18 replies to this topic

[AVV IT]

Hi,

I've been offered an MG metro engine to transplant in place of my somewhat poorly 1275 (carb with CAT) 1993 mini sprite unit. Would the MG Metro engine offer any improvement in performance/ power over my standard 1275 engine, or is it basically the same unit?

Cheers

Dave

[Cooperman]

It's basially the same unit, but the MG Metro had a head with bigger inlet valves, up to 35.5 mm from 33.6 mm and a far better cam. In fat the MG Metro cam is often regarded as the finest cam ever produced for the a-series engine in prodution form. Nominally an MG Metro engine gives, I believe, 73 bhp at the flywheel.

[miRon]

It's basially the same unit, but the MG Metro had a head with bigger inlet valves, up to 35.5 mm from 33.6 mm and a far better cam. In fat the MG Metro cam is often regarded as the finest cam ever produced for the a-series engine in prodution form. Nominally an MG Metro engine gives, I believe, 73 bhp at the flywheel.

your forgeting the alloy rocker cover!

good info there^^

[bmcecosse]

Only the early 'leaded' engine had the larger inlet valve. When it went unleaded - the standard valve size head was used. The MG engine does have higher compression ratio though - by use of slightly taller pistons that come right to the top of the block. And that MG cam is indeed very good - and without having super high lift which soon wears out the valve train!

[mk3 Cooper S]

Only the early 'leaded' engine had the larger inlet valve. When it went unleaded - the standard valve size head was used. The MG engine does have higher compression ratio though - by use of slightly taller pistons that come right to the top of the block. And that MG cam is indeed very good - and without having super high lift which soon wears out the valve train!

Sorry to hyjack, but I I have an early leaded MG engine that is in good order what could I do to optimise it 1.5 rollers ?

[bmcecosse]

The rockers may give you 1 extra bhp........... To improve it - same as any other engine - flow the head and optimise the ignition timing and the carb settings - including 'Vizardising' the carb!

[mk3 Cooper S]

The rockers may give you 1 extra bhp........... To improve it - same as any other engine - flow the head and optimise the ignition timing and the carb settings - including 'Vizardising' the carb!

Thanks, is it worth changing the timing chain and getting a vernier set up?

[minidan]

im taking my mini for a rolling road setup in a couple of hours, and i have an MG metro engine installed. basically standard except for the usual mods like exhaust and k&n filter.

i'll post up the results later on

[minidan]

just got back,

results are:
max power - 81.1bhp @ 5429rpm(flywheel)
65.5bhp (wheels)
max torque - 86.2lb/f @ 4299rpm



pretty happy all in all, but on the second power run the fan exploded into loads of pieces! we think it sucked the breather hose into it causing all 11 blades to fly off and maximum rpm!! ouch.

no bad though for a nearly standard 1275 mg metro engine.

[mk3 Cooper S]

just got back,

results are:
max power - 81.1bhp @ 5429rpm(flywheel)
65.5bhp (wheels)
max torque - 86.2lb/f @ 4299rpm



pretty happy all in all, but on the second power run the fan exploded into loads of pieces! we think it sucked the breather hose into it causing all 11 blades to fly off and maximum rpm!! ouch.

no bad though for a nearly standard 1275 mg metro engine.

Excellent.
I hope mine is as strong as yours.

[Hegnirst]

just to go back to this long lost thread aha
does mileage on the engine account for anything, as i heard that the engine slowly looses it bhp over time,
mine is mg metro one and it has 32K on it XD which im chuffed with!
and it has a kent 276 cam in it,
what do you reckon it will be as im getting it RR'd this thursday

[bmcecosse]

Initially an engine may actually improve as it 'runs in' - but then some wear and tear sets in and the power is bound to sag away with increasing mileage.

[Pigeonto]

We've had some slightly unpleasant threads lately,what with people having a go at each other over poor English,prompting staff intervention and various other stuff and I thought lets get away from that and raise something contentious! I like contentious. OK then, I'm troubled by this.1275 S:- claimed 76bhp. MG 1275 @72. How come?? I've had this discussion with fellas around the country and I wonder you know if the MG is understated.My thoughts:-, Uncle C just said it has the best cam ever fitted. 10.5 CR compared to 9.75 on the S, Same size inlet valves on the pre-unleaded heads, HIF 44 compared to twin 1 1/4"s well thats always reckoned to be as good a set up as twins if not better if you take the view that only one cylinder is drawing mix at any one time, some S engines had 31mm exhaust valves, well if that made such a difference we'd all do it but if you look at modded heads on offer the next stage tends to be 37 ins and 29 exs. What's left? exhaust system? reckoned to be good on the metros with that twin cast manifold,The S didnt have an alloy rocker cover so its not that. Body stickers-yes the MG had em.The S had huge 'kudos' but surely,no. I dont get it and stand to be enlightened by someone.

[racingbob]

regarding the mg metro engine

I have only ever raced minis on the circuit, in historic , mini 7 and club cars

I just recently purchased a mini for raod use and was suprised how well the mg metro engine went

have just modified it a bit and balanced engine and thet cam is soooo good with lots of torque from low down

it realy does go well with keeping the revs down unlike a race car

[twrminisport]

Just a thought...
The Cooper S 1275 engine was produced from sept '67 to '70
The MG Metro was produced in '82

Thats a 15 year design gap....
Think of how much the engine tech changes and how much they find out in 15 years.
Plus the fact that the Metro was 2 years into its production and had not proved nearly as successful as what it intended to replace .... our beloved mini....

With a 15 year engine development advantage and a need to rebrand a so far failing car I'm not surprised at all...

Jesus

Edited by twrminisport, 29 November 2011 - 10:31 AM.