youll develop a natural sweeping motion as you progress.
    Once youve done all the port floors or roofs, turn over the head and do the opposite sides, just
    removing marks and ridges.
    By now youll start wondering if youve done the right thing and worrying how long itll take.
    Its not a fast job and thats where the patience part comes in.
    This is how itll look as you proceed.



    After a few hours youll have removed the casting marks and generally smoothed the surface.
    The valve guide bosses on these can give you a couple of cfm for just a few minutes work, so
    its worth spending that time to reduce their size.
    Just remove the material at either side and lower the height of the surface blending it in to
    meet the guide, making it more aerodynamic.
    Try to get both sides of the boss symmetrical and mirroring its neighbours but dont worry too
    much about surface condition at this point, minor changes wont make any noticeable
    differences and in any case the surface will be addressed lastly after everything else is done.
    Use the photos as a guide for what to aim for.
    Have a look at the following photo of an unmodified intake port.
    Its an experiment I did some time ago using smoke trails to get a visual clue where the air
    was going.
    Look at the right hand trail. Its got a definite bump to it that proves the pressure is higher as it
    travels over the guide boss, its almost a dead copy of the profile in that area.
    What happens is the air is deflected up by the high pressure (well higher than elsewhere)
    created as the air is flowing.
    Its raising the pressure in that place and diverting the air, stopping it from going where it
    would like- straight.
    You obviously cant eliminate this effect entirely but by making the bosses less pronounced,
    that pressure rise isnt as great and Its very easily measured on the test bench.

    Assuming youve got all the guide bosses reduced in height and nicely shaped and the ports
    lead in sections all roughed out, we can turn the head over and start from the other side.
    Position the head so the manifold face of the intake port faces upwards.
    At the bowl area use the oval burr to remove the edges of the alloy that overlap into the
    airstream, blending the material so it ends up level with the valve seat insert.
    Youll notice at the sides of the port a deep ridge that alternates on each set of ports, caused
    by the factory machining.
    Feather these into the seat insert and port as youve done with the rest of the bowl.

  2. #2

    Default

    Now turn the head over ( prop it up on a length of timber if needs be) so the intake manifold
    face is pointing downwards.
    The short side radius turn is next up.This is opposite the bowl that youve just blended in.
    If you look at it, youll notice an apparent lip, almost an overhang where the factory tooling
    has cut into the port to produce the seating area for the insert, its the “arch” shape you can see
    on this port.

    This sharp lip is detrimental ( very) to getting air into the cylinder because air dosent like to
    take sharp turns and when its moving at close to supersonic speeds as in a port it really
    dosent like to change direction because even air has mass. Hang your hand out the car
    window at 80mph- feel the force.
    The air coming off that lip creates vortexes and back eddys that make the stream turbulent
    which stops air further back up the intake from going where we want it.
    When reshaping this turn we want to be making it aerodynamic, as in an aerofoil section of a
    wing, which is what the profile will resemble when we’ve finished on it.
    Ive already done the hard work for you here and made a copy of the profile to aim for in 3D
    out of silicone rubber.
    Compare it with the mould of the stock port on the right for the differences.
    You need to try to copy the shape as closely as you can and use it to check the shape of the
    turn as you go.
    This is one of the hardest parts of the job and itll take quite some time to get it just right but
    the payoff is way better flow with the valves in than youd get just by rounding that edge off.

