[Rehaan]

Originally Posted by Mpower

All BMW M cars have fully CNC machined intake ports

Wow!! Thats pretty amazing.... did a search and heres an interesting read M Power

cya
R

[arctic]

check info on wikipedia....they say all fluids have problems with very smooth surfaces

Cylinder head porting - Wikipedia, the free encyclopedia

[islandman]

Originally Posted by anant_n1

Hi there.......

Firstly let me tell you..........I am not an engineer !!

But porting and polishing............as far as I know is.........

The engine has a head. There is an intake manifold and an exhaust manifold.

For a 4 cylinder engine. there are 4 ports (or holes) on either side of the head.

Your intake manifold and exhaust manifold are connected to the head on these 4 ports.

In your stock car the area of the valve guide that protrudes into the intake or exhaust port is always a place where sharp edges and restriction to Air/Fuel flow are found. A basic porting project seeks to smooth those sharp edges.

A more significant point of restriction is where the intake or exhaust port floor curves down to meet the valve seat. Called the "short side radius," it is also a place where sharp edges and roughness pose a threat to flow. In this cutaway of a stock cylinder head, the short side radius has not one but two very sharp edges (in some cases)
When you say port polish the head.........what the turner does is .........he grinds the 4 holes with proper instruments (it’s very minimal.....around 1-2mm) and polishes the hole. Porting increases flow of Air/fuel mixture going in and polishing improves the flow.

How much air and fuel goes in.....governs the performance of the car. Likewise and free flow header is required on the exhaust to assist this whole process.

Keeping Air/Fuel and Gas flow smooth is the key here !!

So after port polish you engine is taking in slightly more air and fuel and flowing it smoothly. Thus giving your car a 5-10% improvement in power. Believe me.........you can FEEL IT !!

Normally people even face the head......that increases compression.

My explanation might be slightly wrong.......but I hope you get a basic idea from it.

The above is the most simplest explanation that I have understood about porting.I know its about 2 yrs old. Shame on me for not reading this earlier.

However, I was told that the above procedure was not really porting but Blueprinting. Actual porting job is more complicated than that etc... Is that right? if yes then please explain to a layman what porting really is.

Also if the above procedure alone constitutes Porting why are tuners charging 10k. Should it not be 2-3k job or a max of 5k job including the knowledge cost.

I request some members who have actually done a porting job or have seen one being done to respond to avoid speculation.

[islandman]

Originally Posted by islandman

The above is the most simplest explanation that I have understood about porting.I know its about 2 yrs old. Shame on me for not reading this earlier.

However, I was told that the above procedure was not really porting but Blueprinting. Actual porting job is more complicated than that etc... Is that right? if yes then please explain to a layman what porting really is.

Also if the above procedure alone constitutes Porting why are tuners charging 10k. Should it not be 2-3k job or a max of 5k job including the knowledge cost.

I request some members who have actually done a porting job or have seen one being done to respond to avoid speculation.

C'mon guys help me out on this one..... Help would really be appreciated

[v1p3r]

Originally Posted by anant_n1

A basic porting project seeks to smooth those sharp edges.

Originally Posted by islandman

However, I was told that the above procedure was not really porting but Blueprinting. Actual porting job is more complicated than that etc... Is that right? if yes then please explain to a layman what porting really is.

Your answer lies in that single word in bold. A basic port job, or even a blueprint job, will aim to bring the specs of the engine back to stock. This includes removing any impurities (specifically in the ports), and bringing all values back to those rated by the manufacturer. Obviously, the manufacturer does not rate values for curvature of ports, so you are free to iron out any kinks.

More aggressive porting jobs include enlarging the ports, changing angles of the ports where the charge enters the valves, and matching the ports to the intake and exhaust systems. If needed, the intake and exhaust runner lengths are also carefully calculated, to give a ram-air effect to the charge entering the valves.

Originally Posted by islandman

Also if the above procedure alone constitutes Porting why are tuners charging 10k. Should it not be 2-3k job or a max of 5k job including the knowledge cost.

This charge normally included costing for a new head gasket, labour charges of the garage, and consumables (drill bits etc). You could try doing this, but then a single mistake would mean you end up with a rather heavy and useless piece of metal.

I'm not too good on the tech stuff, but I've seen a few being done, so hope that helped.

[rider60]

people just one doubt here can this porting and polishing be done on diesel engines too?
because i have always heard people talk about the port and polish on the petrol engines alone!

[v1p3r]

Yes, it can.

twentyports

[jkdas]

Originally Posted by rider60

people just one doubt here can this porting and polishing be done on diesel engines too?
because i have always heard people talk about the port and polish on the petrol engines alone!

have been in an Indica which was done by Leela. Amazing it was as it was the old non-turbo version.

[rohan_fonseca]

Check this out AutoSpeed - Porting Gains

[1self]

Originally Posted by rohan_fonseca

Check this out AutoSpeed - Porting Gains

Really informative Rohan! thanks for sharing! i really wonder if anyone in india has a flow-bench & the expertise to do what has been shown in the article!

what happens to cars with ECUs, will they permit a greater volume to be injected? no plans to do anything yet, but when the warranty runs out...

[wildchild4lyfe]

so hey does mahesh work with a flow bench?

[pranavt]

Doubt it. Last time I heard, there were no more than a handful flowbenches in India.

[deutscheafrikar]

Originally Posted by wildchild4lyfe

so hey does mahesh work with a flow bench?

Nope, So does that make it a hit and a miss?

[IndrojitSircar]

Originally Posted by rippergeo

what happens to cars with ECUs, will they permit a greater volume to be injected? no plans to do anything yet, but when the warranty runs out...

The ECU has values saved in it like it has got how much fuel per cylinder and how much air intake, how much exhaust timing etc. So if we do that i guess we would have to change the values in the ECU which can be done on a few cars and by only the manufacturing company's authorised service centre or by a very experienced modifier who knows about polishing and porting as well as re-setting the ECU. Its not like its impossible but yes its a bit complicated compared to the carb cars, but those cars had their own complications as well. By the way what car are you planning to get it done on?