41 replies to this topic

[Wiggy]

http://www.minispare.../MDM274MPI.aspx

I'm sure you'll be happy with either.

[PiG]

I've just got the SW5 to go into my MPI, a couple of respected opinions recommended this one.

My build is 1330, had the head sorted but retaining standard ECU, throttle body etc.

 

I'm looking for a B road car with occasional trackday that's maximised torqye.  My interpretation is that this gives the best of what's available given the constraints of the management and should still be safe come MOT time.

It's not going to be driven for a while so can't back this up with experience yet but hopefully my thought process will help.

[jamesquintin]

I'm going to go for a SW5 for my MPI. I've emailed them to see if I need the spring kit, or can just use the double springs I already have in my S head

Q

[ultimax5]

Hello Mini enthusiasts, reviving this thread with a couple of questions. What’s the difference between the Kent 274 cam for SPI vs MPI?

My Mini is a Japanese Rover Mini which has an MPI block (with the oil filter which mounts directly into the block) but the SPI injection unit.

Which Kent 274 camshaft would I need, the SPI or MPI one?

Thanks.

[RooBoonix]

Hello Mini enthusiasts, reviving this thread with a couple of questions. What’s the difference between the Kent 274 cam for SPI vs MPI?

My Mini is a Japanese Rover Mini which has an MPI block (with the oil filter which mounts directly into the block) but the SPI injection unit.

Which Kent 274 camshaft would I need, the SPI or MPI one?

Thanks.

MPIs have a cam sensor, the MPI version of the cam has a lobe ground to trigger this as required. The SPI doesn't need this.

The profiles are the same as far as I know.

[ultimax5]

 

Hello Mini enthusiasts, reviving this thread with a couple of questions. What’s the difference between the Kent 274 cam for SPI vs MPI?

My Mini is a Japanese Rover Mini which has an MPI block (with the oil filter which mounts directly into the block) but the SPI injection unit.

Which Kent 274 camshaft would I need, the SPI or MPI one?

Thanks.

MPIs have a cam sensor, the MPI version of the cam has a lobe ground to trigger this as required. The SPI doesn't need this.

The profiles are the same as far as I know.

 

 

Thanks for your reply, RooBoonix.  I have since discovered that my Mini doesn't have a cam sensor, it's got a blanking plug (part number LDT100030) in place of the cam sensor at the back of the engine.  With this in mind, I believe the the Kent 274 cam would work for my car since I wouldn't need the cam sensor lobes. 

 

My Mini doesn't have a distributor, it has a coil pack just like the UK MPIs.  I'm just a little concerned whether the gear on the 274 cam will foul anything in the MPI engine block which doesn't require a distributor/distributor gear.  I strongly doubt it but was hoping someone would know for sure.     

[Tones61]

A tech question for the pro's in relation to the above post ^^^^

An mpi with no cam sensor?
How's the ecu know when to fire the injectors in time with the inlets if it can't see when the inlet at no.1 is open?

Edited by Tones61, 24 February 2022 - 07:47 PM.

[ultimax5]

A tech question for the pro's in relation to the above post ^^^^

An mpi with no cam sensor?
How's the ecu know when to fire the injectors in time with the inlets if it can't see when the inlet at no.1 is open?

 

I believe it has to do with the flywheel.  Found this discussed in the following post.  

 

https://www.theminif...r-mpi-flywheel/

[mini13]

THE JDM's were an SPI system so dont need the Cam sensor, true MPI cant be done with out a cam sensor,

[sonscar]

The crank can only give piston position,a cam sensor is needed to identify the firing piston.Sequential ignition and injection needs to know the firing piston.Steve..

[FlyingScot]

The crank can only give piston position,a cam sensor is needed to identify the firing piston.Sequential ignition and injection needs to know the firing piston.Steve..

That’s true but JDM is SPi throttle body so more like a carb in operation and the later coil pack ones utilise wasted spark.

 

FS

[mini13]

Yep, wasted spark can be done with just a crank wheel, ( and you can do "wasted squirt" too) but to do individual injection, and the funny stuff that goes on with the MPI system you need the cam sensor