02-01-2018, 10:37 AM
Supercharged Austin seven engine advice
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02-01-2018, 10:57 AM
What is the expected output from a blown engine?
BHP and torque. regards Arthur
02-01-2018, 11:50 AM
There is obviously a great deal of expense replicating the Works' drive-train; surely a much cheaper arrangement would be to have the supercharged mounted on the head and belt-driven?
02-01-2018, 11:57 AM
(02-01-2018, 11:50 AM)Mike Costigan Wrote: There is obviously a great deal of expense replicating the Works' drive-train; surely a much cheaper arrangement would be to have the supercharged mounted on the head and belt-driven? You mean like this, Grasshopper? GHOPPER.jpg (Size: 122.61 KB / Downloads: 708)
02-01-2018, 11:58 AM
The Grasshopper solution...
Austin’s (Harris) father supercharged his RP using a belt system.
02-01-2018, 11:59 AM
I recognise that photo Charles...
02-01-2018, 12:02 PM
02-01-2018, 12:12 PM
It’s there to be shared - in the spirit that others will do so too.
It is Ian’s photo, not mine. The originals are in a flip-type album along with the 35mm negatives, there is a lot of good detail that document the (considerable) differences. It must be the easiest way to make a drive, as Mike suggests.
02-01-2018, 12:20 PM
(02-01-2018, 12:12 PM)Ruairidh Dunford Wrote: It’s there to be shared - in the spirit that others will do so too. Dave Dye was working on an adaption of the Grasshopper drive idea that used a Cozette 4/5 blower but I don't have a photo to hand. It was much lower profile than the exceptionally tall Centric stack Charles
02-01-2018, 12:23 PM
Years ago I ran an Austin 7 special with a belt driven Shorrock C75 supercharger. As tested on Stuart Rolts Dyno, which was accurate, it produced 32.5 bhp at 5000rpm. The car had fabulous torque and most of the time was in top gear, probably aided by the use of 15" wheels. Cooling was a constant problem, even with a water pump fitted. At times there would be ice on the inlet manifold and the exhaust manifold was almost red hot. If it idled too long it would brew up like a volcano.
I removed the blower and still have the engine. Now I am running an Ulster rep which has a Barlow crank, light pistons, a Pigsty trials cam, standard valves, a Ricardo head (excellent product!) and a 1 1/8" down draft SU. It is running on 19" wheels and is every bit as powerful as the blown car, but much more practical. It has ample torque and romps up serious hills. If I was new to Austin 7's and I wanted a sporty model I would go for a very simple Ulster replica with an unblown engine similar to that described above. Keep the weight down and fit a gearbox with suitable ratios. Mine is 3 speed with a high second (the Andes box). An Ulster can be used for almost any type of competition and can be developed into a very potent car as and when time, experience and finances allow. |
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