47 replies to this topic

[Nial]

I can't wait to get the GM fuel injection and a LCB on this thing.

Bill, you do know that getting fuel injection to work with siamesed inlet ports is a bit of a challenge
don't you?

There are some details here..

http://www.planet.eo...chm/efi/efi.htm

...and here...

http://www.planet.eo...efi/siamese.htm

The waxstat carb seems to be holding it back.
Might be time to hook up my Wideband O2 sensor and see where she is at?

If by waxstat you mean SU then you should be able to tailor the needle profile to what you
need, especially if you've got a wideband sensor!


Nial.

[Bill USN-1]

Bill, you do know that getting fuel injection to work with siamesed inlet ports is a bit of a challenge
don't you?

There are some details here..

http://www.planet.eo...chm/efi/efi.htm

...and here...

http://www.planet.eo...efi/siamese.htm


If by waxstat you mean SU then you should be able to tailor the needle profile to what you
need, especially if you've got a wideband sensor!


Nial.

Nial,
Thank you for the links. I have done some reading on the Siamesed port problems and actually had read the second link before.

My plan was to stick to a TBI system simular to the SPI. I would have to assume that the flow would be the same as a carb set up.
But your data does make me wonder how well the cylinders are ballanced on the carb?
Have you already logged data with the WBO2 running a single carb?

I'm interested in your ignition system!! I assume it's a wasted spark set up.
As mentioned earlier, it is one of the things holding me up from using my 1275 MPI block.

I just don't think I can use it with my TBI ECM. It doesn't care where #1 is since it still uses a distributor.
HMM....maybe we need another thread?

[Nial]

Nial,
Thank you for the links. I have done some reading on the Siamesed port problems and actually had read the second link before.

My plan was to stick to a TBI system simular to the SPI. I would have to assume that the flow would be the same as a carb set up.
But your data does make me wonder how well the cylinders are ballanced on the carb?

Because the fuel/air is constantly pre-mixed at the carb the distribution's much better than with injection that
tends to introduce discrete amounts of fuel at certain times.

Carb mixture distribution's not perfect but not too bad.

Have you already logged data with the WBO2 running a single carb?

My 'mini' is a rolling shell in the garage that hasn't had an engine or front end since I bought it. (

I'm hoping to get my kit car (Sylva Striker) back on the road soon and will be buying a wideband
system for use with it. Either the Innovate motorsports LM1 or one of the WB02 systems.
Which have you got and how do you find it in use?

I'm interested in your ignition system!! I assume it's a wasted spark set up.

As above, I haven't anything sorted yet.

As mentioned earlier, it is one of the things holding me up from using my 1275 MPI block.
I just don't think I can use it with my TBI ECM. It doesn't care where #1 is since it still uses a distributor.
HMM....maybe we need another thread?

Have you looked at megajolt/megasquirt? These give you mappable ignition and let you stick with
the carb for fuelling.

This thread's so far off the original topic I'd start a new one.


Nial.

[Bill USN-1]

Nials,
Good to know.
I will be running the throttle body injection that has the injector(s) above the throttle plate just like a carb.

I just picked up a SPI intake manifold and plan to start with it for my conversion.


I run the LM-1. On my V8 I run the WB on the right bank and the NB on the left.

The LM-1 is a nice unit. I bought it before the LC-1 came out. The LC-1 doesn't have it's own display but it is cheaper.

The logging is a must so to help you may want some additional accessories so you can log the RPM with the AFR to assist in tuning.
Right now I only use the AFR output.




I have seriously thought about the megasquirt since it is configurable for any style ignition.
I just hate to abandon the factory GM stuff I am used to. If it breaks I can hit any junk yard or parts store for a spare!!

But the MS may be a nessesary evil for this project to get moving!

Edited by Bill USN-1, 13 October 2006 - 12:54 PM.

[Jammy]

Have split the topic for you.

[Nial]

Nials,

Nials ???

Good to know.
I will be running the throttle body injection that has the injector(s) above the throttle plate just like a carb.
I just picked up a SPI intake manifold and plan to start with it for my conversion.

A good place to start. I wonder if you'd be better with more injectors delivering fuel in smaller 'spurts'
(can't think of the technical term), this would also improve the distribution between cylinders.

I run the LM-1. On my V8 I run the WB on the right bank and the NB on the left.
The LM-1 is a nice unit. I bought it before the LC-1 came out. The LC-1 doesn't have it's own display but it is cheaper.