    Once youve carefully shaped the short side radius, you need to apply some efforts to the sides
    of the port walls where the SSR meets the vertical parts.
    If you position the head on its end and look back up the intake from the valves, youll notice a
    “hump” type shape as the port wall makes the turn.
    Its present on both outer and inner walls ( splitter side).
    Youll need to be careful how you approach this bit of the job, what youre doing is making
    room for the air as it slows and goes around the SSR and blending the sides and SSR
    together, but not cutting into the already modified SSR.
    In my case I transfer the head back and forth to the bench, test it, modify the area then retest
    to check the changes, takes ages.
    Youre not going to be able to do that, so just aim to smooth and flatten that hump on both
    sides of the port, blending it in to the SSR at the apexes.
    A gentle touch with a finger can usually detect what the eye dosent, so use that as a guide and
    stop when it feels smooth and flat.
    Now youve done all these, turn your attention to the port divider/splitter.
    The basic idea here is to slim the bluff nose of it down, reducing its width at the leading edge
    and smoothing the surfaces as it proceeds further into the port.
    No need to knife edge it, just apply a small radius so its not dead sharp and dont work soley
    on one side, itll end up biasing the flow one way or the other which affects overall flow,
    again patience and care will see you right.
    Use a pair of dividers to keep it central in the port by measuring.
    You can see the basic shape to try and reproduce on the following photos of the port moulds.


    Once youve completed all the major works in the ports you can start to apply a surface
    finish.
    I use 80 grit sanding drums and 80 grit emery wrapped around a rod to further flatten and
    smooth the surfaces and impart a nice flow friendly surface.
    Its best to run this at a moderate speed as too fast will just make it uncontrollable and the
    media wears faster.
    You can use wd40 to help but I dont find it always necessary except in the chambers.
    Start at the port mouth and work around the periphery, youll feel and see the effects of it
    almost immediately, continue that method all the way .
    To get that cross hatch effect, stroke the tool back and forth covering the entire port, but be
    sure to not dwell in one area, keep it moving until youre satsified with the results and you
    have a uniform finish.
    This is what youll end up with.

    In the chamber, use the sanding drum to carefully dress the surface and remove the myriad of
    pits and marks in the alloy.
    Youre just aiming to remove sharp edges and blending surfaces.
    Try to form smooth contours where the alloy runs down to the seats.
    There are lots of edges in this part of the chamber and I use a homebrewed cutter to remove
    them evenly, but its possible to use old valves with the outer diameter reduced and the head
    ground with a bevel to protect the seats while youre working in the chamber with a sanding
    drum( its what I use).
    Aim for a 120 grit finish in the chamber. You can go smoother but it takes a lot of effort and
    time and its likely not worth it.
    Aim to get the ports and chambers as shown in the photos.



    The exhaust ports are far simpler to work on believe it or not.
    They too suffer from all the intakes casting flaws and can be improved quite markedly.
    The 3vz fe has a compromised head design especially on the exhaust ports because theyre not
    identical across all three of them.
    Two are of a “dog leg” design whereby one side of the port is a straight shot out with the
    other runner coming in at around 40 ish degrees and merging.
    This creates turbulence and a loss.
    All we can really do here is improve it so it flows better.
    The “odd” port out on the end of the head is more of a siamesed design with almost equal
    length runners and this definitely flows better to the tune of around 10cfm over the other
    exhaust ports.
    That kind of leads to a bit of a quandry.
    Improve it or not?
    Well yes, but bear in mind itll easily outflow the other exhausts if you apply the same
    measures to it as all the others.
    I tend to develop the dog legged ports to flow equally and as highly as I can and then do that
    “straight shot” port last, balancing the airflow to match the others.
    Takes time and effort.
    All youll be able to do, is make them resemble each other as closely as possible and leave it
    at that.
    I have it on great authority that balancing the exhaust flows isnt as critical so im happy to
    bow to much greater knowledge on that score.
    Heres the 3vzfe’s exhaust ports in silicone rubber, not a pretty sight.

    Ok, proceed with the exhaust ports as per the intakes, removing casting lines and
    imperfections at the port exit (at the face and working inwards).
    Theyre awkward to do due to their shape, but stick with it and youll get there.
    The guide bosses are a fair size on these.
    Reduce them as per the intakes, mostly on the widths and the “ramp” at the front of them
    leading to the guide, smoothing and blending them in.
    Once youre happy with these, turn the head over and examine the bowl area ( under the valve
    head).
    Youll notice some material just on and below the seat which needs removing and a rather
    large overhang.
    I try to blend the overhang into the seat insert/ port but its pretty much impossible to remove
    it entirely as youd have to burrow into the material far deeper than really is good and its
    purely an aesthetic operation to remove it which you wont see when its all together anyway.
    In this case, just smooth it as best as possible.
    The sides of the ports at the divider have a similar “hump” to the intakes, so again its a case
    of basically flattening them and blending in to the rest of the port.
    The exhaust also has an SSR which heavily influences how well the port can flow.
    This mould shows the kind of condition the factory leaves the heads in.

