22 replies to this topic

[pyromaniac_yeti]

Hi,

just wondering - looking through here, general idea is if you take a 1275 then put the metro turbo head, turbo etc on then itll blow up.

What would cause it to blow up?

and then the second question...

if you put several head gaskets on, then did as mentioned above....would that drop the compression ratio enough to not make it blow up or would the gaskets just cause a big mess...?

just curious on how to turbo a mini on a non existant budget basicly.

but say you put two gaskets on it, and ran the boost pressure fairly low...i.e less then the 7psi the metro turbo did it with, then would it hold together?

thanks

Iain

[stickycreambun]

hi mate, Im not sure on the turbo stuff, but what I can tell you is
two headgaskets would be rubbish, you can actualy get decompression plates, just really fat headgaskets basicaly to lower the cr, they seem to be frowned upon though..
and I think the turbo on a budget idea is is pretty doomed to start with..

[Turbo Phil]

There are plenty of people Turbocharging standard 998 & 1275 engines now. There's no reason it would blow up as long as the engine was in good condition, set up properly when the Turbo was fitted & the boost was kept to a sensible level.
I certainly wouldn't fit two head gaskets, the best and cheapest method is to have the chambers in the head enlarged to drop the compression. What's the current compression ratio of your engine ? If it's one of the low compression units you'll have an advantage already.

[Grimmy@JHE]

an engineering buddie of mine too some meat off his pistons. worked very well. was in last months mini world. pulled 78 bhp and was a 998

[pyromaniac_yeti]

well i was planning on running it on quite low boost anyway - so how many horses dya think i could get out of it without killing anything if i just took an ebayed turbo, manifold, carb, plenum etc with an intercooler of some description...and ran it with a decompression plate?

i mean im not looking for some kind of 200 break monster, i mean id be happy with 80-90bhp

would i have to scource a metro turbo head to use instead of the standard 1275 head with the decompression plate?
what sort of boost pressure would be the max before things started to pop?

[Ethel]

There are plenty of 1275's that had less compression than the Metty Turbo, on factory engines the different CR was achieved with different pistons. Turbos are rarely a cheap option and a normally aspiratedc engine could quite easily make the modest gains you mention.

[pyromaniac_yeti]

well yes they could,

but the idea is, convert it to turbo then gradually add bits here and there as they need replacing with better parts, then in the end when the engines got all the right bits on it i can turn the boost up...and as the turbo manifolds etc are getting harder to find, then it works out as a good investment in the future.

that plus the concept of a turbo'd mini just always appealed to me...

[matty...]

There really is no need for a turbo head, the only "advantage" of them is sodium filled exhaust valves. I used an N/A head for years wiht no probs as are many others.

The standard CR of a metty turbo engine is 9.4:1 IIRC? So it wouldn't be difficult to get to that figure or lower. If you go too low then the car really will be slugish off boost and not nice to drive. If your running low boost aim for about 8.8:1 to 9.0:1 this should give a good compromise on and off boost.

Your best to get the chambers in the head enlarged as Phil says, as this is the cheapest and safest way.

De-comp plates really are a waste of time and money by the time you've bought one, then bought 2 head gaskets you could of got the chambers enlarged.

[pyromaniac_yeti]

hmm...

so provided i diddent run silly boost or anything - would my standard 91/92 carbed cooper engine take a turbo, manifolds, carb, plenum, & some kind of intercooler? just as a bolt on the back of the engine jobbie?

im assuiming the fuel pumps gotta be swapped for something a bit heavier duty aswell?

[Turbo Nick]

i think they're the high comp engines, about 10.5:1 iirc so you'd need to have a chambered head done really before you put any boost into it.

yeah you need to swap the fuel pump for a metro turbo one, and a pressure regulator and a return fuel line.

[Ethel]

i think they're the high comp engines, about 10.5:1 iirc so you'd need to have a chambered head done really before you put any boost into it.

yeah you need to swap the fuel pump for a metro turbo one, and a pressure regulator and a return fuel line.

Thats my point really, there's loads of little bits, modding and setting up to install a turbo, especially if you you weren't jammy enough to find a complete Metro donor in working condition. You could easily spend a small fortune and never get to enjoy your outlay for the sake of one missing piece to your turbo jigsaw.

I do appreciate your forward thinking though, and yes - an intercooler would help hugely. One of the few bits you could easily and cheaply pick up.

[Grimmy@JHE]

cheaper buying a full turbo unit...

[Tomf]

Also you will have to buy and fit a turbo bulkhead box.

Your best bet it either to buy a complete metro trubo engine or but the bits and fit them to a NA engine. I wouldnt bother with a decompression plate, work out your compression ration and see how much you need to take it down by, then get the head charmers enlarged to bring this down.

[stickycreambun]

dont hack up a carby coopy!!

[Turbo Nick]

why not?

i turned mine into a matt black clubman, lol.

Edited by bud666, 08 January 2008 - 11:28 AM.