A mate who runs hos own single seater hillclimb car has an LM-1 and really rates it. I think the
kit from www.wb02.com is a bit cheaper.

The logging is a must so to help you may want some additional accessories so you can log the RPM with the AFR to assist in tuning.
Right now I only use the AFR output.

More expense, this is where the wbo2 kit has the edge, there's a unit that records and logs RPM with the
AFR.
I think Innovate's Logworks software swings things for me though.

I have seriously thought about the megasquirt since it is configurable for any style ignition.
I just hate to abandon the factory GM stuff I am used to. If it breaks I can hit any junk yard or parts store for a spare!!
But the MS may be a nessesary evil for this project to get moving!

I don't have any experience of it (yet) but have read many good reports over on Minifinity. Much of
this (the ignition packs etc) is sourced from the scrap yard too.


Keep us informed of your progress.


Nial.

[Bill USN-1]

OK, After some research on the MS sight I have decided to just stick with the GM FI system.
But....
My system was originally designed for a distributor.
Thanks to the MS site, it appears that the GM DIS system will be compatible with my system.
I will need to manufacture the timing ring to mount on the front of the crank but it looks like most will plug and play.



Here's some of the parts I have chosen.

For the ECM I have the GM 1227747 and the 1228746 already. These are originally V8 systems but I have already successfully used them on a 4 cyl engine.

For the Throttle body I have several options:
The GM system uses an alternate fire of the injectors so wether I use one or 2 the result will basically be the same. I simply wire both injector wires to the single injector when using a 1 barrel. The ECM does not know the difference and the PW is not long enough to go static.



1. The 2.0 and 2.5L 1 barrel with a 1 11/16(1.685) bore.



2. The 2.8L 2 barrel with 1 3/8(1.385) bores.



3. The factory SPI 1 barrel. haven't measured yet and the injector may be the wrong impedance.



I would have prefered the weber carb manifold but this SPI will have to do for now.
I will just have to make a couple adapter plates out of 1/4" alum to mount the TBI's on.

Now for the ignition system....

The crank wheel.



The DIS pack.



The ECM to DIS wiring.



Someone speak up if this stuff is already done and written somewhere. It may save me a lot of time!!


Now for the questions........

Are all engines internally balanced?
Can I use the early flywheel, clutch and harmonic balancer from my 1098 on my 96 MPI 1275 motor?

What is this sensor on the MPI? Knock?

Edited by Bill USN-1, 13 October 2006 - 03:37 PM.

[fikus01]

it looks like its right where the fuel pump would have been if it was a carb lump so im guessing it would be reading on the camshaft!! possibly engine angle for injection!!!!

[Sprocket]

Sensor in the back of MPi block is cam angle sensor. This gives the VERY clever Rover MEMSJ2 ECU, along with the 36 - 4 crank angle sensor, all the information it needs to perform the very tricky timed sequential injection that limits the port robbing. Note that the MEMSJ2 Ecu was developed originaly for the Rover K series V6 engines with sequential injection and distributorless ignition. Also worth noting that Rover Patented the five port sequntial injection system, because, it was that clever!! Originaly designed for thi Mini and further developed for 8 port engines resulting in lowered cost of production due to fewer injection components.

Sequential port injection on a five port with with ECU's other than the Rover MEMSJ2 have worked but not to the same standards. People have tried, failed and partialy succeded. You need an ECU that you can trim the injection period for individal cyinders. You also need VERY fast response injectors with a fairly large flow to cope with this. The MPi injectors are very very good and can flow 440cc/min. These injectors are also used on the likes of the Rover 'T' series Turbo engines

The spi injector flows 511cc and is low impeadance, the throttle is 41mm. The injection period is not tied in to crank angle, but rather the ECU varies pulse width in relation to lambda feed back to adjust stoichio as required from that of the base map. With the fuel also being sprayed onto the back of the throttle it further turbulates the fuel, it then has to travel down the manifold, round bends into the port, and indoing so the fuel is further turbulated and heated. Remember that Henry's Law states that a solution will find an equilibrium of saturation. Taking that into consideration, i doubt the charge entering the combustion chamber would be any different to that of the carb.

Thing is with this wet manifold set up, is, fuel sits on the port and manifold walls, this can cause issues with emissions and hence why it was dropped in production in favour of the MPi port injection. This should not pose any issues with most that wish to fuel inject their A series engines.

