ghetto 4 rotor build
04-01-07, 04:41 PM
#26
Originally Posted by John64
April fools!
82transam, you won't be disapointed.
Welcome, ducattiman. I'm not sure where you got your 20B information from, but it only weighs about 75-80 pounds more than a similarly equipped 13B. The 4 rotor 12A will weigh about 128 pounds more than a similar 12A. Just get stiffer springs and relocate the battery. Sure it's still more total weight than a 2 rotor, but the stock GSL-SE was front heavy too, with all that AC and power steering stuff. None of that on this car. The intake will be simple IDA carbs and the exhaust will be short headers.
04-01-07, 07:44 PM
#27
Duct-tape fixes all
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OMG. That is my dream engine lol. I want to put one in a drift rx-7, and build a 4wd rally first gen for a 4 rotor lol.
Good luck man.... I might do this some day.
Good luck man.... I might do this some day.
04-01-07, 11:40 PM
#28
Hmmm taking my project ideas are you? LOL You're breaking my ***** Jeff, you're breaking my ***** LOL. I think I have a pretty good idea on how you will attain your firing order, just so long as you find one 
Definitely keep us posted, you may do all the hard work for me LOL
Definitely keep us posted, you may do all the hard work for me LOL
04-02-07, 12:35 AM
#31
Guys, that 6 rotor never ran. It's a mockup at Hurley.
FirebirdSlayer666, yeah I just have to be sure to post each step. Heh.
trochoid, I forgot to mention we haven't decided which radiator to use or how to mount it. We need to get the engine in there first. We'll start with the GSL-SE oil cooler and add a second one if necessary. Not sure which fan(s) to use. We may do a dual fan setup like on this rotary baja we got running last month or so. https://www.rx7club.com/forum/showthread.php?t=624151
FirebirdSlayer666, yeah I just have to be sure to post each step. Heh.
trochoid, I forgot to mention we haven't decided which radiator to use or how to mount it. We need to get the engine in there first. We'll start with the GSL-SE oil cooler and add a second one if necessary. Not sure which fan(s) to use. We may do a dual fan setup like on this rotary baja we got running last month or so. https://www.rx7club.com/forum/showthread.php?t=624151
04-02-07, 08:52 AM
#33
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OMG, at first I thought this was an April fools. Now I don't know which is more shocking, the fact that the terms "4 rotor engine" and "cheap" were used in the same sentence without a negative, or that Jeff will soon have an FB in his possesion! This IS incredible!
Here's a link, maybe it'll help, though you've probably seen it before.
So for all us on the cheap would be followers, would 12A intermediate plates work the same as well?
Here's a link, maybe it'll help, though you've probably seen it before.
So for all us on the cheap would be followers, would 12A intermediate plates work the same as well?
04-02-07, 10:45 AM
#36
ProjectR13B, thankyou.
innertwist, it's not actually MY FB. It's a joint project. Mine is white and it's progressing in a different direction.
You know that link? That 4 rotor engine sounds like two 13Bs reving up together due to phasing. Blah. Mine will sound like a true 4 rotor with one fire every 90°.
karism, you should see the way I do the ignition on the 4 rotor. You'll get a kick out of it.
blwfly, with the favorable exchange rate, the shaft and modded intermediate plates etc come out to around $5000 USD. Not bad. If the two shafts together don't work out, we're getting the shaft from NZ.
innertwist, it's not actually MY FB. It's a joint project. Mine is white and it's progressing in a different direction.
You know that link? That 4 rotor engine sounds like two 13Bs reving up together due to phasing. Blah. Mine will sound like a true 4 rotor with one fire every 90°.
karism, you should see the way I do the ignition on the 4 rotor. You'll get a kick out of it.
blwfly, with the favorable exchange rate, the shaft and modded intermediate plates etc come out to around $5000 USD. Not bad. If the two shafts together don't work out, we're getting the shaft from NZ.
04-02-07, 11:25 AM
#38
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Originally Posted by Jeff20B
ProjectR13B, thankyou.
innertwist, it's not actually MY FB. It's a joint project. Mine is white and it's progressing in a different direction.
You know that link? That 4 rotor engine sounds like two 13Bs reving up together due to phasing. Blah. Mine will sound like a true 4 rotor with one fire every 90°.
karism, you should see the way I do the ignition on the 4 rotor. You'll get a kick out of it.
blwfly, with the favorable exchange rate, the shaft and modded intermediate plates etc come out to around $5000 USD. Not bad. If the two shafts together don't work out, we're getting the shaft from NZ.
innertwist, it's not actually MY FB. It's a joint project. Mine is white and it's progressing in a different direction.
You know that link? That 4 rotor engine sounds like two 13Bs reving up together due to phasing. Blah. Mine will sound like a true 4 rotor with one fire every 90°.
karism, you should see the way I do the ignition on the 4 rotor. You'll get a kick out of it.
blwfly, with the favorable exchange rate, the shaft and modded intermediate plates etc come out to around $5000 USD. Not bad. If the two shafts together don't work out, we're getting the shaft from NZ.
I was about to say . . . .I have seen pictures of that build on Nopistons. :P
Great project, but we need more pictures
04-02-07, 11:49 AM
#39
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Glad to see you did your homework on the e-shaft and yes i think your key in idea will work and the setscrew but please GO TITANIUM lord knows if that brakes your SOL and it would suck to have to rip back open.
At least get a racing oil pump! i would feel safer for sure if you did.
If you need any help a machine notes or any tricks with metal let me know!
Heck i might donate some machine time to get this beast working for you.
At least get a racing oil pump! i would feel safer for sure if you did.
If you need any help a machine notes or any tricks with metal let me know!
