average guys 4 rotor build
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Junior Member
Joined: Jan 2012
Posts: 20
Likes: 5
From: nz
awesome build there.
I'm considering to build a 4rotor some time soon or buy a 3 rotor.
I think the four rotor is more rewarding though.
Do you think you can find sponsors that will give you a free computer because you're undertaking such a massive task?
Best of luck to you mate, i'd love to see you achieve the goals you've set yourself
I'm considering to build a 4rotor some time soon or buy a 3 rotor.
I think the four rotor is more rewarding though.
Do you think you can find sponsors that will give you a free computer because you're undertaking such a massive task?
Best of luck to you mate, i'd love to see you achieve the goals you've set yourself
Thread Starter
Junior Member
Joined: Jan 2012
Posts: 20
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From: nz
Hey I think I've got some photos ill try put up. It's basically your usual tapers pluse some tapers pins and a thread all joined together. Made drill jigs etc. I'll try get the photos up. Cheers
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Junior Member
Joined: Jan 2012
Posts: 20
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From: nz
Been a bit slack with working on it but here's an update. Fitted the dizzy and tried to get it running but it wouldn't go. So pulled the engine out and made a jig with a a electric motor and had it turning over and found a wire was broken from the pickup in the dizzy so have been fixing that and a leak in the sump. Will put some videos up of it shooting flames turning over on two rotors soon.
Last edited by albeeno; Oct 16, 2012 at 04:25 AM. Reason: Finishing
Will you ever show us the inside of your dizzy? 
I modded a dizzy for 4 rotor too. Just a note, I went with 135 degrees for direct fire. Still need to test run it on a 2 rotor to lock in timing on the other pickup.
I modded a dizzy for 4 rotor too. Just a note, I went with 135 degrees for direct fire. Still need to test run it on a 2 rotor to lock in timing on the other pickup.
Thread Starter
Junior Member
Joined: Jan 2012
Posts: 20
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From: nz
Sorry no updates yet. Pulled the sump off and drained the oil that's about it. Dizzy is still sitting there. Just standard internals mounted to a fixed plate. Needs another added to run trailing plugs. Just doing direct dual fire at the mo and was working nicely bar the broken wire from the pickup.
I used all standard internals. Just moved one pickup over to the next hole. Actually the vacuum advance diaphram's connection point (that weird looking screw) is what I relocated. I think I added one from a spare dizzy.
Turns out the threaded holes are located in such a way that one of them worked out perfectly for my 135 degree pickup spacing. That means one pickup is stock. The other was moved from 180 degrees to 135 degrees. I love to repurpose stock parts in ways Mazda may have intended.
I have yet to actually test run it on a 2 rotor to zero the 90 degree firing down at the pulley, using the trailing vacuum advance diaphram to adjust it, but I'll get around to it.
Turns out the threaded holes are located in such a way that one of them worked out perfectly for my 135 degree pickup spacing. That means one pickup is stock. The other was moved from 180 degrees to 135 degrees. I love to repurpose stock parts in ways Mazda may have intended.
I have yet to actually test run it on a 2 rotor to zero the 90 degree firing down at the pulley, using the trailing vacuum advance diaphram to adjust it, but I'll get around to it.
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Joined: Sep 2022
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From: Detroit
Ok so a while back i was doing a machinist apprenticeship and i thought why not do something with these new skills. So i thought ive always liked rotors so why not build one. After a bit of research i settled on the idea of "it has to be a 4 rotor". Months of research and finally i decided i dont have the funds to do it how i want it so i will do one on the cheap and see what happens. Here are the results. Im sorry i didnt document it better and its kinda the finished product but this is what a cheap 4 rotor costs and how it was made.
Heres a run down of my costs making my 4 rotor. Note i made the center gears and ecc shaft and sump etc. Dont forget you also need a computer to run it all and good enough cooling etc. The costs are in nzd and the engine bolts strait into a s3 rx7 with out modifying anything but the front radiator and oil cooler location
2x 13b s4 n/a engine 1500$ each.
New 3mm seals, o rings, oil seals etc 2000$
Computer to run it. 1000$ - though it doesn't work. need a new one.
Coils x4 75$ each.
Plugs if you don't have any 25$ each
Leads 160$
This is basically what i paid for now this is what ive done.
Grind plates, Make thru bolts and nuts. Make two center stat gears. Balanced shaft. Modified for direct oil lube too two more center bearings. Modified ecc shaft. New sump. PP port housings. Make new intake manifold. New coils-dual tower wasted spark plus 8x11mm leads. Modified front plate for direct oil injection. Now im writing this in a rush and am sure ive missed some stuff but if you cant do all this your self i recommend paying the 10k nzd for the ppre.co.nz kit and then a further 3k roughly for two engines and 2k for seals and very soon you will have a worthwhile engine.
Now not to mention putting the engine together the man hours it takes and with out the right tools etc this can be very frustrating and time consuming.
Any questions welcome. Photos attached. Sorry about the quality my dog ate my camera. I have more. Sadly the megasquirt computer i brought is having real trouble sustaining spark for some reason it drops spark randomly on coils 3 and 4 and sometimes 2. I think its the igniters. So i havent been able to run it very long. Can anyone point me in the direction of some good ignition set up. Cheers
Heres a run down of my costs making my 4 rotor. Note i made the center gears and ecc shaft and sump etc. Dont forget you also need a computer to run it all and good enough cooling etc. The costs are in nzd and the engine bolts strait into a s3 rx7 with out modifying anything but the front radiator and oil cooler location
2x 13b s4 n/a engine 1500$ each.
New 3mm seals, o rings, oil seals etc 2000$
Computer to run it. 1000$ - though it doesn't work. need a new one.
Coils x4 75$ each.
Plugs if you don't have any 25$ each
Leads 160$
This is basically what i paid for now this is what ive done.
Grind plates, Make thru bolts and nuts. Make two center stat gears. Balanced shaft. Modified for direct oil lube too two more center bearings. Modified ecc shaft. New sump. PP port housings. Make new intake manifold. New coils-dual tower wasted spark plus 8x11mm leads. Modified front plate for direct oil injection. Now im writing this in a rush and am sure ive missed some stuff but if you cant do all this your self i recommend paying the 10k nzd for the ppre.co.nz kit and then a further 3k roughly for two engines and 2k for seals and very soon you will have a worthwhile engine.
Now not to mention putting the engine together the man hours it takes and with out the right tools etc this can be very frustrating and time consuming.
Any questions welcome. Photos attached. Sorry about the quality my dog ate my camera. I have more. Sadly the megasquirt computer i brought is having real trouble sustaining spark for some reason it drops spark randomly on coils 3 and 4 and sometimes 2. I think its the igniters. So i havent been able to run it very long. Can anyone point me in the direction of some good ignition set up. Cheers
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