Acid Porting

[jschrauwen]

Found this on PT;
http://forums.probetalk.com/showthread. ... id+porting
Has anyone tried this or know about any positive benefits gained?

Author contact throught PT is preferred, if no response for a long period of time another email address is blackjackattack411@yahoo.com.

Things that are needed to be known how to do this outside of of this post, if you don't know already.

1. How to melt and handle melted candle wax, read up on this on the net.

2. How to handle acid's and bases, mixing and the like, again read up on this on the net.

A word on safety, this isn't rocket science, most important thing here is a steady hand and a clear mind. That said, this can be an unsafe thing to do if you don't know how to handle acid, melted candle wax and the like. Things are going to be stated to be done in a certian order, NOT because it quick, BUT DO TO SAFE MANNER, you may not understand why step 1, 2 and 3 are in that order. And you may want to do step 3 first, but I have my reasons for this, that and the other, and this write up is going to try to keep people safe.

Now why would someone want to do this. The inside of the runners on a Kl-03 or Kl-ZE Intake Manifold(IM) are a flow restriction and there is no other way(cost effective) to uniformly increase the runners opening. The runner walls are quite rough, and not perferct in size. After acid porting the inside walls of the runners come out smooth with a dull polished finish, and are uniformly larger in size, depending on the amount of acid used and the number of times to porting process in repeated. Only the last 1 or 1.5 inches of the runners will be unported, and this area is the easy to "clean up" via hand and open the entire runner to the size of the acid porting. I gained about 6 hp and lb/ft at the wheels on a dyno(corrected numbers) with just the acid ported IM and spacers, only ported once via this method, and this on a car without any other breathing mods intake or exhaust.

Why I did this? I have worked with wax and acids, and I had everything other than the wax around so it was cheap, I even repoured the wax into candles when I was done. Also I have acid etched metals in the past and knew that this was used in racing as "the way" to clean up castings.

Time and cost, both are going to be based on the number of times you repeat to porting step, but to just do this once figure 10+ hours and under 200$ for sure, much less if you have some of the stuff needed.

Starting here are the major steps in this process, you will want a spare IM for this as it will take more than one day most likely.

1. Cleaning the IM and gettting ready to plug the runners. 1-2 hours. Clean it out with carb, brake cleaner, cook off any residue, remove all non metal parts.

2. Plugging up the runners. 4-10 hours. Melting and pouring the candle wax, sealing the runner ends.

3. Getting ready to pour the acid. 1-2 hours. Handling the acid and acid solution, setting up the IM and safty gear.

4. Pouring the acid and getting it out. 1 hour. Putting the acid solution in the IM and taking it out.

5. Cleaning up. 1-3 hours. Making sure all the candle wax and acid is out if the IM.

DO TAKE NOTICE; I am not responsiable for what you may do with this info. Don't even think of contacting me to tell me anything otherwise. You are responisable for what you do or don't do in relation to these activies. This has been written to keep people safe, but if your hell bent or hurting yourself or others that your issue.


1. Clean up and the like. Things needed;

Carb or brake cleaner, other cleaner, cans of it.
Water, lots of it.
Bottle brush, other brush?
Tools.

Remove everything non-metal from the IM. Consider removing VRIS plates, if doing anyway for other reasons, do it now. Carb, brake cleaner or other stuff, clean the inside real well, clean is key for runners to remain uniform. Bottle brush the inside of the runners clean if you have one. Throw IM into oven set at 250 for an hour, if after the water boils off you have any oil dripping(line oven with AL foil btw) or oily smoke, reclean the IM. After clean and dry, take a look at those runners.... say bye to the crud on the inside walls.

2. Plugging the runners with wax.

Needed;
Browie pan
Make it 3 pounds of candle wax, high temp if you can find it.
AL foil
Double boiler, hotplate

To plug the runners; First off this works best on non-ported runner ends(i.e. don't hand port first) becuase they are still rough cast and the wax sticks better. Get a brownie pan at least 1 inch deep, big enough to sit all six runner ends into it flat. Line it with AL foil if you wish(easier to clean up). Get 2+- pounds of candle wax, hobby supply store will carry for a buck or two a pound, if you use candles the dye may stain the IM. After this is done the wax an be repoured into candles. Set up a double boiler on the stove an melt the wax(if you don't know how to handle wax, then you can read up on it on the net, liquid candle wax can explode if your really careless). On one runner there are two small vaccum ports theat need to be plugged. Using a finger, or spoon, or something else, feed small balls of soft candle wax into these ports forcing the wax from the inside of the runner to the ouside. A small wax "cap"(dime sized) can be put on the inside of the runner to cover these ports as this area is not hard to clean up later. Pour the wax into the browie pan 1 or 1.5 inches deep and then lower the IM runners into it. Now don't touch it until the wax is totaly hard, a small movement too soon could tear the plugs loose. When the wax is hard the wax hanging on the outside of the IM runners can be broken loose, or just left there. You should have 6 perfect plugs in the ends of the runners, if not pull all 6 plugs out and redo them. If you have 6 good plugs, now is a good time to set up the rig(next section) for the acid solution and practice putting the acid into the IM. Also fill each runner and record how much solution each one holds to you will know how much acid solution to make for the next step.

