ALFAGTV6.COM

[Duk]

Right, I'm bored and thinking out loud..............

With a real question mark hanging over the durability of the internals in an Alfa transaxle being able to survive any decent sort of grunt and having seen mentioned a few times (OK, maybe once...........) that having oil pumped onto key areas could help keep things in 1 piece, I had a thunk.

In an attempt to keep it realistic (no ($1200 Person/Moroso pumps here), how about using a small powersteering pump, mounted to the clutch housing and is driven off of the tailshaft, to draw oil from the base of the gearbox, pump it thru a small oil cooler and then sends it to the pinion/crown gear (diff gears) or even an internal spray bar that pumps oil onto all of the gearbox gears, the bearings and the diff gears???

[75evo]

How about this spur gear pumps. More reliable than diaphragm pumps, according the them

https://www.rbracing-rsr.com/oilsystems.htm

Only US$250.

[Duk]

I did think about something like that too, it'd be much easier to impliment.
What kinda puts me off, and it's not really that bad, is its another electrical load.
Having said that, it'd only need to run when the oil was hot and you could impliment a switch on and fault monitoring sysytem to run it only when needed.

Anyone have any photos of internal oil sprays they're prepared to share?

[75evo]

What do you mean? Everyone today is going electric. PS pump, water pump, thermostat, etc. The days of belt drive is over dude. It's not a smart solution. The electrical load can be more intelligent and variable.

I think the SZ has special gearbox shafts with oil holes (don't quote me on that) and that solution is the one you would like.

But for the rest of us poor sods, we have to resort to a more practical solution. Electric oil pump, oil cooler and maybe an oil jet or two in the box somewhere.

[Duk]

Everyone may be going electric, but the Alfa's electrical system still sucks.
I'm just want to make sure I keep my head wrapped around all pro's and con's.
If the pump draws say 7-10 amps to run and the alternator/electrical system is struggling to keep up with power demands befor a 7-10 amp current dray pump is added, then it certainly won't help things.
I'm sure an upgraded alternator and some smart control of the pump is easy enough. After all, there's no need for it to run when the oil is well within its safe operating temperature or the car isn't being driven with great urgency (making sure that oil is pumped onto the ring gear and pinion regardless of oil temperature).
Like I said, I'm just thinking out loud.

[gtv-racer]

i think the best gain is from tempreture control.
Expansion rate per 1 degree celcius per 1 meter = 0.0000288 mtr (aluminium case)
Expansion rate per 1 degree celcius per 1 meter = 0.000012 mtr (steel axles)
Difference is 0.0000288-0.000012=0.0000168
If the gearbox hits delta 80 degrees thats 0.0000168x80x0.3mtr = 0.0004032mtr growth

Yes thats a whopping 0.4032 mm growth!!!!! In one direction Take in mind that the crown also moves away form the centre of the box.
So the mesh of the pignion is that much off. the worst kind of load on the pignion gear there is. Also think that the bearing plate flexes a lot... And bye bye pignion.

The 0.3mtr is the distance from flange bearing plate to center pignion.

And yes i see those tempreture's on my gearbox tempreture guage.

Cooling is a must under track conditions and hard street driving...

So what i'm about to do is get a cooler and make a stronger intermediate flange.
This should make the box a lot stronger.

Input and output shaft displacement from heat:
Distance radial =72mm
0.0000168x80x0.072=0.1mm

[75evo]

When you say flange, do you mean middle cast aluminum piece of the gearbox with the bearings?

[gtv-racer]

Yes sir

[75evo]

Well I broke one of those. Caused me to lose 4th gear. The part which holds the bearing isn't very strong. So if you can CNC it from billet that would be awesome.

[105gta.]

75evo, in what way did it break? The steel plate broke or pull the threads out? I'm interested to hear about possible weak points and how they occurred.
Ben

[75evo]

That flange holds a roller bearing for one of the shafts. The lip which holds the bearing somehow broke off.

Actually I broke 2 of those flanges. Once in 2000 and once in 2012.

[gtv-racer]

Yes gonna cnc the part. Half of it is done already.

You mean the lip wich is in one piece with the aluminium plate?

I heard more people broke the flange.