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A basic guide to doing head work, I'E port and polish


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-------------------------------------------------------------------------------------WARNING-----------------------------------------------------------------------------------------

THIS IS A GUIDE ONLY, I WILL NOT BE HELD RESPONSIBLE FOR PERSONAL INJERY OR DAMAGE TO ANY CYLINDER HEADS DONE BY FOLLOWING THIS GUIDE, IF YOU ARE UNSURE THEN PLEASE SEND THE HEAD TO A SPECIALIST FOR THE WORK TO BE DONE. I AM MORE THAN HAPPY TO TAKE ON THIS WORK SO PLEASE EMAIL ME AT [email protected].

I HAVE BEEN DOING CYLINDER HEAD WORK FOR THE BEST PART OF 10 YEAR WORKING WITH PEOPLE THAT HAVE BEEN DOING THIS FOR MANY MORE YEARS THAN ME.

I HAVE WORKED WITH SOME MECHANICS FOR GINETTA RACE CARS AND OTHER HEAD SPECIALISTS WORKING WITH THE RIGHT TOOLS AND EQUIPMENT FOR TESTING AND DEVELOPING CYLINDER HEADS ( I.E SUPERFLOW FLOW BENCHES ).

IF YOU ARE ARE AT A STAGE BEONED THIS THEN I WILL BE MORE THAN HAPPY TO SELL YOU A PTS/HYBRID FLOWBENCH CAPABLE OF FLOWING OVER 600CFM'S AT 28IN PRESSURE. PRICES START AT £7000 inc Excel software

Right lest get started

Heath and safety is very important so get yourself some eye protection and a dust mask at least. You don't want aluminium swaf in you eyes or in your lungs from using from the dust produced by the emery cloth from the finishing.

The tools

Over the many year of doing head work you pick up you own ways of doing things and you make your own tools also but the the main tool you need is a air die grinder or a electrical one thats capable of 25,000 rpms, the one you will see i'm using is a electrical one. Don't even bother with a drill with a flex shaft as at the most it will run about few thousands rpm's and is only able to run at less than a hour before it starts to over heat if your lucky.

Here is what i use

Buy Proxxon LB/E Long Neck Straight Drill/Grinder from Axminster, fast delivery for the UK

Buy Axminster Heavy Duty Flexible Drive Unit from Axminster, fast delivery for the UK

Here is a few things you will need

P1050782-1.jpg

As you can see some of the stuff is self explanatory and some not but all of it will be covered as i go though this thread

Carbide burs

I found that the good ones can last a life time if looked after, i Paid £25+ for each of these but i'm doing this a lot so the cheaper ones will be fine for you

Cromwell Industrial Tools UK: Quick Search Results...

P1050783.jpg

Cartridge roll test kit

Used for some of the head to reach places

Cromwell Industrial Tools UK: York Abrasives : CARTRIDGE ROLL KIT 122PCE : YRK-205-9800K

P1050784.jpg

Scotchbrite/emery cloth roll, Flap sander, Scotchbrite roll, split rod to use with emery cloth and two of my tools i made for making sure the ports and round, smooth and uniformed and one that i use the most as to replace the emery cloth is easy and cheaper than the flap wheels.

flap wheel and scotchbrites found at Model Engineering and engineering tools online from RDG Tools Ltd Home Page (Engineering Tools) Tel 01422 885069

P1050785.jpg

Emery cloth 60 grit, 120 grit, 180 grit and 400 grit

Workshop Consumables | Abrasives | Abrasive Cloths

P1050787.jpg

spring calipers set is used to make sure every port is the same size and that each port is the same diameter run though

Found at any machine mart

P1050786.jpg

Spring compressor, this is a great little one that fits zetec, I4 and even Vag 20v head with small tappets, its light and come with different size fitting

Also found at machine mart

P1050788.jpg

Oil seal removal tool, loads better that a pair of pliers, trust me if you ever come to dismantling a 20v Vag head or motor bike head these are a must

I got these cheap on ebay at £20 they have been modified to get a small bore tappet holes.

