4 cylinder mini 12p conversion questions

[budwizer]

Hi im trying to do a bit of research for adapting my 4 cylinder mini to fuel injected 12p. and discover if its possible.. The thing runs like a dog.. and i hate carbies, so figure if i can.. why not! haha

The head on a mini is only a 5 port head, 3 exhaust and 2 inlet on the same side. so with this i want to run to injectors, one in each inlet runner.
Whats the natural state of the batchfire system? once every crank rotation or once every cam rotation?
If it is once every cam rotation is there a way to be able to fire it once every crank rotation? So that 1 and 3 inlet valves get a burst of fuel and then 2 and 4 inlet valves(same injectors- only 2 injectors) gets another burst the following crank rotation.

Also regarding using the camira ignition module can that be pulsed by any electronic dizzy or does it need to be the camira reluctor style?

also my mini is fitted with a 36-1 trigger wheel, is there anyway to use this instead of a dizzy? - something like the ford EDIS system? i assume this is not compatible with delco.

[VL400]

With only two inlet ports and running two injectors it might need some fudging. The delco batch fire mode is per engine cycle - so in single fire mode it injects the desired fuel in one big hit too all injectors once every two revs. If you use the double fire mode (default) it halves the desired pulse width and delivers it once per engine rev. The ECU uses the jumpers on the NVRAM or cyl select in the memcal to know how many reference pulses there are per engine cycle - if you set it to 4 cyl it knows that 4 reference pulses is a full cycle, 6cyl = 6 pulses etc. The software setting in TP for the number of cyl is only for the RPM calculation.

So, if you set the jumper to 4 cyl mode on the NVRAM and set the inj rate to match the injector size you will have half the fuel delivered (as your using half the injectors). So can use the inj rate to fudge it and say the injectors are half the size of actual to get a double size pulse or set inj rate correctly set the jumpers to TBI/2cyl mode (remove the 4/6/8 cyl select jumper).

You still might have issues of unequal fuelling between the two cyl if its not splitting air/fuel exactly in half.

A camira module should work with most (if not all) reluctor dizzies or crank triggers that give one pulse per cyl with a reference angle of around 10deg BTDC. Cant use the 36-1 trigger wheel without some tooth removal!

[budwizer]

Thanks Vl400,

that clears up alot of my questions.
which do you think it would better to run the NVRAM in? im thinking 4 cyl with half the injector size, simply coz if i need to run a standard memcal im not going to have the option for 2cylinders am i?

As for the unequal fuel delivered, is this just to do with the dispertion of the air/fuel once inside the head? would this be rectified if used two injectors on weird angles on each inlet tube to point directly at the inlet valves?

[charlay86]

which do you think it would better to run the NVRAM in? im thinking 4 cyl with half the injector size, simply coz if i need to run a standard memcal im not going to have the option for 2cylinders am i?

you can burn 12P to a standard memcal as a backup (after you have a decent calibration for your setup)

As for the unequal fuel delivered, is this just to do with the dispertion of the air/fuel once inside the head? would this be rectified if used two injectors on weird angles on each inlet tube to point directly at the inlet valves?

yes, it's to do with the spray pattern of the injector; if you have one with a narrow spray pattern it will be hard to get it to spray evenly into both inlets. So, as you said, you could use 2 injectors on weird angles or an injector that has a split stream spray pattern (designed for 4 valve/cylinder heads).

[Jayme]

Hi,
I have used the delco in a similar situation and it has been a headache to say the least... you will definitely find better results if you can spray at each valve with an individual stream... ive found spraying the fuel further back and hoping it mixes well enough to disperse doesnt work well in practice as it condenses to manifold walls then runs down in any direciton it wants.
ford Xr6 injectors are handy as they are designed for a head with 2 inlet valves per cyl. it sprays 4 streams, 2 at each valve. the streams are at enough of an angle from each other to be really handy in your situation. perhaps you can leverage one of those injectors placed strategically in each inlet runner real close to the head?


as for the memcal, you can run a standard memcal and reconfigure it to TBI mode via a resistor mod if you want one injector pulse for every spark ref event.

another way that I was going to try soon is to grab a TBI unit off one of the pulsars or camiras that came out with delco 808 tbi. a mate gave me one the tbi units and wiring harness off a wreck a few weeks back

[Holden202T]

what about a TBI type of setup, would this work better in this situation ?

[budwizer]

Firstly what is TBI mode?

Don't particularly remember what the TBI setup looks like? have you got any pictures?

Yeah do you know what sort of angle is between the two sprays on the xr6 injectors i haven't actually fabbed the inlet runners yet, obviously wanting to do the research first.
But speaking of which, what sort of length runner tubes should i run? 1380 stroker mini and angle wise im thinking around a 45 degree bend up straight out of the inlet and mounting the injector on the underside/back of the manifold, giving me movement and placement of the injector. that or spray a std injector at around 30 degrees either side of the runner tube. towards the valves..

Thanks, cleared up alot of things so far

[Holden202T]

TBI = Throttle Body Injection which means you have the injectors in the throttle body, like this Holley unit. the injectors are the round cylinders pointing into the venturis

holley tbi.jpg

if you can get a webber manifold for the Mini something like this might work too

SR20-throttle-body-set-tbore-525048_484.jpg

i guess if a mini has a webber manifold for 1 or 2 webbers then it would probably work ok with something like that ?

[budwizer]

those webers are pretty wicked! and would look pretty cool on a mini.. but from the reading ive been doing on this site that 12p doesn't really support TBI properly? or at least when those statesments were made.
so knowing that would i be better trying to use a inlet runner with injectors in them?

getting there.. found out today.. that the n12 dizzy.. you can take the drive gear off the mini and put it onto the n12 dizzy and bolt it in and that has one of these:

http://www.ebay.com.au/itm/ignition-mod ... 20ca8aa264

in it.. therefore thinking that should give a descent output for the ignition module

[budwizer]

well i think i struck apon a bit of success today
was at the wreckers looking at n12 pulsars, an there was a n12L turbo'd efi'd one there
and it is different again to the standard electronic ignition one, as it has a CAS in it however its an optical cas that has two outputs,
one with 1 degree increments and the other with 4 increments at 90 degrees with one having a wider slot than the other.
will i be able to use this and directly interface with the delco ecu, out would it be worth remove this and pulling in a reluctor?

here is a picture of it:

IMAG0593.jpg

with this setup, im presuming that ill still need to use an ignition module.. ?

also if im right this should also allow me the flexibility if /( WHEN ) 12p or some other prefix becomes available that supports sequential injection yes?

and with the TBI manifolds.. 1990's minis in europe actually came out with SPI (same effect as) TBI. so i could get the inlet setup from that.. but what i want to know is how tuneable is this on 12P?