From the tone of your inquiry, I get the impression that perhaps you're thinking about what to create as your first "track toy". If this is not the case, please skip the next paragraph.
There are some practical matters that need to be considered when building a track toy; here are a few. If you plan to drive your toy to and from the track, it probably should burn pump gas. Race gas isn't available along the highway and you won't want to carry a whole bunch of gas cans full of it in your car. Besides, race fuel costs about $5 or 6 per gallon (at least in CA it does). Another thing is that a car which is driven to the track needs to be dead reliable. If something breaks at the track and have to get a tow home, it will probably cost you a bunch. Finally, if you're new to the track, having a "high strung" car will only make learning the basics of track driving even more difficult than it already is. You'll have more fun and learn more, if you spend more money on "seat time" and less on creating a hot car.
First of all, let's take a look at hp specifications. The TS spec is 148 bhp vs the stock Spica 1750 which is 132 bhp. The problem is that the 1750 spec, curtsey of the hp crazy '60s, is gross hp while the TS is a perhaps more meaningful NET hp number. I'd venture a guess that the NET bhp on a stock 1750 may be something like 110 to 115 NET bhp. I hope there is an hp wizard out there who can provide a better number but this seems a reasonable starting point for a discussion. In other words, we're looking at pumping the 1750 up roughly an additional 35 bhp which is not a trivial amount. If they were easy to come by, I suspect Alfa would have put them in from the start.
Now, here's my take on a "hotted up" 1750 vs a TS. A bone stock TS produces much more hp & torque than a stock 1750, it will be very drivable and it will burn pump gas. About the only thing I would to do to the TS would be to get it dynamically balanced, add an aluminum radiator for a bit more cooling and install a half ceramic/half composite clutch plate to take the extra load you'll give it on the track. To get a 1750 up to the hp output of a stock TS will require turning it into a much less streetable engine. It almost certainly won't burn pump gas and it is unlikely to be anywhere near as reliable as a stock TS. Oh, it should also be balanced and have the same radiator and clutch as the TS.
As for cost, I would expect the two to be fairly similar. Both will require significant engine rebuilds but where you put $ into an engine swap in one case, you end up paying for engine rework in the other. Safety equipment, suspension upgrades, wheels & tires, etc., will be the same either way.
One final thing, if you plan to run in competitions of some sort, you should pay close attention to the rules imposed by the governing body. Having a TS in a '69 Berlina might force you to run with some pretty heavy hitters in some cases and in others it might not even be allowed period. The same goes for modifications to a 1750.
Bruce Colby - Street = '69 1750 GTV/TS; Track = '65 SGT/TS, '89 E30, '72 914/6
gone to new homes
- '71 Jr. Z, '69 1750 Spider, '62 Spider