DIY Electric Car Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter #1
Hi

I have a little 2 seater MG MGF and am planning to convert it from ICE to twin engine hybrid.

The cars mechanics are based on the Austin Metro (princess Diana had one) and later updated Rover 100 which were originally planned to replace the iconic Mini.

The engineers took the power unit that is mounted on a subframe out of the front of the car and mounted it just foward of the rear axle creating a fun little 2 seater sports convertible. They then used a second front subframe at the front just to mount the suspension, steering and brakes.

Under the bonnet (hood) is a spare wheel and the radiator and lots of space.

My plan is to fit some sort of electric motive unit under the bonnet utilising the hubs and drive shafts of a Austin Metro/Rover 100. I could also use the gearbox as well if that is the way to go.

For batteries I am thinking of creating a vertical stack of lithium AA batteries that fit behind the driver and passenger seats.

I happily engineering solutions and can happily create mountings, brackets etc and can arc and mig weld.

My original idea was to attach a forklift motor to a gear box and some drive shafts and mount it all in the subframe. However the more I read the more confused I become.

Any pointers or advice much appreciated.
 

·
Registered
Joined
·
5,056 Posts
I have a little 2 seater MG MGF and am planning to convert it from ICE to twin engine hybrid.

The cars mechanics are based on the Austin Metro (princess Diana had one) and later updated Rover 100 which were originally planned to replace the iconic Mini.

The engineers took the power unit that is mounted on a subframe out of the front of the car and mounted it just foward of the rear axle creating a fun little 2 seater sports convertible. They then used a second front subframe at the front just to mount the suspension, steering and brakes.

Under the bonnet (hood) is a spare wheel and the radiator and lots of space.

My plan is to fit some sort of electric motive unit under the bonnet utilising the hubs and drive shafts of a Austin Metro/Rover 100. I could also use the gearbox as well if that is the way to go.

For batteries I am thinking of creating a vertical stack of lithium AA batteries that fit behind the driver and passenger seats.
The AWD with electric front motor and engine in the rear motors makes sense, and makes good use of the car's design; this is basically what production vehicles such as the BMW i8 and Acura NSX do. The problem is that it doesn't leave much room for a battery pack. By "behind the seats" do you mean in the interior, or in the engine compartment? There will not be much space in the interior, and of course the engine is in the engine compartment, so there's no space available there.

For batteries I am thinking of creating a vertical stack of lithium AA batteries that fit behind the driver and passenger seats.
I hope you mean the 18650 cell format (formerly used for laptops, still used for some power tools, and used in the Tesla Model S and X battery modules), not the AA size.

My original idea was to attach a forklift motor to a gear box and some drive shafts and mount it all in the subframe. However the more I read the more confused I become.

Any pointers or advice much appreciated.
There are so many possible subjects that I'm not even going to try addressing them. I suggest asking more specific questions.
 

·
Registered
Joined
·
48 Posts
Austin metro had an A series engine and mgf has a k series engine, very little of the mgf is like a metro.
As for making an mgf a hybrid, I would think that almost impossible. The motor required to pull a car along that already has an engine, gearbox and fuel tank. Then you're adding a heavy motor and battery pack to a very small car. Will be interested to see it done.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #4
The early MK1 and MK2 metro was known as a Rover 100 in Europe. Those versions used the A plus engine and are very different to the MGF.

The mk3 and MK4 were known as metro but were official badged as Rover 100. They have K series engines. When they built the MGF they basically took a R100 engine and gearbox and bolted them in the back. Many parts are interchangeable.

I'm not looking at electric power to replace the ICE but to enhance it, although maybe use EV for local driving.
 

·
Registered
Joined
·
5,056 Posts
I'm not looking at electric power to replace the ICE but to enhance it, although maybe use EV for local driving.
That use suggests a plug-in hybrid, not just a hybrid. To be useful, that means lots of battery capacity, and that's a problem in any car, but especially this one.
 

·
Registered
Joined
·
80 Posts
I'm not looking at electric power to replace the ICE but to enhance it, although maybe use EV for local driving.
Yeah, this is going to be nigh-on impossible - There's simply not enough room for a large enough battery pack, motor and full electronics package required under the bonnet. The only reason my plans for a full home conversion are feasible is because the fuel-tank and engine compartment offer a lot of space when the original engine is removed.

To put it into context, my conversion will require all the space occupied by the fuel tank, and the spot for the spare wheel in the front to have a range of around 70 miles (estimated). Having mocked up some of the spaces avaliable for batteries in CAD, there really isn't a lot of room if you have to leave in place all systems required for the engine.

A lot of the advice on this forum is going to end up crushing expectations - if it's a labour of love, then by all means go for it; but for the space avaliable, the EV only range & performance will end up being dissapointing for a home-designed & built system.

Have you tried to get in touch with any of the engineers who worked on the MG TF 200 HPD Concept? I think that's sort of what you're aiming for... I would love to see your idea come into reality - but from what I've read, small means difficult in the conversion game... Vans and pickup trucks convert easily as they have tons of room for equipment and batteries, small sports cars are a bit of a packaging nightmare.

All the best,
Nick
 

·
Registered
Joined
·
9 Posts
Discussion Starter #7
Thanks for the thoughts so far.

I am thinking of having several smaller battery packs rather than one chuffin' great big one.

I think what I need to look at first is battery capacity, can anyone point me to sources of info.
 