P1050789.jpg

When dismantling the head you want to keep every valve component in the right order they came out of as that part is worn matched to the guide, if fitting new valves some time new guides and seats need recutting, if the old parts go back in the wrong order they will wear out faster. This is just a bit of MDF with holes drilled in it marked with what cylinder and valve number

P1050790.jpg

Digital caliper, i will show you what this is used for later in the thread

Also found in machine mart

P1050791.jpg

Magnetic pick up tool for when you remove the collets

Found in most Halfords and motor spares shop

P1050793.jpg

Head stand for disassemble and reassembling the head as this will make things much easier. found very cheap on Ebay

P1050794.jpg

Basic head porting will start latter on as this is just a started

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You've now stripped you head and you've keep everything in order what you need to do next is clean the head and inspect it for any damage, seeing most of you will be reading this to do work on there I4 then you will be looking for cracks. You don't want to be doing hours of work on a head to find out its cracked and rendered useless.

When cleaning a head your best getting one of these but if not a old tube with lots of hot soppy water, a jet wash is another or your mother/other half dish washer.

You could also use brick acid or oven cleaner on stubborn dirt

P1050820-1.jpg

Right your about to start

Its not the easiest to see what your doing so some sort of light is needed the brighter the better, You can also in the picture a vacuum cleaner to keep the dust down

At this point if its a head i've never worked on i will make a mould of the port with silicone rubber to see were the restrictions are but this is something you wont be doing as its one of the advanced side of head portering.

P1050811-1.jpg

Right what are the bits that can be removed to increase flow, the guide is one but if the guide is short in the first place then you don't want to shorten it as this will increase wear anyway this one is small and fine to flatten and make flush with the port wall.

The next this is the siemese split on this 16v head

P1050800.jpg

P1050801-1.jpg

P1050795.jpg

Go round the head check the head and see where you could break though into the water jacket, you don't want that to happen, just use a scribe and your finger to get a idea

P1050796.jpg

When starting take a look at were the seat its and don't grind it or the head will be scrap

P1050797.jpg

P1050798.jpg

P1050803-1.jpg

If you cant see it because of carbon build up then do a bit of valve grinding with some engineering blue

P1050804-1.jpg

P1050799.jpg

You can now see a light grey line were the seat is

P1050805-1.jpg

Use a correct size burr for the size of the port, too big of a burr in the port can snag in a sharp corner of a port and break damaging the head or yourself. This is were the best of the performance will come just behind the valve.

Keep the burr moving, don't stop in one place as you will get a uneven surface

Take it out to the valve seat were the valve sits

DON'T MAKE THE SEAT TO SLIM ON THE I4 AS THEY NEED BIGISH SEATS BECAUSE OF THE HEADS ARE PRONE TO CRACKS BECAUSE OF HEAT

P1050806-1.jpg

Tapper the port here making it flat will loose you bhp

P1050807-1.jpg

Use lube to cool the burr as it works best when cool and it will look after the burr

P1050808-1.jpg

Check your work all the time, stop and blow away all chipping with a blow gun

P1050809-1.jpg

This is were the caliper comes in

P1050812-1.jpg

take note of the size of the port and repeat on the rest of the ports

P1050813-1.jpg

P1050814-1.jpg

P1050815-1.jpg

P1050816-1.jpg

Before you started the head will look like this

Before

P1050822-1.jpg

And what its looks like after

After

P1050821-1.jpg

I've opened the port a bit more on this head to match the gasket line

Repeat on the rest of the ports checking port sizes and valve seats as you go

Thats the main cutting done

More to come, the next lesson is finishing using emery cloth

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Right emery cloth time

You can see other restrictions that can be removed with emery cloth or a flap wheel, starting with a 60 grit

P1050825.jpg

P1050823.jpg

P1050824.jpg

As again keep the tool moving and use WD40 to keep its lubricated

P1050826.jpg

Take a look at your work and this is what is should look like

P1050827.jpg

P1050828.jpg

Now i swap tools to the one i made to do the ports, it make it easier to open the ports all the way though and not at the ends. Now with a 120 grit cloth.

P1050828.jpg

P1050837.jpg

P1050838.jpg

P1050839.jpg

P1050840.jpg

P1050841.jpg

P1050842.jpg

You can also use a split rod with emery cloth in it

P1050844.jpg

P1050845.jpg

P1050848.jpg

P1050849.jpg

When doing the exhaust ports i spend more time on them and take out more metal than i would on the exhaust ports, There tends to be less work done at the factory *on the exhaust ports for economies of scale leaving more scope for gains, its is especially important with turbo engines as this will give better spool up for the turbo.

