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ben.summerfield
Member
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Posted: Saturday April 28th, 2007 04:37 pm |
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how easy would it be to convert my SPI mini to carbs or better yet a whole new carb fuelled engine?
i understand that the sensors begin to fail with old age and electrics isnt my strong point so a simpler carb engine would be prepherable, its currently done 69000 miles im not sure what age they need a re build but i would want to convert it then.
could i fit the injection bits to a new 1380 for example?
any help welcome.
Last edited on Saturday April 28th, 2007 04:44 pm by ben.summerfield |
taffy1967
Member
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Posted: Monday April 30th, 2007 01:40 pm |
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It's possible but not cheap, whichever way you do it.
But 69,000 miles is relatively low mileage and your engine and gearbox should have a fair bit of life left as it is.
Switch to using a better more suitable grade of oil like Duckhams Q Classic 20W/50, then with regular oil changes your gearbox is more likely to go the distance too.
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ben.summerfield
Member
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Posted: Monday April 30th, 2007 05:26 pm |
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cheers taffy i think ill give that a try. Im just looking at alternatives as tuning a SPI is fairly limited, and when all the various sensors start playing up its gonna get intresting!!!
ive never been in a tuned injection mini, are the minisport and John Cooper S packs any good? surely they cant give 90 bhp just from a new head etc!!
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taffy1967
Member
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Posted: Tuesday May 1st, 2007 08:23 pm |
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Yes I've heard that they should give close to 90bhp with a suitable performance head and a good stage one kit etc.
I guess an injection Mini will need the ECU chipped in some way though?
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ben.summerfield
Member
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Posted: Tuesday May 1st, 2007 09:19 pm |
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yeah i think thats the limitation with an injection mini, apparently u can remap the standard ecu but as soon as u turn off the ignition it loses the new map!!! so a piggy back chip is needed.
i think a stage 3 head and a LCB wud give enough power 4 me.
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DaveShreeve
Administrator
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Posted: Tuesday May 1st, 2007 10:07 pm |
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Don't think you'll find anybody offering a bolt on 90bhp kit for an Spi. Neither Minisports 85bhp, for Spi, or 90bhp, for Mpi, kits mention ECU mods. However, the 90bhp kit does have the fuel pressure increased - presumably this then allows the standard ECU to get enough fuel in to make the power.
My Cooper Si (Spi) was originally rated at 85bhp, Grand Prix LE spec, but had a cam change and Weber Alpha ECU.
These items were later removed at JCG, for a previous owner, to cure pinking and emissions problems. Emissions problems due to Weber Alpha not using a lambda sensor so is unable to self regulate. Cooper returned to a standard Spi cam and, I believe, a modified ECU.
Don't have a current power output but spec is: large valve head, high lift roller rockers, oil cooler, modified throttle body, K&N filter element, freeflow back box, and the ECU.
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ben.summerfield
Member
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Posted: Wednesday May 2nd, 2007 12:39 pm |
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| and whats it like to drive? is the power peaky or all through the range?
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DaveShreeve
Administrator
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Posted: Wednesday May 2nd, 2007 01:52 pm |
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| Very drivable. Performance is similar to my tweaked W&P British Open which on the rolling road shows 69.1bhp @ 6407rpm and 69.8lbft @ 3976rpm. This was built to be flexible and is above 65lbft from 2500-5250rpm. I reckon 75-77 from Cooper to make up for slightly taller diff and no 5 speed box. Cooper isn't as happy to rev as W&P but this is more a vibration problem which I put down to standard balance tolerances on the Cooper.
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ben.summerfield
Member
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Posted: Wednesday May 2nd, 2007 06:01 pm |
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wud of thought ud get more than that from those mods especially as mini sport an jcg used to market theres as a 90bhp kit.
thats basically what im planning to do to mine in the near future.
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DaveShreeve
Administrator
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Posted: Wednesday May 2nd, 2007 11:41 pm |
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| Can't say I've ever seen a 90bhp kit advertised for the Spi. 90bhp kits are usually for the Mpi. Discussing with those in the know they seem to consider 85bhp to be absolute tops from the Spi without complete change of ECU. When discussed cheaper options were in the pipeline but we were looking at £750 for ECU, + software for programming, + rolling road time for mapping, + ? So, cost of original conversion to find an extra 5-10bhp!
