Board logo

Mini Gearchange
garethpowys - 28/10/02 at 07:36 PM

Guys,

My plan is to use a Mini engine and tranny in a middy layout. Anybody ever built anything similar? Ifso how was the gear shift operated?

I know it's been done a lot - Terrapin, Landar, Cox GTM, Freestyle, NCF Blitz, etc. So it can't be too hard.

Cheers,

Gareth

Alan B - 28/10/02 at 10:03 PM

Gareth, have you studied the Terrapin gear change? It's quite complex, although it must work I guess.

I'd think I'd look at cables personally. I've done rod changes and play and inertia are big isssues.

gholman - 29/10/02 at 03:21 AM

why dont you try to find a newer engine with current emmission standards and unleaded fuel. definately try morse cables not pushrods unless you aim to fit the engine without rubber mounts.

garethpowys - 31/10/02 at 04:59 PM

quote:
Originally posted by gholman
why dont you try to find a newer engine with current emmission standards and unleaded fuel. definately try morse cables not pushrods unless you aim to fit the engine without rubber mounts.


I want this to be a truly "locost" build, since I already have a complete Mini out the back buying another engine would be an additional financial outlay.

Emissions standards aren't a big issue, it's an 82 engine and documented so it only has to comply with 82 emissions standars - which it does with ease.

Unleaded fuel isn't much of an issue. I can get a head from a later unleaded engine (1990-2000 ish) cheaply from a scrappy.

As for solid mounting the engine I've done it in a Mini before. Made it a bit noisy in the cabin, but is shouldn't be as much of an issue in an open top with the engine behind you.

Oh and I've got hold of a build manual for a Freestyle with quite a neat single rod solution.

Cheers,

Gareth

interestedparty - 31/10/02 at 05:04 PM

I'd like to have a look at the freestyle gearchange, any chance of you posting a piccy?

John

garethpowys - 31/10/02 at 09:17 PM

quote:
Originally posted by interestedparty
I'd like to have a look at the freestyle gearchange, any chance of you posting a piccy?

John


Hi John,

This is the image from the build manual. Hope this is clear enough without the text.

Gareth Rescued attachment freestyle shift.gif
Rescued attachment freestyle shift.gif

interestedparty - 31/10/02 at 10:10 PM

Yes, it's about what I thought it would be, in essence the gear selector output rod and the gearbox input are in line,trouble is the gearbox is in the way, so the selector rod is cranked down under the gearbox. I'll have a look at doint that on mine, even though the gearbox input is over to the left of the car, might still work
Thanks

John

gholman - 3/11/02 at 10:41 PM

I havent worked on a BMC for ages (thankyou Lord!) but...didnt the Austin Kimberley and Tasman have a morse cable linkage from the gearstick, maybe you could match them up with a longer cable if the linkages dont work. My Kimberelywas bored out the fit Australian Holden pistons (pommy stuff too expensive!) but with all the engine mods and additional torsion bar it would beat the 6cyl x-flow cortina's. Triple Su's helped and a straight through exhaust with headers, double clutch plates and landrover master and slave clutch cylinders.
Cheers from Bunbury, West Australia.

TheGecko - 4/11/02 at 03:56 AM

My car will use a Corolla FWD box mounted in the back and I intend to use as much of the Corolla gearshift mechanism as possible. Toyota uses a pair of cables, one of which rotates the selector shaft through a simple crank-arm. The other moves the shaft in-and-out with a bell-crank type of deal. If it would help anyone, I can probably post some pics of the gearbox with cables attached as well as some scans from the relevant workshop manual pages showing the relationship of all the bits. So it may be possible to pull the gearshift from a Corolla and modify it for the Mini box.

Hope this helps,

Dominic

interestedparty - 4/11/02 at 07:49 AM

quote:
Originally posted by TheGecko
If it would help anyone, I can probably post some pics of the gearbox with cables attached as well as some scans from the relevant workshop manual pages showing the relationship of all the bits. So it may be possible to pull the gearshift from a Corolla and modify it for the Mini box.


It would help me, yes please

John

TheGecko - 4/11/02 at 09:03 AM

quote:
Originally posted by interestedparty
It would help me, yes please


John,

I can't get at the gearbox easily right now but here are three scans from the wokshop manual.

Photo 1 is looking down at the selectors on the gearbox Note that the caption saying "SELECTOR LEVERS" actually points at the selector shaft on the right and a support bracket on the left.



Photo 2 is the lever mechanism. The one shown is a big plastic moulding (yuk!) but the one I have from a Jap market 20-valve Corolla is a pressed metal assembly.



