Reliant Scimitar SE5 (1971) with Lexus transmission
Reliant Scimitar SE5 (1971) with Lexus transmission
Hi folks,
I'm converting a 1971 Reliant Scimitar SE5 to electric drive train, using the Lexus GS450H transmission as demonstrated by Damien Maguire at the New Electric Ireland course I attended. I've been collecting the parts I think are required and last week my 4 battery packs arrived (each containing 60s Kokam 100216216H cells) so I'm trying to copy what Damien's been doing but to be honest I'm a bit clueless so any help or advice appreciated. As an example of how much of a novice I am, I opened up the first of four boxes of Kokam cells to discover I don't have any of the necessary tools to remove the BMS boards! (Have been shopping online for some new screwdriver bits etc, so hopefully in my next post I'll have been able to get some of the BMS boards out). Can anyone offer advice on what boards on OpenInverter would be helpful to read?
Once I've got the bms boards out, what would you do next?
(Don't worry, I've got a mechanic booked in to do the work on restoring the Scimitar, whilst I try to get my electric drivetrain working)
I'm converting a 1971 Reliant Scimitar SE5 to electric drive train, using the Lexus GS450H transmission as demonstrated by Damien Maguire at the New Electric Ireland course I attended. I've been collecting the parts I think are required and last week my 4 battery packs arrived (each containing 60s Kokam 100216216H cells) so I'm trying to copy what Damien's been doing but to be honest I'm a bit clueless so any help or advice appreciated. As an example of how much of a novice I am, I opened up the first of four boxes of Kokam cells to discover I don't have any of the necessary tools to remove the BMS boards! (Have been shopping online for some new screwdriver bits etc, so hopefully in my next post I'll have been able to get some of the BMS boards out). Can anyone offer advice on what boards on OpenInverter would be helpful to read?
Once I've got the bms boards out, what would you do next?
(Don't worry, I've got a mechanic booked in to do the work on restoring the Scimitar, whilst I try to get my electric drivetrain working)
- Bratitude
- Posts: 965
- Joined: Thu Jan 02, 2020 7:35 pm
- Location: Canada
- Has thanked: 154 times
- Been thanked: 334 times
- Contact:
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Read, everything.
but seriously.
...and then read it again!
but seriously.
...and then read it again!
https://bratindustries.net/ leaf motor couplers, adapter plates, custom drive train components
-
- Posts: 88
- Joined: Fri Nov 06, 2020 4:56 am
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Thanks Bratitude and bobbjy_408
Yes I've read that thread but I'm definitely going to re-read a couple of times to make sure I know what I'm doing a little bit at least!
So far I've gathered
4 battery packs (each containing 60 Kokam cells SLPB100216216H, which I reckon ought to be about 35kWh)
Lexus GS450H transmission
Oil pump for the above transmission
Toyota Inverter for the above transmission
And now that my new tools have arrived I can make a start on removing these redundant BMS boards
(Rookie mistake #2: I thought the boards themselves selves were a BMS! Well it's a relief that I don't need to rush the removal now)
The high voltage insulated tools were out of my budget range so I'll just need to be extra careful!
Yes I've read that thread but I'm definitely going to re-read a couple of times to make sure I know what I'm doing a little bit at least!
So far I've gathered
4 battery packs (each containing 60 Kokam cells SLPB100216216H, which I reckon ought to be about 35kWh)
Lexus GS450H transmission
Oil pump for the above transmission
Toyota Inverter for the above transmission
And now that my new tools have arrived I can make a start on removing these redundant BMS boards
(Rookie mistake #2: I thought the boards themselves selves were a BMS! Well it's a relief that I don't need to rush the removal now)
The high voltage insulated tools were out of my budget range so I'll just need to be extra careful!
