> Hi, I have spent too many hours flying cross country lately, but on my
> latest trip I cam across an add from a company in England that makes rootes
> type blowers in three sizes to fit 1.5 to 4.7 liter engines. I then
> thought about the possibility of fitting one of these to a 1500 Spitfire.
> I know this was an aftermarket accessory in the 60's, and have an article
> about a blown Herald. I have also seen a blown Bugeye and a MGTD. Anybody
> ever seen, thought about or owned a blown Spit? I would be interested to
> hear from anybody who would know if the 1500 could take it. Thanks,
> oliverc@cc.tacom.army.mil
Judson & Shorrocks produced Rootes type superchargers for a variety of cars in
the '50's & '60's. If you can find one today, it is very expensive. A fellow
TR club member who has been into racing TR's since the '50's basically believes
that the HP gain is minimal. Remember, this type of supercharger is engine
driven and therefore consumes HP. Also, in order to lubricate the vanes, oil
must be added to the fuel, at least this was true with the old Judson and
Shorrocks blowers. These units were designed to be placed downstream of the
carbs. If you try and "blow through" an SU it probably won't work.
Turbocharging is another story. Remember about 10-15 years ago when everything
was turbo'd and there were zillions of aftermarket kits for turbos. Where are
they now? Turbocharging is basically free HP. But along with it comes heat,
turbo lag and variety of other technical challenges. The cars today which are
turbocharged were designed that way from the ground up and have sophisticated
engine management systems to help overcome some of the problems.
The old style Rootes blowers look really neat and are a great period accessory,
but you would probably get more bang for the buck with the more traditional
route in engine mods, cam, flow the head, carb & manifold, header & exhaust,
balance the engine etc.
Having said all that, the sound of a wound up Rootes blower is unworldly!
Cheers
Kurt Oblinger
Redondo Beach, Ca.
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