Archive for the ‘Cylinder Head Porting’ Category

Avoid These Porting Mistakes

Friday, June 18th, 2010

Factory manufactured cylinder heads do not always perform as well as they could due to manufacturing restraints.  A common process performed to modify the ports is called cylinder head porting.  This process is essential in getting the most efficient amount and quality of air flow to the intake and outtake ports.  By porting the cylinder heads, you allow the engine to perform at peak efficiency.  The process is considered one of the most important factors in producing high power output from modern engines.  Cylinder head porting can be used to enhance the performance of a standard racing engine or applied to a factory engine to increase power and performance.

The process is not one that is easy or without complications and is often best suited for a professional who provides cylinder head porting service.  People trained and experienced in cylinder head porting have the skill and knowledge to achieve the desired results.  With that in mind, there are still many people who prefer to work on their own vehicle.  This may be due to budget restrictions or simply a desire to have the hands-on experience.  For those who decline the use of a cylinder head porting service, there are a few common pitfalls in the porting process which should be avoided.  Here are a few tips to ensure these pitfalls are not the downfall of your DIY project.

Be prepared-  There is no point in starting the process unless and until you have all the necessary tools to do so.  This includes the right cutting tools as well as the safety equipment needed to avoid injury.  Flying metal and dust particles require at minimum- a good pair of safety glasses as well as a mask to filter out particles in the air.  Have a shop vac handy to clean up your work area as you go, this can also be used to clear debris from the ports as you work.

Don’t rush the process-  Depending on what material you are working with, the process can take a good 8-12 hours of time.  That is of course if you are working with all the recommended tools and are able to fully concentrate on the job at hand during that time.  Remember that when working with cast iron you will need more cutting time than aluminum.

Do your research before you start- New projects often require a bit of trial and error, however you do not want to begin this process blind.  Research the products you are working with and the correct process used to reach your end goal.  Having a well thought out plan of attack before strapping on the safety glasses will surely increase the likelihood of a positive outcome.

Know when to seek help-  With the proper research and tools there is a good chance that you will be able to pull off the porting process on your own, however it is wise to know when to accept defeat.  If you continue moving forward on a downhill project it will just end up costing you more money and time in the end.  Be reasonable and do not allow your pride to get in the way of seeking professional help from a cylinder head porting service should you notice you are not getting the intended results.

Do it Yourself: Cylinder Head Porting Service

Thursday, June 17th, 2010

More power! Horsepower! The goal of porting is to establish better airflow through the cylinder head.  Some people mistakenly believe that cylinder head porting is about the port size – but it’s actually about air flow and how well the air travels through the ports.  Many companies provide a cylinder head porting service to improve performance – but some die hard horsepower enthusiasts would prefer to do their own cylinder head porting.

For a novice, you won’t want to start with high performance racing heads, since they’re already top of the line and would offer little room to improve those through porting.  It’s also important to understand that porting by inexperienced people offers unreliable results and a lot of trial and error as you learn the process.  Most people who have tried cylinder head porting on their own fail to improve successful porting because they don’t have thorough knowledge of the fluid dynamics involved, or possess the tools and knowledge necessary to optimize a port.

At the very least, porting cylinder heads requires an air flow bench, and ideally the use of engine simulation software.  An egg shaped carbide cutter will help you speed up the process of cutting.  Using a Craftsman Professional 1/4hp rotary grinder and polishing kits from Standard Abrasives will help in the process of deburring a block, and polishing exhaust ports and chambers.

Don’t attempt this process for the first time on a good cylinder head.  You should always practice on one that you don’t care about or need first.

Test the production of the cylinder head on an air flow bench before beginning cylinder head porting so that you can measure the results again when you’re done – to see whether you successfully made improvements – or reduced the air flow.

Remove Ridge from Intake and Exhaust Bowls

Before you start hacking away at the cylinder head, keep in mind that you want to remove as little material as possible.  If you remove too much and create concaved or holes, the air flow is going to be adversely affected regardless of the size of cylinder head you are porting.

Start by placing the cylinder head on it’s exhaust ports and remove the ridge that forms within both the intake and exhaust, being careful to only remove material to half an inch of the bottom of the valve.

Feel around inside with your fingers for any high spots and use a marker to mark any area that still needs material removed.

Flip the cylinder head over so it is sitting on the intake ports, and remove the ridge from this angle.  You should be left with all of the cylinder bowls having a nice, smooth circular contour.

Unshroud the Valves

Remove the good intake and exhaust valve and set aside. Place the old valves in the cylinder in place of the good ones, in case you accidentally nick them when doing the next step.

Get the head gasket to line up with the dowel pins and the bolt holes.  Stay within the bore line of the cylinder, and use the carbide cutter to scribe the line.  Be careful though, if you get carried away and take off too much it will create a problem with sealing.

Replace the bad valves with the good ones again.

Polish

Using a Standard Abrasives (or other type of your choice) porting kit, polish all except for the intake bowls.  Don’t polish the intake.

Test on Air Flow Bench

Once you’ve completed your cylinder head porting service yourself, test the flow of the heads on the air flow bench to see what kind of improvement you’ve made in air flow.  After you test the air flow, test out the horsepower to see how much it increased.