Hensen1954
Active Member
What you lot been drinking ? Mad buggers.
Video may help.........
http://www.youtube.com/watch?v=vWEpJ5OUC2s
Video may help.........
http://www.youtube.com/watch?v=vWEpJ5OUC2s
Bright ideas needed, please.
- Thread starter Hensen1954
- Start date
colnerov
Well-Known Member
Hi, Good stuff!! As this is a design exercise. Could I suggest using a Range Rover ZF 4 speed
Auto with its transfer box? this will do two things 1) The main box is shorter than the BW35 you
presently have. 2 )The transfer box will drop the drive some way as standard, making the prop
shaft angle shallower. This will also save you time and money constructing a drop box and will look
less heath robinson, No offence meant! If you want some measurements from this set up let me
know as I have one of these on the workshop floor.
If you were tempted use this set up in earnest I would have reservations about putting the power from
the first two engines (300bhp) through the nose of the third crankshaft.
Keep up the good work!
Colin
Auto with its transfer box? this will do two things 1) The main box is shorter than the BW35 you
presently have. 2 )The transfer box will drop the drive some way as standard, making the prop
shaft angle shallower. This will also save you time and money constructing a drop box and will look
less heath robinson, No offence meant! If you want some measurements from this set up let me
know as I have one of these on the workshop floor.
If you were tempted use this set up in earnest I would have reservations about putting the power from
the first two engines (300bhp) through the nose of the third crankshaft.
Keep up the good work!
Colin
Another offering....
The main problem I see is in drive shaft droop angles and alignment between the engines and boxes and the diff. So rather than trying to get the drive down to the axle, why not bring the diff up to the level of the engines and transmission?
You are going to have to fit twin rear wheels (?...) so there is going to be some messing around with the outer ends of the axle to accomodate anyway.
So mount a further axle fixed solidly at engine level on top of the chassis rails. Then take drive chains from the hub flanges of the second axle down to sprockets mounted between the hubs and wheels of the road axle!
This also makes it rather simpler to mount a new transmission when the dear old Borg Warner expires after the second run (first run?).
Nice vintage feel to the result and you've halved the torque loading on the drive chains.
Chris
The main problem I see is in drive shaft droop angles and alignment between the engines and boxes and the diff. So rather than trying to get the drive down to the axle, why not bring the diff up to the level of the engines and transmission?
You are going to have to fit twin rear wheels (?...) so there is going to be some messing around with the outer ends of the axle to accomodate anyway.
So mount a further axle fixed solidly at engine level on top of the chassis rails. Then take drive chains from the hub flanges of the second axle down to sprockets mounted between the hubs and wheels of the road axle!
This also makes it rather simpler to mount a new transmission when the dear old Borg Warner expires after the second run (first run?).
Nice vintage feel to the result and you've halved the torque loading on the drive chains.
Chris
Hensen1954
Active Member
Hi, Good stuff!! As this is a design exercise. Could I suggest using a Range Rover ZF 4 speed
Auto with its transfer box? this will do two things 1) The main box is shorter than the BW35 you
presently have. 2 )The transfer box will drop the drive some way as standard, making the prop
shaft angle shallower. This will also save you time and money constructing a drop box and will look
less heath robinson, No offence meant! If you want some measurements from this set up let me
know as I have one of these on the workshop floor.
If you were tempted use this set up in earnest I would have reservations about putting the power from
the first two engines (300bhp) through the nose of the third crankshaft.
Keep up the good work!
Colin
colnerov
Posts: 789
Joined: Sun Mar 21, 2010 9:01 pm
Location: Nr Gatwick
Yes please Colin. Have not made gearbox mounts yet, so can change direction easily. Am wondering how much shorter the gearbox part is, and how much the transfer box drops the output shaft.
Auto with its transfer box? this will do two things 1) The main box is shorter than the BW35 you
presently have. 2 )The transfer box will drop the drive some way as standard, making the prop
shaft angle shallower. This will also save you time and money constructing a drop box and will look
less heath robinson, No offence meant! If you want some measurements from this set up let me
know as I have one of these on the workshop floor.
If you were tempted use this set up in earnest I would have reservations about putting the power from
the first two engines (300bhp) through the nose of the third crankshaft.
Keep up the good work!
Colin
colnerov
Posts: 789
Joined: Sun Mar 21, 2010 9:01 pm
Location: Nr Gatwick
Yes please Colin. Have not made gearbox mounts yet, so can change direction easily. Am wondering how much shorter the gearbox part is, and how much the transfer box drops the output shaft.
colnerov
Well-Known Member
Hi, Hensen1954. It might be a couple of days due to work commitments. What Chrisyork and
Ghce are suggesting (as you are probably aware) is a portal axle which are made and used by
both Volvo and Mercedes, but I am not sure you have enough room around the chassis area.
