Acid Ported Intake today.....

[mgreen1872]

So I spent all day acid porting the intake since the heads are at the machine shop and before I paint the intake I thought I would give the acid porting a shot. I had used it before on other projects but searching shoforum I did not see a lot of info on it. I was able to make a block-off plate for each of the runners using an extremely high tech device (aka: hinge off of an old front door) and a small piece of gasket material. I used a set of dial calipers to gauge the material removed and timed the soaks of each runner to hopefully get them as close to exactly the same as possible. According to the calipers I have removed about .04 in. of material from the runners, not to mention the runners are very smooth now with almost no hint of casting in them.

My question is should I also port the intake "tanks" (larger perimeter tanks that the runners attach too- not sure what to call them) or would it be pointless? I have to disassemble them anyways to put my BBB's on, but I also dont want to play/buy anymore acid unless it would be worth it?? Thanks

 

[zach44102]

I would like to see pics!

 

[kevinspann]

.004? I wouldn't take the time.

 

[mgreen1872]

.004? I wouldn't take the time.

this is just 15 minutes of acid (full strength 31.45% acid), 30 mins. was recommended... I am doing it in 2 stages to ensure uniformity. (The majority of the day was spent disassembling and cleaning the intake, the actual acid was only 15 min.)

For example, a 1.73in diameter inch intake runner minus .08 would equate to 1.81in diameter or each runner volume as follows: (given a 12inch runner for example purposes)

1.73 runner = 24.7044kg/m^3 of air volume in a runner that is 12 inches long

1.81 runner = 25.8463 kg/m^3 of air volume

an increase of 1.14 kg or 1140g of air volume increase per runner... now multiply that by 12 runners = 13.68kg/m^3 of air volume or roughly 30.16lbs more of air volume available from the entire intake...quiet an improvement

That .04 and eventually .08 is not a bad improvement for pouring in a 6 dollar bottle of acid and waiting a little.

And as for the smoothness, I am extremely impressed... in the past I have used this in Edlebrock and Holley intakes and though the finish was smooth... it was never as smooth as it is in the SHO intake... must be the alloy it is made from...

I plan to put the pics together tomorrow!! Thanks

 

[SeanMc]

My extrude honed runners are 37.2mm, while ported were 36.3, and stock are 35.8. Convert that to centimeters, and that's 3.72, 3.63, and 3.58 which in inches is 1.46, 1.43, 1.41. So I expanded my runners by .05". .004" is sort of small, or did you mean .04?

As for smoothness:
Extrude honed:

Stock:

I'd like to see how it compares.

 

[mgreen1872]

My extrude honed runners are 37.2mm, while ported were 36.3, and stock are 35.8. Convert that to centimeters, and that's 3.72, 3.63, and 3.58 which in inches is 1.46, 1.43, 1.41. So I expanded my runners by .05". .004" is sort of small, or did you mean .04?
I'd like to see how it compares.

LOL..wow I feel blonde now I see why kevinspann was questioning!.. got 00000 happy. Fixed now, thanks. :laugh_ti:

 

[mgreen1872]

wow, the extrude hone is nice! wish I had time to send mine off, but I have got to get this car together as soon as I can. Very nice!

 

[mgreen1872]

several sources on the internet state that .08 is possible with long full strength soaks but my question is....

at some point manufacturing differences and wall thickness will vary throughout the intake.. I'm not sure I want this stuff boiling and eating away at my intake that far?? I mean using the acid straight creates some horrific fumes and the acid has to be dumped or topped off every 5 mins to keep it full and at a rolling boil, seems like a lot of opportunity for something to go horribly wrong. I think I will be happy where I am...

 

[kevinspann]

LOL..wow I feel blonde now I see why kevinspann was questioning!.. got 00000 happy. Fixed now, thanks. :laugh_ti:

Ah...that's a little better.

 

[pjtoledo]

this is just 15 minutes of acid (full strength 31.45% acid), 30 mins. was recommended... I am doing it in 2 stages to ensure uniformity. (The majority of the day was spent disassembling and cleaning the intake, the actual acid was only 15 min.)

For example, a 1.73in diameter inch intake runner minus .08 would equate to 1.81in diameter or each runner volume as follows: (given a 12inch runner for example purposes)

1.73 runner = 24.7044kg/m^3 of air volume in a runner that is 12 inches long

1.81 runner = 25.8463 kg/m^3 of air volume

an increase of 1.14 kg or 1140g of air volume increase per runner... now multiply that by 12 runners = 13.68kg/m^3 of air volume or roughly 30.16lbs more of air volume available from the entire intake...quiet an improvement
That .04 and eventually .08 is not a bad improvement for pouring in a 6 dollar bottle of acid and waiting a little.

And as for the smoothness, I am extremely impressed... in the past I have used this in Edlebrock and Holley intakes and though the finish was smooth... it was never as smooth as it is in the SHO intake... must be the alloy it is made from...

I plan to put the pics together tomorrow!! Thanks

would you care to explain that math again? it's been a while since i've been in a physics class, but 30 pounds of air in the intake system seems excessive.


Perry

 

[19sho90]

Pics or it didnt happen...

 

[rubydist]

would you care to explain that math again? it's been a while since i've been in a physics class, but 30 pounds of air in the intake system seems excessive.