Here is what the the port should look like

P1050851.jpg

P1050852.jpg

P1050853.jpg

Going over the port with a scotchbrite to finish off the port

P1050854.jpg

P1050855.jpg

I normally finish off the inlet port with 120 grit and the exhaust with 180 grit and depending on the engine i might go over the exhaust port with 400 grit to stop carbon build up

Going back to my own tool again i use it to clean up the manifold face

P1050856.jpg

P1050858.jpg

P1050862.jpg

P1050864.jpg

The same goes for the exhaust side so just repeat the steps above one that side

Next step with be modifying the combustion chamber and removing valve shrouding

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Right now we go onto the combustion chamber

Most people that do head work over look the chamber and leave it as standard but not me or some others out there.

Why are we doing this? Valve shrouding.. Whats thats you ask.

Anything thats near the valve head is shrouding

As seen below near the spark plug, also we are smoothing the chamber to stop carbon build up

P1050871.jpg

P1050870.jpg

Right this is what you need to smooth the chamber

Find some old valves and ground the face down

P1050877.jpg

P1050878.jpg

Place them in the head and as you can see the valves sit lower in the head

P1050879.jpg

Using your tools seen on page one start to sand down the chamber

As you can see whats been done now

P1050880.jpg

P1050881.jpg

As before start with a 60 grit and work your way down 80, 120 and then 400

Standard

P1050876.jpg

P1050870.jpg

P1050871.jpg

Modified

P1050875.jpg

P1050873.jpg

P1050872.jpg

Once thats done you need to CC the chambers to make sure there all the same and if not you need to even them up

( no pictures of this as i forgot )

Cleaning the valves

Us a wire wheel to get the worst off

P1050883.jpg

Then stick the valve in a piller drill and lube it up and use some 80 grit emery cloth

P1050885.jpg

P1050888.jpg

When there all done its time to lap the valves in with a grinding stick or if you do loads of head like i do then i use a drill but dont run it to fast and make sure the valve steam is lubed up when in the guide.

P1050889.jpg

P1050890.jpg

P1050891.jpg

Now thats all done its time for a skim

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Just to finish off when it comes to the rebuild use some good quality engine assembly lube/paste that can be found on ebay, use loads on the valve before you install them and lots of you cam/cams, tappets/lifter and cam caps

The last thing you need to do is give the head a skim as i bet when you work on your head you will most likely scratch of scuff the face.

The finished this ready to be sent out to the customer

If people like this then i might go on to flow bench work and how to use one and make your own flow bench and design your own software

P1050949.jpg

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You've now stripped you head and you've keep everything in order what you need to do next is clean the head and inspect it for any damage, seeing most of you will be reading this to do work on there I4 then you will be looking for cracks. You don't want to be doing hours of work on a head to find out its cracked and rendered useless.

When cleaning a head your best getting one of these but if not a old tube with lots of hot soppy water, a jet wash is another or your mother/other half dish washer.

You could also use brick acid or oven cleaner on stubborn dirt

P1050820-1.jpg

Right your about to start

Its not the easiest to see what your doing so some sort of light is needed the brighter the better, You can also in the picture a vacuum cleaner to keep the dust down

At this point if its a head i've never worked on i will make a mould of the port with silicone rubber to see were the restrictions are but this is something you wont be doing as its one of the advanced side of head portering.

P1050811-1.jpg

Right what are the bits that can be removed to increase flow, the guide is one but if the guide is short in the first place then you don't want to shorten it as this will increase wear anyway this one is small and fine to flatten and make flush with the port wall.

The next this is the siemese split on this 16v head

P1050800.jpg

P1050801-1.jpg

P1050795.jpg

Go round the head check the head and see where you could break though into the water jacket, you don't want that to happen, just use a scribe and your finger to get a idea

P1050796.jpg

When starting take a look at were the seat its and don't grind it or the head will be scrap

P1050797.jpg

P1050798.jpg

P1050803-1.jpg

If you cant see it because of carbon build up then do a bit of valve grinding with some engineering blue

P1050804-1.jpg

P1050799.jpg

You can now see a light grey line were the seat is

width=800 height=600http://i1001.photobucket.com/albums/af137/flowdynamics/P1050805-1.jpg[/img]

Use a correct size burr for the size of the port, too big of a burr in the port can snag in a sharp corner of a port and break damaging the head or yourself. This is were the best of the performance will come just behind the valve.