But I take there point about doing the drop on the axle, perhaps a bearing carrier and fitments
fixed to the top of the axle and going down to the diff flange.
Chris, this would as you say share the load over 2 sets of chains but the diff ratio would be
multiplying the torque.
Colin
Ghce are suggesting (as you are probably aware) is a portal axle which are made and used by
both Volvo and Mercedes, but I am not sure you have enough room around the chassis area.
But I take there point about doing the drop on the axle, perhaps a bearing carrier and fitments
fixed to the top of the axle and going down to the diff flange.
Chris, this would as you say share the load over 2 sets of chains but the diff ratio would be
multiplying the torque.
Colin
Hi Colin
Not quite.
I'm familiar with the idea of a portal axle - I've run Unimogs which have this in order to raise the axle line out of range of ground obstacles.
What I was proposing was having two seperate axles. The current one in the current location, with a second mounted at chassis level. This axle could be mounted well behind the line of the current axle so that the chain drive from there to the road axle wheels could lie at a decent angle to accomodate the vertical movement of the road axle. (It doesn't matter in this case that the chain is driving "forwards", both sets of sprockets are still driving in the same direction.)
What none of you seem to have factored in is that any mechanism to drop the drive to the level of the road axle still leaves you with an uncceptably short prop from there to the road axle. This will not allow the road axle any vertical movement as it moves on its springs without very large plunge angle changes on the short prop.
The overall effect is similar to that seen on veteran, ie 1905 era, supercars.
Chris
Not quite.
I'm familiar with the idea of a portal axle - I've run Unimogs which have this in order to raise the axle line out of range of ground obstacles.
What I was proposing was having two seperate axles. The current one in the current location, with a second mounted at chassis level. This axle could be mounted well behind the line of the current axle so that the chain drive from there to the road axle wheels could lie at a decent angle to accomodate the vertical movement of the road axle. (It doesn't matter in this case that the chain is driving "forwards", both sets of sprockets are still driving in the same direction.)
What none of you seem to have factored in is that any mechanism to drop the drive to the level of the road axle still leaves you with an uncceptably short prop from there to the road axle. This will not allow the road axle any vertical movement as it moves on its springs without very large plunge angle changes on the short prop.
The overall effect is similar to that seen on veteran, ie 1905 era, supercars.
Chris
There is a seperate issue with the torque capacity of the dear old Borg Warner, which won't be addressed by using the ZF instead. Those three V8's could potentailly be pumping 450bhp, whch is amply sufficient to send any transmission already in use against the Rover V8 into a terminal smoke out.
I have a couple of ideas, but they need input from Harvey.
As far as the actual box internals are concerned the damaging event will be changing gear under load. I could visualise the box surviving the power and torque provided it didn't do that. With the famous low rpm torque of the Rover V8, I could imagine that with three of them you don't really need a gearbox at all to get under way briskly. So why not lock the gearbox in one gear - either second or top (or equivalent on a four speed). Then the torque convertor is doing the work of getting away from rest. Question is, will the torque convertor take the strain? It might provided it had a really effective oil cooler. But we need a comment from Harvey.
Alternatively, modify the box so that it can only change gear to a manual intervention. Dragsters use this method, replacing the fundtion of the hydraulic controls by a conventional change lever. Then you can be sure to throttle off whilst the gear change takes place. Without this mod the gearbox will decide for itself when to change, which inevitably will be unnder full power. You can certainly get aftermarket kits to do this for the GM180 box used behind the V8 in the SD1.
Chris
I have a couple of ideas, but they need input from Harvey.
As far as the actual box internals are concerned the damaging event will be changing gear under load. I could visualise the box surviving the power and torque provided it didn't do that. With the famous low rpm torque of the Rover V8, I could imagine that with three of them you don't really need a gearbox at all to get under way briskly. So why not lock the gearbox in one gear - either second or top (or equivalent on a four speed). Then the torque convertor is doing the work of getting away from rest. Question is, will the torque convertor take the strain? It might provided it had a really effective oil cooler. But we need a comment from Harvey.
Alternatively, modify the box so that it can only change gear to a manual intervention. Dragsters use this method, replacing the fundtion of the hydraulic controls by a conventional change lever. Then you can be sure to throttle off whilst the gear change takes place. Without this mod the gearbox will decide for itself when to change, which inevitably will be unnder full power. You can certainly get aftermarket kits to do this for the GM180 box used behind the V8 in the SD1.
Chris
My suggestion in pictoral form
Google 6x6 axle for more examples, variations and off the shelf units.