·
Registered
Joined
·
22 Posts
As a rough guide, a small EV will use 300 Watt-hours of energy to travel one mile. So if you want a range of, say, 50 miles, you will need a 15KWh battery.
 

·
Registered
Joined
·
48 Posts
The early MK1 and MK2 metro was known as a Rover 100 in Europe. Those versions used the A plus engine and are very different to the MGF.

The mk3 and MK4 were known as metro but were official badged as Rover 100. They have K series engines. When they built the MGF they basically took a R100 engine and gearbox and bolted them in the back. Many parts are interchangeable.

I'm not looking at electric power to replace the ICE but to enhance it, although maybe use EV for local driving.
If you had read my list that precedes this post you will see I said just that, a battery pack and motor that will still have to drag the engine gearbox and fuel tank along. Pay attention
 

·
Registered
Joined
·
9 Posts
Discussion Starter #10
Austin metro had an A series engine and mgf has a k series engine, very little of the mgf is like a metro.
As for making an mgf a hybrid, I would think that almost impossible. The motor required to pull a car along that already has an engine, gearbox and fuel tank. Then you're adding a heavy motor and battery pack to a very small car. Will be interested to see it done.
If you had read my list that precedes this post you will see I said just that, a battery pack and motor that will still have to drag the engine gearbox and fuel tank along. Pay attention
I was paying attention, I was mainly replying to the first line highlighted above.

The Nissan Leaf is 1,470 kilos.
A Tesla Model S 70D weights 2,090 kg.
A Tesla Model X 100D is about 2,333kg,
and a Jaguar i-Pace is 2,133kg.

By contrast the MGF breaks the scales at a whopping one thousand and seventy kilos.

The whole of the electrical power train of the Nissan Leaf is less than 300 kg so adding that to the weight of the MGF with its petrol power train still gives you a vehicle that weighs in 1370 kg, 100kg or roughly 8% less than the Leaf.

I have no idea how the Leaf power train would fit in the MGF but that is a different problem.

Now, what were you saying?
 

·
Registered
Joined
·
9 Posts
Discussion Starter #11
Yeah, this is going to be nigh-on impossible - There's simply not enough room for a large enough battery pack, motor and full electronics package required under the bonnet. The only reason my plans for a full home conversion are feasible is because the fuel-tank and engine compartment offer a lot of space when the original engine is removed...…<<<snip>>>
I was considering several smaller battery packs, custom made to fit the available spaces. One behind each seat as both my wife and I are quite short so have the seats quite foward and another in the front. I don't need the spare wheel, there is room in the engine bay for the cars original 12v battery and I am considering the change to ABS pump built into the master brake cylinder which will free up a bit of space.

One of the reasons I am here is to find out more about the systems needed.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #12
The AWD with electric front motor and engine in the rear motors makes sense, and makes good use of the car's design; this is basically what production vehicles such as the BMW i8 and Acura NSX do. The problem is that it doesn't leave much room for a battery pack. By "behind the seats" do you mean in the interior, or in the engine compartment? There will not be much space in the interior, and of course the engine is in the engine compartment, so there's no space available there.
I have a 6-8" gap behind the seats


I hope you mean the 18650 cell format (formerly used for laptops, still used for some power tools, and used in the Tesla Model S and X battery modules), not the AA size.
Yes, it was a program about the Tesla and their battery packs that first got me thinking about converting the car to some sort of hybrid.

There are so many possible subjects that I'm not even going to try addressing them. I suggest asking more specific questions.
My first question should be "what questions do I need to ask?" LOL
 

·
Registered
Joined
·
80 Posts
As with any engineering problem; start with your requirements and work from there to research ways to try and meet them. If there's issues at that point, revise the requirements and iterate until you have a viable solution.

So figure out what performance from the electric system, EV only range you want and what your budget is - then you can start asking the right questions; "does the tech exist for me to get X performance within £Y,000." If the result comes back as a firm no, then see what you can change in your requirements to fix that.

There will absolutely a solution to your problem out there - whether it is practical for a self-engineered project, or within your budget are different questions entirely which need to be asked.

If I had shorter legs, there would be a similar gap behind the seats in my MG - so having batteries in the interior space could work. With regards to designing and building a battery pack, I strongly discourage you from building one up from scratch with 18650 lithium cells. From a friend who is a member of an Electric racing student team at Bath University, it's needlessly difficult and potentially dangerous to design a pack from scratch. A better approach could be sourcing battery modules from an OEM car - as the car manufacturers engineers have done most of the work, or building a pack from larger cells (Many conversions from a few years ago used a large number of LiFePO4 Prismatic cells in series. There are issues with distributing a battery pack around multiple places in a car - you will need to run high-voltage cables between each part of the pack, have multiple fuses (and potentially safety disconnects) between each part of the battery. Additionally, your battery management system will need to be able to handle a split pack.

If you can, get in contact with some off-forum experts to try and ask their advice. Perhaps try Chris over at Zero-ev.co.uk, or the team at Electric Classic Cars? Maybe have a chat with Mike, who runs a company called Indra near Worcester (Skooler on the forum). They might be able to give you information that may be more specific to converting to a hybrid as opposed to a pure BEV conversion.

---
Nick
 

·
Registered
Joined
·
9 Posts
Discussion Starter #14
I already know I'd be happy with a 50 mile range and I need to haul about 1100kg plus the weight of the EV system so my next quest is batteries.

I need to work out how much electrical storage I can create and thus how much power I can generate. That will guide me to the power unit and what control package I need.
 
1 - 14 of 14 Posts
Top