3. Getting set up to acid port the IM, testing with the U-tube.

A word of caution, the acid comes out soon, no kids, pets, flame, electricty, smoking, eating or drinks anywhere around, people have been killed drinking acids thinking they were soda's, no nothing around thats not there for a reason.

Needed;
Glass bottle big enough to hold all the acid solution, a 1.75L wiskey bottle works great.
Cork or rubber stopper for the bottle, with two holes(drill them) fitting you glass tubing.
Several small pieces of glass tubing 1/8 or 1/4 inch I.D. One straight piece longer than the glass bottle is tall, another about one foot long with the last inch bent 90 degrees, a third 3 to 6 inch piece. This is just normal lab tubing.
Pryex measuing cup, 2 cup volume is good, one cup will do.
4-5 feet ruber hose.
Acid
U-tube on its test stand.
Binder clip, or other strong spring clip, a medium binder clip works great(this to shut of flow through the rubber hose).
Small amount of power baking soda, a box.
Water from hose.
Distilled water one gallon.
Spray bottle with water and baking soda in it.

First some words about acid and makeing a set up with the U-tube to test precentages.

I used 99% sulfuric, cut down to about 30%. You can use other strong acids, hydrocloric or nitric if you wish. Use the U-tube from the IM to test out precentages with other acids. Set up the U-tube so it sits upright with liquid in it, use the bolt hole in the U-tube to attach a piece of sheet metal or wood to the U-tube. Set up all the safety gear, water to flush away the acid solution , baking soda, spray gun with baking soda in it and the like. Next test solutions in the U-tube, this way if you mess up bad your only out the U-tube. When mixing acids into water(always acid into water, never water into acid), there can be a small reaction unless you use distilled water, it's not needed but distilled water works best. What you want in the U-tube is a reaction that after about 10 seconds looks like Sprite(the soft drink) or a little more bubbly then Sprite. If the U-tube foams over then the reaction is too strong, quickly(U-tube will be hot, grab the sheet metal base) dump out the solution and try again with a lower precentage of acid. If the solution in the U_tube doesn't bubble at all, you need a higher precentage of acid. Remember you want a reaction that doesn't go to fast and create so much heat that it will cause the candle wax plugs in the ends of the runners to melt. When I did my IM the 30% sulfuric acid reaction took under 15mins to end(figured by the temp. peaking and starting to go back down) so that's how long the wax plugs need to last. I tested a 50% sulfuric acid solution in the U-tube, just like I described above, it foamed over in just a few seconds and I quickly dumped it out(finding out the U-tube was very hot), and redid with a 33% solution, which didn't foam, but still made the U-tube plenty hot.

Next is building the rig to get the acid solution into the IM. Start with the two hole piece of cork, take the short 3 to 6 inch piece of glass tube and put in into one of the cork holes, take the long straight piece of glass tubing and put into the other cork hole and adjust with the bottle so that the bottom of the tube is 1/2 inch off the bottom of the wiskey bottle. One end of the rubber hose goes on the long tube coming out of the bottle now, and the second end of the rubber tube goes to the glass tubing with the 90 degree bend in it(attached to end away from the 90 degree bend). Now when fluid flows thorugh this you can use the glass tube with the bend to direct the fluid directly down into the runners. If you have never done something like this before practice with water putting liquid into the IM without splashing and getting it all over the inside of the IM. Best to do this before freezeing the IM into the block of ice, but if done already do practice before pulling the acid out in the next step. This is a gravity feed system, the bottle needs to be 2 or 3 feet above the IM and you need a suction to start the flow, NEVER APPLY SUCTION TO THE HOSE WITH YOUR MOUTH WHEN AN ACID SOLUTION IS READY TO BE DRAWN INTO THE HOSE, there is a way around this in the next section. Practice getting the acid into the IM until your good at it, by the time the acid is planned to come out of the IM it will be very weak, so this is the only time your likely to be dealing with a strong solution of acid. And a word about rubber and acid, some wonder how safe it is to have the acid flowing through rubber. While acid will eat rubber away, it does very slowly(at least compared to metals), and the acid should only be in the hose for 5 mins. at the most, I have done fluid transfers with acids and rubber hoses dozens of times, never once have I had a rubber hose leak even after hours of contact with the acid. Not to say it can't happen, just that rubber should not fail in the time your exposing it to the acid.