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chillbean
MCR Committee
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Posted: Friday May 4th, 2007 11:42 am |
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I had a Stage 3 head and 1.5:1 roller rockers from mini sport fitted about 3 years ago to my Spi, there was no doubt that they, along with the Maniflow, LCB and K&N made a noticeable difference especially above 3500rpm. However, myself and another person from Herts and N. London had problems with the Minisport workmanship. I dont know what it is like now, but I was put off, especially as a valve stuck open after only 18 miles, damaging a piston and leaving me stranded for 4+ hours in a layby on the A1 from1am. They replaced the head quick enough but I was left with a hefty bill for fitting and refitting, they where a nightmare to get them to meet my repair costs. Ended up going via the small claims court. So through my experience I cannot recommend. If you want the head, spend the extra money and try MED.
Last year, in addition to the above work, I had the engine and gearbox rebuilt, same final drive, but swiftune SW5i cam, duplex vernier pully, little more work to the head and now 1293cc. No problems with the ECU either, still standard. Massive difference, suprises many boy racers and a few on Minis to Monte last year.
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ben.summerfield
Member
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Posted: Friday May 4th, 2007 11:50 am |
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yes i live near minisport and i have had a few problems myself, i wouldnt buy anything mechanical off them. i was thinking of going for a mini spares stage 3 head and a sw5 cam and lcb, keith calver reckons that high lift rockers give poor emmisions and running problems and arent really nessacary with a modern cam profile.
have u had any running problems?
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DaveShreeve
Administrator
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Posted: Saturday May 5th, 2007 12:00 am |
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In past 3 years My Cooper has managed 3 engine problems none of which have been connected with the conversion. 1) failed lambda sensor, 2) no contents in cat case, caused by regular contact with local speed bumps - now moved house!! 3) high tickover, not sorted by MOTing garage but later identified as a split breather pipe.
Suppliers are a problem, particularly determining who is supplying who. I don't believe any of Coopers parts were 'in house' but rather selected parts from others built into workable packages. I seem to recall Janspeed being involved in the 90's 998 conversion and they definitely supplied exhausts for later Touring conversions. Minisport were the nortern fitting centre for later Cooper conversions and I had heard they supplied the Mpi heads.
My comments on Minisport? Be careful, and don't expect to fit stuff from their workshop straight out of the box.
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chillbean
MCR Committee
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Posted: Saturday May 5th, 2007 10:46 am |
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Emissions always used to be a problem, I never really found out what caused it to fail the Mot each year. It ran fine, but in order to scrape through, just before the MOT I had to change the temp sensor in the inlet manifold. It would pass the MOT, but run very badly, after the MOT I used to swap it back for the old one, it then ran fine for another year. Since having the engine rebuilt, it passes first time.
If your car is an Spi, make sure you get the SW5i not the SW5 cam, the SW5i has a lobe on the end for a sensor for the ecu on the Spi. Duplex vernier pully kit also makes it a lot easier to tune. For cylinder heads, ive also heard that a company called morspeed are good http://www.morspeed.co.uk Companies like this and MED are probably your best bet as they are made to order and not off the shelf.
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ben.summerfield
Member
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Posted: Monday May 7th, 2007 12:27 am |
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| cheers that could be a good solution, sw5 is supposed to be a very good cam is the injection version as good?
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chillbean
MCR Committee
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Posted: Monday May 7th, 2007 11:33 am |
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| Its the same profile, just with a lobe on the end for the sensor for the ecu. Its not a lairy cam, so its fine in traffic. Its progressive, but once you are up in the revs, 3000rpm plus, it really pulls, right up to the red line. its the thing that has made to most difference to the car. If the engine has to come out, say for gearbox repairs, just have one fitted. Swiftune sell the cam with the duplex vernier pully kit.
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hawaiianblue
Member
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Posted: Tuesday June 5th, 2007 11:16 pm |
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The SPI cars were basically carb engines with an electronic carburetor system, which is essentially all single point injection is.
Take off all the injection kit and switch the dizzy back to the earlier one and basically you have and engine ready to bolt your carbs on.
Unlike the MPi's the SPi's were quite extensivly tuned by the factory, all the 90's rally cars were SPi's.
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taffy1967
Member
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Posted: Tuesday June 5th, 2007 11:58 pm |
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Why remove the dizzy for an earlier one? If it's the same electronic type as fitted to my carburetted Mainstream Cooper and the other late non Cooper 1275cc engined Minis that used a carb then it should work fine without the injection system too and it's a very reliable unit. Plus of course there's no fiddly points or condenser to worry about either. 
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DaveShreeve
Administrator
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Posted: Wednesday June 6th, 2007 09:15 am |
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Taffy, unfortunately not. SPi distubutor is exactly that - a distributor of sparks. All spark generation/timing is handled by ECU. Coil poss/neg leads are directly connected to ECU and would therefore require pretty serious rewiring for removal of injection system.
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taffy1967
Member
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Posted: Wednesday June 6th, 2007 12:15 pm |
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| Fair enough, but it's a good ignition system though.
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