Can you swap an si manifold onto the 1.3? If so, with proper tuning, could I increase fuel mileage? I'm sure anything could out do my ragged carb right now, and I should rebuild that first. I'm just daydreaming, I know of 2 or 3 si's in boneyards I could pirate.

yes,
a couple of mates and i have done it and it works,

just make sure you swap the rear water pipe on the motor
coolant temperature sensor
then just put everything else on as normal and use a Si exhaust manifold with an O2 sensor you need to enlargen some of the holes for the studs as they are a tiny bit off.

you also need to install the Si wiring harness to run the fuel injection.
and the si fuel tank pump and lines

i dont know about tuning it but there should be something you can do.

Spend the $80 and get a rebuild kit. Or you can look around in your area, and there are plenty of places that have an exchange program for $100 your carb for a re/manufactured/conditioned/built one.


AND proper tuning will help give your the MPG's you are looking for.


edit for boast here:
Gimpalot and I are currently working on a project that will make all carb guys happier than they are right now. All we need are the materials, and we will get on to the testing.

If you could find slightly smaller fuel injectors, you probably wouldn't need to tune it- I wouldn't turn down the fuel pressure though. Make sure you use a SI cam and distributor, you don't need to use the SI head but it would be a plus IMO.

3GCVC:
Did your mileage (kilometerage?) increase? If so, by what margin?

Does anyone know anything about tuning the carb for fuel efficiency? This is alien technology to me.

it isnt unheard of to get upwards of 55 on the highway with a carb'd 1.3, thats what they were rated at anyways.

i dont know what the fuel mileage did it really needed smaller injectors like D13B ones or something because it ran a little rich we couldnt find anything smaller and didnt have any other way to try turn the fuel down a little,

you could use a piggyback to step it down or turn the pressure down- the problem with lowering the already low fuel pressure is that you wouldn't get the same fuel atomization. I'm sure there are smaller fuel injectors out there, just gotta find them.