    A finger prodded into the port will expose a sharp edge which creates major restriction and
    turbulence just as on the intakes.
    Once youve addressed that and modified it to more closely resemble the next photo, apply a
    similar finish to the exhaust port surfaces as the intakes using the methods youll now have
    developed.
    You can finish these to 120 grit as itll help to reduce carbon buildup than a rougher surface
    which can alter the flow of the ports over time.
    Modified exhaust port shape.




    If youve done a good job, you should have ports that are closely matched for both flow and
    give a good improvement over stock.
    Typical bare port flow for a stock 3vzfe is 204cfm@28", the result of your efforts if you work diligently should enable an improvement to approx 230cfm.
    Typical exhaust flows are 154cfm@28" on exhausts, yours should rise to at least 165-170 after mods.

    At this point in time, ive done limited tests regarding valves and seats, so its far from clear what the ultimate seat angle, width and number of cuts plus optimum valve shape is for these ports, that will come later when I have more time to spend on them.

    Power gain to expect will be from 185 ish stock to as high as 215bhp, that figure being the highest seen thus far.

    Copyright 2009 T.Warren ( 4v6)

  3. #3
    Ultimo Miembro Fantástico Gigantesco MrWOT has much to be proud of MrWOT has much to be proud of MrWOT has much to be proud of MrWOT has much to be proud of MrWOT has much to be proud of MrWOT has much to be proud of MrWOT has much to be proud of MrWOT has much to be proud of MrWOT has much to be proud of MrWOT has much to be proud of
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    Good work, and you got pm
    I really like the way aaawelder put it: "do not include yourself in this circuit"

  4. #4
    CelicaTech Supporter rizin is on a distinguished road
    rizin has been to an annual Dragon Meet! rizin has donated to the forums!

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    Very good write up by what you just talked about and described in detail it will help anyone with any head. I can't wait untill I need to go as far as needing head work I will refer back to this. Oh and is that a pic of a inline 5 head? Good job!

  5. #5

    Default

    Amazing.... thank you so much...

    But because there will be more air flowing into the engine wont this need to be corrected with an AFC or something??

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  6. #6

    Default

    Thanks fellas.

    Rizin, yeah that is indeed a quattro cylinderhead, its a job i did for a friend to get him out the mire, current output N/A in the region of 170 bhp up from 136...apparently goes like a scalded cat.

    Balang, my alltrac v6 has been running with the uprated heads for over a year now, plug colours are as youd expect from a well running engine, even with the afm leaned off it dosent knock at all- ever.
    It appears the management is able to cope with the extra airflow without issue, although i really ought to do something about it shortly because the next upgrade could see the injectors running at 100% duty cycle ( full on all the time=bad).
    Current injector sizes are just about good enough for 240bhp absolute maximum.
    Some other modifications have seen a subtle change in the way the engine makes its power, with a minor drop off in torque low down, but a gain towards the top of the range whereas prior it would tend to start dying at 5k-ish.
    Ill post up some info regarding that when ive got some more data.

  7. #7

    Default

    Update to this thread.

    Seems my photos got erased somehow so ive re-written part of the article and added extra info.

    3vzfe Cylinderhead modifications.

    Most of the 3vzfe info here is applicable to the 1mzfe, note that the exhaust ports on the 1mzfe are more like the 1uzfe and still respond similarly to the 3vzfe when being modified.

