Intake Manifold Cleaning!

[chazdawg35]

Hey Dudes and Dudettes any idea's on cleaning the intake manifold for build up? My S2K has 80k on it now and I have cleaned the throttle body but someone suggested the intake. There are some kit's that have a drip system thru a vacuum port in the intake. Any input good/bad or should I even bother doing it.

[philiam]

If it aint broke... I don't see much build up there. If you mean the air intake, that's what filters are for.

Just my opinion.

[chazdawg35]

Well Phil from what I hear is that there is a hose from the valve cover to the air intake tube and the fumes and traces of oil can build up it the intake manifold passages reducing performance. Do you bite into that? WE NEED MORE INFO!

[philiam]

Never heard that. I'll have to do some research.

[toyrunner]

It can be done with Sea Foam, Half a bottle in the gas, the other half you pour in the intake ( pvc port ) & hold the throttle open as you pour it in.

[TheCarGuy2021]

Originally Posted by philiam

If it aint broke...

+1

[philiam]

The hose attaches to the rubber air intake. Doesn't look like it would be hard to disconnect the intake, remove the throttle body and look inside with a flashlight. I doubt there's enough build up to affect performance.

[TheCarGuy2021]

I had my intake manifold off of my old engine at 70,000 miles, it was still extremely clean (compared to some I've seen). Now if our cars had an exhaust gas recirculation system, it would be a different story. As for the runners not being smooth with the carbon on them, don't worry about it. You do NOT want polished intake manifolds/ports.

[philiam]

"You do NOT want polished intake manifolds/ports."

I'm curious here. Back in the olden days they used to polish the ports. Of course they were running flat heads. Most here probably never heard of "port and relieve", except maybe the sailors.

[RealJoKeR]

EVER HEARD OF ' EXTREME HONING '? I HAD MY HEADS DONE ON MY GMC CYCLONE....BASICALLY REMOVING ALL THE ROUGH OR SHARP EDGES....TO IMPROVE FLOW....WOULD THAT EVEN MATTER IN THE CASE OF THE F22C??? LET ME KNOW CARGUY

[turbosix]

you mean extrude honing.

and i wouldnt mess with the f20/f22 heads... much more likely to mess things up than make any gains

[toyrunner]

^2

[TheCarGuy2021]

I learned quite a few things taking engine airflow classes and doing lots of research on flow benches.

It gets pretty technical, but in laymans terms:

1) More flow does NOT mean more power, flow velocity plays almost as big of a role. Look at the stock ports on old big block engines and you will see they are big and flow plenty, yet they perform terrible. This is because the large size of the ports drastically slows down the flow. The average engine only needs 3.7 CFM (tested at 25" H2O) of air to generate 1 HP, make the ports too large for your power goal and you are only hurting yourself. Another thing to take into account is valve duration. At 4000 RPM the intake valve is only open for .012 seconds and at 6000 RPM the intake valve is only open for .008 seconds!!!, just imagine how long they are open at 9000 RPM FIVE THOUSANDTHS OF A SECOND! If your air velocity is too low you're not going to get nearly enough air into the cylinders fast enough to make good power, even if your ports flow plenty. You need to know exactly what you are doing to port our head, as it is extremely well engineered.

2) You do not want smooth intake ports/runners on any application. This is because you want the air going into the cylinders to be as turbulent as possible (tumble motion + swirl motion or "swumble"). The turbulence results in the air/fuel mix spreading out MUCH more throughout the cylinders resulting in a more powerful, more efficient, more complete burn. Our camshafts are actually "staged" meaning that one intake valve opens before the other to help create swirl motion in the cylinder.

Why is a golf ball with dimples almost twice as aerodynamic as a perfectly spherical ball of the same size?

3) Polished exhaust ports are fine, they will actually resist carbon buildup and you don't want turbulence in the exhaust system.


Hope this helps clear some things up.

[TheCarGuy2021]

Originally Posted by philiam

"You do NOT want polished intake manifolds/ports."

