Saturday, February 27, 2010

Diffs are us


When is a FIAT not a FIAT any more?

Probably when you do this... but I like to think of it as a refinement...

So  here we go again - we have the diff rotating now - thanks to the RHS bearing block and eccentric being machined. The Pictures below are of teh second dummy assembly - not much to do now - bushings and oil seals, diff "muff" , and shim spacers plus some bolt holes and a pinch bolt on each side. But most importans you now get to see the drive side more or less how it should look. I ended up using the evo 1 lower mounting cradle as a spacer in teh dummy assembly hence the odd bits of tube getting in to shot.



For those who havent twigged yet - thats not a Fiat engine in there ..... and last I checked the other  two 128s I raced never had this drive arrangement :-)


Still you should have a good idea by now this is a Yamaha powered Fiat hybrid running chain drive and 6 speed sequential gears and about 155 bhp in a package that weighs in at under 80kgs with the same tourque as my old 1300 FAZA 128 - but in a car weighing 300kg LESS. I havent cut the car and a good 1600 SOHC iron block fiat and 4 speed can be dropped back in the whole in an afternoon and be running by morning a few hours later.....

The precsion maching and welding on this engine install is the work of Graeme Sutton - with me in support doing the time consuming roughing out and drilling/tapping/fabrication tube notching layout stuff - time consuming for me that is!

Neat little package eh!



So there you have it - full exploded view next time - plus throttle cable and pedal and either wiring or headers....

Sunday, February 14, 2010

So whats the Plan....

Well - since I have been just uploading a bunch of photos of late perhaps some explanations of progress are in order:

So here we go -  The diff build is consuming a mammoth amount of time  - to get from  raw billets to the drive stack seen in the photos has taken 4 months of sparodic effort and a machine shop with enough kit to make your eyes water - do not try this at home! Unfortunately I lost the shots of the raw material stage... 

So we stareted with a Toyota Celica Torsen diff - machined the ring gear mounting circle down and sliced off one bearing snout - then took the drive outboard with a couple of big billets of 1045 steel. The drive side bearing runs on these held in an eccentric mount on the side plates - the alloy bits below are the start of the eccentrics -  and on the right a hairy arm and teh eccentric in place - 0.300 or 7.8mm of tensioning for the chain


Diff

Inital stack


Final stack eccentric is the lighter colured piece



All pretty simple really - I will take some detail shots of the whole exploded unit prior to final assembly!

Update photos - Interior panels/gear shift/Diff

lots and lots of stuff going on Interior panels and bias adjuster plus the diff coming together



































Gear Shift






Bias Adjuster



Door Panels