Photo 3 is the actual selector shaft from the gearbox which shows the cranked end. The upper cable in Photo 1 is acting on that crank to rotate the shaft. The other cable works through the bell-crank visible in Photo 1 and slides the shaft in-and-out with a fork that engages on the narrowed part at the left of the shaft.



Hope this is helpful. Feel free to ask for more clarification if needed.

Dominic

interestedparty - 4/11/02 at 11:25 AM

Excellent pics, thanks, Dominic. I think I've got it. If I understand the motions correctly then the upper cable in the first picture is the nearest cable in the second picture, in that it transfers side to side motion of the gearleer into rotary motion at the selector shaft
I now need to consider the reverse detent mechanism (built into the Ford rod remote on my donor.) I might try machining a Ferarri style gate for the gearlever, and build a reverse-guard into that
Thanks

John

garethpowys - 4/11/02 at 11:51 AM

Dominic,

Thanks for that. I can see how that might be adapted to a Mini shift quite easilly. I should be able to put something togerther based on the mini remote housing. The only trick would be finding suitable cables, anybody know of a rear engined car with a cable linkage gearchange. Or maybe I could use clutch cables from a rear engined car.

The other alternative is something an AA man once used on my old Renault 5. The clutch cable went (as they do) and he used a temporary cable. Basically, IIRC this was a cable that he cut to length and then attached clamp on nipple ends to suit. It all came in a kit. Anybody know where I could get such a kit and how much it would cost? Sounds ideal for the job if it doesn't cost too much.

Gareth

TheGecko - 4/11/02 at 12:21 PM

quote:
Originally posted by interestedparty
If I understand the motions correctly then the upper cable in the first picture is the nearest cable in the second picture, in that it transfers side to side motion of the gearleer into rotary motion at the selector shaft
I now need to consider the reverse detent mechanism (built into the Ford rod remote on my donor.) I might try machining a Ferarri style gate for the gearlever, and build a reverse-guard into that


John,

Without dragging my gearbox and cables out of the corner of the garage I can't verify which cable is which but I'm pretty confident you're right.

Re the reverse detent; I think a nice machined and polished gate would not be out of place

Dominic

TheGecko - 4/11/02 at 12:32 PM

quote:
Originally posted by garethpowys
The only trick would be finding suitable cables, anybody know of a rear engined car with a cable linkage gearchange. Or maybe I could use clutch cables from a rear engined car.


Gareth,

You should be able to find a company that'll make cables to suit, particularly if you supply the existing ends. I know of a couple of places here that do that sort of work. The category to search under in the Yellow Pages is Cables - Mechanical. The best known company in the field is Morse Controls who have offices everywhere. Phone around and you'll find a solution.

Hope this was helpful,

Dominic

Alan B - 4/11/02 at 01:04 PM

You may also want to see the MR2 version of the shift bracket.

click here for MR2 gearchange

TheGecko - 4/11/02 at 01:23 PM

quote:
Originally posted by Alan B
You may also want to see the MR2 version of the shift bracket.


Thanks for that Alan, that looks a lot moe like the ones I've got than the workshop manual photo.

Another point I should have put in my reply about cables: these sort of cables are used extensively for throttle & steering in boats and custom lengths are always needed to suit different hull/engine combinations. So, try maritime repairers/suppliers.

Dominic

Alan B - 4/11/02 at 01:48 PM

Cable links:

http://www.controlcables.com/cables.htm
http://www.hersinc.net/Push-Pull%20cables.htm
http://www.uflexusa.com/

Ok, all US, but Dominic is right they are readily available...I think Morse and Teleflex are the most wel known.

After that it isn't much more difficult than than a regular gearchange extension.

interestedparty - 4/11/02 at 03:44 PM

Alan, what is all that brownish/red stuff on your gearchange? Did somone spill something on it?

Thanks for the pic BTW, I guess the other end is similar to Dominic's?

John

Alan B - 4/11/02 at 04:56 PM

Just plain old rust John!
No plating on the part....maybe someone spilled a drink sometime?

Yes the other end is very similar to Domincs pic. I'll post something when I can find a good pic.

Alan B - 4/11/02 at 05:07 PM

Ok this is it.

theconrodkid - 4/11/02 at 08:10 PM

re clutch cables i know peeps who "work" for aa and rac,mail me with what you want and i can post you some.

TheGecko - 30/1/03 at 07:55 AM

Hi all,

Further to the discussion on this topic back in November - I've just come across a nicely detailed set of photos and drawings for a scratch built shift linkage - Link. In this case, it's for an Audi 5000 'box in a Lambo replica but the principle is the same: two cables and a linkage that gives both rotary and in-out motion to the selector shaft on the box.

For what it's worth.

Dominic