Alfa 33 twin carb 1.5 into sud ti, speedo gearing

[Alfa.mg]

Hi,
Looking for a bit of guidance from those in the know.
Ive got a 95hp alfa 33 1.5 twin carb engine that will be going into my sud ti, which is single carb. Was going to use the alfa 33 gearbox as the ratios were made for the engine setup. Do i need to mod anything on the speedo gearing? Is it ok to keep the speedo gearbox from the sud there connected to 33 setup or do i need the one from the 33?
Appreciate any guidance thanks
Mark

[colcol]

Hello Mark,
The Sud has a speedo gear in the gearbox and runs a speedo cable to the Sud speedometer, apart from the odd cable breakage and St. Vitas dance off the speedo needle, it works good.
The 33 has a 'phonic' wheel on the output shaft and a sensor that counts the number of times the output shaft rotates and sends the information to the speedo, that works out the road speed.
The easiest thing to do, is to use the Sud gearbox as the speedo setup will work.
If you want to use the 33 gearbox, because the ratios suit the engine, then you will have to remove the offside output shaft, on the gearbox and remove the 'phonic' wheel on the output shaft and replace it with the speedo gear on the output shaft.
Then you will have to discard the 33 gearbox pickup sensor and replace it with the Sud gearbox speedo cable insert that fits where the 33 sensor was.
The Sud gearbox speedo gears are as rare as hens teeth, so be carefull with them.
The 33 that you had had 14 inch wheels and the single carb Sud most likely has 13 inch steel wheels, so there might be a few % difference, put it all together and go for a drive with a GPS and see how much difference there is, Colin.

[Alfa.mg]

Thanks Col, yes ive just been reading on another site not as easy as i first hoped. Is it possible to take the gear ratios from the 33 gearbox and install them in the sud box, therefore keeping everything sud and retaining inboard brakes?

[colcol]

Hello Mark,
It is possible to take the 33 gearbox innards and place them in the Sud case, however you will need to set up the crownwheel and pinion backlash to suit the Sud gearbox casing, that is different to the 33 and other Suds, due to precise factory tolerances.
There would not be many around who would know how to set up a Sud crownwheel backlash, as it is old school, most just put in another gearbox.
There is a pinion height to set, and where the crownwheel and pinion mate and then there is backlash.
All done by painting up the crownwheel and using indicators, Colin.

[Alfa.mg]

Rightio then. Ill be keeping the sud gearbox for now. Might look at changing the ratios when it comes to. May keep sud gearbox as is with an overhaul, will keep things easy. You should start charging for all this guidance Col!

[colcol]

If i started charging for good advice, i would end up broke, there is no saying that the gearbox in the 33 is the correct one for that engine anyway, as over the life of the car, things get changed around.
The cost for a gearbox overall, can easily exceed the price of a good second hand one at the wreckers, so one that is a goer is put in.
The gearbox in a twin carb Sud was very high geared, which means it barely got into 4th gear around 60 kilometres, as it was high geared to save fuel and to cut emisions, it was for the 95 horse power unit, the 105 horse power unit in the 33 TI had lower gearing due to the fact it had less torque to cope with the higher ratios, so the TI, you could pull 5th gear at 60 kilometres....but not up a hill, but because of the extra revs, it used more fuel, swings and roundabouts, Colin.

[Sportscar Nut]

Col's advice is correct as per usual! The gearbox internals are a straightforward swap and surprisingly was not that expensive when I had the standard Sud box rebuilt with 33IE internals.

5th gear on the Twin Carb is an over drive gear but always found the 1.5 single carb 5th gears too short. Pending your $'s, I would be doubt there are many good s/h boxes left floating around at wreckers.

Enjoy
Paul

[colcol]

And if you intend to fit a 1700 or soup up the 1500, you should put heavy duty spiders, that sit in the synchro drums, they are about 30% wider than standard.
Someone has broken some along the way and this was Alfa Romeo's fix.
I only discovered this part by accident, when i purchased a new synchro drum and it had a wider gap for the heavy duty spider.
Only put them in though, if you are reconditioning the gearbox.
May not even be able to buy them nowdays, Colin.