Before starting this section you should know; how much water and acid is going to go into the glass wiskey bottle, how to get the acid solution from the glass bottle into the IM and how to handle acid in a safe manner in general. To figure the amount remember your going to need a bit more than what fits into the runners(to fill the hose, also some will be left in the bottle) take what you figured you need to fill the runners and bump it up by 25-50% or so.

4. Put the acid in, keeping the IM cool and take the acid out

Warning, this is where 20+ ounces of acid needs to be measured an poured.

Needed;
Sunglass/eye protection.
Rubber/latex gloves.
The "rig" from #3, glass bottle, tubing, rubber hose.
A smaller second glass bottle.
Pyrex measuring cup.
All saftey gear from #3, baking soda, spray bottles.
Acid.
Water from hose.
Distilled water.
Masking or duct tape.


Take the IM and ice and set them up in a area thats safe to drain the acid to without moving the IM, next use the tape to mask off the TB and U-tube holes that the acid will be inserted in through. This way if a stray drop or two gets loose and ends up on these areas you can just remove the tape and not have to wash the IM.

Put on gloves and eye protection, pour proper amount of distilled water into your wiskey bottle and put it into place, put some tape on the bottle marked acid and posion, next in the smaller glass bottle put 20 or more oz of distilled water and place it next to the wiskey bottle.

Get out the rest of the saftey gear and set it up. Get out you bottle of acid and measuring cup.

First using the glass and rubber tubeing and using the smaller bottle of distilled water(remember wiskey bottle is premeasured for the acid) draw plain old distilled water through the tubing and clamp it off with the binder clip, if you don't have a pump to start the flow it's safe to start the suction with your mouth as long as the bottle has only water in it. If at some point when working with acid you lose the flow through the hose, wash the hose out with lost of water and restart the draw using water, NOT ACID SOLUTION. Btw this should not happen.

Second, still using the small bottle of water put a small-tiny amount of distilled water into each runner, just 1/2 or 1 ounce in enough, try and get the same amount into each runner. Clamp of the water flow when done. This is done to protect the wax plugs.

Now get the acid bottle out, pour the amount of acid needed in the measuring cup and then the measuring cup of acid into the wiskey bottle. No need to shake or agitate the solution after pouring, just give it one min. to mix, during this time close up your acid bottle and put it far out of the way.

Next put the cork with tubing, already loaded with plain water in place on the wiskey bottle. Use the measuring cup to run 8+ ounces of fluid into the measuing cup, enough so that the acid solution is now coming out of the end of the glass tubing.

Your ready to put the acid in the runners now, do all 6 quick as they can be filled, when the runners are full dispose of the extra acid solution in the measuring cup, tubing and wiskey bottle and either put them out of the way or start the process of setting up to do this again(but don't measure out more acid as the wax plugs might need to be redone before more porting).

Check on the wax plugs every min. or two by lifting the ice slab covering runner mating surface, wiping the surface with a towel and looking for drips coming out if of the runners.

What to do if you have a leak soon after putting the acid into the IM. Depending on how much is coming out you may have to bail on this right away. If the leak is bigger than a pin hole, pull all six plugs(being careful), and wash away any acid solution with lots of water, then's its back to the wax plug step. If you have just a pinhole leak, you may be able to nurse it along for awhile by lifting the ice off the runner mating surface and squirting the leaking area with water and baking soda from the spray bottle, do this every 30 seconds or so. If the leak starts after 10 or more mins. it's likely the reaction is mostly done anyway, I would just pull the plugs and be done with it. Do remember,if you have a leak the acid solution level in that runner is dropping, so don't ignore it, it's easier to keep everything even than make it up on a later port. The two runners next to the TB flow better then the rest, when pulling the plugs start with these first, and when filling the runners do these last.

When the reaction is done(known for sure by the temp of the IM starting to drop) pull the plugs, dump plenty of baking soda where the acid solution is disposed of, and wash the IM with lots of water 15 mins. or more. Remove by hand all the candle wax that easily can be, don't worry about wax that is hard to remove by hand. After washing put the IM into the oven at 225 to melt out any wax(line oven with AL foil, and watch for smoke coming from oven). Wash again afterwards. After the IM has cooled look at the inside of the runners. The Porting process can now be restarted back to pluging the runners with wax if thats your going for.