I'm curious here. Back in the olden days they used to polish the ports. Of course they were running flat heads. Most here probably never heard of "port and relieve", except maybe the sailors.

Flow benches/swirl meters/turbulence meters/ velocity meters didn't exist back in the "olden days".

MUCH of R&D on current engines is all on flow benches.

[philiam]

Thanks CG. Good to hear from one who knows what he's talking about.

[chazdawg35]

Originally Posted by philiam

Thanks CG. Good to hear from one who knows what he's talking about.

Well Phil I think now we know the answer to my question, LEAVE IT ALONE! BTW CarGuy glad to have you on our side Dude, that was not only informative but very cool.

[RealJoKeR]

Originally Posted by philiam

Thanks CG. Good to hear from one who knows what he's talking about.

+1 I feel better.

[desmo4]

I understand what has been said, however a friend of mine has a patent on a laminar flow air intake. Which was verified in the NASA Langley wind tunnel to give a 12% power gain. And this correlates to the theoretical data as well. This is direct opposition of turbulent air. I think in the automotive world it is just cheaper to leave parts unfinished and allow body style to dictate how the intake an exhaust runs.

The system described above consists of two cones of an included angle of 12 degrees. Joined together at the small ends. By varying the diameter of the opening between the cones the flow varies . And it always laminar. Formula 1 uses a ball valve for a throttle. At some partial throttle and wide open it is laminar. Throttle plates in passenger cars are only laminar at wide open throtlle. No too practical. The problem with this laminar throttle is one of materials. Very few can do what is necessary to make this system work. NASA has mu metal for instance.

Jonathan

[TheCarGuy2021]

Turbulent flame speed across the combustion chamber is 5-10 times faster than laminar flame speed. A totally quiescent (laminar) flow into the combustion chamber will limit engine speed to ~200 RPM.

I have not only been taught these ideas by the most intelligent man I know (in the engine building business for decades, was one of my professors for over 3 years) but have done first hand research with intake manifolds/cylinder heads on a Superflow SF600 flow bench in his airflow classes followed by dynamometer testing on a Superflow Dyno800 series dynamometer in his dynamometer classes. All research I have done has indicated that turbulence and velocity are just as important as flow.

This is all for naturally aspirated/non 100% race engines though. Boost the engine or build it for 100% racing (rebuild after every race) and nearly all factors change. For race/boosted engines the major factor is flow. This is because the extremely high compression (static or dynamic) and head/piston design alone will create all the turbulence needed.

Also, how do you measure a power gain in a flow tunnel?

[Marrk]

Twenty-five years ago, guys were doing "port and polish" on motorcycle engines. Not sure exactly what that entailed.


N.B. This is an extremely interesting thread. Thanks to all.

[chazdawg35]

Let's do it Dude's build a BETTER intake! This sound real fun any input?

[keafun]

Hello,
This may be a late post, however, I'm excited to answer.
I suppose the F20C/F22C engine runs pretty rich at the higher RPMs. What happens if there is more airflow introduced to help balance the A/F ratios? Would it not be better? Polishing the manifold simply lets more air into the chambers does it not? Regardless of how the air will flow into the combustion chamber, has already been solved by Honda Engineers. I believe with port and polishing of the intake manifold, it removes a small amount of air resistance, ever so increasing slightly the airflow. However is it necessary? not really, unless it is formula one.
When should port and polish be done on an exhaust manifold?
If forced induction is involved, the potential difference is much more pronounced.
If natural aspiration tuning is involved. Then Port and Polish is simply a fraction of many tuning methods combined to give an already high level of engineering an opportunity to push the envelope.
Summary?
Port and polish the intake manifold. It will help, a little. Remember, a lot of little things do add up.
So combine port and polish, larger throttle body, high rated petrol, better spark plugs and wires, a fairly decent intake, header and exhaust manifold. All these sum to a great improvement.
Port and polish intake manifold is a fractional step in naturally aspirated tuning.

