Mini mania / mini spares C-STN39

turbodave, and others, if you could email me information on where you got your gears and your recommendations. I can't seem to find the Clubman set for sale anywhere but MED's actual website. And the shipping, etc would be more expensive.

I know some have happily used helical drops, and also helical gears with some pretty high hp. I have also seen some very spectacular failures with them on what I personally would call reasonable HP motors. SC drops seem to just wear out - not fail and take out the transfer housing and/or trans case. That said, A set of A+ drops, well set up, is plenty for a nat-asp motor. If you want to go for belt and braces, you can consider a pressure fed oil feed to the idler bearings, and maybe an oil spray 1-2" before the mesh. ersonally, I'd look at this before sc drops on any kind of road-biased nat-asp mini where a quiet ride and nice manners are important.

For the SC gears, the big thing for me was the better ratios. The A+ set has a really short 1st gear for example...

The "clubman" set which requires you to use your existing 1st and reverse gear sets is a really good deal, and seems to be well upto the abuse of many very high hp turbocharged minis. All minis will really benefit from closer ratios - it is worth a lot in the overall performance.

Thanks Kevin.

 

I'll pay close attention to the end float. I'll be replacing every bearing and race and going with the highest quality I can afford when I do it. Shouldn't have any issues since I'm only planning on having about 110 at the crank at the very very most, but it will likely not even be that. This is not a race monster. It's an up-tuned street motor that can go to the track every now and then.

I have ~125HP at the crank and am still running the A series helical drop gears.
IMO these are fine, IF you change the 2 idler needle bearings at every gearbox major overhaul, and pay attention to idler endfloat. Too much endfloat and they will beat the cases up. .004-.005" endfloat is good.

Just my 2 cents: I installed SC drop gears on my 1293 with a 2.95 final drive. I did it just for something different.

My exhaust was already fairly loud so the extra noise from the drop gears wasn't that big of a deal for me. The only issue is the drop gears are just as loud at at 5mph in 1st gear as they are running 90mph in 4th gear. I don't really mind the noise, but I only drive my car once every couple weeks. There's just no way keep the car quiet when I'm pulling in or out of the neighboorhood early in the morning or late at night.

I won't go through the trouble of removing the SC gears, but if I had it to do again I wouldn't have installed them.

I'm trying to figure out what oil temp probe I want to go with. It's between a few of them, but there's one that goes in where the oil drain plug is, and I'm contemplating that one.

I've already got a X-pin diff on the list of parts. It's going to happen.

Looking like I'll go straight cut for the box, and posibly the FD, but not drop gears.

A well built 1380 has enough power to ruin the drop gear bearings. That is why I chose the SC drop gear. It has a huge bearing ,if you can get that on a helicut gear all the better. You can hear the gear box chatter over the exhaust note. The X pin diff is also a good idea.I also added a layshaft support bearing. And while your playing with the box,add a oil temp probe. Mine enters through the speedo housing. So far we have not seen that the oil temp is getting up to a good working temp. So no oil cooler is needed.

I would agree with this your thought here.  Even the Turbo Mini's forums are debating about High power- High torque and are SC gears needed. There are some very successful cars 125+ HP  Turbo and SC  running standard A+ Boxes with no issue.

Among all  - increased HP or output  with better relability i would consider an upraated Differential among all  X pin Diff that is...

Personally - NO high powered minis Here - and have only heard SC Gearsets passing by-  Too loud for daily Pleasure for me... 

So is there really that much benefit of SC drop gears with a moderately built 1380? Or should the noise be reserved for those who want the "cool sound" and the occasional supremely built engine?

A straight cut box is quiet in fourth gear - the whine goes away.

Straight cut drops are just LOUD ALL THE TIME.
AND I MEAN REALLY REALLY LOUD.

Somewhere I've got video of the six Goodwood Minis driving past the pits taken from on top of the pits.  The howl from Liams drops can be heard over the crowd and the tannoy.

Thanks for the input, guys. I'm trying to find video or audio of someone with straight cut gears but not drop gears. And I'm just sort of curious what it sounds. How much louder are the drop gears and SC gearbox than the gearbox alone?

 

Do the SC gears for the box only come in close ratio? And how does this affect daily driving? I understand the basic concept of close ratio gears, but I'm no gearing expert, so my simpleton assumption is that the close ratio gears would shorten the effective range of power. i.e. losing either top end or low end to some degree.

Smurf - yes, I have pistons, rings, new crank, cam, exhaust, and a few other things sitting and waiting to go when I start machining on the motor.

I would do the straight cut gears but not the straight cut drops. The straight cut drops will way too loud. I would also consider a 3.2 FD because it is a good compromise between th 3.44 and 3.1. I have a BRAND NEW 3.2 final drive if you are interested. I was going to use it on my build but I went with a Jack Knight NOS 5 speed instead.

My understanding on the pros/cons between straight/helical is the following: Straight cut will be louder (pro for some, con for others) Straight cut will wear more quickly due to the stresses of the sudden load as each tooth comes under load, rather than the gradual load shift which is also what makes helical quieter. Helical places side load on the gear sets, forcing the mated gears apart, which is a problem with a high power setup (I've heard conflicting info as to what constitutes too high power for helical).

As I understand, the straight cut gear box shouldn't be any different to shift. It will be quieter than straight cut drop gears, since the transmission gears are bathed in oil.

I have a full set of SC gears in my Cooper S. They are very noisy and at low speed and on over run they give a herky-jerky action. In retrospect I would not do it and when and if I need to do the transmission I will change back. On the plus side, since the teeth are at right angles to the gear there is no side thrust and you get less power loss. The loss with helical gears is the sine or cosine of the helical angle whatever that works out to be. BTW modern transmissions are constant mesh where the gears are always meshed so shifting is not affected by SC gears.

Did you ever buy some 73.5 pistons?

So it's that phase. Thinking about what I want to do in the 1380 I'm building. Do I want a 3.1 FD? Do I want it full straight cut? Helical? Semi?

What about the gears IN the box. What's the pro/con analysis on straight cut vs standard gears? Harder to get a good shift with straight cut gears? Worth the money on a 1380 with a Kent

Drop gears? I know the benefits here, and quite honestly, it's looking like I'm probably going to be getting SC Drop Gears.

 

So what's your take?