Putting a fan on top of air intake?

[Shaun]

Re: Putting a fan on top of air intake?

If so, then all the more better to have ADM. Cos 1.6L air intake at 6500rev is about 145CFM. So at this point with ADM (238CFM), you should have an extra airflow of 93CFM at high end.

There will no be no 93 CFM extra airflow. 238 CFM is the flow potential of the unit at whatever pressure it is rated for. 93 CFM potential extra airflow IF pressure the unit has to face is not above spec. As pressure climbs above spec, flow rating drops. If there was 93 CFM extra airflow, power would be up an additional (93/145) x 100 = 64 %. Obviously this is not so.

ADM doesn't list pressure rating. There are however lots of bilge blowers rated in the 0.5 - 1.5 psi range. This is why I have picked a simple, middle of the range - 1.0 psi. So assuming this 1 psi is right, or close - then effective flow at redline is 145 x (15.7/14.7) = 155 CFM. Gain is 155-145 = 10 CFM. This is the amount of extra airflow. Repeating the power estimate in the first paragraph - (10/145) x 100 = 7% . So expect a 7% power increase at the RPM this calculation is for (6500).

This is rough guide. Accuracy is dependent on actual spec of the blower, what pre and post AFRs are, ring and valve seal, ignition timing. Small factors by themselves, but all adding up and accounting for the variances. Not to mention the variance in the chassis dyno measurement.

 

[Whisky_Tango]

Re: Putting a fan on top of air intake?

Well explaint and illustrated bro...

 

[Alianta]

Re: Putting a fan on top of air intake?

Erm, I have a query to ask and I hope its in the right forum:-
Have anyone tried to install a Cyclone fan(s) into their 2002 model 318iA and experience any visible performance improvements?

Cheers...

 

[ryan]

Re: Putting a fan on top of air intake?

Paging whiskytango...

He's installed a pretty big blower before and custom his setup. Let's see whether he'll see this post. :0

 

[Whisky_Tango]

Re: Putting a fan on top of air intake?

Erm, I have a query to ask and I hope its in the right forum:-
Have anyone tried to install a Cyclone fan(s) into their 2002 model 318iA and experience any visible performance improvements?

Cheers...

Hi Alianta,

1st of all, a warm welcome to our forum.

Your cyclone fan sounds like the static blades type which is installed near the throttle body? If it is, IMO this type of product is beneficial to carburetted engines. Now the cars are fuel injected, where by the cyclone effect incoming air will not 100% stir and turbulate with the fuel inside the combustion chamber.

If it is other product, please share more descriptions.

Cheers!
Eric

 

[Wayansurfer]

Re: Putting a fan on top of air intake?

Paging whiskytango...

He's installed a pretty big blower before and custom his setup. Let's see whether he'll see this post. :0

Big Blower u say??? I likeeeeeeeeeeeeeeeeeeeeeee.....

 

[Shaun]

Re: Putting a fan on top of air intake?

Modern road car manufacturer engineering divisions finely design 4v high-tumble port, squish/quench area, and chamber architecture to minimize emissions especially in the everyday type of driving situation - low rpm, low-medium loads. As such the flow is already heavily biased towards tumble (4v) and away from flow. It is incredibly easy to mess tumble up especially with vortices on a perpendicular axis.

No cheap little gadget will ever improve what they have created (tumble-wise) without hurting flow (power). They have invested tens of thousands of man hours and dollars just to find the balance.

Biasing toward flow and throwing away emissions is preferred over biasing towards lower emissions but killing power. The manufacturers have already carried out he latter for you. Why make it worse especially when, in all likelyhood, you value power over emissions-cleanliness.

 

[Shaun]

Re: Putting a fan on top of air intake?

Same goes for fuel mileage. You won't top the manufacturers without hurting something else - unless you have invested more than them in minds and machines - which no aftermarket gadget company has ever done.

 

[Whisky_Tango]

Re: Putting a fan on top of air intake?

Modern road car manufacturer engineering divisions finely design 4v high-tumble port, squish/quench area, and chamber architecture to minimize emissions especially in the everyday type of driving situation - low rpm, low-medium loads. As such the flow is already heavily biased towards tumble (4v) and away from flow. It is incredibly easy to mess tumble up especially with vortices on a perpendicular axis.

No cheap little gadget will ever improve what they have created (tumble-wise) without hurting flow (power). They have invested tens of thousands of man hours and dollars just to find the balance.

Biasing toward flow and throwing away emissions is preferred over biasing towards lower emissions but killing power. The manufacturers have already carried out he latter for you. Why make it worse especially when, in all likelyhood, you value power over emissions-cleanliness.

Bro, can share some pix of the 4v high tumble port?

Thanx

 

[Shaun]

Re: Putting a fan on top of air intake?

Bro, can share some pix of the 4v high tumble port?

Thanx

Just to clarify - all modern 4V heads that have a symmetry across the intake to exhaust port line, and that are designed for mixture motion, have tumble as the motion, not swirl. In the interest of emissions and fuel mileage, modern street type 4V engines are designed to have considerable mixture motion in the low velocity, low RPM areas - where they operate most of the time. This is why it is certain that lower piston speed, lower output street type 4V engines run high tumble architecture.