Keep the burr moving, don't stop in one place as you will get a uneven surface

Take it out to the valve seat were the valve sits

DON'T MAKE THE SEAT TO SLIM ON THE I4 AS THEY NEED BIGISH SEATS BECAUSE OF THE HEADS ARE PRONE TO CRACKS BECAUSE OF HEAT

P1050806-1.jpg

Tapper the port here making it flat will loose you bhp

P1050807-1.jpg

Use lube to cool the burr as it works best when cool and it will look after the burr

P1050808-1.jpg

Check your work all the time, stop and blow away all chipping with a blow gun

P1050809-1.jpg

This is were the caliper comes in

P1050812-1.jpg

take note of the size of the port and repeat on the rest of the ports

P1050813-1.jpg

P1050814-1.jpg

P1050815-1.jpg

P1050816-1.jpg

Before you started the head will look like this

Before

P1050822-1.jpg

And what its looks like after

After

P1050821-1.jpg

I've opened the port a bit more on this head to match the gasket line

Repeat on the rest of the ports checking port sizes and valve seats as you go

Thats the main cutting done

More to come, the next lesson is finishing using emery cloth

Edited by [email protected]
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Right emery cloth time

You can see other restrictions that can be removed with emery cloth or a flap wheel, starting with a 60 grit

P1050825.jpg

P1050823.jpg

P1050824.jpg

As again keep the tool moving and use WD40 to keep its lubricated

P1050826.jpg

Take a look at your work and this is what is should look like

P1050827.jpg

P1050828.jpg

Now i swap tools to the one i made to do the ports, it make it easier to open the ports all the way though and not at the ends. Now with a 120 grit cloth.

P1050828.jpg

P1050837.jpg

P1050838.jpg

P1050839.jpg

P1050840.jpg

P1050841.jpg

P1050842.jpg

You can also use a split rod with emery cloth in it

P1050844.jpg

P1050845.jpg

P1050848.jpg

P1050849.jpg

When doing the exhaust ports i spend more time on them and take out more metal than i would on the exhaust ports, There tends to be less work done at the factory *on the exhaust ports for economies of scale leaving more scope for gains, its is especially important with turbo engines as this will give better spool up for the turbo.

Here is what the the port should look like

P1050851.jpg

P1050852.jpg

P1050853.jpg

Going over the port with a scotchbrite to finish off the port

[img0]http://i1001.photobucket.com/albums/af137/flowdynamics/P1050854.jpg[/img]

P1050855.jpg

I normally finish off the inlet port with 120 grit and the exhaust with 180 grit and depending on the engine i might go over the exhaust port with 400 grit to stop carbon build up

Going back to my own tool again i use it to clean up the manifold face

P1050856.jpg

P1050858.jpg

P1050862.jpg

P1050864.jpg

The same goes for the exhaust side so just repeat the steps above one that side

Next step with be modifying the combustion chamber and removing valve shrouding

Link to comment
Share on other sites

Right now we go onto the combustion chamber

Most people that do head work over look the chamber and leave it as standard but not me or some others out there.

Why are we doing this? Valve shrouding.. Whats thats you ask.

Anything thats near the valve head is shrouding

As seen below near the spark plug, also we are smoothing the chamber to stop carbon build up

P1050871.jpg

P1050870.jpg

Right this is what you need to smooth the chamber

Find some old valves and ground the face down

P1050877.jpg

P1050878.jpg

Place them in the head and as you can see the valves sit lower in the head

P1050879.jpg

Using your tools seen on page one start to sand down the chamber

As you can see whats been done now

P1050880.jpg

P1050881.jpg

As before start with a 60 grit and work your way down 80, 120 and then 400

Standard

P1050876.jpg

P1050870.jpg

P1050871.jpg

Modified

P1050875.jpg

P1050873.jpg

P1050872.jpg

Once thats done you need to CC the chambers to make sure there all the same and if not you need to even them up

( no pictures of this as i forgot )

Cleaning the valves

Us a wire wheel to get the worst off

P1050883.jpg

Then stick the valve in a piller drill and lube it up and use some 80 grit emery cloth

P1050885.jpg

P1050888.jpg

When there all done its time to lap the valves in with a grinding stick or if you do loads of head like i do then i use a drill but dont run it to fast and make sure the valve steam is lubed up when in the guide.

P1050889.jpg

P1050890.jpg

P1050891.jpg

Now thats all done its time for a skim

Link to comment
Share on other sites

Just to finish off when it comes to the rebuild use some good quality engine assembly lube/paste that can be found on ebay, use loads on the valve before you install them and lots of you cam/cams, tappets/lifter and cam caps

The last thing you need to do is give the head a skim as i bet when you work on your head you will most likely scratch of scuff the face.

The finished this ready to be sent out to the customer

If people like this then i might go on to flow bench work and how to use one and make your own flow bench and design your own software

P1050949.jpg

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