Author Topic: Classic Mini 1400 TBi  (Read 37105 times)

Offline Sprocket

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Classic Mini 1400 TBi
« on: February 07, 2007, 11:52:18 pm »
Right, where to start. This is going to get very long, there is so much going on in my head, as well as on the engine building.

I will start this thread by setting some back ground and then expanding onto the 1400 TBi engine thats currently in the car. I will start another thread for the 16 valve turbo engine that is the current build project.

Most people will know of the Mini, most will know that its unrefined, noisey, uncomfortable and slow. Three of the former are fact, the latter is not! Dont get me wrong there are fast cars out there, but when most people see a Mini they asume its slow.

I have a personal attachment to the Mini, don't know where it came from, maybe when I was a kid, I dont know, but i've always, when i had the chance, mucked about with Minis. However, i will point out this, I am not so sad that I have named any of my minis, or called it a He or a She. Its rather disturbing to think people do :D

Anyway. I've had four Minis and the current one was rebuilt last year in 14 weeks, that included a new engine and gearbox. This Mini is one of the later Single Point Injection veriety.

The original engine was Boggo standard and the injection system was running pants. I bought a Crypton ACT service tool, a complete new injection maniflod and set about fixing the thing. Since then I have bored out the throttle body and fitted a larger throttle disc, fitted a larger injector from a Rover 214, increased the engine capacity from 1275 to 1399cc,fitted an injection Kent MD274 cam, a Group A rally cylinder head, a Mini Cooper ECU, a K&N and a 2" exhaust system. I dropped the Final drive down to 3.76:1 and stripped out the interior partialy. Needless to sayits feckin quick, lol, up to 90mph where it tops out, lol.

The reason i'm here With a VEMS ECU is two fold. The current engine spec outside the capebilities of the standard ECU, and I will also need a programable ECU for the 16 valve turbo.

I did try and overcome the knock issues with the standard ECU by retarding the reluctor ring on the flywheel. Unfortunetly at that time i didn't know that the cold crank degrees were 5. Guess how much i retarded the reluctor ring, yes, 5 degrees. Starting on a cold day is rather difficult. It will turn over and start first time, but then almost imediately the reves die off, and with foot flat to the floor, the reves gradualy rise untill about 3000rpm where it then seems to recover and then all is as normal. Its fine once its running and will start with out problem once warm, or warmer than cold. It does drive a little boggy in the lower rpm but pulls strong from 3k right through the red line on the rev counter without complaint.

I think the standard ECU is not releasing the engines potential anyway, so what with the other engine build, i decided to look into the DIY programable ECU market. On a budget there only seemed to be one option, Megasquirt, that was until i was pointed in the direction of VEMS by a fellow Mini entusiast in Norway. Looked into it and the rest you can work out for yourselfs.

On this engine, the 1400 TBi, i'm looking for 100bhp, thats the target, though if i get into the 90s i'll be a happy bunny. I'm currently pulling appart two wiring looms, one from a Mini and the other from a Rover 820 Turbo. All the screened cables and connectors are terminated, making it easy. This custom loom needs to be a quick swap for a standard loom and will use the same main loom connector to facilitate this.

The ECU itself is being fitted to a Rover MEMS case to give it more of a standard stealth kind of look, even though the original location is being abandoned and being mounted inside the car either under the dash or on the bulkhead. Ther wont be any room in the engine bay with the 16v engine, and as it stands now, the inner wings are removed, where the original ECU resided, and the ECU is now just cable tied to the engine itself, which is far from ideal!

Any way, i think thats enough for now, but i will be back soon for an update.