5. Clean up.

You will notice that the last inch or so of the runners where the wax prevented the acid from doing it's work are still rough and the rest of the runner isn't. Hand porting the last inch to the size of the of the rest of the runners is the next step. Remember to make sure all the candle wax is out, because hot metal shavings from the hand porting will stick to any wax hiding inside the IM and later get sucked into the engine, if not cleaned out. I recomend another trip through both the wash step and oven step after the hand porting.



Q&A?

Q: What else can be acid ported on the KL's?

A: Small(ish) quanities of acid can be used for the following, stock, coned or ported throttle bodies, the heads both intake and exhuast ports and to remove the sharp edge around the combustion chamber pentaroof. Stock exhaust manifolds, some cleanup up of aftermarket headers, piston crowns/tops, inside of fuel rails, banjo bolt mod, coolent passages and water neck. Next best and easy thing useing same procedures and candle wax would be the heads, piece of cake compared to the IM really.

Q: Any chance of you acid porting intakes for the Probe community. Sounds like a great procedure, but I'm not comfortable attemting this on my own.

A: First of lets me say, I stress the safety with the acid alot because there is a danger, but really this is middle school level chemistry, if your set up to be safe you will be too. So I likely discourge people who can do this from trying, and that is a shame. So here's where I say, if your thinking you can't do this, but can hold a glass of water for 10 seconds without spilling it, then you can do this and you will be very safe do to the fact that your safety concerns you. As for myself doing any large numbers of IM's, 1. I don't have the acid, would have to get it in a large amount(see getting acid info.). 2. Not really set up to do this in bulk(I live in a condo). 3. I only would do this on a cold winters day. 4. Would just be a real problem all the way around, getting IM's, acid and the like. Haveing said that, I am considering doing another IM for myself(a double port for NOS use), and if I do this then I could handle up to maybe 5 more at the same time. And for those who live near the DC area, wouldn't be totaly adverse to your IM's, acid, wax and location and I just come by to handle the acid in exchange for a six pack or two(maybe ditigal pics too). Would have to be done safely, and the wax step would need to be done the day before I come over by someone else.

Q: Are the gases given off a problem to breath?

A: Mostly the gas is hydrogen, you don't want to breath the gases. If done as it should be, outside, then there will be no problem unless you are seeking to trap and inhale the gases. No open flames is the real key, not breathing the gases is a minor issue. The reason is the hydrogen gas trapped in the inside on the IM, could expode if there is a flame around, and it would be a very small expolsion(remember only 20oz of acid is in use), but the most likely result of small expolsion in the IM is that the acid solution goes flying out the TB and U-tube sides and thats the real problem with gases. I have never had an accidental explosion of hydrogen gases(I don't smoke btw), however I do sometimes collect the gases to light them off. FYI hydrogen by it's self is pretty stable and will not explode, only when mixed with O2 in the right amount will it explode.

Q&A?

Q: Where' the 200$ figure as the cost to do this from?

A: 200 covers even the temp. cost of a spare IM, for most this is 50-100$ at the most, less with anything you may have around.

Q: How much acid to buy?

A: Depends on many things, such as how many times your going to repeat the porting step. The 6 runners hold a little under 50 ounces(with the plugs in place) and the U-tube about 10 ounces. From there you need to estimate your acid solution precentage. So in the end a guesstimate across all the strong acids 20 ounces, per run though, get more if you likely to find other uses for the acid.

Q: Where to buy the acid?

A: This will be addressed further I'm sure, but I didn't have to buy any, and this stuff is subject to some controls. Chemical supply houses in the yellow pages may be you best choice, here's one on the net http://www.kyantec.com/catalog.htm . Be warned if you trying to buy large amount of acids that they are going to want an ID for sure, and may even want ID for a single gallon. There are places that will not even sell to persons without a company listed. All in all getting a gallon of acid, isn't going to rasie many concerns, order 100 gallons and the FBI might show up before the acid does. The best way to get the acid in small quanities is going to be local rather then mail order, try the local yellow pages looking for chemical supply, cleaning supply, medical and lab supply companies. Unlike mail order places these places may be willing to let you walk in and buy a single gallon without a lot of paperwork and hassle. FYI, Fisher Scientific, the company that does chemical suppy for most schools and the like will not sell persons, you have to be with a bussiness on a credit account to order from them.

Q: How does this affect the VRIS system and butterfly valvles inside the mani?

A: Not much, first of the VRIS plates can be removed, but don't have to be. Second since the runners are bigger the VRIS induced pulse peaks move lower in the powerband by 10-25 rpm, depending on how much larger you port the runners. When combined with spacers(spacers move the powerband lower too) you can see the effect on a comparision dyno chart.