It is always apparent however, that the center two cylinders run richer than the outer two, this is where port injection comes into its own, but then we are back to the sequential injection problem.

Edited by Mini Sprocket, 14 October 2006 - 12:42 PM.

[Sprocket]

Out of intrest though, How can i get hold of one of those twin point TBI units??

If you dont want that one, I can make use of it

Edited by Mini Sprocket, 14 October 2006 - 12:48 PM.

[Sprocket]

Also, after reading this ALL

Be aware that the fueling map will be all wrong. Its based on the theory that the engine is a calibrated vacuum pump and with a specific fuel flow rate. This can be 'adjusted' as such by fitting smaller injectors, fooling the system, but it does have to be a linear reduction in flow in relation to capacity of the engine.

Aslo worth noting that if the injectors were originaly for v8 that the flow rates will be way to high for an A series engine and you will suffer very poor idle.

Not doubting that it will work, just doubt that all this work you are going to will be wasted as you wont get a decent drive out of it, when the SPi system already exists and works very well.

Not saying you shouldnt try it, after all, i'm doing a similar thing with my 16v turbo A series, im retro fitting the Rover 820 Turbo ECU onto it, though i have reduced the size of the injectors, the ECU does have a certain amount of adaption built in.

Oh and make sure you use the softest cam you can find, injection on the five port hates wild cams,

Hope it all works out, i really hate listening to people who say it wont work, when they havent even tried it and i dont want to sound like one of them, because im not.

Edited by Mini Sprocket, 14 October 2006 - 01:09 PM.

[Bill USN-1]

I appreciate the input.
As for tuning the sytem...that's not a problem. That's why I chose to stick with the GM system...it's what I know.
I have been doing FI conversions for about 4+ years on other motors using this system.
The system you see on the laptop allows me to have complete control of all the ECM parameters as I drive.
So it is "real time" tuning. Combine that ability with simultaneous data logging, and I can be real close on the fuel table withing a few test drives. If you look at the multicolor table, that is the fuel table displayed with the gragh. My thought is to go with a heated O2 in the collector of the LCB. That way I will get the average of all 4 cylinders. So the fuel trimming should be uniform across. The outboards may end up slightly lean and the inboards slightly righ but the overall should average out. But Minis have been racing on carbs since the beginning so it should work out.

Finding out what the motor wants for timing is another story!!!!

Like you, this is all building blocks. My original plan was to use one of the VW Polo belt driven superchargers.
I can make an ECM swap and install one designed for a turbo system to deal with map above 1.
Or by them a swap to the MegaSquirt ecm and continue to use all the GM sensors.


As you pointed out, The 2 barrel TBI would be great if I could find a weber manifold.
(Was it you that beat me out of an SPI manifold for 99p a couple weeks ago?) Maybe minidave?

I do have access to TIG so a few mods may be in order!!


I can probably find you another TBI if you really want to play with one.
Shipping is cheap to me from the states but the prices from the UK are killer.

I can possibly get it to a Military base near London cheap, but that's about as far as i can get it without all the Taxes....

IIRC the injectors are Peak and hold and are about 1.7 ohms.


How about the engine balance and flywheel swap? Is it do-able?


If interested, I have my FI conversions documented here.

Edited by Bill USN-1, 14 October 2006 - 02:56 PM.

[Sprocket]

Flywheels should come with a factory balance as should the clutch. If you buy a lightweight steel wheel from new, it needs balancing first off.

It wont be perfect but it should be good enough. I fitted a flywheel from one engine, fitted a new clutch to it, the crank was from another engine, the pistons were new, the rods were from another engine again as were the crank pully and timing gear. Never had anything balanced and its not bad. Obviously a full balance will be much better, but its good enough for the time being.

It should be fine

[vasi]

(Was it you that beat me out of an SPI manifold for 99p a couple weeks ago?) Maybe minidave?
If interested, I have my FI conversions documented here.

That may have been me, apologies if it was. It's for a prototype WB ecu which runs on MS code.

[Bill USN-1]

(Was it you that beat me out of an SPI manifold for 99p a couple weeks ago?) Maybe minidave?
If interested, I have my FI conversions documented here.

That may have been me, apologies if it was. It's for a prototype WB ecu which runs on MS code.

NP I found another with the TB on EBay.it!!
It actually saved me the UK shipping and VAT!!

Just wanted to say Thanks!!

What's the WB ecu?