View Full Version : 13B EFI into a 323 hatch
22-06-02, 11:21 PM
I have a '78' 323 and have bought a 13b efi engine with
gearbox and computer to put into it which came out of a '89' RX7
but I'm having a little trouble to put it in.
It does not have the usual front mounting brackets like the older type of 13b but rather it has one on the side and the other
is mounted through the sump.
Just wondering if anyone has ever done this conversion and/or
if you had any ideas or advice.
Please get back to me cause I'm at a bit of a loss.
Hey dude,you need to get the front timing case of an older 13B to put it into your 323 so that it bolts onto the crossmember. You probably need a custom exhaust manifold too if its a turbo.
24-06-02, 11:54 PM
I looked at doing that but it seemed to be too different
I have (what looks like) an electric oil pump and the olde rones did not
also because mine is EFI it uses coilpack (or whatever they are called)
and not a dizzy
so not too sure if it was possible to change them over and still keep the EFI.
in that case (i.e. not using an old timing case) see if you can get your hands on the factory crossmember, use its mounting points and have a new x-member fabricated to fit your car or do it yourself. This would seem to be the best solution.
25-06-02, 12:39 AM
sounds like a bit of a plan
might have to chase it up
I have modified the original 323 xmember
but it might be a bit dodgy
also the motor sits a bit too high I think
the bonnet won't close with the EFI manifolds on top
but then they are pretty high and I can always get a bonnet scoop
Do a search - this question has been answered in accurate detail before today. Look for old threads involving rotarising 323s and old threads about 13BT-ing any early Mazda - you should be able to work it out from there. If not, ask about the bits you don't understand, and I'll explain them.... just getting a bit sick of repeating myself over and over....
nah Spac, you looooove it :D
Here is a copy of a 12A into a RWD 323 conversion details Spac sent to me ages ago .... so you can save your breath Spac - hope you dont mind :D THANKS!
"OK, the 323s are very similar to the 808/RX-3
floorpan, so if you know how to do a RX808 conversion
you can skip most of the following... I am assuming
that you know a rotary needs its own raditator, oil
cooler, gearbox etc etc compared to any piston motor.
1. Crossmembers. The original one can have the mounts
cut off, or be replaced with a RX-3 one (bolts
straight in). You then add a RX-3 engine crossmember
(bolts striaght in. These are expensive though, so
lots of people make aftermarket ones, or you can cut
down a RX-4 one - either way, make sure the engine
bracket matches the crossmember.
2. Clutch hydraulics. Rotaries have hydraulic clutch
acutation, so you need to replace the original 323
push cable set-up. Any Capella, 929, rotary, 626, etc
master cylinder will work, bt be aware that some have
studs sticking out of the firewall, and others have
studs sticking out of the master cyl itself. You can
make either one work. The slave cyl shold be RX type,
with the bleed nipple on top, but a Capella, 626 etc
one can be made to work if you are prepared to muck
about a bit with bleeding the system. The steel and
flexable lines between them are easily modded to the
3. Electrics. This is the scariest bit for most
people. Basically just parallel up the existing coil
wiring and that's all. Some wires will have to be
lengthened, but it is nothing to worry about - the
exact same wire that goes to the starter motor
solenoid on the 323 motor will do its job perfecty on
4. electric fuel pump. I usually just take a power
source from one of the reverse light wires - don't
even need a relay for a stock pump. The pump could be
mounted on top of the panhard rod bracket on the body
- it is nice and out of the way there.
*** The above is common to RX808 conversions, the
following is 323 specific.
4. Radiator support panel. This requires some cutting,
and some thought - depends a lot on what raditaor you
use. The mounts on the passenger's side line up with
most of the common RX rads, but the driver's side is
too narrow. You don't have the luxury of spacing the
rad back, as the 323 engine bay is shorter than an
808's by about 120mm. If this scares you, have a good
look at both a 32 and a RX-3's radiator supports
before starting - it houldn't scare you, but...
5. Exhaust. Front section is the same as any 12A
powered Mazda, but has to cross over under the car
just behind the gearbox. Only an issue if you are
trying to scrounge a secondhand system really...
6. Gearbox mounting. There are differences between
factory 4-speed and factory 5speed 323s (auto same as
5-speed) mounting points under the car. All I can
really say here is "measure carefully first". RX-4,
RX-5 and Series 1 RX-7 gearboxes will be easier than
anything else I can think of.
7. Shifter hole in floor. Depends heaps on which
gearbox you use - again the earlier boxes (RX-4/5, S1)
will be very close, with the later ones being much
more of a hassle.