Q: Is the acid porting provide(ing) a consistant bore throught the runners and bends?

A: Well, yes through the runners, the other parts of the IM are not gettting ported for several reasons the biggest of which is that the metal is much thinner then on the runners. But the entire point of acid port is a uniform and smooth runner surface all the way through the radius of the runners bend. My one porting opened up the runners a bit more than one MM, some of that being the smoothing of the rough surface. So I would guess that each porting can remove about 1/2 mm of metal from the runner wall. That said a "acid wash" could be done to the rest of the IM, inside and outside, but the need isn't there, and to do inside and outside might take hundreds of ounces of acid for just that one step.

Q: So I am guessing you did one runner at a time right?

A: Not that you have to do them all at once, but you can. Really no reason to do them at the same time, other than just to save time and make everying uniform. To be sure that each runner gets the same amount of time exposed to the acid, and the same solution of acid was used in each runner. I would do them all at once.

Q: How long did you let the acid sit before removing it?

A. Different acids and solutions precentages will require different times. But about 15 mins. The one sure way to know when the acid is done is the temp. peaks and starts to go back down, when that happens 95-99% of the acid in the runners has been used up.

PHOTOS, I don't have a digital camera, and I did this a year ago anyway. If someone wants to take some pics I would be happy to incorporate them and give photgraphic credit for them to the taker.


Quote:
Originally posted by slvr gts
Why is it not necessary to acid port the whole inside of the intake? Are the runners the biggest bottleneck in the flow throught the manifold? I thought you wanted the entire inside of the IM to be as smooth as possible to promote air flow. Thanks.


Becasue the runners are the real restriction to begin with, the rest of the intake, i.e. the plenum the walls are about 1/4 inch thick to start with, the runner walls are over 1/2 inch thick. Also the plenum outflows the six runners to start with, it's hugh in there. Yes it would be better for the walls to be smoothed, but there is risk there. There are dividers inside the plenum, so if you were trying to port it you would be porting both side of these dividers at once, and with them being so thin to start with I just felt the risk was unacceptable. That said the way to deal with plenum would be to use a much lower precentage of acid to do them. This means it would go slower, and you would have more control of the amount of metal removed. If I were to try it with sulurfic acid I'd be trying it with a 10% solution at first to be on the safe side.


Do you think this should be stickied or at the very least put into the FAQ's?

[fieromx3]

thats a long a-- post! ur not to familiar with short posts r u john lol i didnt read quite all of it....yet but anyway good write up so far.

[JM1EC-V6]

I've read the entire method, and it looks like to be very nice.

Definitely a great FAQ doc !

Notes:

Sulfuric Acid= H2SO4
Nitric Acid= HNO3

[PATDIESEL]

FAQ for sure. I jsut hope that people can follow the whole thing properly. Also it needs to be proof read for errors and sentence structure.

It does pose a question though. If you port the intake enough you will need to port the head to match as to optimize the gains of having a larger diameter intake. So then, how can you easily port the heads? I only know to take them off and port them by hand with a dremel. That is of course after you have made a template of the port size needed from the intake manifold. Also, making the ports larger around the VRIS butterflies is going to cause a loss in their ability to seal. So what effect will this have on the HP/torque curve??

[93_mx3_gs]

Couldn't you have a machine shop make new butterflies after the porting and have them measured to seal ?

[JM1EC-V6]

Yes, there some bad things in my head when I think to the VRIS plates.

Acid will overbore and the plate will not sit air tight anymore ...

Only bad point to my eyes. Could the guy who did it can help us with this issue ?

[PATDIESEL]

New VRIS plates would be in order, but at what cost. What I'm saying is that this mod while cool in its design and probably cost effective (as long as you have health insurance ) needs to state the "hidden" costs that are going to be associated. I'm pointing this out for the FAQ version, not to discount J-Beefs post.


(sorry can't type all that screen name, so your J-Beef forever to me) and PS, thanks to whoever it was that came up with J-Beef, it is alot easier to type. Mitmaks or some old member...

[ikarus1]

Would this be similar to Extrude Hone?

[kiwi_MX3]

John John John, I go away for a while and you just have to go and get
bored don't you?

Acid porting was developed for racers running under "stock" rules
where no porting of the heads are allowed in class. and finish had
to remain stock, Ie no bead blasting to hide the tell tale marks of the
pencil grinder / dremel.

Is it effective, hell yea but the acid "eat's" everything thats not protected
by wax ( which you use to protect parts when hard crome plating )

Effort Vs gain's not a lot really