Engine Specification

Austin Rover A Series Transverse engine http://www.austin-rover.co.uk/index.htm?engineaseriesf.htm
5 Port EX Works Group A cylinder Head http://www.wpm.co.uk/worksminis/
8 Valves
Inlet valve Diameter: 35.4mm
Exhaust Valve Diameter: 30.1mm
Stroke: 81.33mm
Bore: 74mm
Compression Ratio: 11.2:1
Cam spec: Kent MD274
K & N 57i Induction Kit
44mm Throttle Body
611cc Throttle Body Injector
Slark Race Engineering Re Worked Inlet Manifold
Maniflow Injection LCB exhaust Manifold
PlayMini 2" Big Bore 304 Stainless single box Exhaust System
Gearbox Final Drive Ratio: 3.76:1











Retarding the reluctor ring in the flywheel







« Last Edit: February 08, 2007, 12:27:53 am by Sprocket »

Offline rob@vems.co.uk

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Re: Classic Mini 1400 TBi
« Reply #1 on: February 08, 2007, 08:42:12 am »
Nice project, thanks for putting it on the forum.
I've always had a soft spot of the Mini as it was the first car I modified.
It was a 1380 I build using Vizard's book

This was taken at a sprint at North Wield about 18years ago.

What 16V head are you going for?  The BMW one or one of those exotic CNC'ed ones?
« Last Edit: February 08, 2007, 08:46:05 am by rob@vems.co.uk »

Offline Maff

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Re: Classic Mini 1400 TBi
« Reply #2 on: February 08, 2007, 01:58:16 pm »
Nice project! Im gonna keep a close eye on this thread as i have a 1275 midget that will get the VEMS treatment at some point :)  Vizzards book is on my shelf too  ;D

Offline dnb

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Re: Classic Mini 1400 TBi
« Reply #3 on: February 08, 2007, 02:11:11 pm »
Vizzard wrote some good books. :)  (There's even a Rover v8 one...)

Rob:  You're making me feel young!  ;)

Offline Sprocket

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Re: Classic Mini 1400 TBi
« Reply #4 on: February 09, 2007, 01:44:48 am »

What 16V head are you going for?  The BMW one or one of those exotic CNC'ed ones?

Its the BMW head, those KAD and JKD heads must be gold plated :o

I'll get that topic started soon. There is a growing interest in this conversion, so plenty of potential for some VEMS sales, if you can turn them from Megasquirt (you know my opinions on that Rob).

Jim Lyons of Sheepspeed Racing in South Wales got the first ever 16 valve turbo A series running at the British Mini Showdown last year, July 15 and 16th. After a marathon build and three full days over the weekend of the racing trying to get the engine to fuel/ spark right, other things hindered a run down the drag strip. However history had been made and witnessed by virtualy all those interested in Minis and engines that were at the strip, a 16v turbo A series Mini driving under its own power. Later development saw Jim at a Mapping session on Emeralds rollers. There were still some issues, namely the lack of control of boost, Dave Walker ended the session with 200+bhp and 178lbft torque at 6500rpm and 21psi boost with the power curve still ging in the upwards direction :o. All that from 1330cc :D This was reported by Dave Walker in his column in Practical Performance Car in the last few months. Other than that, Jim is keeping the final figures under the hat for this years British Mini Showdown. There is going to be a few of these engines knocking about soon. >:(

Offline Sprocket

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Re: Classic Mini 1400 TBi
« Reply #5 on: February 09, 2007, 01:53:38 am »
Nice project! Im gonna keep a close eye on this thread as i have a 1275 midget that will get the VEMS treatment at some point :)  Vizzards book is on my shelf too  ;D

If you can bear butchering a block, the BMW head is the only way to go. It would certainly put you in standing on the Midget arena ;D recon on 130bhp+ normaly aspirated from 260 duration cams. right up to 170bhp on 300 duration cams. These heads flow more standard than a fully modified offset valve five port head considered the best possible.

Like i said, im going to start another topic soon

Offline Sprocket

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Re: Classic Mini 1400 TBi
« Reply #6 on: February 20, 2007, 09:41:01 pm »
Right then ???

I am close to finishing building the VEMS. I am half way through the spaggeti that is the wiring loom. I now want to clear up some uncertanties. Now, to some, these questions may be, and have, a simple answer, but I am either asking because I am seeking confirmation or I just plain dont know or understand. Please bear with me, I do learn quick though, however my mind is a fuzz with three projects on the go :-\

I shall post individual topics regarding each area of questioning/ discussion and then link them on here. So off to start my questioning ;D

