Story time...
Several years ago my dad bought this rather nice MG Midget. It's an early 948cc GAN/1 car with almost all of the original features intact including the original engine and 'smooth case' gearbox. At some point the car has been repainted and restored to a fairly decent standard. It and has lost the original steering wheel and mirrors but has clearly been looked after.
Out for a winter blast over Ashdown Forest
The engine was very tired indeed so was treated to a standard unleaded A+ head after a compression test gave low readings which were unaffected by oil in the bores(thank you Metro!). This improved things a bit.
The distributor had to have a repair where the die casting had collapsed allowing it to move in the clamp.
Repaired distributor
The front suspension was also given a refresh at a 'specialist' garage who blew the head gasket, warped the head by 10 thou' and cracked the radiator after leaving it running with low coolant for some time. nevskills532 and I spent a large amount of time getting the head flat again on a sheet of glass and repaired the radiator but my dad was never that confident with the car again.
After considering rebuilding the engine a plan was hatched to retrofit an a-series derived Nissan CG engine which would offer reliability (yes, an a-series can be very reliable), increased performance and a bonus reduction in weight all in the same package space. As an added bonus even the capacity is a-series (998 and 1275). The conversion has been popular for ages with Minis but I could find no evidence of a rear wheel drive install so set to work. The plan was to design a simple kit that would use the original gearbox, clutch and engine mounts so no modifications would be required on the car at all.
A bare CG block was bought on eBay and digitised on a CMM along with the bell housing of a spare Midget gearbox. I also took measurements from an MG front plate for the engine mounts. Sadly I seem to have lost the photographs of everything being digitised. With this I was able to design an adaptor plate and engine mounts which were laser cut and welded together.
Some CAD
I then started to put together the assembly with a starter motor, flywheel, alternator mount etc along with a conversion for the clutch release. Unfortunately it was necessary to trim the gearbox to clear the Nissan cylinder head which overhangs the back of the block but given that the gearboxes are still plentiful I wasn't too upset about it. The original gearbox will be left completely unmolested.
Bell housing adaptor on trimmed gearbox
Clutch conversion parts
Work then stopped over a year ago when my dad decided he would rather sell the car so all of the bits sat in the garage and shed, went up for sale on here, and ultimately ended upforgotten about getting in the way.
Thankfully the car never did get out on the market but last weekend it change hands. Into mine.
The wiring is old and a bit 'got at'.
A fair bit of faffing about was required to get the old car cranking over and running with the battery terminals in poor shape and bad contacts on the starter switch but with some coaxing she fired up okay. After a test run and good check over I set off from Crowborough back down to Emsworth on a lovely Saturday afternoon. It drove really very nicely, I love the gearbox and can't get over how good the steering is. The driving is properly go-kart like but with very good ride quality.
Quick photoshoot at Bosham and a cheeky half at the pub.
Before being locked up for the night.
Sunday was the Goodwood Members Meeting and I was really looking forward to taking it along so was pretty devastated to find the radiator empty and cylinders 3 and 4 with an inch each of water in them. On inspection with the bore scope I also found extremely rusty bores so I have to count myself lucky at getting home at all. The temp gauge was a steady 160F rising occasionally to 190F on long climbs.
Sad old engine.
This means the CG13 conversion is very much back on. I have a good, known engine in the shed which I am currently refreshing with a new timing chain and a check over and am going to try and keep the project moving at a decent pace. Modifying the car in any permanent way is not an option and I am very keen to keep the feel of the car as much as possible. A distributor is not going to happen because the heater is in the way so a Megajolt will have to be tucked away but carbs are a must. To start with this will probably be a downdraft Weber on the standard manifold but ultimately I want to run SUs again, or maybe quad Amals with trumpets.
The eBay special Peugeot 106 manifold looks like it can be made to work.
Now to start putting it all back together.
If it works out and there is interest my ambition is to sell the kits as an alternative to a highly strung A-series build for MGs and Minors etc. If the internet is to be believed a 1275cc CG13 can make 100bhp with a free flowing exhaust and a half decent carb setup. Combined with the fact that I can comfortably pick up and walk around with the fully built engine I think that there is potential.