Regarding your question..you can't see the port trajectory or shape and how it integrates with the cylinder unless you have one of those deals where they run a clean cut cross section of both - like they do in display models for new engines. The new M5 V10 engine had somewhat of a cut made to it which showed a nice and high approach intake port.

The valve angle (horizontal to valve head) [13ish] and included valve angles (angle between intake and exhaust valve stems) [30ish] are all low and characteristic of a low tumble port. It is designed to provide some tumble at high RPM, high flow - which means there is next to none at low RPM. Taking it to extremes, F1 stuff goes down to low 20 included valve angles. Low tumble, high compression, on a huge bore near flat top piston. Lower performance street stuff is designed to provide substantial swirl at low RPM, low flow, which compromises flow (power) in the upper areas. I haven't come across, or looked for, any pictures of this kind of lower performance street type high tumble head. Just picture the opposite - high valve angles, low port approaches.

Even with the cross sections you can only get a rough idea. Flow and combustion video is still needed to complete the picture. I don't know how to describe it. I've got some simulation and actual test presentations by lead engineers from Daimler-Chrysler, Mitsubishi, Chevrolet, but I don't have the equipment to rip the video sections. I'll bring them back in the future and then if you want you can watch it. I'll let you know.

 

[Shaun]

Re: Putting a fan on top of air intake?

Found a street type head. 6cyl Valvetronic. Higher valve angle, lower port approach..

 

[Whisky_Tango]

Re: Putting a fan on top of air intake?

Thanx Shaun, well explain. Only one thing i cant visualize is air/fuel tumble instead of swirl.

Ok, pls bring along those videos, I really want to see it.

Cheers!

 

[Shaun]

Re: Putting a fan on top of air intake?

In the meantime...

a.jpg - MB approach to variable tumble, besides the point but shows tumble

b.jpg - same as a but mixture path highlighted

c.jpg - useful model. The swirl model has 2 intake valves so it is either a single or dual exhaust valve (total 3 or 4 valve) head. Like I said in an earlier post on swirl, it can't happen as long as there is non-symmetry across the intake to exhaust port line. In this case, both intake ports are canted (no symmetry across mentioned line) which is why they can generate swirl. The only other way is if you disable one intake port if such a system is installed.

 

[Whisky_Tango]

Re: Putting a fan on top of air intake?

Beautiful diagrams!!

Now I understand much better.

Thanx bro...

 

[Shaun]

Re: Putting a fan on top of air intake?

you're welcome

Incidentally, the flathead model showing illustrating swirl is a diesel. Flatheads are characteristic of diesels that require very high compression levels in order to operate.

Something very important I forgot to mention is that all swirl and tumble designs utilize geometric flow biasing to create large vortices in the cylinder. They never use generators in either manifolds, or ports to create micro motion because it is just too small and is lost when the port exits into the much larger bore cylinder. You lose flow and pick up no useful motion. Another reason why all these little swirl gadgets just don't work.

 

[Whisky_Tango]

Re: Putting a fan on top of air intake?

you're welcome

Incidentally, the flathead model showing illustrating swirl is a diesel. Flatheads are characteristic of diesels that require very high compression levels in order to operate.

How abt "conehead" type? Even higher compression pressure?

 

[Shaun]

Re: Putting a fan on top of air intake?

What is a conehead?
Do you mean pentroof as in the usual 4 valve chamber?

 

[Whisky_Tango]

Re: Putting a fan on top of air intake?

Hahaha... tats why i put inverted cormas.

ok, some piston head the center part is higher than the edge.

 

[Shaun]

Re: Putting a fan on top of air intake?

Oh hehhe

Any design that adds to chamber volume reduces compression ratio potential. Doming the piston is always an option but is bad for flame propogation - poor substitute. You always want the smallest chamber volume to get to your compression ratio target - smallest chamber volume along with a flat, dished, or reverse dome piston top.

Talking strictly about compression.. best to worst..

1) Flathead (as in diesel type not valves-in-block type)
2) Wedge
3) Pentroof
4) Hemispherical
5) Flathead (valves-in-block)

But considering other factors besides compression ratio in making power - flow, mixture motion (minimal), valve area, scavenging, head packaging, mechanical simplicity, nothing beats a 4 valve pentroof. 5V heads have been allowed in F1 for a long time but no one runs them.

 

[Shaun]

Re: Putting a fan on top of air intake?

Oh hehhe

Any design that adds to chamber volume reduces compression ratio potential. Doming the piston is always an option but is bad for flame propogation - poor substitute. You always want the smallest chamber volume to get to your compression ratio target - smallest chamber volume along with a flat, dished, or reverse dome piston top.

Talking strictly about compression.. best to worst..

1) Flathead (as in diesel type not valves-in-block type)
2) Wedge
3) Pentroof
4) Hemispherical
5) Flathead (valves-in-block)

But considering other factors besides compression ratio in making power - flow, mixture motion (minimal), valve area, scavenging, head packaging, mechanical simplicity, nothing beats a 4 valve pentroof. 5V heads have been allowed in F1 for a long time but no one runs them.