    I have tried to ensure as much relevant detail as possible is included but errors and omissions
    can unfortunately creep in, so if in doubt at any point, re-read and if still unsure, ask!
    Now thats out of the way, lets see what tools are needed.
    Youll need either a high speed air or electric die grinder (electric is best) although an electric
    drill can be used and at a pinch a dremel type tool- however theyre generally unsuitable
    because the tools are smaller and remove less material.
    Better to use that for detailing/cleaning up jobs later on.
    A supply of 80 grit abrasive cloth on a roll.
    A carbide “Oval” Burr.
    Some wd40.
    Paper towels ( lots of them)
    A vacuum cleaner would be useful also.
    A plastic storage box for washing purposes.
    A valve spring compressor to remove the valves.
    A piece of ¼ inch rod around 6 inches long with a slot hacksawed into one end.
    A dust mask and some eye protection.
    At this point ill assume you have enough knowledge to have removed the heads off the engine,removed and ordered the valves correctly.
    Read the engine manual if youre unsure how to do that and get familiar first!
    Clean the head in the plastic box with Jizer or some other engine cleaner that has a corrosion inhibiter in it otherwise the guides and seats will rust.
    Once done with the majority of cleaning, dry the head and blow it off with compressed air if available and use your can of WD40 to coat the guides both inside and out and the seats to further protect them along with the cam cap retaining studs.
    Unless you want your hands torn to shreds, its a good idea to deburr all sharp external edges with a carbide cutter or sanding roll, so do that next and save your fingers.
    Deburr all the coolant transfer passages also, build ups of corrosion here can impede cooling.




    Ok, if you look down the intake ports youll see all manner of interesting stuff.
    Casting marks, valve guides, the bosses and ridges left by machining ops at the factory etc.
    The first thing to note is this: Be guided by the fact that youre not going to be making these ports monstrously bigger so resist vigorously the urge to go bananas with your carbide cutter!
    If youve got a pile of chippings as deep as your armpits when youre finished, then you may have gone a little too far.....
    This first photo shows a view down the port as itd normally appear minus the valves of course.



    Things to note.
    Rough surface texture, guide bosses and guides, fairly wide splitter, machining ridges left by
    the factory.

    The next shot shows the chamber, the seat and bowl areas.



    Note the thin light coloured ring of material around the base of the seat insert.
    Thats been left by the machining ops.
    At the top of the port theres a sharp edge.
    The clean ring around the valve seat is where i already cleared the usual ridge left by the factory.



    So where to start?
    First attach a vacuum cleaner to the port and use it to keep the dust and chippings down.
    If you cant use a vacuum cleaner, then wear a dust mask, aluminium dusts not supposedly good for your memory ( alzheimers) so protect yourself just in case.
    I usually start at the port mouth and smooth the surface, just removing casting lines, flash etc.
    Its important to run the tool fast enough to cut the port material but not press on it as itll clog
    up rapidly and end up slowing you right down.
    Just let the tool cut steadily and keep it moving.
    Youll develop a natural sweeping motion as you progress.


    Once youve done all the port floors or roofs, turn over the head and do the opposite sides, just removing marks and ridges.
    By now youll start wondering if youve done the right thing and worrying how long itll take.
    Its not a fast job and thats where the patience part comes in.
    This is how itll look as you proceed.






    Ok so youve removed the casting marks and generally smoothed the surface.
    The valve guide bosses on these can give you a couple of cfm for just a few minutes work, so its worth spending that time to reduce their size.
    Just remove the material at either side and lower the height of the surface blending it in to meet the guide, making it more aerodynamic.
    Try to get both sides of the boss symmetrical and mirroring its neighbours but dont worry too much about surface condition at this point, minor changes wont make any noticeable differences and in any case the surface will be addressed lastly after everything else is done.
    Use the photos as a guide for what to aim for.
    Assuming youve got all the guide bosses reduced in height and nicely shaped and the ports lead in sections all roughed out, we can turn the head over and start from the other side.
    Position the head so the manifold face of the intake port faces upwards.
    At the bowl area (arrowed) use the oval burr to remove the edges of the alloy that overlap into the airstream, blending the material so it ends up level with the valve seat insert.
    Youll notice at the sides of the port a deep ridge that alternates on each set of ports, caused by the factory machining.
    Feather these into the seat insert and port as youve done with the rest of the bowl.
    Now turn the head over ( prop it up on a length of timber if needs be) so the intake manifold face is pointing downwards.
    The short side radius turn is next up.This is opposite the bowl that youve just blended in.
    If you look at it, youll notice an apparent lip, almost an overhang where the factory tooling has cut into the port to produce the seating area for the insert.
    This sharp lip is detrimental ( very) to getting air into the cylinder because air dosent like to take sharp turns and when its moving at close to supersonic speeds as in a port it really
    dosent like to change direction.
    The air coming off that lip creates vortexes and back eddys that make the stream turbulent which stops air further back up the intake from going where we want it.
    When reshaping this turn we want to be making it aerodynamic, which is what the profile will be when we’ve finished on it.
    Ive already done the hard work for you here and made a copy of the profile in 3D and scanned this radius gauge thatll allow the port to flow close on 245cfm as opposed to just 204 if that radius is wrong.
    You need to copy the shape as closely as you can and use it to check the shape of the turn as
    you go.



    Typical flow result from simply rounding the edge.



    Result of modifying to the shape shown with the radius gauge.


  8. #8

    Default

    This is one of the hardest parts of the job and itll take quite some time to get it just right but the payoff is way better flow with the valves in than youd get just by rounding that edge off.
    Once youve carefully shaped the short side radius, you need to apply some efforts to the sides of the port walls where the SSR meets the vertical parts.
    If you position the head on its end and look back up the intake from the valves, youll notice a “hump” type shape as the port wall makes the turn.
    Its present on both outer and inner walls ( splitter side).
    Youll need to be careful how you approach this bit of the job, what youre doing is making room for the air as it slows and goes around the SSR and blending the sides and SSR together, but not cutting into the already modified SSR.
    In my case I transfer the head back and forth to the bench, test it, modify the area then retest to check the changes, takes ages.
    Youre not going to be able to do that, so just aim to smooth and flatten that hump on both sides of the port, blending it in to the SSR at the apexes.
    A gentle touch with a finger can usually detect what the eye dosent, so use that as a guide and stop when it feels smooth and flat.
    Now youve done all these, turn your attention to the port divider/splitter.
    The basic idea here is to slim the bluff nose of it down, reducing its width at the leading edge and smoothing the surfaces as it proceeds further into the port.
    No need to knife edge sharpen it, just apply a small radius so its not dead sharp and dont work soley on one side, itll end up biasing the flow one way or the other which affects overall flow, again patience and care will see you right.
    Use a pair of dividers to keep it central in the port by comparison.

    Incidentally, i discovered that a small pea sized piece of plasticine applied to the bottom of the splitter had the effect of altering the air flow characteristics so a totally unmodified port would flow something like 225cfm, although post modification the phenomenon is absent.

    Once youve completed all the major works in the ports you can start to apply a surface finish.
    I use 80 grit sanding drums and 80 grit emery wrapped around a rod to further flatten and smooth the surfaces and impart a nice flow friendly surface.
    Its best to run this at a moderate speed as too fast will just make it uncontrollable and the media wears faster.
    You can use wd40 to help but I dont find it always necessary except in the chambers.
    Start at the port mouth and work around the periphery, youll feel and see the effects of it almost immediately, continue that method all the way .
    To get that cross hatch effect, make a copy of the split fork deburrer tool shown in the photo,stroke the tool back and forth covering the entire port, but be sure to not dwell in one area, keep it moving until youre satsified with the results and you
    have a uniform finish.





    Basic shape differences between the modified on the left and the as factory cast ports on the right, notice the nice smooth radius.




    In the chamber, use the sanding drum to carefully dress the surface and remove the myriad of pits and marks in the alloy.
    Youre just aiming to remove sharp edges and blending surfaces.
    Try to form smooth contours where the alloy runs down to the seats.
    There are lots of edges in this part of the chamber and I use a homebrewed cutter to remove them evenly, but its possible to use old valves with the outer diameter reduced and the head ground with a bevel to protect the seats while youre working in the chamber with a sanding
    drum, something i also use.
    Aim for a 120 grit finish in the chamber and use a small piece of red scotchbrite to polish the chamber off with.
    You can go smoother but it takes a lot of effort and time.
    Aim to get the ports and chambers as shown in the photos.



