Post here for Porting and Polishing thread.

[BushWakr - RIP]

Post you questions here regarding the porting and polishing thread. .



edit: Ok I better put this in here regarding this series' of posts...



ALL of this work/thread is compliments of Dave Miller aka: hdm48

Dave has been doing this sort of thing for a while now and has chosen to share his experience with us... .

All I did was collect it up, tweak some picutures a bit of spell checking (not all done) and lots of cut 'N paste to get it in here...



Thank you Dave... good job. .



Pastor Bob.

 

[78repowerwagon]

Great info, Pastor Bob.



On average, how long does it take you to port/polish a manifold/turbo housing?

 

[GIT-R-DONE]

Before this thread gets too far, can you explain to us all what it is when you port and polish? I know about polishing up the "runners" on a gasser, is it the same here as far as matching mating surfaces for porting? Hope this isn't a bad question, I just want everyone to understand more. Is it just the heads or turbos too... ... what all can this be done to on our trucks that will help us out. Thanks Don

 

[JLEONARD]

On average, how long does it take you to port/polish a manifold/turbo housing

I spent about 45 minutes to an hour doing my turbo housing. I didn't have any cutting tools, just a bunch of grinding stones.

what it is when you port and polish

Yes, porting is actually the "gasket matching" process, and as you read in Bob's text you want the openings to get larger in the direction of the air flow... . think of it as water flowing... you want to reduce any resistance to the flow... . sometimes it's easier to visualize the concept if you think of water flowing.



Polishing is the process of removing the "bumps" , such as casting ribs, rough "as cast" surfaces, etc. Again, think of water flowing down your driveway in a rain storm... . it will flow faster down a smooth asphalt surface than down a gravel surface... . now lay a piece of 2x4 across the driveway and you can see how a casting rib will impede flow... . even rounding the corners of a casting rib will help tremendously.



Hope this helps.

Jay

 

[Greenleaf]

I did my OEM manifold just as described as well as my new 16 housing cause it just made sense to me to open it up to the gasket surface. Took me a few hours. If the manifold should crater I'll install the ATS



I had a big mess after wards. Metal all over everything including "in the shorts"



Don't know how much it improved things as I did several mods at that point (in time). I simply followed Bob's directions and was careful not to get too carried away.



Somebody send me one,,,,,I'd love to do another!



Scott

 

[jdurham]

Somebody send me one,,,,,I'd love to do another!

:--) I had no idea metal shavings in the shorts could make you want to do it again!!!!!!!!



:-laf :-laf :-laf :-laf

 

[Greenleaf]

I suppose I can tolerate a-lot when it comes down to working on Diesels. At present, I'm rebuilding a two barrel carb. Not much fun. Rather have sand in the shorts,,,, IMHO Heck, I USED to work on Detroit Two Strokes



Scott

 

[hdm48]

I think I had better jump in here and help out poor ole Bob.



What is "porting and polishing"? It is an effort to make (in this case) the exhaust manifold flow more air than it could in unaltered form. Thus reducing back pressure and the heat generated by that back pressure. The exhaust housing is ported to match the manifold and to encourage a ventury effect in the entrance to the turbo itself. Remember, engines don't breathe air in a continous manor, they breathe in pulses. And these pulses have high and low pressure areas leading and following them. As they are traveling down the manifold they are cooling and increasing in mass. Making these pulses "blend" with one another and with less effort is what this is all about.

Notice I used the term "breathe" in reference to the exhaust. Well, the exhaust must Breathe just as the intake does or we are all in trouble. You keep throwing all that fuel into a motor and forget the simple things like an exhaust manifold and all you are going to do is make a nuclear reactor with no cooling under your hood.

Porting can be nothing more than simply polishing a surface. But in this case it refers to the reshaping of the inner workings of the components themselfs. This in itself does not make much power, but it does make more tourque and cools everything off. Plus you will find quicker spool-up of the turbo and a flater HP and TQ curve.

And like what was said earlier, think in the lines of water. Gasses have mass. And mass is heavy. You are trying to steer that mass and make it go where you want it to.



How long does it take? For me, being a perfectionist, it takes about 4 hours to do a manifold and housing. And that is with the proper tools.



Head porting, mine's not done yet, but soon,, very soon.



Intake system, yes, do the air horn, intercooler, compressor housing to elbow. Any back pressure here will make the turbo work harder trying to push the air charge to the engine.







Dave

 

[GIT-R-DONE]

I do have some questions about porting and polishing. What kind of set up do you use for grinding, smoothing, fine sanding, that type of thing? How do you find out exactly where to port on you manifoldor turbo, by using a gasket? Are we using something like a dremel tool ? I geuss maybe a better stated question would be... ..... I am going to start this right now, what tools will I have at my disposal to get the job done, and done right.



I also want to know when you buy a new manifold or turbo, do they come already polished? Thanks Don

 

[Greenleaf]

Tools

I use two straight die grinders and one right angled unit all pneumatic.



Use several differently shaped burs as well as several shaped stones.