Dual chanel knock detection http://www.vems.co.uk/forum/index.php?board=5.0

Tacho options http://www.vems.co.uk/forum/index.php?topic=41.0

Crank sensor positioning http://www.vems.co.uk/forum/index.php?topic=42.0

Wide band Lambda sensor loction http://www.vems.co.uk/forum/index.php?topic=43.0

I Button http://www.vems.co.uk/forum/index.php?topic=44.0

Extra Input Chanels http://www.vems.co.uk/forum/index.php?topic=45.0

Output chanels http://www.vems.co.uk/forum/index.php?topic=46.0

I think thats it for now. My head is mashed so no doubt i have missed loads i want to ask. ;D
« Last Edit: February 20, 2007, 10:54:02 pm by Sprocket »

Offline Sprocket

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Re: Classic Mini 1400 TBi
« Reply #7 on: March 26, 2007, 10:33:30 am »
Right, because the engine is only going to be in the car for another two or three weeks, and ive had other issues, namely a bent valve, i cant be arsed pulling the flywheel again to alter the relucter ring in the flywheel ::) So, i fitted the trigger wheel i bought for the 16 valver and made up a bracket for the sensor. This bracket actualy doubles up as a lower engine steady as well for the 16 valver.



I have also modified the stepper motor. The motor is a 6 wire Unipolar motor and obviously the VEMS stepper driver is a Bipolar. This was simply a matter of seperating the two common center tap connections that the Rover MEMS used as a +ve. This was simply done by scratching the track away on the small connecting PCB on the motor itself. I also removed the wire.



Ive finished the wiring loom pending the arival of a wideband lambda and its connector and im also waiting on a two wire knock sensor turning up.

Heres the ground wiring. I actualy found this a bit of a bugger TBH, it was re hashed a few times until i felt happy that it was adequate. I followed Robs instructions, 0.75mm wires for the grounds as short as possible, all grounds connecting at the same common ground point, sensor grounds attaching to sensor ground wire at aproximately 20mm away from the common ground point, cable screens attaching to the common ground point at the body (Rob recommended the engine, but the starter is mounted to the engine as is the alternator and its a small engine, I chose to follow the original loom). The common ground point is then extended with 4mm wire to the ground point on the car. The original factory location.



LCD is now up and working, just need to find a place in the car to fit it, lol there is no dash, just the clocks. Config of the VEMS is underway. Woo its nearly there

It wont be long now ;D
« Last Edit: March 26, 2007, 10:06:18 pm by Sprocket »

Offline Sprocket

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Re: Classic Mini 1400 TBi
« Reply #8 on: May 02, 2007, 12:32:21 am »
ok

Update on this.

I have been fiddling around with this for a few nights now. Its going to be the last week with the 1400 in the car so trying to get it to a point where its driveble so i can use the config as a base start on Jackmans engine. On that note Ive persuaded him to go OEM system untill the engine is run in and he has returned from the International Mini Meet in Denmark. He still has a fair bit of the car to finish assembling and the time left to map the engine is going to be very short, going OEM will elimniate this time consuming event in what is a very tight schedule.

I have got the stepper motor up and working and tuned, works really well actualy. Steps to extend set to 190, steps at 77c 80 and -40c 180, follow TPS enabled and step sequence set to 216, as for the wire configuration, i'll have to get back to that, but its easy enough to work out any way. Very important to mod the motor as in the above post. This also works on the idle valves with the same mod to the motor.

Finaly got the warm crank PW to 1.5, afterstart and idle VE set up so that it idles as even and smooth as its ever going to be and starts without giving it gas first try. Just need to see tomorrow if the cold crank PW of 4.5 is about right. Ignition table is prety generic but from what i have seen of others maps of varying levels of tune and cc for the A series, its fairly standard across the board, so i think its a good base to start.

Warm up enrichments i have yet to tune.

All the outputs other than the emissions purge valve work correctly, but still think the misc outputs needs a temperature refference to make them truely universal and versatile.

I have set the acceleration enrichment amounts to 0 for the momment as the higher VE load sites are way off causing any sort of hard acceleration with acc enrichment to overfuel and almost kill the engine.

I have tuned the EGO, whether its correct and what i should do i dont know but before i did, the engine speed fluctuated with EGO correction, I altered the cycles before change, slowing it down a bit.

