Cars


Mini Rebuild

 

Step 42 - Radiator and Transfer Box

 

 

Mini Rebuild Step 42

Before I removed the engine to install some of the new parts, I decided to try to find mounting locations for the remote oil filter, coolant reservoir, and transfer box cooling pump. Things were a bit tight but I think I found good locations for everything. I'll drill most of the holes after the engine is out and there is more room to work.

 

Mini Rebuild Step 42

This is the remote oil filter housing (silver) with a sandwich plate (blue) mounted directly beneath it. The plate has 4 ports, giving me a convenient place to screw in sensors for my Smiths oil pressure and oil temp gauges.

 

Mini Rebuild Step 42

With that done, I pulled the engine.

 

Mini Rebuild Step 42

This is the cush drive bushing, which acts as a buffer between the powerplant and transfer box. Because I will be using the car in competition, Mark at MINIeXvo shipped me a firmer bushing (green) to replace the standard one (pink).

 

Mini Rebuild Step 42

This is the transmission countershaft. Typically on a motorcycle this is where a small sprocket is mounted which the chain rides on, sending power back to a larger sprocket on the back wheel.

 

Mini Rebuild Step 42

With the MINIeXvo kit, power is taken off and sent directly into a custom transfer box. Here is the first part of the assembly.

 

Mini Rebuild Step 42

 

Mini Rebuild Step 42

Here are the tools included with the kit to tighten countershaft gear.

 

Mini Rebuild Step 42

 

Mini Rebuild Step 42

This is one third of the cush drive, connecting the engine/transmission with the transfer box.

 

Mini Rebuild Step 42

Some people asked for more photos of the MINIeXvo transfer box so here you go. It is the key to taking power from the R1 engine/transmission and getting it to the Mini differential without needing chain drive. A standard Mini differential fits in the lower section, sending power out to standard Mini driveshafts. So from the diff onwards, its all stock Mini, meaning minimal trouble switching from the standard A-series motor to the MINIeXvo, as well as high parts availability - any MIni shop will have what you need.

 

Mini Rebuild Step 42

Here you can see part of the optional reversing mechanism. It consists of this externally-mounted gear and a large starter motor mounted next to it. Whenever I push a button in the cockpit, the starter motor engages the gear, propelling the car backwards.

 

Mini Rebuild Step 42

 

Mini Rebuild Step 42

My plan to use a cable-actuated clutch fizzled out last month. After putting most of the pieces in place I found that it was not going to work with the parts I had and the space I had to work with. I ordered this hydraulic clutch kit and decided to fit it with the engine out of the car. It is made for a Yamaha Quad, which I assumed would increase the chance of it working on the R1. No such luck. It just doesn't have the length of travel necessary. Time to order a larger slave cylinder from Wilwood.

 

 

Mini Rebuild Step 42

Knowing that the R1 engine will be putting out a serious amount of heat, I purchased a heavy-duty aluminum radiator. One peculiarity of all but the last Mini's is that their radiator was mounted to the side of the engine bay with an opening cut into the lefthand fender well for the hot air to escape. No big surprise since the Mini was first and foremost all about packaging. I didn't end up with any more room with the R1 engine than a stock A-series motor so my radiator is in the same spot. Besides potentially reduced airflow, the other downside of this arrangement is the likelihood that the tires will flip up rocks and damage the radiator. To protect it and the cooling fan I decided to install a mesh stainless steel screen.

 

Mini Rebuild Step 42

 

Mini Rebuild Step 42

 

Mini Rebuild Step 42

 

Mini Rebuild Step 42

 

Mini Rebuild Step 42

 

Mini Rebuild Step 42

The driveshafts will have to be installed soon so time to clean off the surface rust and give them a quick coat of paint.

 

Mini Rebuild Step 42

 

Mini Rebuild Step 42

I had to come up with a custom method of securing the radiator in the car. On the advice of a friend I decided to make a tray at the bottom which the radiator would rest securely in. I will then make short brackets to hold the top of the radiator in place as well. I made a quick cardboard template and fitted it to the radiator as well as the car. When satisfied, I traced the design onto some sheetmetal stock and started cutting.

 

Mini Rebuild Step 42

Once the tray was made, I drilled a couple holes in the subframe for locating bolts. I then placed a bit of grease on the heads of the bolts and carefully set the tray in the final mounting position I wanted. When I lifted the tray back off, there were small blobs of grease exactly where the bolts needed to go.

 

Mini Rebuild Step 42

I marked those locations, wiped the grease off, and proceeded to tack the bolts to the underside of the tray.

 

Mini Rebuild Step 42

After test-fitting, I fully welded the bolts to the underside of the tray and ground down all the welds.

 

Mini Rebuild Step 42

Here are the compenents - the radiator (with some protective cardboard temporarily taped on), the tray I just fabricated, a piece of rubber sheet cut to fit into the tray and protect the radiator, and some bolts and washers to mount everything in place.

 

Mini Rebuild Step 42

And here is the tray mounted in place. By putting a pair of locknuts on the locating bolt above the subframe, I was able to set the tray height at either end precisely, then tighten everything into place.

 

Mini Rebuild Step 42

 

Mini Rebuild Step 42

 

Mini Rebuild Step 42

Now I just need to secure the top of the radiator and I'm done.

 

Mini Rebuild Step 42

More new parts arrived this week, including this nice oil cooler from Setrab. Once the engine is back in the car, I will find a good mounting location for it. The electrical system work is just around the corner so I began ordering various parts for that as well.

 

Mini Rebuild Step 42

 

Mini Rebuild Step 42

I had a few hours last night and was able to finish installing the coolant reservoir and the transfer box oil pump underneath. With the right fittings, there should be just enough room for all the lines and hoses to all fit.

 

Continue to Rebuild Step 43

Return to Mini