    The exhaust ports are far simpler to work on believe it or not.
    They too suffer from all the intakes casting flaws and can be improved quite markedly.
    The 3vz fe has an odd head design especially on the exhaust ports because theyre not identical across all three of them.
    Two are of a “dog leg” design whereby one side of the port is a straight shot out with the
    other runner coming in at around 40 ish degrees and merging.
    This creates turbulence and a loss.
    All we can really do here is improve it so it flows better.
    The “odd” port out on the end of the head is more of a siamesed design with almost equal length runners and this definitely flows better to the tune of around 10cfm over the other
    exhaust ports.
    That kind of leads to a bit of a quandry.
    Improve it or not?
    Well yes, but bear in mind itll easily outflow the other exhausts if you apply the same measures to it as all the others.
    I tend to develop the dog legged ports to flow equally and as highly as I can bearing in the mind the exhaust to intake ratio and try to get them at 80% and then do that “straight shot” port last, balancing the airflow to match the others.
    All youll be able to do, is make them resemble each other as closely as possible and leave it at that.
    I have it on great authority that balancing the exhaust flows isnt as critical so im happy to bow to much greater knowledge on that score.
    Ok, proceed with the exhaust ports as per the intakes, removing casting lines and imperfections at the port exit (at the face and working inwards).
    Theyre awkward to do due to their shape, but stick with it and youll get there.
    The guide bosses are a fair size on these.
    Reduce them as per the intakes, mostly on the widths and the “ramp” at the front of them leading to the guide, smoothing and blending them in.
    Once youre happy with these, turn the head over and examine the bowl area ( under the valve
    head).
    Youll notice some material just below the seat which needs smoothing and a rather large overhang.
    I try to blend the overhang into the seat insert/ port but its pretty much impossible to remove
    it entirely as youd have to burrow into the material far deeper than really is good and its
    purely an aesthetic operation to remove it which you wont see when its all together anyway.
    In this case, just smooth it as best as possible.
    The sides of the ports at the divider have a similar “hump” to the intakes, so again its a case of basically flattening them and blending in to the rest of the port.
    The exhaust also has an SSR which heavily influences how well the port can flow.
    A finger prodded into the port will expose a sharp edge which creates restriction and turbulence just as on the intakes.

    Exhaust port mould, notice the sharp edge at the left, (short side radius is non existent).



    Using the template for exhaust ports, develop a nice radius as shown here which will flow a significant amount more than stock.





    Use the tool template shown to develop a highly flowing port.
    Once youve addressed that, apply a similar finish to the exhaust port surfaces as the intakes using the methods youll now have developed.
    You can finish these to 120 grit as itll help to reduce carbon buildup than a rougher surface which can alter the flow of the ports over time.
    If youve done a good job, you should have ports that are closely matched for both flow and give a good improvement.



    Areas requiring attention.

    Heres a 3vzfe head in section view, the most important areas to modify are between the red lines.
    This ports already had the sharp edges removed and flows better than stock but its nowhere near as good as it can be.




    Added extra info.

    Refer to the two photos of the sectioned lower intake manifold.
    Note the "bump" in the roof just prior to the injector.
    This creates a loss and should be reduced as much as possible to match the intake port size.
    Care needs to be taken to remove only enough material so as not to break into the the air assist channel that feeds the injectors.
    Remove material also from the sides and upper corners of the runner using a pair of dividers calibrated to the port size as a guide, leave the floor of the runner alone, removal of material here has no effect.

  9. #9

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    Looking down the lower intake, notice the top of the runner is closed off by that "hump" in the roof.




    Note: the radius gauge templates should display at full size (119mm long on the longest run) simply trace it to paper or plastic and transfer to steel or alloy sheet.


