Mini Engine Conversion – Driving

Mini 1275GT Resto-Mod, Jun-2018

Have completed nearly 100 miles with the new engine and nothing has yet broken or failed. There are however some issues that need addressing:

The cooling system using the standard Mini radiator is marginal at best. So the first major “enhancement” will be to replace this with a high flow aluminium one. I’m still retaining the standard Mini type radiator mainly because it has a built-in header tank – there’s barely enough room to fit a separate one as many modern radiators require.

With the lighter engine, the front suspension (with Hi-Lo’s) now can’t go low enough. Will need to get the car corner weighed and set up correctly to ensure an accurate measurement of ride height. It’s possible that the front trumpets may need a few mm shaved off to get the front lowered satisfactorily.

Also, the front tyres now come in contact with the tie-bars when approaching full lock. It’s not an issue during normal driving but maneuvering in tight spaces is more difficult. This is due to the tie-bar pivot on the subframe being moved further outboard to accomodate the bigger engine. I can either make up some new tie bars with a slight bend or add a wheel spacer.

As far a driving is concerned, it’s still pure Mini when you drive with a light touch on the throttle. There’s less steering effort because of the lighter front end but otherwise the handling & roadholding seem unchanged from standard. But when you open the tap a little, it becomes a different machine altogether. First thing you notice is the loud growl from the exhaust and although I’ve still not “floored” the throttle yet, the huge increase in torque is immediately apparent. Strong acceleration is achievable in all gears, even 5th. 

So far, I’ve only experienced a little torque steer which is easily checked as long as you keep a firm grip on the steering wheel while accelerating.

Short video of recent test drive: