Supercharger basics
Turbo Mini Forums

Evening everyone, it’s been ages since I’ve been here! I’ve been driving a 1293 Wolseley Hornet for a few years- and finally decided it’s not fast enough, or won’t be once I’ve made it ‘civilised’. I’ve got hold of a M45 supercharger (sorry), which I hope will suit my 1293 with Sw5 cam, 21253 pistons, and metro head for a fairly conservative pressure. Trouble is, it’s been so long that I’ve forgotten all I learnt here years ago. I want to keep it simple, so no mega jolt etc- I’ll run it suck through; what do I need parts wise? I can remember the following:

Supercharger (duh)
Intake manifold
Crank pulley
Tensioner and belt
Boost gauge and valve
Carb to charger piping
Decompression plate (doesn’t do enough mileage to warrant going too silly with machining pistons, head etc)
Carb conversion kit? Or is this for turbo only?
Anything I’ve missed?

And what CR should I be looking for? And what boost is sensible? Thanks in advance.

From memory....
The M45 will produce quite a lot of heat above 10psi; so without IC going higher could give you challenges.
Having said this I think the suck through versions Stuart Gurr made produced 14psi using std MPI and SC pulley IIRC.
Icing of the suction tube is a realistic issue, I have seen versions with a water heated outer core; you don't want your throttle to freeze wide open (not sure if those stories are genuine).
Get your head done by Phil or Benross.
I think in the past there have been examples of the bowl of the 21253 being enlarged for reduced CR.
As you go for suck through std carb is ok.
Also consider your ignition; an upgrade would do you well and many versions available.

I am no connoisseur by any means and my project has been progressing very (very!) slowely so do bit of searching, there is a lot of info on here.
Might want to check if Stuart is still around for info.

Dazed and Confused....

Thanks for your thoughts. I was looking at fitting a short suction tube to avoid that or fuel pooling. I have had a throttle ice open before, on another car- interesting experience! I have electronic ignition; hopefully this should suit?

How did you get on with this. Was going to post a similar question looking for advice on installing a Supercharger on my (not yet finished engine build. Problem is I have already installed the pistons P21253 and the are standard +40 e.g. 8cc and the head is being done by me looking at 9.75:1 CR

That is a highish cr for a non inter cooled cr.

Timing, fuel and boost control will help not turning your pistons to liquid.
You might also want to use water or water meth injection to help cool your intake.

If your running an ecu you can’t keep a eye on intake temps, but you will need to run a sensor that can live in the harsh intake after the charger which means it could be a little slow.
An ecu will help you control stuff when it all gets into the red…

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!