Cylinder Head Porting

Hi i'm new. I am currently starting a Cylinder head Porting project. I have previously ported an 8V VW head very basically. The head i will be porting now is a 16V 1.6 Zetec. I would like some advice on how to get the best flow throught the ports. I have acess to a Superflow Flowbench and all the tools required for porting.

Heres some moulds i took. Intake: [URL=http://img816.imageshack.us/i/img0730i0.jpg/][/URL]

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[URL=http://img220.imageshack.us/i/img07310.jpg/][/URL]

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[URL=http://img444.imageshack.us/i/img07320.jpg/][/URL]

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Exhaust: [URL=http://img593.imageshack.us/i/img07330.jpg/][/URL]

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[URL=http://img718.imageshack.us/i/img0734t.jpg/][/URL]

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[URL=http://img213.imageshack.us/i/img0735vj.jpg/][/URL]

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[URL=http://img689.imageshack.us/i/img0736sh.jpg/][/URL]

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The actual Head : [URL=http://img508.imageshack.us/i/img0725j.jpg/][/URL]

[URL=http://img121.imageshack.us/i/img0727k.jpg/][/URL]

Cheers

Having more chocolate than biscuit will certainly help.

"blend" the bowls - where the machined part meets the casting. "Blend" the valve guide port so it isn't so pronounced.

That is where I'd begin.........

I would like to see a head porting article in GRM

belteshazzar wrote: I would like to see a head porting article in GRM

+1

This seems like the ultimate low-buck way to gain power. You, some time, and a die-grinder = more horsepowers in a totally stock appearing package.

belteshazzar wrote: I would like to see a head porting article in GRM

that isn't as easy as it may seem.... for each head is different, and it takes more than a flowbench to determine what to do.

John P. on teamzx2.com. does a lot of porting on the 2.0 Zetec. He may be of some help.

oldeskewltoy wrote:

belteshazzar wrote: I would like to see a head porting article in GRM

that isn't as easy as it may seem.... for each head is different, and it takes more than a flowbench to determine what to do.

that's fine, have a running series.

caveat: im not suggesting you didnt already know the information i disclose below but i figure someone could benefit from it.

it is important to understand how dynamic this subject is, changing one piece will have an impact on the whole system.

i would look at some dynos sheets to get an idea where power tends to fall off with various mods to better understand what may be limiting the efficiency of the system. velocity should be considered more than flow. losing to much velocity (over porting) may cause the fuel to lose it atomization resulting in pour flame propagation -> lose of power. if you port consider also changing other pieces to compliment the added flow; e.g. shape/length/size of intake runners, position of the injectors, size of the intake plenum, lift and duration of cams. proper modifications with the above components is why one engine will make more power then another. the changes to various pieces do not need to be arbitrary there are calculators and guidelines available online that will encourage an efficient end result. ill try and keep track of this thread to see how it turns out.

The problem with head porting is theres no Best way for all heads, What work for one my not for others and Large flow numbers are not always the best. You need Velocity of the flow too, even in EFI motors velocity plays a big part in cyl filling with ram efects.

GRM did do a small article a few years back. David Visard wrote it i recall.

44

@ fitzi - tell us how you made those molds. That would be good to know.

I'm surprised at how sharp the angle change is on the intake from the runner to the bowl. It looks like there is an opportunity there to increase flow without killing the flow velocity.

Plenty of potential by increasing the individual runners volume in relation to the single port. JMO.

But agreed on the there is no "one size fits all" port work. Just like the shirts/pants/sweats that say that, they don't fit anybody because they fit everybody.

Brian

In reply to fitzi:

Fitzi How did you make your casting?

drmike wrote: @ fitzi - tell us how you made those molds. That would be good to know. I'm surprised at how sharp the angle change is on the intake from the runner to the bowl. It looks like there is an opportunity there to increase flow without killing the flow velocity.

There is a 2 part rubber mold kit out there to allow someone to see what stuff looks like inside. Here is a link: Port molding

Brian

Here is an example of some porting I've done - Toyota 4AG head. The majority of 4AG work should be done in the exhaust

I did some Miata head porting recently:

GRM link to Miata head porting

Also here is an (OOOOLD) webpage on MINI head porting I did a while ago:

Link to MINI head porting pages

I learned allot here:

http://www.theoldone.com/articles/

Here is a forum on homebuilding flow benches.

http://www.flowbenchtech.com/forum/

How many heads do you have to get it right?

What's the intake to exhaust flow ratio, up to the limit of available cam lift?

Thanks for all the replys! By far the best forum i posted this on! @iceracer Waiting for my activation email :)

@Drmike @vazbmw It is a silicone moulding kit containing a tin of dilicone and a bottle of curer. i bought mine from trylon.co.uk but im from the UK. Its quite expensive 500grams £25.

@paulvr6 I only have one so ive ported carefully. Started it today took advice on blending the bowls seems to come out well. One thing im struggling with is valve guides and weather to smooth them right down so they are almost flat to the port wall. I have smothed them down but they still protrude. On the flow bench tomorrow :)

Cheers for all the other replys :D

Did you flow it before? For guides usually I'll port the guides flat to get the transition right and then press in new tapered ones. I don't like running street heads with flush guides (unless they're really long valves).

I've seen the biggest bang for the material removed in the area you're getting into. Bowl work, guide area and a reworked short turn usually are all you really need.. unless the actual port size is too small for the valve size. If you are increasing port size in a certain area, make sure you're doing it for a good reason, to get rid of a choke point. You can increase the size up the runner, but only go a few % per inch and make sure that it doesn't go up then back down.

You will have to worry about velocity even on a fuel injected head, so don't go whole hog!

I know for a bitter fact that flush guides are not a good thing. The valves wobble in the seat and cause all sorts of grief. The worst is that you'll do a BUNCH of work for naught, and have to redo guides and seats at best, and guides, seats and valves at next best, and the whole lot at worst.

just for a E36 M3s and giggles butt dyno level data point. I ported a head on a 96-00 d16- y5 or y8 casting (same thing flow wise) based on what i learned at the endyne site and the info gleaned from the proprietor at R&B machine in portland oregon (great guy). the changes: 9.3 ish compression uped to 10.5, a fairly conservative porting job that was only aggressive on the "short radius". otherwise it was mostly cleaning up core shift and matching the mildly opened up intake manifold runners to the intake ports, and opening up the exhaust ports to the honda oem EX header while leaving the "floor" and "roof" very nearly alone (that is very common advise if one does a bit of research). R&B also did a full radius valve/seat interface with very current machinery. With a stock ecu, the car was solidly quicker across the entire power band. I was pleasantly surprised. It particularly pulled much better from idle. The car was stolen and the head was removed by the berkeleying asshats. I bough a stock head and put it on to get the car to get it running. Ouch. Not as much fun. I was very impressed with what a slight bump in compression and a little cleaning up can get you.

There might have been some good all around power in that valve job too.