Porting and Polishing...?

[dubumb]

What exact is 'porting and polishing'? can someone explain this to me so i understand what it is and how it creates more power...

thanks.

[Hoppy's535i]

as far as i know its boaring out the cylinders and polishing them up for more volume, and less friction.

[dubumb]

What kinda power will this add? And how much would it cost to get done?

[Hoppy's535i]

well im not really sure if im right. so i tried alil research, and i found this http://www.exoticsportbike.com/porti..._polishing.htm
its about motorcycles but i believe the theory is the same as cars.
iv reached the end of my tech knowledge here. i hope some one who knows can help answer this question

[roloson]

Hoppy what you are thinking of is something different. Boring out cylinders increases displacement. Anyway I could write a book on this but I will try to hit the fundmentals. Power is gained do to the increase of air flow to the engine. After all remember, engines are no more them air pumps. The more air they pump the more HP we get. IE supercharging and turocharging runs much larger amounts of air through the engine. Porting and polishing is done to the head or heads of an engine. The cars today have very efficient heads to begin with. Treating an M3 head for example would only produce small gains and cost would be considerable when done by a good engine builder with the proper equipment. I have had head work done in the past by Jegs automative in Columbus Ohio. I have done basic head work myself on early model engines that were very inefficient from the factory. Intake gasket and head port alingment for example. Porting is part science and part art. There is a balance of flow volume and flow speed that is desired to achieve proper atomazation of the fuel air mixture. Proper port wall finishing is needed to achieve optimun results. Work under the valves is important, along with multi angle valve seats. Many times larger valves are added during this process. Unless you are building a serious street car, or an all out race engine should look somewhere else for power. Sorry to go on and on. There is alot involved. Much more then I have touched on here.

[dubumb]

Originally posted by roloson@Jan 17 2004, 05:24 PM
Hoppy what you are thinking of is something different. Boring out cylinders increases displacement. Anyway I could write a book on this but I will try to hit the fundmentals. Power is gained do to the increase of air flow to the engine. After all remember, engines are no more them air pumps. The more air they pump the more HP we get. IE supercharging and turocharging runs much larger amounts of air through the engine. Porting and polishing is done to the head or heads of an engine. The cars today have very efficient heads to begin with. Treating an M3 head for example would only produce small gains and cost would be considerable when done by a good engine builder with the proper equipment. I have had head work done in the past by Jegs automative in Columbus Ohio. I have done basic head work myself on early model engines that were very inefficient from the factory. Intake gasket and head port alingment for example. Porting is part science and part art. There is a balance of flow volume and flow speed that is desired to achieve proper atomazation of the fuel air mixture. Proper port wall finishing is needed to achieve optimun results. Work under the valves is important, along with multi angle valve seats. Many times larger valves are added during this process. Unless you are building a serious street car, or an all out race engine should look somewhere else for power. Sorry to go on and on. There is alot involved. Much more then I have touched on here.

thanks a lot for your informative responce... i appreciate it. I guess i will steer away from thinking about that since i do not want a street racer. thanks again.

[CBA]

Originally posted by roloson@Jan 17 2004, 06:24 PM
Hoppy what you are thinking of is something different. Boring out cylinders increases displacement. Anyway I could write a book on this but I will try to hit the fundmentals. Power is gained do to the increase of air flow to the engine. After all remember, engines are no more them air pumps. The more air they pump the more HP we get. IE supercharging and turocharging runs much larger amounts of air through the engine. Porting and polishing is done to the head or heads of an engine. The cars today have very efficient heads to begin with. Treating an M3 head for example would only produce small gains and cost would be considerable when done by a good engine builder with the proper equipment. I have had head work done in the past by Jegs automative in Columbus Ohio. I have done basic head work myself on early model engines that were very inefficient from the factory. Intake gasket and head port alingment for example. Porting is part science and part art. There is a balance of flow volume and flow speed that is desired to achieve proper atomazation of the fuel air mixture. Proper port wall finishing is needed to achieve optimun results. Work under the valves is important, along with multi angle valve seats. Many times larger valves are added during this process. Unless you are building a serious street car, or an all out race engine should look somewhere else for power. Sorry to go on and on. There is alot involved. Much more then I have touched on here.

this dudes on the ball

[bimmerfan620]

you should Port and Polish your wheels...... hahahahah

[CBA]

lmao... pour some 15W40 on them for a great lookin shine.. lolol

[docrobot]

Has anyone here EXTRUDE HONED their Intake or heads?

[roloson]

Docrobot, I have never used this process but at one time I know it became popular amoung some engine builders. I don't know that everyone knows that this involves pushing a grit material through the ports to smooth them. I think this process fail out of favor because it produced the same wall finish throught the port. I think most engine builders want the finish to be slicker in some areas and a little rougher in others. I have been away from this stuff for awhile. Are people still using that process. I am guessing it may be a less expensive way for some small power gains as far as head and intake work is concerned. I am curious why might you ask?

[docrobot]

IMHO, Extrude Honing is right on topic as far as maximizing Hp and Torque in the engine - which is what Porting and Polishing aims for too. EH is very effective in equalizing a part's air flow and volume among individual runners to/from individual cylinders; this also tends to increase torque throughout the RPM range.

Ford's SVT Division (to name one manufacturer) has openly used EH to bump up power on a number of models recently. I would not call Ford a world expert in engine design, (not compared to BMW, Mercedes, Ferrari, etc.) but neither would I consider extrude honing outdated technology.

Like balancing and blueprinting, or porting and polishing, EH is used to increase the efficiency of the engine to wring out a little extra power and torque from a given engine.

[docrobot]

Oh yes, EH gains much of its power gains from reducing pumping losses by dramatically smoothing the surfaces that the air mixture flows past throughout the engine.

[roloson]

So some of the manufactures actually use this process now. I can see from a mass production stand point how it could be very effective for power gains. Very interesting stuff. Enjoy.

[dubumb]

would EH be a good idea to do for some extra power? or will it result in a gas guzzling streetracer...?