Thanks for reading,
James
Several years ago my dad bought this rather nice MG Midget. It's an early 948cc GAN/1 car with almost all of the original features intact including the original engine and 'smooth case' gearbox. At some point the car has been repainted and restored to a fairly decent standard. It and has lost the original steering wheel and mirrors but has clearly been looked after.
Out for a winter blast over Ashdown Forest
The engine was very tired indeed so was treated to a standard unleaded A+ head after a compression test gave low readings which were unaffected by oil in the bores(thank you Metro!). This improved things a bit.
The distributor had to have a repair where the die casting had collapsed allowing it to move in the clamp.
Repaired distributor
The front suspension was also given a refresh at a 'specialist' garage who blew the head gasket, warped the head by 10 thou' and cracked the radiator after leaving it running with low coolant for some time. nevskills532 and I spent a large amount of time getting the head flat again on a sheet of glass and repaired the radiator but my dad was never that confident with the car again.
After considering rebuilding the engine a plan was hatched to retrofit an a-series derived Nissan CG engine which would offer reliability (yes, an a-series can be very reliable), increased performance and a bonus reduction in weight all in the same package space. As an added bonus even the capacity is a-series (998 and 1275). The conversion has been popular for ages with Minis but I could find no evidence of a rear wheel drive install so set to work. The plan was to design a simple kit that would use the original gearbox, clutch and engine mounts so no modifications would be required on the car at all.
A bare CG block was bought on eBay and digitised on a CMM along with the bell housing of a spare Midget gearbox. I also took measurements from an MG front plate for the engine mounts. Sadly I seem to have lost the photographs of everything being digitised. With this I was able to design an adaptor plate and engine mounts which were laser cut and welded together.
Some CAD
I then started to put together the assembly with a starter motor, flywheel, alternator mount etc along with a conversion for the clutch release. Unfortunately it was necessary to trim the gearbox to clear the Nissan cylinder head which overhangs the back of the block but given that the gearboxes are still plentiful I wasn't too upset about it. The original gearbox will be left completely unmolested.
Bell housing adaptor on trimmed gearbox
Clutch conversion parts
Work then stopped over a year ago when my dad decided he would rather sell the car so all of the bits sat in the garage and shed, went up for sale on here, and ultimately ended up
Thankfully the car never did get out on the market but last weekend it change hands. Into mine.
The wiring is old and a bit 'got at'.
A fair bit of faffing about was required to get the old car cranking over and running with the battery terminals in poor shape and bad contacts on the starter switch but with some coaxing she fired up okay. After a test run and good check over I set off from Crowborough back down to Emsworth on a lovely Saturday afternoon. It drove really very nicely, I love the gearbox and can't get over how good the steering is. The driving is properly go-kart like but with very good ride quality.
Quick photoshoot at Bosham and a cheeky half at the pub.
Before being locked up for the night.
Sunday was the Goodwood Members Meeting and I was really looking forward to taking it along so was pretty devastated to find the radiator empty and cylinders 3 and 4 with an inch each of water in them. On inspection with the bore scope I also found extremely rusty bores so I have to count myself lucky at getting home at all. The temp gauge was a steady 160F rising occasionally to 190F on long climbs.
Sad old engine.
This means the CG13 conversion is very much back on. I have a good, known engine in the shed which I am currently refreshing with a new timing chain and a check over and am going to try and keep the project moving at a decent pace. Modifying the car in any permanent way is not an option and I am very keen to keep the feel of the car as much as possible. A distributor is not going to happen because the heater is in the way so a Megajolt will have to be tucked away but carbs are a must. To start with this will probably be a downdraft Weber on the standard manifold but ultimately I want to run SUs again, or maybe quad Amals with trumpets.
The eBay special Peugeot 106 manifold looks like it can be made to work.
Now to start putting it all back together.
If it works out and there is interest my ambition is to sell the kits as an alternative to a highly strung A-series build for MGs and Minors etc. If the internet is to be believed a 1275cc CG13 can make 100bhp with a free flowing exhaust and a half decent carb setup. Combined with the fact that I can comfortably pick up and walk around with the fully built engine I think that there is potential.
Thanks for reading,
James
