KM132 Narrow with Starion internals.

[Superscan811]

Looking at modifying a KM132 Narrow block gearbox to use Starion internals.
This is for a N/A 4G63 twincam conversion I'm wanting to do, for one of my LC hatchbacks.
Since I don't expect to make more than 130 RWKW, this should be more than good enough.
I have thought about using a starion block (have 2 of them currently) with a twincam head, but it would require more fabrication/modification work if done properly.
With a Narrow MMC 5 speed gearbox, it will almost be a direct bolt-in (I HOPE).


The gearbox I'll be using is out of a 2.0L Scorp.
The guy I got it off said it had a loud whine in it and when I opened it up, I found out why.
The idler shaft had over 3mm of end float and around 1.5mm if radial play in it. Apart from that, it looks fine.

Opened up 5 of my MMC gearboxes during the week,
1. Early Starion.
2. GH Scorp wide (short gearstick extension housing).
3. GH Scorp narrow (short gearstick extension housing).
4. L300 narrow.
5. Early Galant 4 speed.


Thing I noticed.
1. All the starion gears, on both the idler and output shafts, were 18mm wide.
2. On ALL gearboxes, 1st and Reverse gear on the idler shaft (the one down the bottom) were also 18mm EXCEPT the Galant 4 speed.
3. All the other gears are 15.5mm wide.
4. The output shaft, after the speedo gear, is much thinner on the GH narrow and the galant gearbox.

I'll post a few pics in the coming weeks.

Cheers.

[Billsy]

so what your saying is swap in some starion gears and theyll be considerably stronger, except first is the same???

[Superscan811]

so what your saying is swap in some starion gears and theyll be considerably stronger, except first is the same???

Not just the gears.
Will be swapping the non thrust ball bearings for roller bearings.

For the thrust bearings (deep grove ball bearings) I'll swap them out for tapered roller bearings (same as in the starion gearbox).

Roller and Tapered roller bearing can handle a higher load than their ball bearing counterparts,
BUT,
there will be a bucket load of catalog cross checking before finding the correct ones required, and at the right price.

Priced some tapered roller bearings for my lathe headstock and they varied from $35 to $400- for almost exactly the same bearing (0.5mm width difference)...

Hope to be get a detailed list in the next week of all the bearings for every KM13- gearbox so I can see what the standard bearing are and what can be used.

Cheers.

[Billsy]

i like the sound of that, could be a reasonable option for an upgraded gearbox

[A112H]

+1

[Superscan811]

i like the sound of that, could be a reasonable option for an upgraded gearbox

+1

That is what I'm trying to achieve, a relatively strong, bolt in upgrade.

There are after-market gearbox options but most require a fair bit of fabrication work.

I'm trying to avoid that if possible BUT it will still require a donor Starion gearbox and a rebuild.

The gearbox should be only a few kg's heavier at most, which is a good thing.

As for its "strength", I'd say it should be a bit better than the standard Starion, but that will depend on the flex of the MMC gearbox aluminium casing more than anything else.

Cheers.

[Billsy]

out of interest, whats a stazza gearbox good for horsepower wise?

[Superscan811]

out of interest, whats a stazza gearbox good for horsepower wise?

The standard G54Bt intercooled starion produced 225hp at the flywheel, approx 170hp at the rear wheels, using the standard gearbox.

Depending on the driver (aggressive but not agro), 275+ RWHP reliably on a freshly rebuild Starion gearbox shouldn't be too much of an ask.

A lot does depend on your driving style. Dump the clutch doing 6000rpm from a standing start with slicks, and unless your clutch or wheels slip, something will most likely give way.

The Alison truck transmissions are now a lot smaller and lighter than they were several years ago, not just because the metallurgy is better, but because the gearbox tells the engine to reduce power on gear change and then ramps it back up.

Food for thought.

Cheers.

[A112H]

You don't work for MTU anymore, stop selling the Alison

[Superscan811]

You don't work for MTU anymore, stop selling the Alison

Best analogy (short of a hammer and glass) I could think of.