One thing i noticed was I cant get the idle MAP down below 30kpa, it hovers around that point, maybe the valves are bolloxed again, or is this about right??? VE at idle is 18% with Lambda 1.00 and 15 degrees advance and 900rpm, TPS is 2% and PW of 1.3 ( big injector) Im running a low impeadance single TB injector with a resistor.

All is going well as far as i can see, hoping to go for a short drive with VE learn to get the VE table closer than it is and then hopefully set up accelerator enrichments by feel.

Then its on to the Knock set up :-\ and then engine out and 16valver in and start all over again :(, well at least ill have a base to start from ;)

LOL i spent a few hours in the car just trying to get it started and idling well, playing with numbers, thats all its down to now, having to charge the battery twice, setting up the primary trigger, stepper motor and the outputs, it all takes its toll on the battery :D

On a note, i have been reading of people complaining that the over run fuel cut causes the engine to go verry lean, this is not so, there is no fuel there so no burn the engine becomes a vacuum pump, pumping air. The lambda sensor sees it as very lean as there is 20.9% oxygen present. This is not bad and the OEM ECU also pics up over run fuel cut as off the scale lean. On investigating this on the OEM ecu, i noticed just before fuel resume the lambda voltage of the narrow band rose to 206mv from the base line of 200mv during fuel cut, maybe a pre stage fuel resume or some thing?? possibly to prevent the engine undershooting the idle rpm, stepper follow TPS enabled helps prevent this as well.

Offline rob@vems.co.uk

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Re: Classic Mini 1400 TBi
« Reply #9 on: May 02, 2007, 08:27:48 am »
One thing i noticed was I cant get the idle MAP down below 30kpa, it hovers around that point, maybe the valves are bolloxed again, or is this about right??? VE at idle is 18% with Lambda 1.00 and 15 degrees advance and 900rpm, TPS is 2% and PW of 1.3 ( big injector) Im running a low impeadance single TB injector with a resistor.

I'd be suprised to see vaccum below 30kpa at idle, what sort of value were you expecting?

Rob

Offline Sprocket

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Re: Classic Mini 1400 TBi
« Reply #10 on: May 02, 2007, 04:50:44 pm »
One thing i noticed was I cant get the idle MAP down below 30kpa, it hovers around that point, maybe the valves are bolloxed again, or is this about right??? VE at idle is 18% with Lambda 1.00 and 15 degrees advance and 900rpm, TPS is 2% and PW of 1.3 ( big injector) Im running a low impeadance single TB injector with a resistor.

I'd be suprised to see vaccum below 30kpa at idle, what sort of value were you expecting?

Rob

LOL

Well all the gauges i have seen and the OEM ECU have values in mmHg with idle above 500mmHg (or is that below :P) I haven't really bothered to refference it across to absolute scale. I understand the metric values well as these are what i use every day, i was just sumising that it would have been nearer the 25 to 20 kPa.

Coolio, all is well then ;D
« Last Edit: May 03, 2007, 01:33:54 pm by Sprocket »

Offline rob@vems.co.uk

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Offline Sprocket

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Re: Classic Mini 1400 TBi
« Reply #12 on: May 03, 2007, 01:32:19 pm »
Coolio

Only problem with that is that the conversions are not for absolute pressures, which is what we are dealing with. It can and does get confusing more so when converting from an atmospheric scale to an absolute scale

0mmHg = 100kpa absolute

Therefore 735.559/100*30=220.668mmHg.

If you are not carefull and look at that, you may be confused into thinking that it is wrong, but the numbers when using an atmospheric scale are inverted so its actualy 735.559-220.668=514.891mmHg

Basicaly the numbers on a atmospheric scale rise with vacuum , and fall with an absolute scale

Offline rob@vems.co.uk

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Re: Classic Mini 1400 TBi
« Reply #13 on: May 03, 2007, 03:55:07 pm »
I find the whole range of SI units upsetting.

Offline Sprocket

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Re: Classic Mini 1400 TBi
« Reply #14 on: May 03, 2007, 05:46:43 pm »
Imperial is too random for my liking ;D

I mean, who would convert the "Hg to mmHg to metricise it ::) As far as im concerned its still an imperial scale :D and still random

The Germans knew what they were doing when they invented Metric :D How simple is that when everything is divisable by 10 :D

However, each to thier own. I was taught metric so there :P