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Thinking.....4 Rota Wankel in my RS30


NZeder

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Well after 4 or 5 years with the Z of the road I am now thinking about putting her back together. Problem is should I repower it? I still have the standard/original L26 Block-flowed E88 head with new value train semi race cam etc. My panel better (read my bro) wants to put a Infinity VH45 V8 in or a RB25DET or RB26DETT. These will cost $$ in engineering work and getting the car certified so I can drive it on the roads here in NZ.

 

So I visited a Rotary workshop in here Auckland today that rebuilds/builds Mazda Rotaries. They have build a number of custom 4 Rotors race engines over the last few years. One is a N/A RX7 Series VI here in NZ that does low 10sec 1/4 mile, I believe the other engines were build for US, UK and Japan customers (with turbos). We discussed the idea of a 4 rota in my Z. The owner of the workshop has installed a 3 Rota into a 240Z a few years back when living/working Australia but we both agree that a 4 rota would be very very different and due to the rarity of the 3 rota the $$ involved is only a few $1000s more for custom 4 rota.

 

So where is my head at? Well I will have to sell my left nut for the engine this is not going to be cheap :cry: But I am now a daddy for the first time so I am thinking I might have to sell one of my toys....Yep I am thinking the Motorbike will have to go (I want to be here to see my young lad grow up, I don't want to give the responsibility of my life to some other nut on the road...I do a good job of that by my self thank you)

 

Anyway if the bike does go down the road I will have some $$ to start the engine - I would say enough to buy the bits for the basic 4 rota - I will then need to save for the labour to put it together, then there will be the custom intake manifold/ECU/EFI bits, oil cooler, gearbox, clutch/flywheel etc. So if I do start this project then I will post pics etc here - however I have only just started thinking I have not run this past the boss (reads my better half).

 

So should I do this? The car will be a street/custom car with the odd visit to the strip and track but not an out and out track car and I am not into hair dryers either so it will be n/a.

 

I estimate the repower will be in the order of $20-30K NZD so don't tell the boss if I do go down this path. I think this engine will output about 500 reliable HP.

 

This project is not a happening thing yet.....thinking....thinking....I will sit on this for a while - also I have dial-up access so I don't visit this site every day. So if I don't reply to any questions etc I will be looking after the new born or working or working on the boss re this project

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The coolest RX7 I ever saw belonged to one of my best friends. It was an 85 GSL-SE (not sure if you got those) but they came with the 13B. His was Bridge ported with a 7lb flywheel and a single sidedraft Mikuni 44. Had a header and a decent exhaust system. All that stock FI crap all over the engine was GONE.

 

That car would bog off the line really bad, but at about 3000 rpm it would light up the tires and wouldn't stop if you kept your foot in it. Totally illegal for smog though, so my buddy sold it to someone who turned it into a full on track car.

 

I can only imagine what a quad rotor with 2 Webers or Mikunis on it would be like. I say forget the FI and pick up 2 of those carb intake manifolds. That thing would HAUL ASS!!!

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The Carb option was discussed - it would be cheaper than the custom FI system that will need to be made. The issue is that I will still need a comptuer for the timing - 4 rota timing is not a common thing you know. So if I have to spend the $$ on a ECU for the timing then this can be used for the FI. The cost of the FI custom mainfold would be about $1800 NZD (this is just a guess for now) + fuel rails, injectors, butterflies, TPS, MAP, AFM etc. May be Carb to begin with then FI with tidy FI setup. Here a pic of a 20B with custom FI manifold so I guess the 4 rota would be like this = nice and clean - without the turbo...I don't want that much power for now (will add more $$ to build)

hot20b.jpg

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You could start with sidedrafts then put dual TB's on from TWM in their place when you went FI.

 

As to ignition, why couldn't you just get a DIS ignition system from Electromotive or someone like that? Are those setups not compatible with rotaries? Wouldn't surprise me if they weren't...

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yup. and you can show up to a hybridz meet, open up your hood, and be just like 20 other people next to you. with smallblock chevies.

 

amen!

 

mike

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Yep don't want a SBC everyone else has done this install....I want to be different....as for the cost a good strong SBC here in NZ will cost almost the same $$ (by strong I mean forged internals, 4 bolt etc). I mean you start with a standard SBC (push rod....how old is that....don't get me wrong SBC are a excellent engine just everyone has one). Now before someone jumps down my throat and informs me that there are OHC SBC I bet they cost $$ here in NZ. So this was why I was thinking VH45 DOHC. These can be picked up here in NZ for $1500-3000 NZD that is $900-1800 USD. You then want to put new internals (just never know what you are getting from a JDM import engine)...etc. Again not a SBC and a V8 cool. So for me it is a toss up between the 4 rota and the VH45. I am thinking 4 rota as these are very very rare...ie never a factory engine only ever a race engine from mazda or custom build. Given they build them here in NZ then cool....I think this it the one for me. Plus my car is a 1977 260z = 2.6l and the 4 rota is 2.6l in mazda sizing. I have been told that it will sound like a F1 car when on song....how cool is that....