- ggeter
- Posts: 135
- Joined: Wed Nov 18, 2020 1:56 pm
- Location: Houston, TX
- Has thanked: 4 times
- Been thanked: 26 times
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Congrats on the start of your build. I've got a 1979 MG roller and considering using the 450h trans. How do you plan to mount the trans? Far forward where the original engine was? Modify the tunnel and push it farther back? I will have similar challenges.
Houston, Texas, USA
EV Newbie
1979 MG Midget + GS450h = "Mexus?"
IT Consultant
EV Newbie
1979 MG Midget + GS450h = "Mexus?"
IT Consultant
- SciroccoEV
- Posts: 370
- Joined: Thu Oct 10, 2019 1:50 pm
- Location: Luton UK
- Been thanked: 15 times
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Use selective covering of adjacent components, so that a dropped tool is unlikely to cause a short.
Use heatshrink to make you own insulated tools.
Never get complacent.
This should be a cautionary tail to all; http://evdl.org/pages/plasmaboy.html
- clanger9
- Posts: 203
- Joined: Mon Oct 28, 2019 7:41 am
- Location: Chester, UK
- Been thanked: 1 time
- Contact:
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
I like his description of using uninsulated tools being "like changing a fuel filter while smoking a cigarette". Bad idea all round...
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Good luck, take care with the batteries. was looking at the axles from the scimitar, you can fit a Jag Powerlock diff into the Salisbury axle if you want somewhat inexpensive limited slip 

Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Good question! Ideally I'd like to keep everything looking as original as possible so my initial thought was to move the transmission forward until it fits in the tunnel. I should do some measuring soon to see how much room I have to play with. Do you have any thoughts on this dilemma with your MG?
I'm getting some professional help with the restoration of the Scimitar and his advice was to modify the tunnel to fit the Lexus transmission.
This has the added advantage of making more space for battery packs and therefore keeping the weight as much as possible between the wheels, and low down (He suggested this would improve performance, sounds logical to my inexperienced ears!)
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Thanks SciroccoEV. I'll read that linked article before I even look at my batteries again!SciroccoEV wrote: ↑Thu Nov 26, 2020 5:20 pmUse selective covering of adjacent components, so that a dropped tool is unlikely to cause a short.
Use heatshrink to make you own insulated tools.
Never get complacent.
This should be a cautionary tail to all; http://evdl.org/pages/plasmaboy.html
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Thanks TFirenza, that's exactly the sort of help I need! (I think I'd heard of Scimitar owners using Jag LSD's but didn't know if it was viable, will look into it. I had been thinking of buying a Quaife LSD but perhaps that's overkill and I could do with keeping the budget down)
- ggeter
- Posts: 135
- Joined: Wed Nov 18, 2020 1:56 pm
- Location: Houston, TX
- Has thanked: 4 times
- Been thanked: 26 times
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
I've updated pics on my project thread. Look for 1979 MG Midget in Texas. I have done a dry fit already and you can see the kind of room I have left to work with. Like you, I'd rather not do any modifications to the car. Modifying the tunnel may not be the best thing for me anyway because the tunnel and foot well share a common wall. Not sure it'd be worth it for three or four extra inches, but something I'll still consider.slanceley wrote: ↑Mon Dec 28, 2020 4:02 pmGood question! Ideally I'd like to keep everything looking as original as possible so my initial thought was to move the transmission forward until it fits in the tunnel. I should do some measuring soon to see how much room I have to play with. Do you have any thoughts on this dilemma with your MG?
I'm getting some professional help with the restoration of the Scimitar and his advice was to modify the tunnel to fit the Lexus transmission.
This has the added advantage of making more space for battery packs and therefore keeping the weight as much as possible between the wheels, and low down (He suggested this would improve performance, sounds logical to my inexperienced ears!)
Oddly enough, this big transmission didn't even begin to compress the front springs...
Batteries are where I'll spend most of my design energy. Just the cells weigh 384 pounds, and with boxes and extras, I'm sure I'll easily push 430 or so. I need to get as much of that 430 out of the rear as possible. When I placed all 12 boxes of cells behind the seats, the rear springs compressed about 3 inches. But, maybe with stronger springs or helper airbags, it'll work out.
