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New guys first rotary rebuild.

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Old 05-26-15, 11:33 PM
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New guys first rotary rebuild.

I bought a sorda "barn find" esk s4 Turbo II. The rear rotor failed a compression check miserably, the front was around 80-90ish psi. Any way, I've already searched and learned as much as I could, and I'm pretty confident about doing it. Just posting this to ask if ask if there are any like While I'm in there sorda things I should try and do. Obviously I would like more power. Any recommendations?

Thanks
Old 05-26-15, 11:46 PM
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Porting is the only really thing that will net you more power internally (well easiest DIY-esque thing you can do). But you should look into that a fair bit before havin a go at it I'd say. People just clean up the bowls apparently and get a good bit of gain without messing up timing/port closing n opening too much.

There's a lot to learn in reality. But you seem like you're going down the right path/have the right idea.

Never hurts to balance rotating assembly.

P.S I am by no means experienced.
Old 05-27-15, 04:46 AM
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Aaron cake is God.
Old 05-27-15, 01:59 PM
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I was thinking about porting, I would like to do a half bridge or something for more revving and the neat idle that happens. but i was reading that on turbo cars it isn't really needed to do anything more than a street port because the air is forced in. I was also planing on removing the air pump/cat, my city doesn't do emissions.

And I am looking for a local place to turn/balance my rotors but ill plrobably end up sending them to mazdatrix or something.

Who is Aaron cake?
Old 05-27-15, 02:47 PM
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Originally Posted by Kane Jacobs
I was thinking about porting, I would like to do a half bridge or something for more revving and the neat idle that happens. but i was reading that on turbo cars it isn't really needed to do anything more than a street port because the air is forced in.
it helps to think about the engine as a complete system, from the air filter to the exhaust tip. the stock porting is really optimized for a small turbo with a lot of back pressure, which is what a T2 turbo is.

the larger you port the ports the more air is can flow, but also the more sensitive it will be to exhaust back pressure, and so forth. so to take advantage of a bridge port, you really need a bigger turbo, and a bigger exhaust, etc etc.

so stock ports actually work really well with a turbo, i have an engine simulation, and sticking Mazdas porting into any engine works well for a turbo, if you really must port a small street port does add power, but there is no real reason to go bigger, especially with the stock turbo.

or to put it another way the stock turbo is the restriction, after the exhaust.
Old 05-27-15, 04:15 PM
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Originally Posted by Kane Jacobs

Who is Aaron cake?

Old 05-28-15, 02:15 PM
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Originally Posted by Kane Jacobs
I bought a sorda "barn find" esk s4 Turbo II. The rear rotor failed a compression check miserably, the front was around 80-90ish psi. Any way, I've already searched and learned as much as I could, and I'm pretty confident about doing it. Just posting this to ask if ask if there are any like While I'm in there sorda things I should try and do. Obviously I would like more power. Any recommendations?
It depends on the answer to these three questions:

How much do you have to spend?

What is the primary use for the car?

How much power do you want?

And yes, those questions are in the order of importance.

In general, the engine is fairly well set up as it is, so unlike many (older American) piston engines, there isn't a ton of stuff to do "while you are in there". Mostly we just substitute a few parts for newer versions.

Use 2 piece apex seals (already OEM, and all aftermarket). Use FD corner seals and springs. You can use the RX-8 front cover gasket with some minor gasket mods as it replaces a weak o-ring between the front iron and cover.

That's really it for incidentals unless you are chasing the power dragon. And what you do there depends on how much dragon you want.


Originally Posted by Kane Jacobs
I was thinking about porting, I would like to do a half bridge or something for more revving and the neat idle that happens.
While bridgeports are fun, I think you'll get tired of the fact that car now gets 8 MPG, everyone thinks your idle is broken, and it will take some tuning to make it work. Plus all the mods required to make that bridgeport worthwhile. You're not going to get "more revving" unless you build the internals to handle it. Which means balancing, clearancing, lightening. That's when the machine shop costs start adding up.

Really, all of this is academic anyway since it depends on the answer to those three questions.

but i was reading that on turbo cars it isn't really needed to do anything more than a street port because the air is forced in.
Wherever you read that, you now have a source that you know you can ignore.

I was also planing on removing the air pump/cat, my city doesn't do emissions.
Before you start tearing things off, let's discuss your goals.


Who is Aaron cake?
No idea. Some weirdo I think who needs to grow up and stop playing with cars and stuff.
Old 05-28-15, 09:51 PM
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roTAR needz fundZ

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New guys first rotary rebuild.

Originally Posted by Aaron Cake
Some weirdo I think who needs to grow up and stop playing with cars and stuff.
and needs to cut his lucious locks and donate them for charity
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