I used the gasket as the primary guide and finger as the other in places I can't see.



I also have a good dust pan and shop Vac face shield and gloves. A bit of time/patience too



Greenleaf

 

[hdm48]

As Greenleaf said, a good supply of cutters is helpful. However, I use electric drive instead of air. I like the way I can be in control of cutter speed with electronic foot controls.



No, nothing that you buy will come polished. That is all up to you. Polishing to a mirror finish will look good for a while but will be dull in a few miles driving. Make it as smooth as you can to limit carbon build-up, but don't spend too much time trying to be able to shave with it.



Where and how I cut on a unit is the result of doing this kind of thing for 41 years. I can look at something and determine where to improve flow. It is an aqquired thing. I don't expect you to pick this up in 5 minutes, that is why I posted these pictures.



LOOK at them, READ the words. And if you are in doubt, STOP, ask what to do next. There is NO dumb question.

Play with your garden hose in dirt. watch how the water tries to avoid going around corners and what it does when it does go around a corner. Look at the turbulance. This is what is going on inside the system.



Just remember to go slow and ask questions. That is what this site is for.





Dave

 

[JLEONARD]

I use a dremel, and grinding stones I can get from work (price is right if you know what I mean). I can only get two styles... cylindrical and cone, and I do the best I can with those two.

I use the gasket as a basic guide, and sometimes use dychem or magic marker for a more refined guide mark.

If you grind conservatively you should be ok. Like Mark said, try to imagine where the air (fluid) will hit an edge and get slowed or stopped... . and make improvents there. Even if you're not an expert (and I'm certainly not) , if you get it 80% of the way there, you'll be miles ahead of stock conditions.

Jay

 

[GIT-R-DONE]

OK, since I am allowed to ask the stupid questions... ... . ... ..... How much does really affect the HP of a motor? I mean like . 010 or . 020, is that much really making a big difference? I can understand the reasoning behind it to a certain extent, but is , say, . 125 make a big difference in performance and if so, how much, maybe 5-10 HP? Just trying to get some type of idea here how much one can really gain by doing this. Thanks Don





PS Good thread ( by the way )

 

[JLEONARD]

To answer your performance question indirectly... .

I went from a restrictive stock air filter to a K&N ... . noticeable difference (eliminated low/mid range smoke).

Went from a 3 in to 4 in exhaust... huge difference (+ 3psi boost).

I ported my turbo housing when I installed it so I can't comment about that, but from the first two it is apparent that better/more air flow makes a difference.

The principle has to apply to every part of the system.

Now quantifying that difference is another story. I'm sure there's some general data available ... perhaps an engine performance book?

I have a diesel engineering book... . I'll look thru that over the next week and see if thewre's anything in there.

I can give some specifics in terms of boating and water flow and fairing that involve the same priciples but that would bore this crowd.

Jay

 

[hdm48]

Jay, I liked your answer.



But to answer it directly, porting allows for better flow in the item being ported. In our case here, it is the exhaust. What you will find happening is the turbo will spool up to max boost sooner resulting in a flatter torque curve and more torque overall. Horsepower will come in a little sooner and also have a flatter curve. Max horsepower may increase depending on how you are tuned and what setup you are running. ie; injector size, pump settings, air intake, turbo size and type, exhaust size. No two engines will realize the same benefits due to these variations.

The main reason to do this is to reduce exhaust temps so you may acually use the power you have rather than just dyno runs. Really now, do you just want to post great numbers on a dyno or do you want to pull a load or cruise down the hi-way without worrying about EGTs?

You spend money on a good exhaust pipe and never give a thought to how the exhaust gets to the pipe.



Dave

 

[BushWakr - RIP]

"..... Where and how I cut on a unit is the result of doing this kind of thing for 41 years. I can look at something and determine where to improve flow..... "





Ok now, lets see... ... Dave is 42. . hmm and he's been doing this for 41 years... hmmmmm 42 minus 41 = 1 .....

OHhhhhh yaaa, that's right, he did his first port 'N polish on his baby bottle and nipple..... what was I thinking.....





Pastor Bob... pass the holy water... errrr diesel. .

 

[hdm48]

OK, BOB!! Thank you for the age decrease. Do it some more. 42!! ha ha ha ha ha ha ah I WISH!!!







But to tell a secret, I started building engines when I was 10. And building real race engines when I was 13.





Thanks again for the age reduction





Dave

 

[JLEONARD]

OHhhhhh yaaa, that's right, he did his first port 'N polish on his baby bottle and nipple.

Now that's funny!!!

Jay

 

[Greenleaf]

A BOMB'd Tricycle I'm sure

 

[JJump]

Check out this site

For those of us that are new to this type of operation, Standard Abrasives has a nice Do-It-Yourself article explaining alot about how to do porting. The article was written with the gasser in mind, but the same principals apply. They also give info on their abrasives kits, which look like a pretty good value. See it here...



http://www.sa-motorsports.com/diyport.htm



Hope this helps & Merry Christmas!



Joe Jump

St Louis