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Graham Bichard
Member
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Posted: Monday March 3rd, 2008 07:29 am |
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I'm trying to increase my knowledge of the car (and I'm reading Vizards tuning the A Series!).
So, my question is, has anyone got the timing specs for the standard MPi cam? Was it the same as the SPi cam?
Has anyone got any experience with aftermarket Injection cams? And the timing specs if possible?
Cheers
Graham
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DaveShreeve
Administrator
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Posted: Monday March 3rd, 2008 09:25 am |
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Haven't got any specs but Mpi cam definitely changes part number. Spi standard/auto is LGC10231, high performance LGC10231, and Mpi LGC105380.
Could be change relates to the camshaft sensor and detection of the camshaft.
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Graham Bichard
Member
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Posted: Monday March 3rd, 2008 11:12 am |
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Dave, I didn't realise there was a 'high performance' SPi cam shaft. Was this part of a factory 90hp type kit? Are these still available somewhere?
Do you know if the basic fuelling parameters were the same for the SPi as the MPi(i.e. was it the same ECU control unit, was it firing the single injector four times against the MPi firing each injector twice for example)?
Does anyone know the relevant timing for these and if the camshafts are interchangeable?
You've may have just opened up a whole new range of possibilities Dave!!! 
ETA Just re-read your post Dave - standard/auto camshaft, can you expand this a bit please?
Last edited on Monday March 3rd, 2008 11:14 am by Graham Bichard |
hawaiianblue
Member
| Joined: | Saturday June 2nd, 2007 |
| Location: | |
| Posts: | 214 |
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Posted: Monday March 3rd, 2008 07:26 pm |
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the 'high permorfmance' cam shaft for the SPi is just for the high performance engine (ie Cooper 65ish bhp/Metro 70bhp) as oposed to the 'standard performance' engine (ie Mini Mayfair/sprite 55ish bhp)
In short no you can only fit an MPi camshaft in an MPi, the only real difference between the MPi one and the High performance SPi one is the fact the MPi one has no distributor drive gear machined on it and to replace it the lobe for the cam sensor was added further along. An Spi one wont work, probably fits, but wont work. This is the reason the MPi changes part number, because otherwise how would you order one for an MPi from the dealer?
I dont know what the specs are for the standard MPi cam (all MPi cams, Mini and Mini Cooper are the same), the 90bhp kit used the standard MPi cam with high lift rockers.
As far as i'm aware its generally accepted that the Swifttune SW5i cam is the best for MPi's, it fits in without fuelling issues and gives power without sacrificing smoothness. SW5i's are made for swifttune by Kent Cams, i suspect Piper Cams could make you one without the Swifttune branding if you wanted.
A quick note; the Cooper Branded MPi's and Plain 'Mini' branded cars both used the same engine, both the MPi Mini and MPi Cooper use identical power units. Technically the non-Cooper is probably very slightly quicker, due to the weight saving through the lack of extra trimings (fog lights, leather seats for example) not a lot in it though.
Last edited on Monday March 3rd, 2008 07:27 pm by hawaiianblue |
DaveShreeve
Administrator
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Posted: Monday March 3rd, 2008 11:14 pm |
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Cheers hb, I'd have got there eventually.
Hadn't thought about deletion of distributor drive, I was thinking more about what the Mpi needed rather than what could be got rid of.
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Graham Bichard
Member
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Posted: Tuesday March 4th, 2008 11:39 am |
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Of course!!! Doh!
I realise the MPi was exactly the same engine (Cooper/non-Cooper), but it hadn't even occured to me that it wasn't the same for the SPi! Bang goes that idea!
However, going back to the cam timings, does anyone know the BTDC/ATDC in degree's for the inlets/exhaust. Also what is the lift of the standard cam?
Has anyone fitted 1.5 roller rockers to a 1275 MPI to get more lift and NOT fitted the uprated fuel regulator? Was it worth it, what gains did you see, how were the emissions and did the ECU cope with the fuelling requirements (i.e. not running too lean at the top end)?
(I'm sure you can all see where this is leading )
Cheers, Graham
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mpiman
Member
| Joined: | Monday January 23rd, 2006 |
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| Posts: | 5 |
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Posted: Tuesday March 4th, 2008 09:22 pm |
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I have 1.5 ratio rockers and an SW5i cam fitted to my mpi plus lots of other engine mods, I still retain the standard ECU which seems to cope very well, I did originally fit an uprated regulator ( Minispeed part no mpifpr @ £53 which is what JCG fitted in their 90 bhp kit) and it did seem to improve performance. Now with all the other mods I have fitted a fully adjustable one. The car has always passed it's MOT and has the cat left on, it's probably near 90 BHP at the fly but no more.
I have the JCG uprated regulator which you are welcome to borrow to try, simple straight swop for your original one and takes couple of minutes only.
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DaveShreeve
Administrator
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Posted: Tuesday March 4th, 2008 10:42 pm |
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Graham Bichard wrote: Has anyone fitted 1.5 roller rockers to a 1275 MPI to get more lift and NOT fitted the uprated fuel regulator? Was it worth it, what gains did you see, how were the emissions and did the ECU cope with the fuelling requirements (i.e. not running too lean at the top end)?
Didn't JCG do just that on their lower output kits? Thought the uprated fuel regulator was added to cope with the added air through the S works modified air filter case on the 90bhp kits.
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hawaiianblue
Member
| Joined: | Saturday June 2nd, 2007 |
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| Posts: | 214 |
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Posted: Friday March 7th, 2008 04:35 pm |
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| TBh i think the 's works' air filter housing was more cosmetic than performance, yes it did have some improvments in air flow, but i dont think it was a huge amount really.
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