And that's all my sleep deprived brain can come up
with right now - I'll probably remember a hundred
other things tomorrow, but I can confidantly say that
potential dramas like tail-shaft splines won't be a
problem - Mazda was pretty good with keeping things
the same (or at least interchangable) between models,
at least until the S4 RX-7s.
You will want to do something with brakes - RX-4 on
the front, with 626 drums on the rear would be an
absoloute minimum, IMHO. Much better would be vented
after market kit on the front with 626 drums on the
rear (don't be snobby about drums - these things are
Diff will be marginal - dickhead driving WILL kill it,
but sensible fanging shouldn't be too much of a
drama... If it is, a RX-3/1600 808 (they're the same)
will be a worthwhile upgrade, albeit not
Hope it all helps,
26-06-02, 08:38 AM
thanks spac and 333000 for the info
my conversion differs somewhat but you been helpfull
I still have a few questions though
1 Crossmember. I had a look around for a RX3 crossmember and couldnot find one for under $295 so I decided just to mod my originall one by cutting off my engine mounts and welding up some new ones.
also because I have a s5 efi non turbo 13b which does not have the front mounts I had a look for
the bits I needed but for the front engine mounts, timing cover,
Rx3crossmember and freight was just over $500 so I decided to skip it
How legal is it to make up your own engine mounts?
2. Clutch I got one out of 82 626 and got the pedals too for a pretty cheap price. it all seems to fit alright but havent put it in yet also it came wth the hydrolic lines and a flexible hose which actually screws
into the s5 5sp gearbox cause it still had the slave cylinder on it.
3. Electrics. I'm not too worried about I have worked with wires in cars for years
also I managed to find a mechanic who said he will print out a wiring diagram for me
which should help but will still be a huge undertaking as it is the s5 efi engine
and I have to hook up all the sensors and computer.
4. Fuel. I havent thought about this too much yet and thanks for the info
will a efi pump out of a VL or XF or alike do the job.
also do I have to install a surge tank? someone said I did but I thought you only needed one if you a turbo which I do not.
I do have to put in a return line.
4.Radiator. Not too worried about this one as I'm getting one
custom made from a radiator place.
The guy is mates with my boss and will do a good job he is also into rotaries so n\knows what I need.
5. Exhaust. Once again I'll get it custom made
6. gearbox. SDhould be no problem I am looking at making a new mount for it.
How legal is it to do so?
7.Shifter hole could be a problem cause I have a s5 5sp box the shifter is right back on those
but because the motor is mounted a bit too far forward I should be right
it will position the shifter to come through just in front of the handbrake. I was think about filling up the old hole with some fibreglass.
how legal is this?
Brakes diff and suspension
brakes I had heard that you can use rx7 front calipers which bolt straight on but haven't got into it yet
I figure I'll put the lot in first and then do it
diff I was thinking about leaving cause I had an auto box in it I have 4.11 gears so should do nicely I am also planning
on leaving the original 155/13 tyres on it so not too much friction.
suspension once again I was going to wait to see what it was like when we finished but I did get a quote to get
the whole lot redone and steering bushes too and it came to only $559
Now my problem is this because I have the efi engine it has a whopping huge manifold on it
which when I bolt it on leaves me unable to close the bonnet,
I could try to redo the engine mount and it might drop slightly but I think it will still hit
how legal is it for me to just cut a hole in the bonnet and put a scoop on it?
I didn't really o\want one cause I wanted to keep it a bit of a sleeper but I just want to get it in now.
I just want to drive the bucket
OK, you have the 1st half of the equation, now go dig up some old threads, and look for what is required to put a 13BT into an early car, and apply that too. Only difference is that you can ignore all references to "turbo" and "turbo manifold'...
X-members.... RX-3 bits make it a LOT easier. you can buy re-production ones for MUCH less than you've quoted. Try Reliance Automotive here in canberra, and even with freight added, you're still looking at about 1/2 the prices you mentioned... All this will let it sit under the stock, uncut bonnet, and give a much more profesional job. I wouldn't bother pissing around for another minute with DIY engine mounts, and would just go for the "conventional" approach.
You will need a surge tank. It is possible to cut open your original tank, and baffle it like a factory EFI tank, but a LOT of hassle when you can just go out and buy a surge tank... Almost any EFI pump will work - something like a VL pump will be ideal.
Brakes. No easy bolt ons. Simplest solution is to put 808 or 929 struts in, and then buy one of the many vented disc/ Commodore caliper kits to suit. And no, they won't work on stock 323 struts (shitty integral hub/disc stops that).
Pretty sure 626 pedals are different. 808 and 323 ones are the same, and dead easy to find - use one of them. And take the manual bolt too!