[knuckles]

Originally Posted by chazdawg35

Well Phil from what I hear is that there is a hose from the valve cover to the air intake tube and the fumes and traces of oil can build up it the intake manifold passages reducing performance. Do you bite into that? WE NEED MORE INFO!

thats PCV valve if am not mistakin, i cleaned that and didnt notice a difference tbh, replaced it with breather also didnt notice anything

[flyingarmadillo]

Originally Posted by keafun

Hello,
This may be a late post, however, I'm excited to answer.
I suppose the F20C/F22C engine runs pretty rich at the higher RPMs. What happens if there is more airflow introduced to help balance the A/F ratios? Would it not be better? Polishing the manifold simply lets more air into the chambers does it not? ...

While most engines run rich at wide open throttle introducing more airflow won't do anything to change the mixture since the MAF will sense the increased airflow and the ECU will increase the fuel flow in response to the higher airflow. The only way to change the mixture would be to reprogram the ECU. And you wouldn't like the results - the rich mixture essentually increases the octane of the fuel - the rich mixture retards combustion. Peak power isn't usually achieved in piston engines with a lean or even stochiometric mixture - it's someplace on the rich side. In some small private piston powered aircraft you have manual control over the mixture and the procedure is to lean the mixture for maximum RPM, then richen it up just slightly (100-200 rpm drop). This gives max power. Some of it also depends on what you call polish - a mirror polish will absolutely kill performance on a carburated or throttle body injected engine - some turbulence is needed to keep the fuel suspended in the air, with a mirror polish it tends to deposit on the walls of the intake. On direct injected engines it doesn't make much difference. If you're talking about polishing as in removing machine and casting marks and just cleaning up the intake, then it helps but you still need to leave enough roughness to control the airflow.

[TheCarGuy2021]

Originally Posted by keafun

Hello,
This may be a late post, however, I'm excited to answer.
I suppose the F20C/F22C engine runs pretty rich at the higher RPMs. What happens if there is more airflow introduced to help balance the A/F ratios? Would it not be better? Polishing the manifold simply lets more air into the chambers does it not? Regardless of how the air will flow into the combustion chamber, has already been solved by Honda Engineers. I believe with port and polishing of the intake manifold, it removes a small amount of air resistance, ever so increasing slightly the airflow. However is it necessary? not really, unless it is formula one.
When should port and polish be done on an exhaust manifold?
If forced induction is involved, the potential difference is much more pronounced.
If natural aspiration tuning is involved. Then Port and Polish is simply a fraction of many tuning methods combined to give an already high level of engineering an opportunity to push the envelope.
Summary?
Port and polish the intake manifold. It will help, a little. Remember, a lot of little things do add up.
So combine port and polish, larger throttle body, high rated petrol, better spark plugs and wires, a fairly decent intake, header and exhaust manifold. All these sum to a great improvement.
Port and polish intake manifold is a fractional step in naturally aspirated tuning.

[TheCarGuy2021]

Originally Posted by flyingarmadillo

While most engines run rich at wide open throttle introducing more airflow won't do anything to change the mixture since the MAF will sense the increased airflow and the ECU will increase the fuel flow in response to the higher airflow. The only way to change the mixture would be to reprogram the ECU. And you wouldn't like the results - the rich mixture essentually increases the octane of the fuel - the rich mixture retards combustion. Peak power isn't usually achieved in piston engines with a lean or even stochiometric mixture - it's someplace on the rich side. In some small private piston powered aircraft you have manual control over the mixture and the procedure is to lean the mixture for maximum RPM, then richen it up just slightly (100-200 rpm drop). This gives max power. Some of it also depends on what you call polish - a mirror polish will absolutely kill performance on a carburated or throttle body injected engine - some turbulence is needed to keep the fuel suspended in the air, with a mirror polish it tends to deposit on the walls of the intake. On direct injected engines it doesn't make much difference. If you're talking about polishing as in removing machine and casting marks and just cleaning up the intake, then it helps but you still need to leave enough roughness to control the airflow.