Let's keep in touch. I have all my major components with the exception of Damien's VCU. I'll be building the mounting plates, battery packs and coolant loops until that VCU comes in.
Houston, Texas, USA
EV Newbie
1979 MG Midget + GS450h = "Mexus?"
IT Consultant
EV Newbie
1979 MG Midget + GS450h = "Mexus?"
IT Consultant
- Uppertown
- Posts: 69
- Joined: Wed Dec 09, 2020 10:57 pm
- Location: North East England
- Has thanked: 118 times
- Been thanked: 34 times
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
I think you will struggle to find a cheap working Jag lsd nowadays but this isn't too pricey ; https://www.rallydesign.co.uk/product_i ... s_id=25503
However the Scimitars rear suspension is very good and you can go a long way with an open diff, I used to sprint a 265bhp 302V8 powered SE5 and rarely had trouble getting the power down.
Unfortunately the front suspension is crap and they roll badly with the std antiroll bar- fit a second std bar piggy back or get a heavy duty one made. Uprate all the bushes and the brakes as they are hopeless too.
I think the chassis will limit how far back you can push the transmission but don't worry about cutting the tunnel, it's not structural but you might have to junk the heater, something you'd probably do anyway.
The fuel tank sits well back and quiet high and the handling would change quite a bit depending on how full it was, so I'd avoid putting too many batterys there.
The engine sits back behind the front wheels and you can trim a lot of the body from around the engine bay to make room for batteries up front.
However the Scimitars rear suspension is very good and you can go a long way with an open diff, I used to sprint a 265bhp 302V8 powered SE5 and rarely had trouble getting the power down.
Unfortunately the front suspension is crap and they roll badly with the std antiroll bar- fit a second std bar piggy back or get a heavy duty one made. Uprate all the bushes and the brakes as they are hopeless too.
I think the chassis will limit how far back you can push the transmission but don't worry about cutting the tunnel, it's not structural but you might have to junk the heater, something you'd probably do anyway.
The fuel tank sits well back and quiet high and the handling would change quite a bit depending on how full it was, so I'd avoid putting too many batterys there.
The engine sits back behind the front wheels and you can trim a lot of the body from around the engine bay to make room for batteries up front.
slanceley wrote: ↑Mon Dec 28, 2020 4:26 pmThanks TFirenza, that's exactly the sort of help I need! (I think I'd heard of Scimitar owners using Jag LSD's but didn't know if it was viable, will look into it. I had been thinking of buying a Quaife LSD but perhaps that's overkill and I could do with keeping the budget down)
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Thanks Uppertown, invaluable to have suggestions from people who clearly know a lot more than me on this! Thank you!
Maybe I'll hold off on the LSD till I've driven it. Sounds like something I could upgrade to later on (and spend the money on more important things like the brakes and heavy duty anti-roll bar!)
I'm still at the point of waiting for my eBay workbench to arrive so I have somewhere neat and tidy to bench test components.
In the meantime, I'm having a go at restoring the Lexus transmission oil pump.
I've got the replacement bearings suggested on this wiki...https://openinverter.org/wiki/Lexus_GS4 ... ansmission
But I've already managed the strip the + screws! Will post some photos later so I can show others how NOT to do it!
PS Can anyone tell me how to tag someone in a reply on here without including their whole post? I assume it's annoying the way I've done it!
Maybe I'll hold off on the LSD till I've driven it. Sounds like something I could upgrade to later on (and spend the money on more important things like the brakes and heavy duty anti-roll bar!)
I'm still at the point of waiting for my eBay workbench to arrive so I have somewhere neat and tidy to bench test components.
In the meantime, I'm having a go at restoring the Lexus transmission oil pump.