Heck i might donate some machine time to get this beast working for you.
04-02-07, 01:06 PM
#40
Terrified.
Everytime I sign on to rx7club you are doing something else that is insane. I have to hand it to you, and give you all the props I have because, let's face it, not too many people have the ***** to attempt the things you do in fear of failure, and yet you undertake it all even if all you learn in the end is that it won't work. So to that, I've got to say its admirable, and a waste of money. In saying that - anytime you modify a car its a waste of money to someone, so I say you spent the money wisely, lol.
-Dustin
-Dustin
04-02-07, 02:14 PM
#41
lol it's only ever a waste of money if you SELL the car. Ever wonder why you see so many V8 RX-7s for sale all the time? If they were so great, why sell them? Of course they usually sell quickly but that's beside the point.
I believe once people see how easy and cheap it is to do a custom 3 or 4 rotor engine, the V8 conversion will lose some of its appeal. Just think about your own reaction every time you see another V8 RX-7 thread here or there on the forum. It's a real yawnfest. Then this thread appears and it erupts with positive comments. It's only been in existance for about 24 hours and we're already on page three!
V8s are cheap in this country, and if you're into that, that's cool, but you know not just anyone can pull off a 4 rotor project, making them rare and extremely awesome. Maybe that is the underlying motivation for sharing this info with the forum, to remove the romantic notion of the 4 rotor from its pedestal and place it in the hands of fellow 1st gen owners. Or something like that.
How many of us can spend $5000 on parts from NZ? How about another $5000 on misc things like carbs/fuel injection, exhaust, suspension, brakes, tires, tranny+driveshaft+rearend etc. How many have already spent $10,000? Does it sound more appealing if I mention the car will have the performance of a typical new $50,000 sports car? What if you can cut corners during the build? What if you don't change parts until they become inadequate/break like tranny, rearend etc? What if the bare mininum for just the engine and a couple other parts like some Weber IDAs, some basic exhaust components and an upgraded fuel cell with high volume fuel pump only comes out to $7000? Sound a lot more appealing then?
By the way when the mockup was in the bay, the front end did not sag at all. That's on stock springs. I even leaned on the bumper and it didn't go down much. The internal guts of the engine don't weigh too much at around 9 pounds per rotor and whatever it is for the shaft, plus it's located further rearward than I was on the front bumper. I don't anticipate any front end sagging problems with this build. We'll be going with RB or Eibach springs though as a matter or course.
Ever wonder why you see so many V8 RX-7s for sale all the time? If they were so great, why sell them? Of course they usually sell quickly but that's beside the point.I believe once people see how easy and cheap it is to do a custom 3 or 4 rotor engine, the V8 conversion will lose some of its appeal. Just think about your own reaction every time you see another V8 RX-7 thread here or there on the forum. It's a real yawnfest. Then this thread appears and it erupts with positive comments. It's only been in existance for about 24 hours and we're already on page three!
V8s are cheap in this country, and if you're into that, that's cool, but you know not just anyone can pull off a 4 rotor project, making them rare and extremely awesome. Maybe that is the underlying motivation for sharing this info with the forum, to remove the romantic notion of the 4 rotor from its pedestal and place it in the hands of fellow 1st gen owners. Or something like that.
How many of us can spend $5000 on parts from NZ? How about another $5000 on misc things like carbs/fuel injection, exhaust, suspension, brakes, tires, tranny+driveshaft+rearend etc. How many have already spent $10,000? Does it sound more appealing if I mention the car will have the performance of a typical new $50,000 sports car? What if you can cut corners during the build? What if you don't change parts until they become inadequate/break like tranny, rearend etc? What if the bare mininum for just the engine and a couple other parts like some Weber IDAs, some basic exhaust components and an upgraded fuel cell with high volume fuel pump only comes out to $7000? Sound a lot more appealing then?
By the way when the mockup was in the bay, the front end did not sag at all. That's on stock springs. I even leaned on the bumper and it didn't go down much. The internal guts of the engine don't weigh too much at around 9 pounds per rotor and whatever it is for the shaft, plus it's located further rearward than I was on the front bumper. I don't anticipate any front end sagging problems with this build. We'll be going with RB or Eibach springs though as a matter or course.
Last edited by Jeff20B; 04-02-07 at 02:22 PM.
04-02-07, 03:41 PM
#42
The General RE
04-03-07, 01:36 PM
#46
you've got to post pictures of all the maching that has to be done for the stationary gears to fit the intermediate plates, there is so much engineering in that alone. as a matter of fact, i'd love to see any and all of the maching work that goes into this build. things like this amaze the hell outta me! good job man!
04-03-07, 04:30 PM
#47
Originally Posted by rotarycrazy
what are planing on doing for the ports becouse from what I see you will starve the two middle rotors of air with such a small ports.
i beleave he is going to be going PP... so there should be no starving of the rotors
04-03-07, 07:10 PM
#48
What kind of baseline would you anticipate for this? I love the idea, but I look at things in a price to power ratio. I am sorry, but if I were to invest the money in something like this, I would build a 4 rotor out of two 13B-REW's I wonder if you could run a sequential QUAD turbo engine..... ::drools:: oooh man I think I am going to blow a load because of this thread...
Not trying to take away anything from what you are doing, it is truely awesome..
Not trying to take away anything from what you are doing, it is truely awesome..
04-05-07, 01:18 AM
#50
Do you think there is a way to optimize the intake flow on the center rotors to possibly build for a non-PP set up? I would want something more streetable than a PP, I can live without four rotors though. But I still would like to see this build completed, oh and sorry about the quad turbo comment, I had the Veyron on the brain earlier in the day