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Old 11-08-08, 07:23 PM
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Question Engine Porting questions

What are the Pros and cons to engine porting? (yes I have searched and read up but I want to hear it in a more consolidated format) From what I have read it sounds like you increase your redline, allow the capability to run higher boost, and of course more power out of the standard 13b block. But what are the negatives?

Is the engine more susceptible to blowing seals? Compression and vacuum get weaker?

I see all the positives (and now that i have some options after my FD was hit) but I am just more curious about the whole picture.
Old 11-09-08, 10:08 PM
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your question is not bad, but it's still a bit vague. you'll have to provide some context. you need to give specifics of what you want to know ... like what kind of port you're considering and the primary use of your car.

speaking generally, as you've probably gathered, porting is about increasing airflow into the engine. increased airflow (with the appropriate fuel and ignition) will increase power. i'm a tad uneasy with your simply mentioning a higher redline. that's not the point - especially if you're porting in conjunction with forced induction.

also, you have to understand that each type of port has it's advantages and disadvantages. you MUST compromise - no choice in that! - the only thing you can control is how much compromise.

as far as the reliability question, if the engine is built right AND tuned right, it will last. obviously, power is addictive and more of it leads usually leads to harder use and that "can" mean less longevity, but if you're diligent with maintenance it doesn't have to be.
Old 11-10-08, 06:53 PM
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Porting is increasing the port timing and area of the port. The equivalent on a piston engine is, increasing the profile of your camshaft (more duration and lift)and larger intake valves. Air flow is governed by what the compressor flows on your turbocharger.

Negatives are, cost (to get it all done), increased fuel comsumption, driveability will suffer
Old 11-10-08, 07:34 PM
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first you have to ask yourself what are you gonna use the car for
Old 11-10-08, 07:45 PM
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Check this thread for a similar discussion:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/limits-stock-ports-795074/
Old 11-10-08, 09:52 PM
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Thumbs up

thanks for the input guys. I am looking for an engine that will provide more power and provide me the most flexiblity to add power mods while compromising with drive ability. I want to track and be competitive, yet I also want to enjoy Friday Cruise night (at least whenspring comesbackaround).

As I understand the larger the port the more you can push the amount of boost and he power of the engine. However, many have opinions stating porting will reduce the life of your engine, which spider webs into a whole slew of other questions in how to ensure when you ask someone to build a motor for you that it is done right. Part of this is due to the fact that I am in the market to buy another FD, and part is still me trying to make sense of the complete picture.
Its fortunate and unfortunate all at the same time that all of this information is out there as I feel like I understand the pieces, but find it difficult to truly capture the whole.

As I try to truly understand the impacts of decisions or well laid out plans, I some times wonder if my masterpiece will come together like the Mona Lisa, or mis-shaped like Quasimoto. Bear with me as I ask questions. I am trying not to comeoff as a total n00b, and sometimes you just need that third party to affirm or rebuff ideas.

Thanks.
Old 11-10-08, 10:01 PM
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Great Thread Link Mahjik! Never thought of it that way.
Old 11-27-08, 12:05 PM
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Porting wont shorten the life of your engine, that thing at the end of your leg will do that for you (FOOT), and yes it will help you go past the red line and that falls back on to the (FOOT) Doring normal driveing it will feel the same until (FOOT). and this is if this is on a stock engine, but once you go beyound stock, poor idle, hard start up, flate spots. But when (FOOT) the fun starts (STAY AWAY FROM RED LINE) the biggest killer of rotary engines
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