6 replies to this topic

[R32Egor]

HI all,

 

I bit of current situation -

 

I have a 1997 MPI, stripped and I want to start the restoration.

 

The engine has been out a stored for around 6 years.

 

Obviously I have to do complete refurbishment of the engine (at this stage do not know what the condition is like inside - will it need a rebore etc)

 

A final goal some time in the Future would be to supercharge it with the VMAX kit.

 

first stage is to get it back on the road with a stage 3 kit.

 

Basically the question is -

 

What needs/should be done during the engine build for the final goal to happen but not at first.

 

Should I be changing cam?

Pistons?

 

etc to help me later in my goal or will I have to build it as normal and then do some modifications when/if i fit the supercharger.

 

I am thinking more about compression - If i lower the compression with pistons before fitting kit then without the supercharger it will not run well?

 

Am i asking to soon before I have stripped the engine and seen what needs doing??

 

Thanks J

 

 

[rich_959]

I researched this a little bit when starting my own MPI restoration, as I always had an eye on a VMAX kit further down the line if I felt like splashing out, and depending how the car performs in general. From what I've heard/read of the VMAX kit, it works very well with everything from a bog standard MPI, up to highly tuned engines - it just varies how much eventual power/torque you'll get from the conversion.

 

I went for a full strip and rebuild with a Swiftune SW5-7 cam and a bit if head work. Lightened/balanced clutch and flywheel, and a duplex timing kit. I'll see how it goes in that form with the standard ECU etc, then decide from there. More knowledgeable engine folk will confirm, but I think you've hit the nail on the head with a good full rebuild to ensure your engine is in good health, then it's a matter of how much cash you want to splash. 

Edited by rich_959, 07 May 2020 - 06:10 PM.

[Steve220]

If you want stage 3, and later to charge it, go for 1293 pistons so you have a fresh start on the bores. Your piston dish choice will depend on a few things:

 

Low comp pistons - you'll lose a bit of power but will be ready to boost it

 

High comp pistons - will work for your stage 3, but will need a way to lower CR later, be it a decomp plate (not advised) or machine the cylinder chambers.

[R32Egor]

Thanks for the info.

 

1293 pistons this is a 0.20' overbore yes?

 

And the pistons - high comp means the standard flat top pistons yes?

 

low comp pistons - I presume these are the 8cc dished pistons.

 

 

By the way what compression ratio are we looking for when you have a supercharger fitted?

 

Thanks for the info.

[mini13]

I would say rebuild it with the standard head so keeping the compression standard, then when you fit the charger swap to a modded head with larger chambers to drop the compression.

 

In tems of cams, the Kent 274i would be a good upgrade, I would also stay clear of the high lift rockers, as they will add overlap. It might be better to not fit the stage 3 kit.

 

I would recomend taking to Stuart at V max, he's chaged a lot of MPI's so can advise on what bits would be best to fit

 

https://www.vmaxscar...ercharger-kits/

 

[Mark B]

Hi, I've just built a fuel injected supercharged mini using Vmax's old kit spec as follows:

- Vmax fast road cylinder head
- swiftune sw5 cam
- omega forged 18cc dished pistons
- lightened and balanced rods
- balanced crank
- lightweight minispares mpi flywheel
- rebuilt gearbox and crosspin diff (you need this because the standard single pin will break under the extra load)
- Homemade RTS clutch and standard sprung clutch plate (again to take the extra power, do a search you will find lots of info)
- minispares 4 pot calipers and 7.5" cooper s discs
- emerald ecu

Loads of other bits as well, too many to mention. You don't need to go quite as mad as this especially if your MPI engine is good, you could rebuild it to a fairly standard fast road spec (too tuned and your standard ECU will not cope) then if you wanted to go down the supercharged route, you could use a decompression plate to reduce the compression ratio at a later date and an emerald ECU just as a starter for 10 and go from there? It will not run properly if you reduce the compression ratio now without forced induction (turbo or supercharger). Hope this helps

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[R32Egor]

thanks all for the info

 

I think for the moment I will think about getting it to around 90HP (limits of the ecu) and then later think about supercharging it.

 

 

By the way I am drooling over the pic of your engine bay.