Using a HS Carb as a throttle body
Turbo Mini Forums

Hi, new here

I'm restoring a '63 850 Super Delux that will be used as a daily driver and wish to convert to injection.

I'd like to keep it looking standard at first glance and had the idea I could mod an alloy inlet by placing the injectors underneath like a upside down MPI manifold and then using a HS4 for air contol only with the tps mounted on the spindle

Would emerald support this dual injector setup or would ms be required, plus does any one think this is unworkable

Note big bhp is not required with this setup

Ta

Can't see this working too well tbh. By the time you removed all the innards of the carb there would be gaping holes all over the place for the incoming air charge to go and get lost

I wouldn't remove the inards on a HS4, just block off main jet and dash pot holes as butterfly is still required

You would keep the dashpot and spring then?

I'm sure with a bit of thought that this is doable.

I think I'd look at getting a tube inserted to coved the hole left by the removal of the dashpot.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

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Have a search, I'm pretty sure somebody did it before with reasonable success.

I could line bore the SU body and insert a tube if needed, in addition I'd like to keep the dizzy with the coil being ecu fired. I'm thinking that a cam sensor could be fitted in the dizzy base under the rotor arm

I know the SPi uses this setup and basically I'd like to do simular using the 25D4 dizzy.

I already have an MS V2 ecu that I used on my old Sierra, its currently setup to use the ford edis. This is easy enough to change to drive the coil, the vr for the crank can stay the same so I'd only need to add either a vr or hall pickup for the dizzy.

Once I've made the changes is anyone will to look over it to check I've done it right (happy to pay)

Yes the MS can do this. It's a compromise but would retain the look.

I did hear that Aldon were developing a fully mapable dizzy, but never seen one.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

I don't mind compromise as long as it doesn't effect driveability or the Mrs will moan forever as she likes the Spi conversion I did to her Piccadilly a few years ago.

Does emerald support port injection or is it only wet support?

Have a read of this:

http://www.turbominis.co.uk/forums/index.p...id=249927&fr=75

Rod's dizzy based HAL sensor build is half way down that page

[X] nail here for new monitor

Nice.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

Why not just use the ecu to control ignition, but still retain a single coil and dizzy for allocating spark to each cylinder.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Stevie, thats what I'm hoping to do but with the phase senosr in the base of the 25D4 dizzy

This should help to maintain the stock look. Hiding the injectors under the inlet and using a HS4 to replace the HS2 but using a modified HS2 airbox to complete to illusion

Unless you are attempting to try fully sequential injection, you don't require a phase sensor - the MS2 (or any other comparable ECU) can get all it needs of a 36:1 wheel or similar and drive a single coil using the dizzy to allocate sparks.

In the case of an MS2 you just need to make sure the (single) VB921 is installed, it may have been omitted if it was built specifically to work with EDIS.

And if you are going to try fully sequential, you need to read up on the siamese code as it is the only code (that I am aware of) that can allocate the injection pulses in the right order with variable timing for port injecting a siamesed engine.

Edited by Rod S on 18th Jan, 2011.

Schrödinger's cat - so which one am I ???

How much of an issue is charge robbing in afr terms compared to a carb without going sequential on a virtually standard N/A engine and does sequential require 4 injectors

Edited by Ratty on 18th Jan, 2011.

Without over-complicating it, charge robbing is potentially more of a problem with injection than a carb becuase injection is delivered in pulses rather than one continuous atomised stream that comes from a carb.

If you inject "wet manifold" the AFR difference may be no worse than a carb despite the above, better fuel control than a carb will help (as per the SPI).

But if you inject in the ports you have to, (IN MY OPINION), do it sequentially and timed. (just like the MPI).

Otherwise you will just put fuel on unopenned valves, which is fine on an 8 port engine, but will just go into the first openning valve on a siamesed intake engine which is all wrong.


Sequential doesn't need four injectors on the siamese code, the two are just fired A,A,B,B, etc (where A is 1&2 inlet port and B is 3&4 inlet port) so matching 1,3,4,2,1,(3,4),(2,1),3,4,2,1,3,4,2........ Then we adjust the timing of each pulse to match the valve openning and transit time.

We only use more than two if we want staged injection but that's only for turbo engines.

I hope that makes sense, the siamese code is a bit of a taboo subject on this forum at the moment.

Schrödinger's cat - so which one am I ???

Perfect sense thanks, sequential with 2 injectors it is then :)

Edited by Ratty on 18th Jan, 2011.

Ratty (John?!) I'm currently manufacturing a vane for use with a hall sensor (got the sensor from jaycar very cheaply) so that it'll fit inside the dizzy. I'm using the back of an old small gauge that didn't work. I've shortened the body and will be cutting slots to form the four pulses needed for my ignition module. Once finished it'll be epoxied to the rotor arm or dizzy stem with the hall sensor fitted where the points were.

Hi Al, I was thinking along simular lines

John

If you want to use sequential injection, you need ONE trigger from the cam (ie, one per engine cycle), not four.

Four is just for basic electronic ignition systems, not for Engine Management ECUs.

Schrödinger's cat - so which one am I ???

On 17th Jan, 2011 Ratty said:
Hi, new here

I'm restoring a '63 850 Super Delux that will be used as a daily driver and wish to convert to injection.

I'd like to keep it looking standard at first glance and had the idea I could mod an alloy inlet by placing the injectors underneath like a upside down MPI manifold and then using a HS4 for air contol only with the tps mounted on the spindle

Would emerald support this dual injector setup or would ms be required, plus does any one think this is unworkable

Note big bhp is not required with this setup

Ta

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Ratty, I like your thinking - keep the look but go modern, would like to see this work

Paul

I seriously doubt it!