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Old 04-24-2004, 12:22 PM   #1
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Default Is the number of ports in engine really tied to performance?

Hi guys,

I have a question, is there a direct relationship between the number of ports of an engine and its performance?

e.g. Is a 3 port .12 engine really slower than a 5 port engine?

My experience is that I have a Max S5 which is a 5 port engine, on a Mugen MTX3. Then later I got a Sirio Collari modified 3 port engine. Both these engines have been running on the same car and same exhaust. However, I feel that the Sirio is a bit faster than the Max. Well really I do not have a laser gun to check what's really the speed of the car, its purely based on my feeling and the observation of my peers.
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Old 04-24-2004, 03:42 PM   #2
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depends on how they are arranged, and what each one actually contributes. so the answer is yes and no.
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Old 04-24-2004, 03:54 PM   #3
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Adding more ports is a way of getting more port surface area without having such large ports that the piston gets stuck in them.

For example if you make the exaust port super wide, the edge of the piston can catch on it. So you make three exaust ports, one large in the center and two small ones on either side. This effectively make a much larger port to evacuate the exaust.

Intake ports are a little more complex. You are still increasing port area, but also controlling the flow rate and direction around the piston and into the chamber to increase swirl and reduce air/fuel from being thrown out the exaust port(s).

Now you take a stock 3 port and have it modified by a tuner(Rody, Colari, etc), they maximise port flow, direction, intake and exaust timing, even releave the inside of the case to obtain much of the same effects of having more ports.

This accounts for how a modified 3 port can out perform a 5 or even 7 port motor.
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Old 04-24-2004, 09:39 PM   #4
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Quote:
Originally posted by DMACK
Adding more ports is a way of getting more port surface area without having such large ports that the piston gets stuck in them.

For example if you make the exaust port super wide, the edge of the piston can catch on it. So you make three exaust ports, one large in the center and two small ones on either side. This effectively make a much larger port to evacuate the exaust.

Intake ports are a little more complex. You are still increasing port area, but also controlling the flow rate and direction around the piston and into the chamber to increase swirl and reduce air/fuel from being thrown out the exaust port(s).

Now you take a stock 3 port and have it modified by a tuner(Rody, Colari, etc), they maximise port flow, direction, intake and exaust timing, even releave the inside of the case to obtain much of the same effects of having more ports.

This accounts for how a modified 3 port can out perform a 5 or even 7 port motor.
100 % agree. No metter how many ports, metter where mixture goes. Even 2 ports ( 2 transfer) can do and do work. It is depend on angles, radiuse of cutting ( not a radius of mill) etc.
Just for instance, if everything goes as we assuming ( bunch of work and tria have been done) new generatin of PS12 will be 2 ports. Configuration will be realy interesting, but only 2 holes.
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Old 04-25-2004, 12:22 AM   #5
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Quote:
Originally posted by DMACK
Adding more ports is a way of getting more port surface area without having such large ports that the piston gets stuck in them.

For example if you make the exaust port super wide, the edge of the piston can catch on it. So you make three exaust ports, one large in the center and two small ones on either side. This effectively make a much larger port to evacuate the exaust.

Intake ports are a little more complex. You are still increasing port area, but also controlling the flow rate and direction around the piston and into the chamber to increase swirl and reduce air/fuel from being thrown out the exaust port(s).

Now you take a stock 3 port and have it modified by a tuner(Rody, Colari, etc), they maximise port flow, direction, intake and exaust timing, even releave the inside of the case to obtain much of the same effects of having more ports.

This accounts for how a modified 3 port can out perform a 5 or even 7 port motor.
now, thats really make sense. great stuff here.
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Old 04-25-2004, 11:20 AM   #6
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Thanks guys! This is great information! I always thought more ports = more power, but now I am thinking differently.....
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Old 04-25-2004, 11:25 AM   #7
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I asked another racer yesterday the same question. Now I got my answer
Thanks guys
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Old 05-09-2004, 12:08 AM   #8
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also with more smaller ports as opposed to just a few big ones theres more parts around the piston skirt touching the liner & this is very important to aid the piston to transfer heat out into the liner
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