I have a question regarding the electrics that were mentioned.
Will the twin coils run effectively just parralleled off the old coil wiring for the single coil?
Or is it best to wire it up to the Rx3 wiring. (This is for an 808 conversion)
What I have done is just cut the wires from the +ve and -ve coil terminals and run long wires to the other side of the car, split it to two wires going to the seperate coils. That should run shouldn't it?
spac i too have a question which i am hoping you will answer :)
ok you say (and have heard it b4 as well) the rx3 xmember makes it much easier. but is this for 808/323's only?
is there a perfect crossmember to fit a 13b to a 1300?
Thirsty, it depends on whether or not yours is a "wide" model 1300... If it has square head-lights like a R100, then the answer is no. If it has round head-lights, it is a "wide" one, and a RX-3 x-member will either fit perfectly, or will at least be close enough to cut-down and re-drill. (Apologies for vagueness here, but I measured them years ago).
jon, if you can find original RX-3 bits, use 'em. But good luck in finding an un-molested RX-3 wiring loom! And your car being a '76 almost certainly WON't have the original RX-3 plug in front of the passenger's side strut tower like the earlier 808s did. Are you using the electronic dizzy? you should be!
Assuming you are, just ignore the ballast resistors, and take power directly from the +12V wire and parallel the coils - easy peasy. Just remember that the power to the +12V ISN'T THERE when the engine is cranking over, so you'll also have to parallel the cranking power wire too.
If you're using a points dizzy(s), you'll need to use ballsat resistors - same deal with the wiring, but a lot harder for me to explain in words!
so my 72 808 has the rx3 plug? :confused: I'm chucking in a twin dizzy.
I'll take those words of wisdom home, or to my mechanic anyway. Yes I'll be using the electronic dizzy (I've got a choice between the one with the two vacuum advance diaphrams free or one that has them solidly welded into a permanent position)
Funny thing about mechanics, he decided that my car was a "fill in" job. So I'm not going to be on the road for ages.....Bugger!
my car has been off the road for about two weeks now and it is giving me the shits!:mad:
Try two months......makes you not want to have a car with problems and drive like a boring corolla!
i feel for you mate! Nah, it makes me want an absolutely insane rota!!!! I suppose it also makes me want a good daily driver too!
Is your 12A twin dizzy motor in yet?
You know with a quick change of the timing cover, you could convert it into a single dizzy.
I've converted my 10A to run a single electronic dizzy.
I think in the future I'll be keeping my eyes open for a good running mild port 12A and do another motor change.
Or I could forget old cars all together......oh that would be hard.
no, it is still on my garage floor, next to the 1.3 motor! Unfortunately i have run out of money!!! I could convert my 12A to single dizzy but i don't think it is really worth the money if i'm going to change to a different engine again later. Are you putting a 10A in your 808?
The 10A is in already as well as the 121 5 speed. Just now need new exhaust then it'll fire up.
I'm getting the mechanic to put on my brake kits at the same time too.
What do you have left on your car to do to make it work?
12 twin dizzy + 4 speed (thanks to Buzz)
RX2 radiator and oil cooler (thanks to GRUMPE)
modded rx4 crossmember, mounts + bracket (thanks to BadRx)
lightened flywheel and one tonne pressure plate (also thanks to GRUMPE)
other stuff i've forgotten
I still have to get:
little odds and ends
I still have to make or modify:
more stuff i will encounter along the way
So far i have bought all my stuff for under $1000 which is pretty good. Its all thanks to the good blokes i have met through the forum!
ahh damn, mines the r100 width version (early version)
thanks anyway :)
07-07-02, 12:12 AM
just a bit of an update
I have finally mounted the motor and gearbox
by making my own engine mounts and a gearbox mount
I have also had to cut a new hole for the
gearlever but managed to get it mounted
just in front of the handbrake
now the real fun begins
and I have to spend some dollars to get
I will keep you up to date
07-07-02, 01:17 AM
here is a pic of the motor mounted
it is a bit rough but it is only early days yet
07-07-02, 01:50 AM
it didn't work
I'll try again
i never seen a rotary mounted in a early mazda like that! Was it very difficult? Why did you choose to do it this way? That's a good effort!:)
07-07-02, 12:03 PM
I did it like this cause I'm cheap
I got the engine and gearbox cheap
and did not want to buy all the right bits
like the rx3 xmember and new timing cover
I made new engine mounts out of 8mm steel
and put it to my originall crossmember
on some 626 rubber mounts
and yes it was pretty difficult
it took many hours of measuring to work it all out
this is my second lot of mounts too
the first ones made the engine sit too high
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