    Ive got a 3vzfe cylinder head on its way and ill use it as a test head for valve seat mods as theres absolutely no info out there whatsoever on seat angle combos for these motors.
    They do have a multi angle cut on the intakes but whether or not its anywhere near optimal is unknown.
    Ill try and fill those particular blanks in shortly.

    Meanwhile i did some in depth testing on a Vw/Audi head for a friend who wanted more more more specifically on valve seats, the results of working purely on those can be found in the following article.

    Valve seats.

    Are critically important really, basically they seal the chamber and allow the gases in and out to state the obvious.
    Whats not so obvious is the impact the valve seat angles can have on the efficiency of inducted and exhausted flows.
    So what about the angles and what works best?
    Unfortunately theres no single one size fits all we can use on all heads as each head (different makes/marques/models) all have differences that dictate what will work best for it, things such as port downdraught angle, short side radius shape, valve shape, chamber shrouding (if any).

    What i can show you here is the results of some optimisation on an intake valve seat, the port isnt modified at all, the differences generated come entirely from the seats unless otherwise stated.

    Ok, so lets have a look at a typical valve seat that you might find on just about any head.
    This is a VW/Audi head i did recently, all its had done at this point is to lap the valve to its seat so it seals ok, the guides were absolutely worn out though, no wonder the engine didnt make any power.
    45 degree seat angle, 75 lower cut into the valve throat.





    Heres a link to a video i made. Have a listen to the whistling sound that occurs when the valve hits about 2.5mm off its seat.
    It got so loud at one point the camera started to overload.

    Valve lift test.

    http://www.youtube.com/watch?v=SyUio7RaL0Y


    That whistling sound is caused by the port oscillating , created in this case by a "backcut" thats been applied to the valve head, we've all heard of that operation at one time or another.
    Its created a seat combination that performs very badly, worse than stock in this case, it destroys low lift flow, although it does recover later on and is better than the standard valve shape at higher lifts on this head.



    Hers a comparison of two intake valves.
    Stock item on the right, modified on the left is the one making all the noise.




    Heres a look at the modified seats created some 24 lift tests( thats about 528 individual measurements) later to get somewhere close to optimal.
    I still think theres some flow left in this one because the lower seat angle flows worse at 75 degrees but better at 60 degrees.
    I think if i went about half way between those two at about 67 degrees id be pretty much spot on.
    I wasnt able to try that out though as the cutter needed for it is a special order item, i could have gone with a 70 cutter i suppose but the gains for the cost of the cutter made it uneconomical in this case.





    So whats all that effort get us from an otherwise standard port?

    Heres a graph of the best curve generated by the above.




    As you can see, its flow gained for really not much work ( once the developments done!) and at this point the ports not even touched.

    The red line incidentally is the flow of the port with no valves in and represents the maximum possible flow it can make as is.
    If the lift curve can intersect with it (not always possible) then at some point the valve will no longer be the restriction and youll be getting the maximum you can out of it, which is the whole point.


    This final graph shows the results of both seat and port mods on another same head from the same maker, the development work from the other head having been implemented on it.
    Yellow-modified intake.
    Red stock intake.
    Blue-modified exhaust.
    Black0stock exhaust.





    Gains on newer heads probably wouldnt be quite so marked as the above becuase manufacturers have gotten smarter and make them better, still, theres usually something left to get.
    Last edited by FourVeeSix; 03-17-2013 at 08:36 PM. Reason: Added extra info.

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    this is awesome information. now we need to apply it to 1MZ 3MZ heads.
    2001 Celica GT-S Turbo 2ZZ-GTE
    1997 Supra TT 6 speed 2JZ-GTE
    1997 Celica GT 1MZ/3MZ V6 hybrid
    1990 Celica All-Trac 3S-GTE

  11. #11

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    Well i have a 3vzfe head here to play with which ive already started on.
    Looks like its not very responsive to mods to the seats at least at this point.

    More when ive got some time to get on it, this audi turbo motors taking a lot of effort .

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