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MG Midget and Sprite Technical - Nissan Micra engine in Midget

Hi

Anyone come across this conversion of fitting a Nissan Micra CG engine to a Spridget?

https://barrattengineering.co.uk/ This company uses the midget ribcase gearbox and even shows some engines using twin SUs (later ones) and nice coloured rocker covers, as well as more modern induction.

Pity the Micra was FWD otherwise there may have been another source of Datsun gearboxes!

Cheers
Mike
M Wood

Also see: https://forum.retro-rides.org/thread/208938/midget-nissan-micra-engine-conversion
M Wood

He's been plugging this on facebook groups recently. Didn't seem to be very well received as the 'installation kit' is £1275 and you still have to source your own engine...
David Smith

I commented on the facebook messages that although the installed engine looked good and the parts in the kit look well designed and nicely made, the standard 16 valve micra engine only just exceeds the power output of a standard 1275 A series. Seems a lot of work and cash for much the same performance. Better to go for a breakfast cereal car ( Special k)
GuyW

Agree with Guy - why bother? Just been out testing the bike carb set up on the 2.0 Zetec powered Midget on a glorious spring day here up in the foothills of the Cairngorms. Utterly magnificent. I fear I need stronger brakes and a bung for my rear end.....
Oggers

Guy

Interesting point about Special K.

I noticed it had the original 948cc engine was a desirable 9CG unit (correct for the car and with better camshaft bearings that a Frogeye). A rebuild with 998cc Mini pistons and 1098cc rods could have been done for under the conversion cost and mated to a later Midget ribcase gearbox.

Did like the initial approach of making the mods reversible. And no cutting to fit a gearbox. I note in his Retrorides thread he has moved away from using a Midget gearbox and instead a modified Suzuki box.

Cheers
Mike
M Wood

There aint no substitute for cubes. As has benn pointed out, if you are going to the trouble to change the engine type then you might as well go for something with a lot more poke. Mating it to the std box is even more pointless. Plus there seemed to be distinct lack of the 1300 version for sale on eBay and finding tuning parts for them would be difficult.

I did like the look of the engine in the Midget engine bay though and also the supposed similarity to the A series.
John Payne

I still think there is merit in an electric Midget. I saw an article in the D.T. this week ref. (I think) MGBs. Some company was doing the conversion - which looked very nice - but for 80K or so, stupidly priced.

I think a conversion could be done for less than 10K plus the cost of the car, far less if DIY. I may even give it a go sometime!
Oggers

Since I was somewhat critical earlier of this conversion- although only in terms of the power gain, I am reactivating this thread with the kit desisigner, J Barratt's answer from the other thread about it. Just to round off this thread in the archive:
(I suggest any further discussion continues on the other thread, not this one, or it will get confusing!)

<<<<<<I'm James from Barratt Engineering, hopefully I can answer a few questions regarding the kit I've developed.

Regarding performance the aim of the conversion was never to set the world on fire, more to provide an alternative way of getting decent road performance and durability without changing the feel of the car. This week I had the development car on the rolling road at Stanton Motorsport and achieved 73hp at the rear wheels. The engine is a standard 1275 has over 100k miles with no service history. I am running 36mm Mikuni carbs and my own 4-1 exhaust manifold.

Rolling road result
https://imgur.com/OA9WYB7

I was advised that this will equate to around 88bhp at the flywheel allowing for a 20% loss in the drivetrain. The engine itself weights 77kg with all ancillaries so the overall improvement to the power to weight is actually rather good.

The camshafts fitted as standard are exceptionally conservative but there are plenty regrinds and billet performance camshafts on the market

http://www.catcams.com/products/camshafts/datasheet.aspx?ENGINE_id=242&CAMSETUP_id=1009&Language=english

The 5 speed conversion will be on sale as soon as all the parts are in stock, with costs looking like they will be similar to the ribcase version, An A-Series 5 speed is in development as well.>>>>>>>>>>>
GuyW

For comparison, a standard 1396 K series makes 105 bhp at the flywheel. Mine made 113 in my midget, all internals standard, 121 with aftermarket ECU. On the road cost of a built up kit is always going to be more, but mine was done for 800 quid.

On the flip side, £1200 is a chunk of cash to make an A series quicker, that'd probably get you to a reliable 90 bhp....

I applaud the engineering but it's not for me. I'm not quite sure who it's aimed at.
Rob Armstrong

Well, there may be another reasing to go for this Nissan Micra engine: I already have the Datsun 5 speed box in. It would'nt surprise me if one could just bolt it on..

Anyone?
a.o. arnold

had a big capacity bored/stroked B series engine in my Midget - best fun ever
William Revit

That's interesting Willy.

