feralsprint wrote:
Ken
you really need to talk to Warwick Agustin who fitted a toyota twin cam to a mini mini box 15 years ago, he has been racing it for many years and he will tell you of the troubles you can expect, his is chain drive to the mini gearbox and that itself causes problems
Warwick did it around 1990-91. I know, I was watching it come together in his workshop
He did not cut down the gearbox, as he was building to supermini rules which said that you had to retain the mini gearbox entirely. His solution involved cutting the flywheel housing in half and welding in some plate to raise the flywheel housing to the Toyota crank centreline. The alignment for the oil seals was a bit of a bitch. He also welded the crank tail on rather than bolting it on. This was a major source of problems with it cracking until he solved it. The gearbox casing was extended lengthwise with some plate welded on as the Toyota block is longer.
He used the chain to drive the gearbox, as the Toyota engine
rotates same as a mini engine but he wanted something to take the power to the input of the gearbox without having to cut a custom idler gear and line up its centreline. Chains are a lot more forgiving of misalignment than gears. The problems in this area were because he was welding the chain drive sprocket to the idler gear and input gear. If you had them machined up from scratch I doubt you will have the same problems. The gear set is a straight cut from Harrop I think.
Now his biggest problem is breaking driveshafts.
A major thing to be worried about is the sharing of the gearbox and engine oil. Why not separate the oil systems if you are doing all that fabricating anyway?
good luck
michael
<edit> got my rotations mixed up
_________________
the world is a book, and those who do not travel read only a page
66 Mini Minor sponsored by
http://www.lifeonthehedge.com.au/ The Dog Harness Specialists
It was a pleasure ausmini. I'll miss all you misfits and reprobates
