14 replies to this topic

[roy1964]

Hi, after a little advice please. I have access to a MG1300 block and head setup which i thought might be a good starting point for a rebuild engine project for the 64 mini that I'm restoring at the moment. Im planning to do a complete strip down and rebuild of the engine but do these blocks differ in anyway than any other 1275 engine. are they better in the head department? 

[DomCr250]

There are a few types of MG1300 ... hopefully it's not a MG Midget engine as that differs in a few areas and cannot be used as a complete unit?

 

If it's a transverse MG1300 it could be out of either an early 1970's Austin MG1300 or a later Metro MG1300, these are ideal for using in a mini.

 

All MG's have better heads than the standard 1300, depending on their specific fitment they also could have slightly better cranks and an improved cam.

 

Best bet is to post some pictures or if possible an engine number to help with ID. 

 

When they were plentiful in the scrappies it was a great upgrade, you could get a complete Austin MG1300 engine, box and carbs for less than £100 and humble mini's used to fly!

[Spider]

Fundamentally and from a rebuild point of view, they are the same as any other 1275, though the early ones had smaller Big Ends and similar Con Rods to the Cooper S. The Heads from memory, had bigger Inlet Valves and slightly improved Inlet Ports.

[roy1964]

The engine in question has 12G 1979 cast into block and a tag on the deck which looks like 2H 353E plus some other numbers that are hard to read. Am I right in thinking that it's from a 1300 MG land crab.

[Spider]

The 12G Blocks are rupuded to be MKI Cooper S Blocks, and it is also claimed they have the EN40B Nitrided Cranks and Cooper S Con Rods, basically a de-tune Cooper S Motor.

[mab01uk]

The engine in question has 12G 1979 cast into block and a tag on the deck which looks like 2H 353E plus some other numbers that are hard to read. Am I right in thinking that it's from a 1300 MG land crab.

 

'Land crab' is usually the nick name of the larger Issigonis designed BMC1800/2200 range of cars which did not use the A series engine.

The BMC 1100/1300 is often referred to as the ADO16 as there were so many 'badge engineered variants like the MG 1100/1300.

 

A lot of info on these cars and their engine/gearbox differences to Mini's can be found on the Mk1 Mini forum here:-

http://mk1-forum.net...336dbd3485718c6

Edited by mab01uk, 20 December 2016 - 12:35 PM.

[DomCr250]

If it's out of the ADO16 range then it's a nice little engine.  Block, crank, head and transfer case are the same as a mini.  12G940 head with decent size valves as standard.

 

As stated above, some of them came with better cranks and almost all of them with the extra cylinder head bolts and studs .. so they make them look like S lumps, but they are not because these blocks did not have the tappet covers as true S engines did ... you can check this really easily.

 

The gearbox (if it's still attached) differs in that the remote is rubber mounted and not solid mounted.... if it's still with it then you can use it but you need the correct remote, not a mini solid remote....think it had a CR gear set, but a much lower final driver for the bigger wheels....we used to get the mini speedo's to whizz past the 90 mark because the gearing was out and the speedo's incorrectly calibrated!

 

These engines also had an additional engine mount that ran from the back of the timing chain plate to their subframes ... we used to just chop the extra bit of metal off with a saw before fitting.

 

Nice find.

Edited by DomCr250, 20 December 2016 - 04:17 PM.

[Cooperman]

The Mk1 Cooper 'S' engines were numbered 9F-SA-Y-*****

[mab01uk]

This long thread (28 pages) on the Mk1 Forum surprised many about the 12G engine......(for quote below see page 4 of thread link)

http://mk1-forum.net...start=30#p95057

 

Quote:

"ADO16 cars did have S type engines fitted from June to September 1967 and this is no myth. Think about it the 12H 1275cc engine was first built post September 1967. In order for BMC to provide a 1275 cc ADO16 from June 67 they used the 1275 cc S type engine as a stop gap. Some claim less than 900 cars were built.