Our car doesn't have a MAF, it has a MAP. Our car will use its O2 sensors (and others) to keep A/F ratios constant.

[flyingarmadillo]

Originally Posted by TheCarGuy2021

Our car doesn't have a MAF, it has a MAP. Our car will use its O2 sensors (and others) to keep A/F ratios constant.

Essentially the same thing. With a MAP the ECU takes the MAP data and coverts to volume (which is then a MAF reading) for use in the fuel calculation, then uses the O2 sensors to fine tune the mixture. With a MAF the flow volume is fed directly to the ECU which calculates fuel mixture, then fine tunes using the O2 sensor. The MAP is less sensitive to contamination, the MAF method is slightly more accurate for the initial mixture calculation. At least that's the way I understand it. Either way the ECU is going to compensate for the increased volume unless you reprogram it.

[philiam]

Originally Posted by knuckles

thats PCV valve if am not mistakin, i cleaned that and didnt notice a difference tbh, replaced it with breather also didnt notice anything

Snot the PC valve. The hose in question is further forward and connects
to the rubber intake hose.

[knuckles]

whats dis, and where the other side connected n for what purpose

[TheCarGuy2021]

Originally Posted by knuckles

whats dis, and where the other side connected n for what purpose

Air pump intake.

[keafun]

Originally Posted by TheCarGuy2021

?? why ??

[gomarlins3]

Originally Posted by keafun

All these sum to a great improvement.

Define 'great'.

[TheCarGuy2021]

Originally Posted by keafun

?? why ??

Alright then...

I suppose the F20C/F22C engine runs pretty rich at the higher RPMs.

Define "rich", either way this typically isn't the case.

What happens if there is more airflow introduced to help balance the A/F ratios? Would it not be better?

1) What do you mean "balance" the A/F ratio?
2) No, the sensors would detect more air and add more fuel.

Polishing the manifold simply lets more air into the chambers does it not? I believe with port and polishing of the intake manifold, it removes a small amount of air resistance, ever so increasing slightly the airflow.

1) No, it "simply" doesn't. Mind explaining the science behind your reasoning? Didn't think so.
2) When the valves are all the way open the intake throat diameter (valve seat) is the biggest restriction, making the ports/manifold runners bigger will do nothing as the intake throat is still much smaller. Think about having a fire hose and a garden hose both with a 1/2" hole or orifice. At the same pressure they are going to flow the exact same amount.

When should port and polish be done on an exhaust manifold?
If forced induction is involved, the potential difference is much more pronounced.
If natural aspiration tuning is involved. Then Port and Polish is simply a fraction of many tuning methods combined to give an already high level of engineering an opportunity to push the envelope.

This all depends on many other factors.

So combine port and polish, larger throttle body, high rated petrol, better spark plugs and wires, a fairly decent intake, header and exhaust manifold. All these sum to a great improvement.
Port and polish intake manifold is a fractional step in naturally aspirated tuning.

1) A port and polish isn't going to help.
2) A larger throttle body will cause "vena contrata" if the manifold isn't matched, if the manifold is matched you will slow down your velocity.
3) Higher octane gasoline isn't going to do anything unless you can advance your spark timing.
4) Better spark plugs and wires will do nothing.
5) An intake will have minimal gains.
6) Header and exhaust will have minimal gains.

So as a "summary" these will all do nearly nothing.


And as for your rude comment on my profile:

keafun
The Car Guy does not really provide any assistance to people who are here to share and learn and teach. Please, grow up and learn, read and share before you make unthoughful comments to other people and then save yourself some embarassment.

Regards.

I enjoy sharing my automotive experience and knowledge with this site and enjoy having debates about different topics, but don't be rude about it. Agree or don't, but my ideals come from 7 years of automotive service, automotive engineering, and high performance automotive schooling. I'm not telling anyone "that's the way it's gonna be, no exceptions" because if I were I would always be wrong, there is always an exception. Hell, even I have learned quite a bit from other people on this site. Agree or disagree but there's no need to be rude about it.