I would rather see the transfer box unit integrated into the differential housing. This route allows future transmission changes, and a longer propshaft that would run at a gentler angle, although still rather steep but look at some of the extreme off-road stuff out there that run high lifts.
Google 6x6 axle for more examples, variations and off the shelf units.
I would rather see the transfer box unit integrated into the differential housing. This route allows future transmission changes, and a longer propshaft that would run at a gentler angle, although still rather steep but look at some of the extreme off-road stuff out there that run high lifts.
Hensen1954
Active Member
Hold on everybody, you seen to have ignored the information in the video. The gearbox will probably never see even 100bhp. As explained, it is for shows, not the drag strip. And even if all 400bhp was used, the 4" artillery tyres would just spin, taking any strain off the gearbox etc. I doubt the car will ever see 60mph, and actually maybe only trundle along at 40mph or less.
Hensen1954 said:
This is where clearly defining the design aspects and criteria is essential, I am on a terribly slow internet connection and cannot view many videos because of the time it takes to load, then I'm on rubbish headphones that barely work I cannot be the only one like this.
It would help if you stated a rough budget, as some suggestions would clearly require serious money, whilst others are more realistic, also what skills you have, where your comfort zone is, and are you prepared to push your knowledge and experience further?
For large projects like this, are you fully aware of the UK rules and regs regarding vehicle registration and ID with DVLA and VOSA, and for everyone interested, a little background into the inspiration and research for this project, why you've chosen that particular chassis and other aspects of the build, engine height, etc.
I for one LOVE aero engined cars and vintage engineering, and would love to see this project completed and running.
colnerov
Well-Known Member
Hi, sowen. I remember those 6 wheel drive Range Rovers, usually fire tenders, but I seem to remember
they were bespoke items and would hard to find and expensive, if you could convince them to sell you it.
Chris, sorry I misunderstood what you were saying (not now). However if the diff ratio is 4 to 1 the half
shafts 'see' 4 times the torque that the propshaft does. What could be done is turn the axle so the diff
flange faces rearwards and have a transfer box at the rear of the chassis from something like a LR 101
forward control gun tractor which had a prop flange out of the PTO to take drive to the towed gun or
trailer. So one has the power from the gearbox and the lower one comes forward to the axle, careful
positioning it would keep prop angles shallow. I also agree about that the gearbox could be dispensed with.
When I worked at the bus company the vehicles had fluid flywheels which had a flange out of the centre
and only used the oil contained in it, i.e. not pumped at all, which was then connected to a separate
epicyclic gearbox.
Hensen1954, The only thing that limits what the gearbox sees is your right foot. Even if you only use a light
throttle and medium revs that is still 600 lbs of torque. But as you say very narrow tyres will spin up, in fact
it could be difficult to attain any sort of speed easily and drama free.
I have to say I am enjoying all this discussion and bouncing ideas around.
Colin
they were bespoke items and would hard to find and expensive, if you could convince them to sell you it.
Chris, sorry I misunderstood what you were saying (not now). However if the diff ratio is 4 to 1 the half
shafts 'see' 4 times the torque that the propshaft does. What could be done is turn the axle so the diff
flange faces rearwards and have a transfer box at the rear of the chassis from something like a LR 101
forward control gun tractor which had a prop flange out of the PTO to take drive to the towed gun or
trailer. So one has the power from the gearbox and the lower one comes forward to the axle, careful
positioning it would keep prop angles shallow. I also agree about that the gearbox could be dispensed with.
When I worked at the bus company the vehicles had fluid flywheels which had a flange out of the centre
and only used the oil contained in it, i.e. not pumped at all, which was then connected to a separate
epicyclic gearbox.
Hensen1954, The only thing that limits what the gearbox sees is your right foot. Even if you only use a light
throttle and medium revs that is still 600 lbs of torque. But as you say very narrow tyres will spin up, in fact
it could be difficult to attain any sort of speed easily and drama free.
I have to say I am enjoying all this discussion and bouncing ideas around.
Colin
colnerov said:
My understanding of the Range Rover and other 6x6 Land Rover conversions are that the majority of them are selectable, in that they run the third driven axle off the pto. The axle family also looks different, so even finding a Land Rover 6x6 unit it would not be bolt on.
Much of this build is bespoke, so finding potential donors for working parts and other examples of similar setups is key to moving forward with a realistic and viable plan of attack.
Hi Colin
I'm sure the key to this conundrum is to gain more distance to permit shallower prop angles. I like the idea of taking the prop to well behind the axle - dropping gently all the while - and then having a "round the corner" box similar to what Steve photo'd on the 6WD to get the drive down to axle level. Just need to crack the direction of travel issue, but I've employed reversing boxes within the driveline before now - just need to find one!
