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PostPosted: Thu Jul 02, 2009 6:08 am 
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Joined: Fri Nov 28, 2008 3:42 pm
Posts: 36
Location: Tempe, AZ
My goals are:
-fit in a book chassis
-reliable
-close to 200 hp
-$1400-$1600max (ideally $400 lol, but under a grand would be great)
-somewhat upgradeable

I'm aprehensive with the rotary as repairs/rebuilds will be expensive, and the reliability is in question. Definate wow factor and decent horses for the price.

Undecided whether high revs or tq as a priority. Exploring my options, I suspect I will find qualities about each I like. However, I need to decide soon! Almost done building all I can without the motor! Trying to finish before school starts again.

-JD


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PostPosted: Thu Jul 02, 2009 11:18 am 
My suggestion would be to do 13b na with a single carb. Street port would get you about the same power as the stock turbo motor. Bridge port would get you above 200hp but with a lumpy and anoying idle.

Na rotarys are really reliable, the turbo ones are too but you have to build them that way. What makes them unreliable is when people try to get more power out of them without upgradeing other things. Since your on a tight budget, dont think you want to be buying a stand alone ecu, injectors, fuel rails, and all the other stuff to make power and keep it safe. Basicly, if you want to make 300hp, built it to make 500hp.

Your other option is an s2k motor. May be a little more expencive but if you keep it stock, you know you can get hundreds of thousands of miles out of it.


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PostPosted: Thu Jul 02, 2009 10:25 pm 
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Joined: Fri Nov 28, 2008 3:42 pm
Posts: 36
Location: Tempe, AZ
More info on the 13B NA.... Is it an S4 or S5? Any links to the carb? Thanks ahead of time.


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PostPosted: Fri Jul 03, 2009 11:14 am 
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Weight watcher
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Joined: Tue Mar 07, 2006 6:15 pm
Posts: 2287
Location: Northridge, CA
The NA 13B is a decent option for your HP goals, better than the turbo rotary IMHO.
The only problem you'll have is to keep it quiet - NA rotaries without sufficient muffling make your ears bleed.

Moti

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PostPosted: Fri Jul 03, 2009 11:20 am 
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Joined: Sun Apr 23, 2006 8:26 pm
Posts: 4744
Location: SoCal
Agreed, it's not so much that good mufflers don't exist, it's that there is so little room for effective units on a Locost. The typical "Cobra" side-mounted mufflers aren't good enough.

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PostPosted: Mon Jul 06, 2009 3:51 pm 
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Joined: Wed Sep 27, 2006 11:12 am
Posts: 347
Location: Darboy, WI
What about a modern all aluminum 4 cylinder from FoMoCo/GM/Mopar? From my research 200hp is fairly easy to reach without any forced induction. Take the ford duratec:
http://www.sbdev.co.uk/History_files/History_DuratecTuning.htm

"Still, you can get over 200 bhp from it without touching the engine internals, which sound a bit more like it. "

And you can find different rwd transmissions for it too. (miata, ranger, Q4R bellhousing & T-5). It should be close to fitting in a book frame, but you should ask A.Moore since he's using a duratec. Dont know his frame size though...

Plus you can get sexy Cosworth parts for the duratec too... :D


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PostPosted: Wed Aug 19, 2009 12:41 am 
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Joined: Sat Feb 09, 2008 1:11 pm
Posts: 52
Location: denver, co
I'm bringing back 1 month old thread, but I find that engine weights as reported are grossly too low. They don't include accessories and tranny. I became curious about various engine weights and bought a crane scale (think of a giant fish scale). Here is an example of a 13b-REW, fully dressed with a tranny:

Image

I can't see how the single turbo version weighs 80 pounds with another 100 pounds for a tranny. There's no way I can lift the twin turbo sitting in the basement.

Nor can I lift my Miata engine. It's on a movers dolly and is a struggle just to move around. It is a Miata 1.6 with accessories and tranny (it has a turbo)

Image


I had a Hayabusa motor a couple of years back, and while I could pick it up, it felt a lot heavier than 100 pounds.


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PostPosted: Wed Aug 19, 2009 7:57 am 
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Joined: Tue Jun 09, 2009 12:10 pm
Posts: 122
Check out Pineapple Racing, Mazdatrix or Racing Beat. They're three good sources of rotary stuff. Mazdatrix also has some tech info on their website on 13B porting. As for mufflers, you'll need something that's all stainless. Exhaust temps on a rotary are several hundred degrees higher than for a piston engine and they're known for frying regular mufflers. And yes; they're LOUD.
A friend of mine went to the 24 hours of Daytona years ago and the GTU Mazda's were the loudest cars on the track, louder than the GTO's and GTP's.
If you really want to use a turbo rotary, Google "rotary locost". There's a guy in Houston who did a turbo rotary locost. He should have lots of info for you.


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PostPosted: Wed Aug 19, 2009 12:46 pm 
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Joined: Tue Sep 05, 2006 11:00 pm
Posts: 716
Location: Columbia SC
How about the suzuki Swift GT motor with a turbo. VERY light, it really IS a
light motor. Under 300# with a 2wd sammy tranny. Lop 200lbs off your
car compared to most other lightweight engines. I've heard it works well
with mild boost in stock form 150-170hp. Not tons of power but 150lbs
lighter than a Miata setup and very small to boot. Just a thought.

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