Given the availabilty of them, if the swap to a B series engine wasn't too difficult, I wonder why it never caught on. What gearbox did you use?

anamnesis

ran a lotus bullet c/r box and an anglia diff housing with a Escort l/s centre, all good bullet proof stuff in a light car.
William Revit

Sounds really good. Was the B lump an easy fit?
anamnesis

I once viewed a Midget for sale, which had an MGB engine. It had been hacked about quite a lot in order to get it in there.

I didn’t buy it.
Dave O'Neill 2

surprisingly easy to fit, I had it as far back as possible without butchering the firewall, did have most of that battery tray area removed though, the front pulley was roughly 250mm back from the rack, the main issue was the crossmember under the front of the gearbox, had to redo that lower to fit the box but that ended up a real pain as it stuck down below the floor level by about 25mm and hit on everything going, kept hitting the ground hillclimbing and was forever getting hooked on the end of the trailer. I'd planned to do a tubular horseshoe up over the top of the box instead to get rid of it on the next car but that didn't get built.
William Revit

a.o. Arnold, - you know the story behind the choice of nissan 5 speed box - for A series engine?
In the 1950's UK engineers were sent over to Japan to help Datsun to get re-established post war. Part if that was to permit a licenced copy of the A series engine (and I think the B series as well?) This engine, or a development of it was used in the Datsun who developed their own 4 and 5 speed gearboxes to fit it (later, renamed Nissan). As their gearbox matched to the Nissan development of the A series, it also fitted the original BMC engine, making their 5 speed an ideal Spridget upgrade. The only downside was the rarity in the UK of the 5 speed version. Far more common in the USA where I think it is usually referred to as the rivergate.

Quite interesting to now come full circle with the Nissan engine fitting that gearbox because of the licencing to Datsun of the original engine pattern.
GuyW

Aside from the one Dave saw, there must be some more B Spridgets out there I would think Willy.

And that's another interestingstory Guy. I don't think I've read that more full account before. I remember when I first saw a Datsun engine bay, and thought how much it looked like a B or A, without realising it was modeled on bmc stuff.
anamnesis

Nissan initially assembled BMC cars from crated kits sent from UK. I believe that the major machining dimensions of Datsun engines continued from the licence built A and B series engines they previously made. You can drop a Datsun electronic dizzy into an A series.
Les Rose

>>Far more common in the USA where I think it is usually referred to as the rivergate.<<

If my recollection is right Rivergate was/is the company that marketed the conversion kit?
That doesn't detract from your post, Guy. Interesting bit of history there.

Rivergate also offer a 5 speed all-synchro gearbox fitting kit for MGBs, using the box from a 280Z. This is said to be about 10kg lighter than the original box and a very strong unit.

In either case you have to find your own gearbox and the kit is a bit on the spendy side.
Greybeard

Some years back three of my club members had three Datsun kits crated and sent here, by Rivergate, for me to fit.
Alan Anstead

Yes Rob, Sorry, a bit of a shorthand on my part about Rivergate. I see it looks like I meant the Nissan gearbox was called a rivergate though what I meant was that the most common USA installation of it was as you say, done by the Rivergate company.
GuyW

Thanks guys. But my question is: would a Nissan Micra CG 13 fit on a B210 dog leg Datsun box? Found this: http://datsun1200.com/modules/mediawiki/index.php?title=63-Series_Transmission
a.o. arnold

A mate did that with his Datto 1200 ute---There was an issue with the Micra flywheel being too large in diameter to fit in the bellhousing and the flywheel that was with the box had a different number of crankshaft bolts--something like 6 vs 4 but he found a flywheel off another model engine that bolted up. Also, if I remember correctly the bellhousing holes had to be opened up a bit as the bellhousing bolts were slightly bigger diameter.---------?
William Revit

Hi William, thx. Any chance that I contact him / her directly for more details. The reason is simnple for me:

- end of oilleaks
- direct bolt on
- no siamese ports >> make EFI more simple
- better base for next step (supercharger on)
a.o. arnold

Sorry mate, no , he passed away late last year, I know the bloke who has the ute but he bought it as is and wouldn't know any of the details unfortunately.
willy
William Revit

I think he used a cg 1.0 flywheel and clutch but can't be 100% sure, but i think that was the right dia. and 6 bolt same as the micra crank---apart from that i don't know anything else much about it--sorry
William Revit

If I compare this woth the CG engine, I see not so much difference





a.o. arnold

There is also a supercharged Nissan engine :-)
a.o. arnold

Always been interested at garage pics. it's just interesting to see what others have in their's
Can I ask please what that frame setup is over the back of the bench where your engine is there.I've seen them before but just can't think what it is--thanks
willy
William Revit

Looks like a saw device to make 90 or 45 degree sawcuts?
for wood, steel or tiles?
A de Best

Mitre saw, possibly?
Dave O'Neill 2

Arie is the winner :-)
a.o. arnold

Thanks--
William Revit

This thread was discussed between 21/03/2021 and 19/02/2025

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