Chris
I'm sure the key to this conundrum is to gain more distance to permit shallower prop angles. I like the idea of taking the prop to well behind the axle - dropping gently all the while - and then having a "round the corner" box similar to what Steve photo'd on the 6WD to get the drive down to axle level. Just need to crack the direction of travel issue, but I've employed reversing boxes within the driveline before now - just need to find one!
Chris
Hensen1954
Active Member
Sorry, I thought most people had seen my original post from before Xmas, here it is..
viewtopic.php?f=20&t=14815
One point, I am going for artillery wheels, so bought some in haste, only to find that I made a boo boo. Said wheels only came in 2 sizes, 19 and 21 inches, 19 for cars etc, and 21 for omnibuses etc.
Anyway, its gonna cost, but I have found that I can have new rims of my choice sent from New Zealand , where they have a huge rim factory, and mate them up - with some machine work - to a set of new - yes new, 10 spoke solid alloy wheels as made in the north of the good old UK.
Regardez vous.....
http://www.dragondriving.co.uk/harnessf ... 13996.html
Probably cost about £1500 for the 5 with tyres, but should look fantastic.
viewtopic.php?f=20&t=14815
One point, I am going for artillery wheels, so bought some in haste, only to find that I made a boo boo. Said wheels only came in 2 sizes, 19 and 21 inches, 19 for cars etc, and 21 for omnibuses etc.
Anyway, its gonna cost, but I have found that I can have new rims of my choice sent from New Zealand , where they have a huge rim factory, and mate them up - with some machine work - to a set of new - yes new, 10 spoke solid alloy wheels as made in the north of the good old UK.
Regardez vous.....
http://www.dragondriving.co.uk/harnessf ... 13996.html
Probably cost about £1500 for the 5 with tyres, but should look fantastic.
I had another think about the driveline problem last night.
The basic problem is that your current take off from the engines/gearbox is too far back in the chassis.
So why not take off the power from the engines between the 2nd and 3rd engines? There is a happy by product of this in that the crank of the third engine has much less power to transmit so is less likely to break!
You still need your chain drive - unless anyone can think of a neat way of using a L/R transfer box to drive backwards? - but you then have a second lower transmission axis starting below the third engine. That ought to be far enough forward to get a decent drive axis slope back to the diff and give you enough space to include a gearbox straight behind and below the third engine.
Chris
The basic problem is that your current take off from the engines/gearbox is too far back in the chassis.
So why not take off the power from the engines between the 2nd and 3rd engines? There is a happy by product of this in that the crank of the third engine has much less power to transmit so is less likely to break!
You still need your chain drive - unless anyone can think of a neat way of using a L/R transfer box to drive backwards? - but you then have a second lower transmission axis starting below the third engine. That ought to be far enough forward to get a decent drive axis slope back to the diff and give you enough space to include a gearbox straight behind and below the third engine.
Chris
Willy Eckerslyke
Well-Known Member
I almost hate to suggest this, but as there's no intention to use the full power, a lot of effort could be saved by only having one engine driving the thing. The other two could still be running in sync, throttle controls connected, etc, so the sound effects would be there. Some sort of dummy casings between each engine would obscure the reality and nobody'd know any better.chrisyork said:
Hensen1954
Active Member
Yes, I did think of using just one engine, and actually cheating by lowering the driving one down for a straight prop - - - - but its cheating, so does not rest easily with me. Prefer to go the long route and at least be honest to the public.
colnerov
Well-Known Member
Chris. Regarding some thing you said yesterday and again today, the LR/RR transfer box
would not be required to reverse direction of rotation, to drive the turned axle in the
forward direction.
Hensen. Quite right!! If it has three engines they all have to work.
The LR/RR transfer box has high and low range, so could this be used
as a gearbox? A method of controlling the power delivery from the engine(s) is needed. I
thought about either a epicyclic gear cluster with a brake band as a method of control or
better still a multi plate clutch, which would have the added benefit of being better able
to handle the power and torque for a given size. This would remove the need for the auto
box and being manual would be more suited to the style of the vehicle.
Colin
would not be required to reverse direction of rotation, to drive the turned axle in the
forward direction.
Hensen. Quite right!! If it has three engines they all have to work.
The LR/RR transfer box has high and low range, so could this be used
as a gearbox? A method of controlling the power delivery from the engine(s) is needed. I
thought about either a epicyclic gear cluster with a brake band as a method of control or
better still a multi plate clutch, which would have the added benefit of being better able
to handle the power and torque for a given size. This would remove the need for the auto
box and being manual would be more suited to the style of the vehicle.
Colin