35 replies to this topic

[clivemk1mini]

as above really i have a 1300gt short block also a stage 2 head. was just wanting to no will a 1275 gearbox fit onto it? also will all 1275 parts be ok for example

1) alternator
2) starter
3) dizzy
4) cam
you get the idea

thanks

clive

Edited by clivemk1mini, 28 February 2011 - 08:47 PM.

[mk3 Cooper S]

Parts should be OK.

You will need an extra bracket for the Alternator.
The dizzy/dizzy drive needs to be matched i.e A series not sure if A+ is ok probably with the different bracket.
Is the starter pre inertia?

1300gt motor is a great base unit.

[clivemk1mini]

I don't no about the starter I don't actually have any other parts other than the short block and head.

Just trying to see which bits I can use from the mini or if I have to get stuff for a 1300gt engine.

What about the flywheel do I need a 1300gt one or will a 1275 one be better?

Thanks for your help

And sorry for all the questions

[Dan]

You need to understand that it was the car that was called a 1300, it didn't describe the engine. The engine was a 1275 and was essentially the same engine and transmission as in the Mini. In fact other than some bracketry, it was a Cooper S 1275 engine.

[Cooperman]

Except that the Cooper 'S' engine had a different block, crank, rods and an 11-stud head! It's the 1275 GT Mini engine which is virtually the same as the Austin 1300 lump and which is also, as you rightly say, 1275 cc capacity as standard..

[Dan]

The late Mk3 Cooper S units were the same though to my knowledge, the ones that were contemporary to the 1300GT. Could well be wrong though.

[Cooperman]

The late Mk3 Cooper S units were the same though to my knowledge, the ones that were contemporary to the 1300GT. Could well be wrong though.

To the best of my knowledge, all Cooper 'S's should have had blocks with the cam-chest covers, 11-stud heads and 1.625" dia big ends with the EN40B crank.
However, the Innocenti Mini-Cooper 1300 from 1972 did have the 1300GT block with the larger 1.75" big ends and no cam chest covers, so it's quite possible that for the very last U.K-built Cooper 'S's (in 1971) that engine was fitted. I did strip my Inno engine when i first got it and it has the equivalent to the 510 cam ('S' cam), an 11-stud 'S' head and twin HS2's with the BMC inlet manifold and 3-into-1 ex. manifold.
I have re-built a 1970 'S' and it had the correct 'S' engine which I was told was original.
Certainly no Mk.2 'S's had the 'GT engine, unless fitted later after the owners had 'blown-up' the original.
It's an interesting topic and I would love to know whether any Mk 3 'S's had the GT block, crank & pistons as ex-factory standard (anyone?).

[mk3 Cooper S]

The late Mk3 Cooper S units were the same though to my knowledge, the ones that were contemporary to the 1300GT. Could well be wrong though.

To the best of my knowledge, all Cooper 'S's should have had blocks with the cam-chest covers, 11-stud heads and 1.625" dia big ends with the EN40B crank.
However, the Innocenti Mini-Cooper 1300 from 1972 did have the 1300GT block with the larger 1.75" big ends and no cam chest covers, so it's quite possible that for the very last U.K-built Cooper 'S's (in 1971) that engine was fitted. I did strip my Inno engine when i first got it and it has the equivalent to the 510 cam ('S' cam), an 11-stud 'S' head and twin HS2's with the BMC inlet manifold and 3-into-1 ex. manifold.
I have re-built a 1970 'S' and it had the correct 'S' engine which I was told was original.
Certainly no Mk.2 'S's had the 'GT engine, unless fitted later after the owners had 'blown-up' the original.
It's an interesting topic and I would love to know whether any Mk 3 'S's had the GT block, crank & pistons as ex-factory standard (anyone?).

Most Mk3 S has no tappet chests and an 11 stud block and head.
S crank and rods.

1300GT has an 11 stud block, S rods but a tuffrided crank.
Still a very good base unit only slightly susbstandard from an original S engine.
The cams are different I think

[Cooperman]

The late Mk3 Cooper S units were the same though to my knowledge, the ones that were contemporary to the 1300GT. Could well be wrong though.

To the best of my knowledge, all Cooper 'S's should have had blocks with the cam-chest covers, 11-stud heads and 1.625" dia big ends with the EN40B crank.
However, the Innocenti Mini-Cooper 1300 from 1972 did have the 1300GT block with the larger 1.75" big ends and no cam chest covers, so it's quite possible that for the very last U.K-built Cooper 'S's (in 1971) that engine was fitted. I did strip my Inno engine when i first got it and it has the equivalent to the 510 cam ('S' cam), an 11-stud 'S' head and twin HS2's with the BMC inlet manifold and 3-into-1 ex. manifold.
I have re-built a 1970 'S' and it had the correct 'S' engine which I was told was original.
Certainly no Mk.2 'S's had the 'GT engine, unless fitted later after the owners had 'blown-up' the original.
It's an interesting topic and I would love to know whether any Mk 3 'S's had the GT block, crank & pistons as ex-factory standard (anyone?).

Most Mk3 S has no tappet chests and an 11 stud block and head.
S crank and rods.

1300GT has an 11 stud block, S rods but a tuffrided crank.
Still a very good base unit only slightly susbstandard from an original S engine.
The cams are different I think

That's good info. When the EN40B crank was fitted to the GT-type block without cam chest cover plates, what was the arrangement at the centre main bearing as regards cap widths and thrust bearings?
The only 1300GT engine I've ever stripped had 1.75" big-ends. I thought only EN40B forged and nitrided cranks had the 1.625" big-end journals. My '73 Innocenti certainly has the GT block with 11 studs, an 'S' cam, but 1.75" big-ends.
Oh, the wonders of BMC/BLMC engineering. No wonder they were always short of money for developoment. No other company could make so many different variants of one basic engine size and cause such confusion.

[Cooperman]

Mk3 S's & 1300GT's. should have EN16T cranks.

What size big-end journals and which con rods should a Mk. 3 'S' have?

[clivemk1mini]

I will try to take some pictures the engine is sat in the back of my shed in bits. It is a 11 stud block and head I no that much. I will need to get someone to rebuild it any ideas of anywhere near me that can do it?

[clivemk1mini]

ok managed to get some picture so people what have i got and is it any good lol.

Edited by clivemk1mini, 02 March 2011 - 05:26 PM.

[clivemk1mini]

the head has double valve spings the valves are 35mm and 28mm the only number i can see is 19m5 (what head is it?)

[clivemk1mini]

only number i can find on the crank our 81dh




numbers on the rods our 12G1298/9 F&P53 1WO and on the pistons our AEG341v21



and other bits i have

[clivemk1mini]

i also have this engine sat in the garage so is it worth building the 1300 engine and use this for bits or should i just put this one in the car