I've got the replacement bearings suggested on this wiki...https://openinverter.org/wiki/Lexus_GS4 ... ansmission
But I've already managed the strip the + screws! Will post some photos later so I can show others how NOT to do it!
PS Can anyone tell me how to tag someone in a reply on here without including their whole post? I assume it's annoying the way I've done it!
Uppertown wrote: ↑Fri Jan 01, 2021 11:40 pm I think you will struggle to find a cheap working Jag lsd nowadays but this isn't too pricey ; https://www.rallydesign.co.uk/product_i ... s_id=25503
However the Scimitars rear suspension is very good and you can go a long way with an open diff, I used to sprint a 265bhp 302V8 powered SE5 and rarely had trouble getting the power down.
Unfortunately the front suspension is crap and they roll badly with the std antiroll bar- fit a second std bar piggy back or get a heavy duty one made. Uprate all the bushes and the brakes as they are hopeless too.
I think the chassis will limit how far back you can push the transmission but don't worry about cutting the tunnel, it's not structural but you might have to junk the heater, something you'd probably do anyway.
The fuel tank sits well back and quiet high and the handling would change quite a bit depending on how full it was, so I'd avoid putting too many batterys there.
The engine sits back behind the front wheels and you can trim a lot of the body from around the engine bay to make room for batteries up front.
-
- Posts: 559
- Joined: Mon Feb 24, 2020 8:59 pm
- Location: Ireland
- Has thanked: 377 times
- Been thanked: 80 times
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Ha, I hear ya on the oil pump screws. Had two to do and the first one disassembled lovely, job done. Second one the screws were solid and ended up stripped too. Thought I had messed it up, but drilled the screw heads slightly to smooth them out, wd40, then used an opposite hand drill bit on slow speed and they loosened up handy enough.
- New Electric Ireland
- Posts: 172
- Joined: Sun May 31, 2020 12:22 pm
- Location: Ireland
- Been thanked: 2 times
- Contact:
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
I don't think tagging works here (it didn't last time I tried) but most forums use @slanceley (did that work?).
I just edit the relevant part of the post to make it more succinct

In Ireland we undertake training & open source RND for the New Electric group, 5 companies converting boats, buses, cars and trucks to electric drive since 2008.
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Decided to tackle this "easy" first job on my conversion, refurbishing the Lexus GS450H transmission oil pump that I had to buy (naively bought a transmission without one)
It has been a swine so far. Hope the other jobs on this conversion aren't as tiresome! (I enjoyed it really) The four bolts (10mm hex) came out no problem... but the three cross head screws were totally seized and I manage to strip them. Oops Out came my now indispensable induction heater and plenty of WD40... ...still no joy so I resorted to cold chisel (making a little notch first and then angling the chisel blows to eventually turn them enough to use a "damaged screw remover" bit. Bingo!
It has been a swine so far. Hope the other jobs on this conversion aren't as tiresome! (I enjoyed it really) The four bolts (10mm hex) came out no problem... but the three cross head screws were totally seized and I manage to strip them. Oops Out came my now indispensable induction heater and plenty of WD40... ...still no joy so I resorted to cold chisel (making a little notch first and then angling the chisel blows to eventually turn them enough to use a "damaged screw remover" bit. Bingo!
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Oh that sounds like a great trick! Opposite hand drill bit... hang on this isn't like 'tartan paint', a replacement spirit level bubble or a long weight is it?
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Ah thanks for that, I'm still learning how to use forums!New Electric Ireland wrote: ↑Wed Jan 13, 2021 7:37 pm
I don't think tagging works here (it didn't last time I tried) but most forums use @slanceley (did that work?).
I just edit the relevant part of the post to make it more succinct![]()
I think I might be going overboard with my photos so by all means let me know if this is too many!
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Next I need to get some replacement O rings (as some corrosion had breached the pump housing and damaged them - you can see in the photo that the metal is a little corroded too, I guess I ought to sand/brush it clean. Any tips for this?).
