12 replies to this topic

[dannyjames]

Im Currently running a low mileage MG Lump standard apart from exhaust, filter and MegaJolt in the near future i was thinking of going the vmax charger route but just wondering how much it would cost to turbo it?

I would be using mirage? manifold but anyone have a idea how much the turbo and other little bits can be had for?

Also is it possible to have a reliable engine with a decompression plate? Im wanting about 100 BHP so not mega power just nippy and hopefully reliable

[dannyjames]

After a bit of reading it seems decompression plate is a no no , So im thinking maybe standard Turbo pistons and get the head chambers opened up, would this make a decent motor for running 8 - 10 psi ? anything else to consider?

Seen a set of metro turbo pistons and rods for £150 is that the going rate?

Sorry for all the questions but im trying to read as much as possible

[Ethel]

You seem to be on the right lines, the main issue with an MG spec engine is the high CR. Std Turbo pistons are good but others will do.
Can't comment on the price with any authority but it seems a bit high to me considering what you might pay for a whole A series, or new pistons.

[John H]

If you sre only looking for 8-10psi get the cylinder head opened up to 28cc this would bring your CR down to about 8.8:1 (assuming you are using a standard leaded mg metro engine) get an efficient intercooler in there and you will be good for a safe & reliable 100-110bhp-ish. Maybe even more if you have a well worked cylinder head.

Please bear in mind this is assuming your engine/box is in tip top condition. It would also be good practice to at least rebuild your diff for peace of mind.

[Mr Joshua]

The MG Metro cylinder head was fitted with TAM 1059 exhaust valves and TAM 1061 inlet valves, your basic early stage of big valve head. The exhaust valves need to be replaced with ones suitable for a turbo application. You can get 29.2 after market valves suitable to the task from Mini Spares the inlets will be 35.6 and can be left in. You don’t need to do anything to the chambers unless you are trying to build in the option of going for monster power. Plus you need to invest in a set of double valve springs. On the subject of pistons, you can probably get an after market piston to fit the standard bore but you wont get the rings to fit. Best advice is to re-bore to first oversize (+0.20”) for a 1293 capacity which gives you a good platform for any spec engine build fitting used pistons and rings into another block is just trouble, not asking for trouble in that it may work, just trouble period!

You won’t need to change the cam as the MG one is one of the best options for upgrades, the crank is just fine unless the shells are fubared.

Best advice is to price up the cost of building your short motor then look at the cost of buying one off the shelf from some where like Minispeed. I caution buying the components individually to do this from so called specialist companies as they take pleasure in dicking you around.

[dannyjames]

The MG Metro cylinder head was fitted with TAM 1059 exhaust valves and TAM 1061 inlet valves, your basic early stage of big valve head. The exhaust valves need to be replaced with ones suitable for a turbo application. You can get 29.2 after market valves suitable to the task from Mini Spares the inlets will be 35.6 and can be left in. You don’t need to do anything to the chambers unless you are trying to build in the option of going for monster power.

When you say i don't need to do anything with the chambers is this with the standard compression/pistons or with fitted low comp pistons?

[wolfie]

You seem to be on the right lines, the main issue with an MG spec engine is the high CR. Std Turbo pistons are good but others will do.
Can't comment on the price with any authority but it seems a bit high to me considering what you might pay for a whole A series, or new pistons.

Thats not true as both the MG and MG turbo have 9.4:1, the difference is in the thickness of the crown

[Mr Joshua]

The MG Metro cylinder head was fitted with TAM 1059 exhaust valves and TAM 1061 inlet valves, your basic early stage of big valve head. The exhaust valves need to be replaced with ones suitable for a turbo application. You can get 29.2 after market valves suitable to the task from Mini Spares the inlets will be 35.6 and can be left in. You don’t need to do anything to the chambers unless you are trying to build in the option of going for monster power.

When you say i don't need to do anything with the chambers is this with the standard compression/pistons or with fitted low comp pistons?

The head castings are the same except for the machining for the bigger valves, so the chamber volumes will be the same. The compression is lowere by the dished pistons on a turbo. Or you could fit a cometic head gasket.

[Turbo Phil]

The MG Turbo is 9.4-1 compression ratio, the NA MG Metro is 10.5-1.

[Ethel]

Unleaded MG's were 9.75:1 I think, certainly less than the original MG with 1.4" inlets.

[John H]

From my findings.

Leaded MG Metro engines had a CR 10.5:1
Unleaded MG Metro engines had a CR 10:1

[bensonmi]

im also interested in this, how easy are the exhaust manifolds and turbos to obtain? i once owned a metro turbo but ended up having to sell it for £75 due to my boss not letting me keep the car in the car park. huge regret!

[Ethel]

I think every A Series Turbo component in existence is now circulating between various Minis and Ebay