Charged Spitfire 1500 . . .

[restoman]

Anyone tried fitting a charger from a BMW Mini to the Spitfire 1500 engine?

[Wizardskills]

Best bet would be to try the club triumph forums. Although I doubt it would take the extra strain with out serious modification.

[varsas]

There where period 'charged modifications. Look up 'shurrock' these just bolted on, with no other mods other then for the high compression spitfire engine. There was one for sale at Stafford this year. I believe these where for the 1200 engines though?

http://9700vc.blogspot.com/2008/09/shorrock-superc...

http://www.shorrocksuperchargers.co.uk/ShowDocumen...

I would imagine the weaker bottom end of the '1500' engine might need strengthening to take much extra boost, maybe you'd be better off starting with an early 1300 engine?

[restoman]

Thanks for the input, and the links. I was aware of the Shorrock set-up but when these are available they tend to be very pricey whereas there are a number of BMW Mini Eaton 'chargers available for not alot of money at any one time.

As for the strength of the 1500 bottom end, then yes this is a concern, but hey, I can always get another engine . . .

[//j17]

restoman said:

As for the strength of the 1500 bottom end, then yes this is a concern, but hey, I can always get another engine . . .

Don't worry about it - supercharging actually DECREASES the peak loadings in the conrods* so if anything should be kinder to the bottom end.

You will also tend to use lower RPM in a supercharged car as you don't need to push up the rev range hunting for power.

• Peak load is the tensile load that occures as the piston goes past TDC and wants to keep going up but the crank starts to pull in the opposite direction - the same for 'charged/NA on the exhaust/intake stroke but reduced on compression/ignition one as there is more charge in the cylinder pushing back against the piston.

[//j17]

restoman said:

As for the strength of the 1500 bottom end, then yes this is a concern, but hey, I can always get another engine . . .

Don't worry about it - supercharging actually DECREASES the peak loadings in the conrods* so if anything should be kinder to the bottom end.

You will also tend to use lower RPM in a supercharged car as you don't need to push up the rev range hunting for power.

• Peak load is the tensile load that occures as the piston goes past TDC and wants to keep going up but the crank starts to pull in the opposite direction - the same for 'charged/NA on the exhaust/intake stroke but reduced on compression/ignition one as there is more charge in the cylinder pushing back against the piston.

[mattius]

1500 would not be strong enough bottom end, it has a well documented floppy crankshaft throwing the 2nd/3rd main if the revs get too high or too much torque is being used.
Josh Bowler a few years back supercharged a 1300 with a BMW eaton supercharger, iirc he snapped a 1300 crank on one of his first runs, not to mention a driveshaft.
That was a very specially modified engine to cope with it, lives on in a spitfire in scotland somewhere, i sold it after writting off the car minus the supercharger.