Sounds silly but when you are a newbie you soon find every little thing needs to be ordered in! eg rubber O rings, replacement screws that I stripped taking this apart, etc
Oh and the plastic seal thing, anyone who's done this refurb job already on the oil pump... did you replace the plastic seal thing? Can you point me in the direction of the correct part please if so? And any tips for how best to get the other bearing off (the rotor)? And lastly for today... am I right in thinking there's a gasket between this oil pump and the transmission? Any tips on how to do that/source one?
Sounds silly but when you are a newbie you soon find every little thing needs to be ordered in! eg rubber O rings, replacement screws that I stripped taking this apart, etc
Oh and the plastic seal thing, anyone who's done this refurb job already on the oil pump... did you replace the plastic seal thing? Can you point me in the direction of the correct part please if so? And any tips for how best to get the other bearing off (the rotor)? And lastly for today... am I right in thinking there's a gasket between this oil pump and the transmission? Any tips on how to do that/source one?
-
- Posts: 559
- Joined: Mon Feb 24, 2020 8:59 pm
- Location: Ireland
- Has thanked: 377 times
- Been thanked: 80 times
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
[/quote]
Oh that sounds like a great trick! Opposite hand drill bit... hang on this isn't like 'tartan paint', a replacement spirit level bubble or a long weight is it?
[/quote]
Ha, no not a rubber hammer suggestion. It grips in the opposite direction. Similar to the dedicated tools for the job. Doesn't always work that great though.
Oh that sounds like a great trick! Opposite hand drill bit... hang on this isn't like 'tartan paint', a replacement spirit level bubble or a long weight is it?
[/quote]
Ha, no not a rubber hammer suggestion. It grips in the opposite direction. Similar to the dedicated tools for the job. Doesn't always work that great though.
-
- Posts: 559
- Joined: Mon Feb 24, 2020 8:59 pm
- Location: Ireland
- Has thanked: 377 times
- Been thanked: 80 times
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
I've changed the bearings on two of these pumps but didn't have to change the seal you mentioned so can't help there.
For getting the bearing off the rotor, I found these weren't overly tight. I let them soak up some wd-40 for a bit, then used two flat screw drivers opposite sides of the bearing pushing on the rotor (maybe not the best anchor point) but worked slowly and kept an eye for any issues. Once the bearing started to move it came off handy. A small bearing pullers would be better solution possibly but more bits to buy for one off jobs!
For the seals, one of the pumps came with the seal. I can't find a pic from when I removed it. Was a profiled plate seal, so I refit that. Wasn't one on the second pump so I used a small bead of gasket sealant instead. I couldn't find the correct seal to buy any way handy. Not tested with full oil pressure yet though!
For getting the bearing off the rotor, I found these weren't overly tight. I let them soak up some wd-40 for a bit, then used two flat screw drivers opposite sides of the bearing pushing on the rotor (maybe not the best anchor point) but worked slowly and kept an eye for any issues. Once the bearing started to move it came off handy. A small bearing pullers would be better solution possibly but more bits to buy for one off jobs!
For the seals, one of the pumps came with the seal. I can't find a pic from when I removed it. Was a profiled plate seal, so I refit that. Wasn't one on the second pump so I used a small bead of gasket sealant instead. I couldn't find the correct seal to buy any way handy. Not tested with full oil pressure yet though!
- SciroccoEV
- Posts: 370
- Joined: Thu Oct 10, 2019 1:50 pm
- Location: Luton UK
- Been thanked: 15 times
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
You need a puller plate, something like the one I made for overhauling Morini starter motors, you can see it shortly after the 3 minute mark;
Re: Reliant Scimitar SE5 (1971) with Lexus transmission
Ah thanks nkiernan, appreciate your input. I've asked a Lexus parts place for the gasket but if i don't hear back from them, it sounds like i might have to use the gasket sealant idea.