whats my engine??????
Turbo Mini Forums

hi just stripped an 12h engine i had laying around. to build a turbo motor, the head is 12g 940. but i cant figure out what the engine is. the number is 12hco1aa 114253. and on the top of the dished pistons is, a 21268 g7L18. can anybody help me as i need to know if this is a good basis for a budget build. thanks.

I have the same engine code. I've found one source saying 9.75:1 compression 63HP, and another 8.8:1 compression 55HP.
I found this on the Deves piston rings site:
Allergo 1.3, A+ Series 1981-82 4 70.63 1.59 1.59 4.00 - - - 1251 B
Meastro 1300, Metro 1.3 1980- 2.780 1-K 1-SK 1-O
Metro Vandenplas 1300 1982-
Montego 1.3 1984-
(AE Piston #21268, 20755 & 21031)

Doesn't tell the compression ratio or dish size, but it does say these use 1.59mm compression rings and 4.0mm oil ring.

1275 with Back Door Turbo

One more thing: Mine runs fine with 8psi boost on 95 RON gas. So I'm thinking it is the 8.8:1.
Does anyone have an AE piston reference with dish sizes?

1275 with Back Door Turbo

Found this on Mini Forum spreadsheet:

12H C01 --> 11 1275 A+ L D I Metro, 9.75:1CR

A German source also lists it as high compression.

Can you post a piston picture or measure the dish volume? I would very much like to know the compression.

1275 with Back Door Turbo

A 12HC01 is a standard compression ratio 1275 (9.4:1) originally fitted to a 1985 -1987 Metro.

thanks for all the help so far this is a great info source. im new to the turbo game. is the 9.4:1 cr to high to run decent boost. and the othe question is the 12g940 head has been skimmed on the top surface. anyone know of a reason for this.

The metro ran a max of 7psi with a similar cr, wouldnt recommend going any higher (without adressing cr & fitting an IC), but you will need to recalculate the cr if the head has been skimmed (would of been skimmed if head was warped/ head gasket problems, reset rocker geometry)
If you wanting to turbo the engine you have there are a few other areas you will need to check/spend money on to ensure the engine lasts, eg diff, gear box, and drops, Compression ratio, choice of cam, the list goes on, but if your carefull a reliable/ powerfull engine can be built for not hugh somes of cash, just be realistic with the power you want to achieve, vs the buget you have.
Shane

Edited by shane on 5th Dec, 2007.

how would i identify what gearbox i have is it the dam 66 etc numbers

There is a guide to idenifieng engines and gear boxs in a mini mag a few years back?, I will be most supprised if there isnt the info somwhere on this site, have you tried the seach button?
Shane

yeah no luck yet. is it possible to buy re-build kits for a standard hif44 to convert it to a sealed unit.

Edited by spudmini on 5th Dec, 2007.

Oddly enough, the Metro Haynes manual that I recently bought on Ebay arrived today. In the back on page 176 it has engine codes. There it states that 12HC01AA is for a 9.75:1 compression engine. According to this manual, which covers 1980-1987 Metros, 1985 and on Metro 1.3L engines had 9.75:1 compression standard, and only the turbo engine had 9.4:1 after 1984. There are a few engine codes listed as 8.0:1.

Dunno if it is right, but it is the only document I've seen so far that has some authority behind it. The online sources I've found are just spreadsheets with no hint of where their data came from.

Edited by fortfun on 6th Dec, 2007.

1275 with Back Door Turbo

you done your homework mate well done. so 9.75:1 is my cr. are the pistons standard. the numbers are at the top of the thread

can't find anything on that piston number so far. You should find an AE pistons dealer and get them to look up the dish size on it. If you've removed a piston though, it should be easy to measure with a piece of plexiglass and a pipette.

1275 with Back Door Turbo

I have just dug out my genuine Austin Rover workshop manual for the Metro, and the 12HC01 is indeed listed as 9.75:1. The engine is a 1986 vintage, as well.

Sorry for the earlier duff info. I used the Unipart parts catalogue to decode the engine code, and it is normally accurate.

you people are too good!