These engines had an ENB40B crankshaft and con-rods with tappet chest covers and are known as 12G engines: - buyers of early BMC 1100 / 1300 cars had the option of 1098 cc or 1275 cc engines. The first 1275 cc engines were suffixed by engine number 12G and are extremely rare. These engines all had a 9 stud cylinder head, AEG510 cam, forged rocker assembly and the EN40B crank with smaller 1.5/8 inch journals, connecting rods, crankshaft diameter being the same size as the Cooper S engines. The cranks were all marked EN40B and dated. They also all used a single 1½ inch carburettor. This engine was only fitted to the very early MG, Wolseley, Riley Kestrel and Vanden Plas which were called the 1275 model. Some refer to this model as the Mk1½ in the 1100 club.
In November 1967 BMC introduced a completely different 1275 cc engine block, crankshaft, connecting rods and these were suffixed by engine number 12H. These engines were used in the normal run of the mill BMC 1300 cars and 1275 GT Mini from 1969.
To further complicate matters the very early 12H 70 BHP engine had an EN40B crank with 1.5/8 inch journals, and large valve 11 stud cylinder head. These engines are solid wall blocks and date from late September 1967 and were only used in the Riley and MG 1300. It is important to remember that the EN40B crankshaft out of this solid wall engine has a different centre main bearing width.
The 12H 70 BHP engine a sister of the above had an EN16T crank with 1.3/4 inch journals, heavier connecting rods, same pistons and large valve 11 stud cylinder head. These engines date from November 1967 and were only used in the Riley 1300, MG 1300 and Austin / Morris 1300 GT. This same engine was also fitted to the Innocenti Cooper 1300.
Years ago Dave Gilbert explained to me this piece of information was not common knowledge in Mini circles as smart individuals kept these facts undisclosed? Dave was of the opinion that all the 12G tappet chest engines ended up in Coopers and the early 12H solid block engines were used in motorsport."

http://mk1-forum.net...hp?f=28&t=12136

Edited by mab01uk, 20 December 2016 - 08:08 PM.

[Spider]

The Mk1 Cooper 'S' engines were numbered 9F-SA-Y-*****

 

I did make a blue in not reading Roy1964 post completely, he was referring to a casting number, not the engine no. The 12G1979 were solid tappet Chested 1275 Blocks, shared with the 1275 GT.

 

However, my mis-read post was in regards to the 12G Engine Numbered Blocks, repudedly Cooper S Blocks. Yes, when fitted to Cooper S's they were stamped 9F-Sa-Y-***, however, when used in the early MG1300 they had the Engine No. Prefix of 12G:-

 

From 'Supersonic' on the MKI Forum;-

 

"ADO16 cars did have S type engines fitted from June to September 1967 and this is no myth. Think about it the 12H 1275cc engine was first built post September 1967. In order for BMC to provide a 1275 cc ADO16 from June 67 they used the 1275 cc S type engine as a stop gape. Some claim less than 900 cars were built.

These engines had an ENB40B crankshaft and con-rods with tappet chest covers and are known as 12G engines: - buyers of early BMC 1100 / 1300 cars had the option of 1098 cc or 1275 cc engines. The first 1275 cc engines were suffixed by engine number 12G and are extremely rare. These engines all had a 9 stud cylinder head, AEG510 cam, forged rocker assembly and the EN40B crank with smaller 1.5/8 inch journals, connecting rods, crankshaft diameter being the same size as the Cooper S engines. The cranks were all marked EN40B and dated. They also all used a single 1½ inch carburettor. This engine was only fitted to the very early MG, Wolseley, Riley Kestrel and Vanden Plas which were called the 1275 model. Some refer to this model as the Mk1½ in the 1100 club."

 

The page can be found here (it's a long thread):  http://mk1-forum.net...=12136&start=30

 

The whole thread here:   http://mk1-forum.net...hp?f=28&t=12136

 

<Edit: mab01uk beat me to it! >

Edited by Moke Spider, 20 December 2016 - 08:02 PM.

[mab01uk]

 

<Edit: mab01uk beat me to it! >

 

 

Only by 2 minutes!

Edited by mab01uk, 20 December 2016 - 08:11 PM.

[Spider]

 

 

<Edit: mab01uk beat me to it! >

 

 

Only by 2 minutes!

 

 

Bah!  It's a longer string out here to the colonies and back

[DomCr250]

I think it was common knowledge back in the late 70's and 80's that some of these cars came with these engines ... Well it was if you had a copy of David Vizzards book because he described the engines in it..

[roy1964]

So yes grab it if I can??

[Spider]

So yes grab it if I can??

 

Ordinarily, I'd say "No, best leave it for me" but given where it is, YES, grab it, BUT do an internal inspection if you can. While you can expect to have to overhaul it, you just want to check that there's nothing unexpected to rectify too.