Perry

well, the air is really heavy in Atlanta.....


for the rest of us, the volume of air in a 1.81 diameter by about 6" long runner is around 15 cubic inches or about .010 cubic feet. the mass of air is around .075 lb/cu ft, so that .010 cubic feet of air has about .0075 pounds mass. the 5% increase in air mass from the increased diameter is about .0004 lbm per runner or less than 0.1 ounces total.

 

[intimdatr]

Wow, that really not near as much air as i thought was in there.

 

[mgreen1872]

Wow, that really not near as much air as i thought was in there.

I don't claim to be a math expert but using this formula, I assumed I was pretty close....

The density of air is approximately 1.19g/L

1L is defined to be exactly 1 dm^3 (one cubic decimeter), so
1L = 0.1m * 0.1m * 0.1m = 0.001 m^3

1.19 g/L = 1.19 / (0.001 m^3) = 1190 g/m^3
Remember that 1kg = 1000g, so
1190 g/m^3 = 1.19 kg/m^3

the volume of a space is W*L*H (1.73inch circle diameter * 12 inch runner)

and Mass= volume*density

so basically figuring the volume of each runner and multiplying the approximate density of air gave me the air mass?

that multiplied by 12 runners equals to 13.68kg/m^3 or roughly converted to 30.16lb/m^3 of air mass now.... not be confused with CFM, simply more air mass...


Correct me if I am wrong... math is not one of my favorite things?

 

[kevinspann]

I don't claim to be a math expert but using this formula, I assumed I was pretty close....

The density of air is approximately 1.19g/L

1L is defined to be exactly 1 dm^3 (one cubic decimeter), so
1L = 0.1m * 0.1m * 0.1m = 0.001 m^3

1.19 g/L = 1.19 / (0.001 m^3) = 1190 g/m^3
Remember that 1kg = 1000g, so
1190 g/m^3 = 1.19 kg/m^3

the volume of a space is W*L*H (1.73inch circle diameter * 12 inch runner)

and Mass= volume*density

so basically figuring the volume of each runner and multiplying the approximate density of air gave me the air mass?

that multiplied by 12 runners equals to 13.68kg/m^3 or roughly converted to 30.16lb/m^3 of air mass now.... not be confused with CFM, simply more air mass...


Correct me if I am wrong... math is not one of my favorite things?

The short runners are significantly shorter than the long runners. It's not exactly an circle shape either.


Using some of these numbers I calculated the amount of air in the runners to be about 12 pounds, but that still seems very high.

 

[19sho90]

The only problem with the number you have for density of air is it is changed by altitude abd temp. so it would be very difficult to get an accurate number.

 

[rubydist]

I don't claim to be a math expert but using this formula, I assumed I was pretty close....

The density of air is approximately 1.19g/L

1L is defined to be exactly 1 dm^3 (one cubic decimeter), so
1L = 0.1m * 0.1m * 0.1m = 0.001 m^3

1.19 g/L = 1.19 / (0.001 m^3) = 1190 g/m^3
Remember that 1kg = 1000g, so
1190 g/m^3 = 1.19 kg/m^3

the volume of a space is W*L*H (1.73inch circle diameter * 12 inch runner)

and Mass= volume*density

so basically figuring the volume of each runner and multiplying the approximate density of air gave me the air mass?

that multiplied by 12 runners equals to 13.68kg/m^3 or roughly converted to 30.16lb/m^3 of air mass now.... not be confused with CFM, simply more air mass...


Correct me if I am wrong... math is not one of my favorite things?

well, you are so confused it will be a challenge to explain in short order what all is wrong with your explanation. First, you are mixing inch units with metric units, which is a guarantee to result in a wrong conclusion. Second, you are looking at volume of the runners (which are not nearly as long as you say) and then somehow jumping to mass incorrectly because you have the units all wrong. if you read my post above, you will see results that are at least on the proper order of magnitude.

 

[mgreen1872]

well, you are so confused it will be a challenge to explain in short order what all is wrong with your explanation. First, you are mixing inch units with metric units, which is a guarantee to result in a wrong conclusion. Second, you are looking at volume of the runners (which are not nearly as long as you say) and then somehow jumping to mass incorrectly because you have the units all wrong. if you read my post above, you will see results that are at least on the proper order of magnitude.

As I said I was ASKING for help in the equation...as for the runner length if u will read my post the measurement was for example sake only. Was only trying to be helpful to others considering acid porting which is very expensive to have done professionally... But given the **** attitudes I will bow out of the conversation, heaven forbid someone be wrong, admit they are not an expert, ask for clarification and still get flack and stuck up attitude from some. If anyone would like pics of my PERSONAL, UNPROFESSIONAL, NON-EXPERT acid porting experience feel free to pm me.... IMO my results are very impressive for a guy in his garage. You gentlemen have a good day

 

[vortex2450]

Can you post some pictures? I wanna see the results.

Also, exactly what acid did you use?

-Josh

 

[mgreen1872]

Can you post some pictures? I wanna see the results.

Also, exactly what acid did you use?

-Josh

I will send you a PM shortly, I plan to use a flashlight and take better pics of the runners when I get home.

First, I used acetone to remove/clean grease and carbon build up.

Second, Caustic Soda (lye) aka: most drain cleaners for 15mins.

Lastly, 15 minutes with Muriatic acid

be careful with both Lye and acid as it will boil when in contact with the aluminum.

Gloves, safety glasses and absolutely no beer...