 

As you might have guessed I think I will be doing this install - just a question of how long it is going to take to save the $$ - will buy bits as $$ are saved so I would say a 12-18month project. I guess time and $$ will tell. I will work on getting the Z back on the road with the standard L26 with all the other body mods done while the engine is getting built - then install complete the engineering work and certification - repaint the engine bay and hopefully in 12-18months my hybridz will be complete - now just need to visit the bike shop to sell my motorbike.......

:cry:

 

to ZZ4 $10k car I assume USD = $16K NZD an excellent start on the with the 4 rota (might have the base complete at this point)...and finding a good rust free Z in NZ (which is what I have in bits already) is going to cost anything between $10-20k NZD = $6-12K your money

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Aux thanks for putting me straight on the pushrod thing - I am not an engine expert if fact I know nothing about SBC, VH45 and Wankels or any other engine for that matter. I know how an engine works does that count :?:

 

I have always like the Wankel engine and how it works (never owned a Rotary before, 4 Z and motorbikes and three 4 cylinder cars) Love the shape of the Z too much to look at old school rotaries (RX3 or the RX7 batman Series 6 would be the only ones I like. Lots of RX7 S6 here in NZ now....we get a lot of JDM imports as we don't manufacture/assemble vehicles here any more).

 

Currently we don't have any smog laws either so anything goes (this is changing very soon).

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Rotary's are cool. when built, no doubt.. but anyone who knows about rotarys will tell you they can be .. finiky. And from evrything I'v ever heard, it's hard to get a lot of milage out of them. As in, after about 100k, they will pop and you have to rebuild. And when they go, it's suddenly and without warning. But hey.. its gona be a cool hybrid man! :) I say do it!

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For those that are interested in what a 4 rota would sound like here is URL to a video of the Le Manns winning 4 rota

http://www.mymazdarotary.com/mazda_rotary_general/787b/787b_videos/787b_videos.htm

 

Also in this thread on this forum there is a link to a video of one of the 4 rota's build here in NZ (in fact the drag strip in the vid is the local strip in Auckland NZ)

 

http://hybridz.org/nuke/index.php?name=PNphpBB2&file=viewtopic&t=31085

 

see post by 240Zduz10s on second page

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Rotary's are cool. when built, no doubt.. but anyone who knows about rotarys will tell you they can be .. finiky. And from evrything I'v ever heard, it's hard to get a lot of milage out of them. As in, after about 100k, they will pop and you have to rebuild. And when they go, it's suddenly and without warning. But hey.. its gona be a cool hybrid man! :) I say do it!

 

Rotaries can be finicky, yes, but how long it lasts is all in the tuning and build up...as well as how it's driven too! I've seen plenty of rotaries with more than 100K miles on them, daily drivers mind you, not race cars. So it's all how you treat it, you could blow up an SBC in a couple of months if you wanted to.

 

NZeder,

For the EFI, Haltech is based in Australia aren't they? And you've probably heard of the Hitman who tunes rotaries.

 

I say do it!

 

Owen

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Guys,

 

Thank you for your comments etc. Owen yes Haltech is what the engine builder recommends for this type of build. From what I have read/be told Rotaries can be very reliable if built correctly and maintained correct, the same can be said about any engine, I know of 3.1 L28 that only lasted a few laps of a track (holed the piston - well 2 of them) and the motor cost $$ to build. :cry:

 

I think I will do this build.... Might take longer than I first thought though - family issue to work though...

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huston we have a go....well came home from work yesterday...family have changed their minds..if they do this again I will go postal on them.. :twisted: kidding :)

So as soon as the bike sells it will start the engine build

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Guest bastaad525
Rotary's are cool. when built, no doubt.. but anyone who knows about rotarys will tell you they can be .. finiky. And from evrything I'v ever heard, it's hard to get a lot of milage out of them. As in, after about 100k, they will pop and you have to rebuild. And when they go, it's suddenly and without warning.

 

 

Why does that 100k rumor persist so.....

 

 

I used to hear this same thing allllll the time. Well variations... anything from, "after 100k they leak oil like crazy" to "after 100k they're completely dead". But I've seen several 1st gen RX7's, owned by friends or being sold in the classifieds (was very close to buying one) with over 100k on them and no such problems. Granted, they were all pretty much stock so far... so can't say for tuned ones or turbo ones. I know they have a really bad rep, and with later ones (3rd gens) I know that they have EARNED that rep (over complicated messes they are, with lots of electrical gremlins and heat related problems from the super hot running engine), but the motors themselves seem to be stout as any japan-built motor if treated right.

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