MG 1300 engine

The Home of the Bigger Brothers, BMC 1100s, 1300s, A40s, A35 etc.
Post Reply
User avatar
woodypup59
Posts: 1060
Joined: Thu Jun 24, 2010 5:28 pm
Location: London UK

MG 1300 engine

Post by woodypup59 »

We've just collected a "barn find" MG 1300 ADO 16 and were interested to see the 9 + 2 cylinder head bolts & studs.

It was suggested that for a period, these cars had a 1275 Cooper S engine.

However, there are no tappet chest covers so what is it ?

Can anyone confirm the spec of the engine ?
You do not have the required permissions to view the files attached to this post.

Beatie
Posts: 671
Joined: Mon May 30, 2016 1:04 pm
Location: Norfolks highest point

Re: MG 1300 engine

Post by Beatie »

Very close woody but not quite the cigar :lol: as close as it can be ?
I’ve got one of these which I’m using on my 72, it’s from a 71 MG1300 .
Same pistons ,Nitrided crank,11 stud 805 big valve head ,close ratio 1128 box on rubbers .
Twin SU’s ect but the new non tappet chested solid block .
I think the mk2 MG1300’s were rarer than MK3,S’s ? So quite a find :D

swifty
Posts: 1190
Joined: Thu Jun 24, 2010 11:19 pm

Re: MG 1300 engine

Post by swifty »

Great engine with I think 70bhp . Alan ( supersonic ) knows the ins and out of these engines ... ken
1963 austin Cooper s mk1 1071
1966 Austin Cooper s mk1 1275
1968 Austin Cooper mk2 998
1962 Morris mini super 850
Porsche 997 turbo S
Ford transit van 280s

Supersonic
Posts: 1924
Joined: Fri Mar 20, 2015 5:25 pm
Location: Crossgar County Down Northern Ireland

Re: MG 1300 engine

Post by Supersonic »

swifty wrote:
Fri Aug 21, 2020 10:56 pm
Great engine with I think 70bhp . Alan ( supersonic ) knows the ins and out of these engines ... ken
As Ken said these are great engines with 70 BHP in standard form. I never understood why these engines were not fitted to factory 1275GT Minis. That unit should have the 12G1805 big valve cylinder head with 1.401” inlet and 1.156” exhaust valves. If standard it will be 21.4cc. The con rods are all numbered and balanced and they have strengthening webs halfway up the rod. The crankshaft should be marked 12G1683 or 12G1687 which is a 12G1505 casting tuftrided with 1.75” con rod journals and balanced. The gearbox should be 22G1128 4 synchro remote with 22G1040 laygear. The final drive will be 3.65. The cylinder block will be marked 22G1279 thick flange. Some of these engines had the solid wall above the centre main which makes them great race engines. The three engines I have all have the solid wall. The black short motor on the bench is the later one which lost the 1275 badge at the back. In my opinion these are stronger engines than the Cooper S engine as I’ve never seen one break a crank unlike the S crank which gives problems when highly rotated.

That Oselli engine I have produces 85 BHP with their cylinder head, Kent 256 cam 1.4 ratio rockers and balanced assembly.

Alan
DSC01542.JPG
DSC01541.JPG
DSC01540.JPG
DSC01539.JPG
You do not have the required permissions to view the files attached to this post.

Supersonic
Posts: 1924
Joined: Fri Mar 20, 2015 5:25 pm
Location: Crossgar County Down Northern Ireland

Re: MG 1300 engine

Post by Supersonic »

What I should also have said that if it is an early car it will have engine number 12H-199-0000, if post 1968, 12H-298F-0000.The Mk2 ADO16 MG also had a 12G engine which had small journals the same as the Cooper S. The Mk2 cars never had a Cooper S engine fitted. Only the Mk1 MG, Riley Kestrel, Wolseley and Vanden Plas were fitted with S units from October 1966. In saying Cooper S engine, only the block, crankshaft and rods were Cooper S. They had the standard 1100 gearbox, a 9 stud cylinder head, low compression pistons and a single carb. I recently owned an October 1966 Riley Kestrel 1275 as they were known and which I regret selling as they are rare birds without doubt :(

Alan

User avatar
woodypup59
Posts: 1060
Joined: Thu Jun 24, 2010 5:28 pm
Location: London UK

Re: MG 1300 engine

Post by woodypup59 »

Thanks people. The car is late '69 and does have a 298 engine no. = 12H 298F 23731.
You do not have the required permissions to view the files attached to this post.

User avatar
Costafortune
Posts: 1056
Joined: Thu Feb 16, 2017 10:26 am
Location: Sheffield On Thames

Re: MG 1300 engine

Post by Costafortune »

Supersonic wrote:
Sat Aug 22, 2020 1:39 pm
What I should also have said that if it is an early car it will have engine number 12H-199-0000, if post 1968, 12H-298F-0000.The Mk2 ADO16 MG also had a 12G engine which had small journals the same as the Cooper S. The Mk2 cars never had a Cooper S engine fitted. Only the Mk1 MG, Riley Kestrel, Wolseley and Vanden Plas were fitted with S units from October 1966. In saying Cooper S engine, only the block, crankshaft and rods were Cooper S. They had the standard 1100 gearbox, a 9 stud cylinder head, low compression pistons and a single carb. I recently owned an October 1966 Riley Kestrel 1275 as they were known and which I regret selling as they are rare birds without doubt :(

Alan
I have an old Glass' Guide that quotes May 1965 for the 1275 engine option on the VdP, and June 1967 for the MG and Riley. I'm pretty sure the pre Mark II 1275 engines were using a solid wall block, first introduced on the 1966 Midget/Sprite.

Supersonic
Posts: 1924
Joined: Fri Mar 20, 2015 5:25 pm
Location: Crossgar County Down Northern Ireland

Re: MG 1300 engine

Post by Supersonic »

Firstly I want to correct what I posted yesterday; I should have said the crankshaft will be 12G1683 or 12G1817. With that engine number it will have the 12G1817 crankshaft with a grey finish to its webs which shows its tuftrided with 12G1817 cast into the crank like an afterthought.

In regards to the timeline for when the ADO16 got the 1275cc motor I think that is hard to establish. Some years ago at an 1100 Club National Rally, I remember speaking with the late Allan G Webb who worked as a development engineer on the ADO16. I asked him about the timeline for engines. Back then I had an October 1966 Mk1 1275cc Riley Kestrel and my friend had a March 1967 Mk1 Vanden Plas 1275cc. Both cars were factory original, my Riley had the 58 BHP 1275cc block with tappet chest covers and my friend’s VP had the solid block 1275cc block.

I recall Allan G Webb saying that the 1275cc transverse solid wall block followed the inline engine by about six months and crankshafts by another couple of months. Allan told me that in order to meet early demand for the 1275cc upgrade Cowley fitted detuned 1275cc engines from Morris Motors and used the Midget / Sprite cylinder head cast at the Wellingborough Foundry. He also told me that the 12G1505 transverse crankshaft with 1.75” journals was the last item to be produced for the new 1300 saloons that appeared in 1967. When we were involved in writing the book “The Story of the BMC 1100” no one was able to establish dates for many changes during ADO16 development.

As the years unfold and people like Allan G Webb pass on we may never date the changes and in all honesty many people are now too young to remember the 1100 / 1300 cars or care about them at all. :) :)

Alan

Post Reply