Cheers.

[A112H]

[Billsy]

id have thought it would be capable of a fair bit more than that, providing your not being silly with a puk clutch and being a mechanical vandal.

i had a km132 last a few years with approx 300rwhp. it wasnt till i was being a dick that i sheared the teeth off second
but i had a very heavy but still soft full face organic clutch.

[Superscan811]

id have thought it would be capable of a fair bit more than that, providing your not being silly with a puk clutch and being a mechanical vandal

Agreed, but if I was putting out 300RWHP, I'd go another step up in gearboxes because I prefer to have things over engineered.

Cheers.

[Billsy]

yeah, im keeping my options open at this stage. ill see how long this km132 lasts.
the car will hopefully be pushing 400+ rwhp when its done so im in for some problems with gearbox, being the only weak link left

[A112H]

I was concerned about my 132 but as I am expecting well under 190rwhp so the box should be fine. And I am too old for side stepping the clutch anyway

[cheaterparts]

id have thought it would be capable of a fair bit more than that, providing your not being silly with a puk clutch and being a mechanical vandal

Agreed, but if I was putting out 300RWHP, I'd go another step up in gearboxes because I prefer to have things over engineered.

Cheers.

something to keep in mind also is where the engine makes 300 hp

if is was at 5252 rpm that is 300 ft lb torque
if it was at 2626 rpm that is 600 ft lb torque
and if it was at 10504 rpm it is 150 ft lb torque

a quick look at these figures shows where a turbo engine gets hard on gearboxs as most get much higher
HP and torque in the lower rev range than even very high performance NA

[Superscan811]

Completely dismantled both gearboxes today, the 2.0L and a stuffed starion.
Didn't take my camera today but I'll take some photos tomorrow.

Output Shafts.
The output shaft bearings are all the same dimensions in the 2.0L and the Starion box, the only difference was the bearing closest to the tailshaft was a sealed bearing in the Starion box???

Idler Shafts.
The idler shaft bearings are different but apart from the front of the 2.0L shaft being 3mm longer, the shafts are the same.
The starion runs tapered rollers on both the front and center bearings and a standard ball bearing on the back.
The 2.0L runs a needle roller on the front, deep groove double row ball bearing in the center and the same standard ball bearing as the Starion on the back.

Input Shafts.
The input shafts are different of course BUT they would be interchangeable as long as you used the correct needle roller bearing between the input and output shaft.

As far as the gearbox case differences, minimal, except for the idler shaft front bearing hole.

So in a nutshell,
A rebuild kit for the Starion gearbox plus 1 extra bearing and it'll work.

The only thing that may need to be looked at is the front bearing retainer. When I use a tapered roller bearing I may need to internally shim it to get the correct preload.

Looking at replacing the center angular contact double row ball bearings with tapered roller bearings, just for a bit of added strength/life.
Will also try to replace the other ball bearings with roller bearings.

Cheers.

[Superscan811]

Just some pics of the differences between the 2.0L and Starion gearbox.


The Idler shafts.Starion on the left.
1.The Starion idler shaft front bearing surface is shorter.
2. The Starion gears (except 1st) are wider.


The Output shafts.Starion on the bottom.
1.The shaft tapers down to a smaller spline on the 2.0L
2. The bearing mount surface is shorter on the 2.0L



The Front bearing holes.Starion on the bottom.
The Starion has a 52mm hole for the Tapered roller bearing.
The 2.0L has a 45mm Hole for a needle roller bearing.




The Front bearing retainers.Starion on the bottom.
The 2.0L front bearing retainer has been machined slightly to allow for the different front idler shaft front bearing.



The Input shaft Needle Roller Bearings.Starion on the right.
The 2.0L needle rollers are smaller in diameter but the both have the same Inside Diameter (they fit onto both shafts)


The rear output shaft bearing.Starion on the right.
The Starion bearing is a sealed bearing.


Cheers.