Head porting + gutted cat

sleeper2 · Aug 18, 2007

I would like to know if some of you done that?

Since my motor is dead, ford will change the base, i asked to get the head some time just enough to make a lil port job...
I have all the tools needed, and i already done that to a zetec head, do the D23 head has something particular to watch?

I would like to buy a header too, but since i don't found anywhere that they sell the flex with it, i would like to "port match" my oem and empty the cat.
Would it worth the job?

3xzsucof · Aug 18, 2007

ford racing now has ported heads for the duratec.

Qwik1 · Aug 18, 2007

The Duratec head already flows extremely well. So well, that a port job is much more likely to hurt than to help! Please don't.

whyme · Aug 18, 2007

port matching and hollowing the cat will improve performance but a well built header is designed to maintain flow velocity to improve torque.

F2USA.com does sell headers w/ the flex and the cosworth header can reuse the stock flex (unless it is a single piece manifold/flex), in that case you would need the separate flex. the stock flex is constricting anyway though.

be careful with the duratec head, talk to someone who has done it on one before because the optimum design isn't far off the stock casting and you could easily hurt flow if you aren't totally clear on what you are doing.

pitchblack23 · Aug 19, 2007

Gutted cats suck. A cheap high-flow cat will be better for your emissions and flow better than a gutted stocker.

sleeper2 · Aug 19, 2007

whyme said:
be careful with the duratec head, talk to someone who has done it on one before because the optimum design isn't far off the stock casting and you could easily hurt flow if you aren't totally clear on what you are doing.

thats why i've posted!

i know gutted cat is not the best.. for the moment i do not have the cash for the header since my motor is in rebuilt.
i was looking at gut the cat to get more flow til i get a header, i dont worry about emissions
i have a 1 piece header/flex

Oreo · Aug 19, 2007

Well then my recommendation would be to do this... Find yourself a local junkyard & see if you can't find a duratec 2.0 or 2.3l bare head for real cheap. I think there's one or two near me that will sell these for less then $100. Use this spare head for practice. You've got 3 tries. The fourth should be left as stock for a control comparison.

Go to the library & see if you can check out any books on head porting. There are quite a few decent resources with pics online if you spend the time to search for them. Understand exactly what it is you're trying to do first. Then keep in mind that the less material you remove from our heads the better your results will be.

Try out your skills on the spare head. Do each cylinder a little different, perhaps a little mild on one, a little more agressive on the other. Now take that head to a local performance shop & get them to flow test it. If you're results are better then the one you left as stock then you know you're on the right track. For the cylinder that scored the best on the flow bench, try to duplicate what you did to it exactly on all for cylinders of the head you intend to use on your engine.

Predator · Aug 19, 2007

If it was me,
The head flows very well in stock form. I would remove any flashing, smooth parting lines, and round any edge. I would not remove much material.

I would spend my time polishing the ports. I would get the exhaust side as smooth as I could. I would get the intake smooth, but since I want low/mid torque I wouldn't get it to shine like the exhaust. A little bit of turbulance will help mix the mixture.

pitchblack23 · Aug 19, 2007

sleeper2 said:
i was looking at gut the cat to get more flow

I gutted the cat on my first car and it flowed worse. There's a real problem with stagnation, the same problem you get when you slap a huge coffee can muffler onto a small exhaust.

whyme · Aug 19, 2007

just a thought, if you really cant afford a header and dont whant to wait cut out the section of the manifold that houses the cat and weld in a piece of exhaust that is the same diameter as both ends.

in either case you will get a CEL and will need a tune or MIL eliminator to fix it.

sleeper2 · Aug 19, 2007

Predator said:
If it was me,
The head flows very well in stock form. I would remove any flashing, smooth parting lines, and round any edge. I would not remove much material.

I would spend my time polishing the ports. I would get the exhaust side as smooth as I could. I would get the intake smooth, but since I want low/mid torque I wouldn't get it to shine like the exhaust. A little bit of turbulance will help mix the mixture.

thats exactly what i have in mind

i already done the job on a zetec head and it gved me very good results, so the dura head is much better and doesn't require so much job, i am just looking to smooth port, and port match with the head gaskets/manifolds.

But sometimes there is someting precise to remove, and since i do not have it in hands now, i am asking if you already done the job and if you have seen something very special.

arty · Aug 19, 2007

Have you seen the ported head graphs I posted for the ported heads I have for sale? The max ported head is sold the mild port job is still available. Check it out.
http://forums.focaljet.com/power/547434-sale-duratec-2-0-2-3-ported-head.html

Depending on mods the 2.3L Duratec head does not need much work. FI head will flow lots more air so it all helps. Let me know if I can help.

Z63R · Aug 20, 2007

One had better choose an experienced head porter; as said elsewhere in this thread, it'd be very easy to ruin a perfectly good casting which, by the way, flows enough air to make 220 HP as cast.

"Gutting" a catalytic onvertor is one of the most retarded things to do to a modern car. Don't.

Buy a reputable aftermarket high flow cat instead if you must.

biscuitninja · Aug 20, 2007

If you have a 2.0L then just get a 2.3L header, they flow MUCH better than the regular 2.0L unit and are factory fit! It may not flow as well as an aftermarket header, but it will be MUCH cheaper than it. Anyways good luck.
-bix

Oreo · Aug 20, 2007

Predator said:
If it was me,
The head flows very well in stock form. I would remove any flashing, smooth parting lines, and round any edge. I would not remove much material.

I would spend my time polishing the ports. I would get the exhaust side as smooth as I could. I would get the intake smooth, but since I want low/mid torque I wouldn't get it to shine like the exhaust. A little bit of turbulance will help mix the mixture.

For the record, you don't ever polish the intake ports. Since this is the area the fuel is injected into, the rough texture provides more surface area for any condensed fuel to evaporate from. The exhaust ports get polished to help prevent / shed carbon deposit build-up.

I've done some research on what the duratec head needs. Aside from some light finishing work to take off the rough edges, there is a little work on the combustion chamber side to be done to unshroud the valves. The idea is to use the head gasket to precisely mark the cylinder wall boundaries. You can remove a little material between the valve & the wall. However, some thought needs to be given to keeping all the cylinders exactly the same, (there's a technique for this) and removing as little material as possible to get the job done. Additionally, on some heads they shape this area to aid swirl. I'm not sure if this technique is used on the duratec heads though.

vin0410 · Aug 20, 2007

remember also to match the inlet ports with manifold and exhaust ports with header exactly. this will smooth the flows.
I saw one article saying most power gain from porting come from where the valve meets the combution chamber. So I believe unshrouding will help a lot. So the inlet valves cone are also worth some attention to imrpove the air flow around it.
You may also shape the bottom of the exhaust valves a little bit convaxed to aid the exhaust flow.

sleeper2 · Aug 23, 2007

Finally ford get the whole engine replaced.. so i did not do the job on the head.

and guys i take a look at the head and realize that no one here never looked theirs.. there is at least 1/8 all around the exhaust ports that can be removed just to match the gasket size, and the exhaust ports finish is like it had been sandblasted.. there is place for improvements.

Head porting + gutted cat

sleeper2

3xzsucof

Qwik1

whyme

pitchblack23

sleeper2

Oreo

Predator

pitchblack23

whyme

sleeper2

arty

Z63R

biscuitninja

Oreo

vin0410

sleeper2

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