26 replies to this topic

[DeadSquare]

 

I was thinking how would a chain cope instead of the drop gears? This could remove the idler and get the gearbox to run in reverse while the engine still running forwards.

Chains have been used in many engines to transfer power from Crank to gear box. The Saab 2.2 engine being one. It used a triplex chain IIRC. Back in the 80s there was talk of a chap in Greenfield that had done a chain drive to replace the Mini Drops. Never found him or any other info. Not sure it was a Mini engine though.

 

A Saab 2.2 engine in a Mini won the "Trafficlights GP" every time, (depending on wheel-spin).

 

I found that it had a very strong desire to continue straight on, at corners.

[nicklouse]

 

 

I was thinking how would a chain cope instead of the drop gears? This could remove the idler and get the gearbox to run in reverse while the engine still running forwards.

Chains have been used in many engines to transfer power from Crank to gear box. The Saab 2.2 engine being one. It used a triplex chain IIRC. Back in the 80s there was talk of a chap in Greenfield that had done a chain drive to replace the Mini Drops. Never found him or any other info. Not sure it was a Mini engine though.

 

A Saab 2.2 engine in a Mini won the "Trafficlights GP" every time, (depending on wheel-spin).

 

I found that it had a very strong desire to continue straight on, at corners.

 

One guy at Saab put one in the back of an Imp.

[gazza82]

I could be wrong but a few year ago I thought I read something that said when the A series was first developed it was designed as a diesel not petrol and ran the other way.

As I say this was something I read years ago and I could have my wires crossed.

Obviously any work that has been done to the engine including A plus has stuck with petrol fuel since then.

That was never done for transverse orientation. the A diesel was put and can still be found in some Tractors and was also modified as a marine units.

Photos of the prototype "Mini" has the engine in the opposite direction with the carb and manifolds at the front. It also had a vertical rad grille a bit like the A30/A35 that came before it to disguise it when being road-tested:

https://www.theminif...mini-prototype-

Edited by gazza82, 26 March 2023 - 04:04 PM.

[gazza82]

I could be wrong but a few year ago I thought I read something that said when the A series was first developed it was designed as a diesel not petrol and ran the other way.

As I say this was something I read years ago and I could have my wires crossed.

Obviously any work that has been done to the engine including A plus has stuck with petrol fuel since then.

That was never done for transverse orientation. the A diesel was put and can still be found in some Tractors and was also modified as a marine units.

Photos of the prototype "Mini" has the engine in the opposite direction with the carb and manifolds at the front. It also had a vertical rad grille a bit like the A30/A35 that came before it to disguise it when being road-tested:

https://www.theminif...mini-prototype-

That would suggest that it also had a different gearbox system as the engine would still rotate clockwise but that would be backwards if a direct drive.

[DeadSquare]

 

 

 

I could be wrong but a few year ago I thought I read something that said when the A series was first developed it was designed as a diesel not petrol and ran the other way.

As I say this was something I read years ago and I could have my wires crossed.

Obviously any work that has been done to the engine including A plus has stuck with petrol fuel since then.

That was never done for transverse orientation. the A diesel was put and can still be found in some Tractors and was also modified as a marine units.

Photos of the prototype "Mini" has the engine in the opposite direction with the carb and manifolds at the front. It also had a vertical rad grille a bit like the A30/A35 that came before it to disguise it when being road-tested:

https://www.theminif...mini-prototype-

That would suggest that it also had a different gearbox system as the engine would still rotate clockwise but that would be backwards if a direct drive.

 

 

The prototype in the A35, drove straight from the crankshaft to the gearbox, without the idler gear.

[Spider]

The Orange Box (the prototype referred to above) had no idler gear, it came off the primary gear and drove in to the input gear of the gearbox.

An issue they did find here was that these gears were rather large in size and also on the heavy side. With the inertial they built up, this made for quite slow gear shifting and caused very heavy wear of the cones in the gearbox.

[DeadSquare]

I have also wanted to drive a gearbox  "in reverse", and the nearest that I have come to a theoretical solution is to get busy with a welder and:-

 

A)  Make a shaft that can be welded inside the lay shaft, and extend through the end web into the transfer case with splines to take a gear that will mesh with the drop gear.

 

B)  Build up the end web and machine it to take a substantial bearing for the new lay shaft, to run through, and something similar at the centre web.

 

C)  Modify the transfer case and gearbox by the oil plug to allow room for the new gear that drives the lay shaft.

 

There is not a lot of room for a gear in this position, so it would be a smaller diameter than the existing one on the first motion shaft, thus increasing the RPM of the gearbox which would mean higher friction losses, but  hopefully the overall gearing would not be too high with a 4.63 diff ratio.

[KTS]

..why not simply (?!?!) replace the crown and pinion gears with a chain drive ?

[Spider]

I like the chain driven final drive idea.

 

 

I have also wanted to drive a gearbox  "in reverse", and the nearest that I have come to a theoretical solution is to get busy with a welder and:-

 

A)  Make a shaft that can be welded inside the lay shaft, and extend through the end web into the transfer case with splines to take a gear that will mesh with the drop gear.

 

B)  Build up the end web and machine it to take a substantial bearing for the new lay shaft, to run through, and something similar at the centre web.

 

C)  Modify the transfer case and gearbox by the oil plug to allow room for the new gear that drives the lay shaft.

 

There is not a lot of room for a gear in this position, so it would be a smaller diameter than the existing one on the first motion shaft, thus increasing the RPM of the gearbox which would mean higher friction losses, but  hopefully the overall gearing would not be too high with a 4.63 diff ratio.

 

I've had similar ideas over the years but for different reasons. Rather than weld a shaft in to the Laygear though, I had thoughts of internal splining the large end of the Laygear and having a separate shaft. Make for easier assembly

[Jon9379]

..why not simply (?!?!) replace the crown and pinion gears with a chain drive ?

Thank you KTS.

I knew there was a better way of doing it, just couldn't think how to do it.

[mab01uk]

 

 

 

 

I could be wrong but a few year ago I thought I read something that said when the A series was first developed it was designed as a diesel not petrol and ran the other way.

As I say this was something I read years ago and I could have my wires crossed.

Obviously any work that has been done to the engine including A plus has stuck with petrol fuel since then.

That was never done for transverse orientation. the A diesel was put and can still be found in some Tractors and was also modified as a marine units.

Photos of the prototype "Mini" has the engine in the opposite direction with the carb and manifolds at the front. It also had a vertical rad grille a bit like the A30/A35 that came before it to disguise it when being road-tested:

https://www.theminif...mini-prototype-

That would suggest that it also had a different gearbox system as the engine would still rotate clockwise but that would be backwards if a direct drive.

 

 

The prototype in the A35, drove straight from the crankshaft to the gearbox, without the idler gear.

 

 

Photos below of the early 'Orange Box' Mini prototype added for reference.

 

Edited by mab01uk, 29 March 2023 - 08:02 AM.

[DeadSquare]

 

..why not simply (?!?!) replace the crown and pinion gears with a chain drive ?

Thank you KTS.

I knew there was a better way of doing it, just couldn't think how to do it.

 

Please  tell  us  how  you  get  on with  your  chain  drive.