Hi All. I have been a X1/9 owner for about 10 years now having owned a standard 1987 1500 and for the past 4 years own a 1985 1500VS. I have just got hold of a Uno turbo engine mark 1 (I hope!) and am in the process of geting ready for the transplant.
Been a member of xweb for a few years and everyone says to use the X gearbox with the turbo gbox internals. Can I just use the X gearbox directly with the turbo engine without swaping the internals? What difference would it make?

First of all, good luck on the transplant!

The internals of the Uno Turbo gearbox are nearly identical but the Uno Turbo has slightly different gearing. The big and rather important difference though is the bearings.

In order to reduce the parasitic losses and improve reliability Fiat changed the bearings on the gears. The outward appearance is the same but once you start pulling gears of the shafts you'll find that the Uno Turbo gearset uses a nice selection of needle roller bearings where the X1/9 used solid bushes (this is all from memory I'm afraid). I do know that it is a straight swap on all but one of the gear pairs but I can't remember which.

All of that said I did use my first Uno Turbo engine with the gearbox my car came with and only swapped the 5th gear pair to improve top end running. Unfortunately it wasn't an original X1/9 gearset having replaced in the past by a Bacchi Romano gearset so the 5th gear change went too far the other way making 5th gear pretty useless. The BR gears definitely took the punishment though. Whether or not the Fiat gears would do the same I just can't say.

Just remember that you need to transplant the sensor from the Uno Turbo Bellhousing to the X1/9.

Thanks for that info. I'm sure there will be loads more questions!

Hello,

better late then never-For past 2 years I've been running a stock 4 speed X trany with the uno turbo mk 1 motor.
Boost set at about 13.5lbs (nearly at 1 bar). No issues.

Walter

Is the gear change not on the wrong side of the box of the Uno? I am considering a 2.0L Lancia beta transplant and have to solve this problem, I am considering an hydraulic master/slave set up, worked on Doe dual drive tractors in the 50s and 60s

if using the uno trany, you have to source an earlier bottom change model.

w