11 replies to this topic

[krez]

12A 497
with 12g295 head

anyone know anything???

[Retro_10s]

It's a 1990 onwards 1275 block.

[fikus01]

with a 998 cooper head

[krez]

It's a 1990 onwards 1275 block.

urm i owned it since about 1989/90 and it was old then so it cant be 90 onwards
i found a post on some other site saying a 12a497 is 998 so gets confusing
http://www.minimania...3/msgthread.cfm

Edited by krez, 14 March 2007 - 11:56 PM.

[fikus01]

with engine numbers if they are on the rover plate and they start 12 its a 1275, weather its 12A 12H 12HC 12HF

if the head is cast 12A then its std 998
if its 12g 295 its a 998 cooper
if its 12g940 its 1275 head

there is usually more chracters to the engine number tho, is that the whole thing?

have a lookie on here http://www.theminifo...x...ost&id=8738

[Guess-Works.com]

if the 12a497 is cast into the block then it's a part number and not an engine number... you need to look at the engine number on the flat above the alternator mount..

As for fitting a 12G295 onto a big bore block..... WHY ???

[krez]

if the 12a497 is cast into the block then it's a part number and not an engine number... you need to look at the engine number on the flat above the alternator mount..

As for fitting a 12G295 onto a big bore block..... WHY ???

unfortunatly i do not have the engine number plate attatched! that is why i am trying to find which model used the 12a497 block, i have been told it is a 998 or 1100 not a big bore block, head coming off tomorrow

[Retro_10s]

Ah,.... I see.... 12A is the Engine number prefix that told me it was 1990 onwards 1275.... But If you'd said that you hadn't given the Engine number, but given a cast code, then I wouldn't have thrown the suggestion in, sorry!

Sorry to have confused the matter mate. Is the engine in the car? whip the head off and look at the pistons/ measure the bores...

then you'll at least know the cc.

[krez]

whip the head off and look at the pistons/ measure the bores...

then you'll at least know the cc.

right, head has been off 2 day, whats my cc ? im calculating about just over 1100 is that right? stroke 76.2 bore 65.5 head looks standard spec 12g295 valves about 25 mm an 30 mm dished pistons. what cc do people think then?
cheers
krez

Edited by krez, 22 March 2007 - 12:09 AM.

[Retro_10s]

The 12G295 Head was fitted to the 998 Cooper & MG1100, Now, the stroke for the 1100 is 83.82mm,... so bearing the shorter stroke in mind i would put forward that you have either a 998 Cooper engine, or a standard 998 with a Cooper head on....

If it's the latter... you might have a fancy cam in there too!

Edited by Retro_10s, 22 March 2007 - 10:36 AM.

[ferrox_666]

i also have a block with 12a497 cast into it, it is a 1098 with an 83.72mm stroke and 64.59 bore though mine is 65.10mm meaning +20thou over, i have a 12G940 head attached and you'd need to make sure you block off some of the waterways because they overlap the bore slightly.. standard C?R is 8.5/1 by the way..
mine will be turbocharged, was in the 998 turbominis forum but not really allowed because its over a litre..

[62S]

12A 497 is a commonized small bore block so could have started out as 997, 998, or 1098.

The Cooper 998 had 'D' top pistons so if they are dished they are not UK Cooper 998 spec. It's had a fair size overbore so might have a nice cam in it.