19 replies to this topic

[fox815]

Hi

 

My car is 97 Mayfair 1275cc SPI.  I would like to upgrade to stage 3 engine kit.

 

Which brand of Cylinder Head is best?

If it is upgraded, do other components need to improve performance, such as suspension, etc？

 

thanks

 

[brivinci]

Never been a fan of "stage" conversations. What exactly are you looking to get out of this motor is a better way to start and will yield better, more specific answers.

[Tones61]

M.e.d. Inc anything else for performance

[joekenton]

I'm researching what I want to do to my 1275 SPI Copper, but here is a very rough list of what you can do to improve performance without negatively effecting regular town driving:

 

Small upgrade: Maniflow LCB injection manifold + Single 1 3/4" exhaust + k&n air filter

Medium upgrade: Above + Cylinder head (lots of options here, look at minispares, KAD, MED, and a million of other places

Bigger upgrade: Above + injection cam such as Kent 274, if you want to go further you could get a slightly lightened steel flywheel

 

The above ignores the small bits such as uprated gaskets, spark plugs etc. I'm also by no means an expert. 

[brivinci]

You really won't "see" any real gains before you get a head on there. Exhaust and filter will not add much. If you want to improve the performance, I would start with a good head, and then add the rest of the parts needed to compliment it. If pulling the engine is no in the cards, a set of 1.3-1.4 high lift rockers will squeak out a bit more from the motor. I know most go to 1.5's, and some of the kits, including the Cooper one, use 1.5 but you are not gaining anything from them. Even though stock is quoted as having 1.3 ratio rockers, they are more like 1.2. 

 

Weight reduction can also be very beneficial. A good light weight flywheel with upgraded clutch and pressure plate would be a very nice thing to include while you are adding power. MED has a lovely unit that comes pre-balanced, so no need to have to take it to get done. and trust me, you NEED to have them balanced.

[Pops_Guild]

brivinci is correct, the head is where the main gains will be found but I do somewhat disagree that exhaust/filter wont do anything. From my own experience it will, but there are limits.

 

There is a base performance difference between Mayfair (50bhp) / Cooper SPi (62/63bhp) to consider to. I believe the ECU and cam is different on the Coopers. I think you also have to bear in mind that the current state of your Mini may not be in out-of-factory condition...basically all perf gains you might get are relative to the real starting point of your engine. There is a limit to the perf you can achieve with the stock Injection setup and ECU.

 

My own experience is that I have 96 Cooper SPi (Cooper 35LE), when I first bought it, it was stock exhaust, stock filter...it ran but wasn't very Cooper-like. I took it for a rolling road session to see where it was, 52bhp.

 

5 years later, fully restored Mini, head has been refurbed but just to standard spec, fuel system refurbed & setup correctly, cooling system fully refurbed (the engine block water jacket was blocked in places), SC LCB, standard original cat, Fletcher side exit back box, 1.3 MED rockers (I did this because it was quicker than refurbing the standard set, not for perf). It is still a 1275. It's basically a "Small Upgrade/Stage 1 and a bit". Took it to the rolling road a few weeks back, now 68bhp. 

 

That new bhp is not headline grabbing, but it's not nothing either. But I will say I spent a lot of time making sure the stock engine was in good shape, so some of that gain could just be from that.

 

I'm currently on a mission to find out what the bhp cap is without changing the head but that's another story :).

[fox815]

brivinci is correct, the head is where the main gains will be found but I do somewhat disagree that exhaust/filter wont do anything. From my own experience it will, but there are limits.

 

There is a base performance difference between Mayfair (50bhp) / Cooper SPi (62/63bhp) to consider to. I believe the ECU and cam is different on the Coopers. I think you also have to bear in mind that the current state of your Mini may not be in out-of-factory condition...basically all perf gains you might get are relative to the real starting point of your engine. There is a limit to the perf you can achieve with the stock Injection setup and ECU.

 

My own experience is that I have 96 Cooper SPi (Cooper 35LE), when I first bought it, it was stock exhaust, stock filter...it ran but wasn't very Cooper-like. I took it for a rolling road session to see where it was, 52bhp.

 

5 years later, fully restored Mini, head has been refurbed but just to standard spec, fuel system refurbed & setup correctly, cooling system fully refurbed (the engine block water jacket was blocked in places), SC LCB, standard original cat, Fletcher side exit back box, 1.3 MED rockers (I did this because it was quicker than refurbing the standard set, not for perf). It is still a 1275. It's basically a "Small Upgrade/Stage 1 and a bit". Took it to the rolling road a few weeks back, now 68bhp. 

 

That new bhp is not headline grabbing, but it's not nothing either. But I will say I spent a lot of time making sure the stock engine was in good shape, so some of that gain could just be from that.

 

I'm currently on a mission to find out what the bhp cap is without changing the head but that's another story :).

thank you very much for your reply.

 

my engine no. 12A2EK71

i saw the base hp is 63, is it right?

 

thanks

[Pops_Guild]

Yep from GuessWorks engine ID that engine number looks to be a Japanese export Cooper but you said Mayfair in your original post?

So it’s a re-imported Japanese Mini then? With Air Con?

If it’s a Cooper it will be 62/63 bhp spec when it left the factory.

[fox815]

Yep from GuessWorks engine ID that engine number looks to be a Japanese export Cooper but you said Mayfair in your original post?

So it’s a re-imported Japanese Mini then? With Air Con?

If it’s a Cooper it will be 62/63 bhp spec when it left the factory.

yes, its imported from japan with air con, but sub-model is mayfair. 

engine no is 12A2EK71.

 

so 50 bhp or 63 bhp?

thanks

[Pops_Guild]

 

Yep from GuessWorks engine ID that engine number looks to be a Japanese export Cooper but you said Mayfair in your original post?

So it’s a re-imported Japanese Mini then? With Air Con?

If it’s a Cooper it will be 62/63 bhp spec when it left the factory.

yes, its imported from japan with air con, but sub-model is mayfair. 

engine no is 12A2EK71.

 

so 50 bhp or 63 bhp?

thanks

 

>> You know as much as any of us here, we're only going off what you tell us :). That engine number is a Cooper engine according to GuessWorks Engine decodered (Google it!).

 

As to whether it's 50 or 63bhp, as per my initial reply, after 20+ years or wear & use, in reality it is very unlikely to be either. If you really want to know for sure the only way to know is get it to a rolling road and they will tell you...anything else is guess work! 

[Wazzah]

JDM Cooper engines are high compression motors with the slightly hotter MNE10351 ECU.

The Vin number is also a clue.

It is my understanding that the 6th letter will be an N for Cooper or a W for Mayfair.

The 8th letter will be X for the low compression SPI motor or Y for the high compression SPI motor.

Not sure of Mayfairs but Coopers are Y's.

[fox815]

JDM Cooper engines are high compression motors with the slightly hotter MNE10351 ECU.

The Vin number is also a clue.

It is my understanding that the 6th letter will be an N for Cooper or a W for Mayfair.

The 8th letter will be X for the low compression SPI motor or Y for the high compression SPI motor.

Not sure of Mayfairs but Coopers are Y's.

my vin no: SAXXNWAYCWD1434--

[Curley]

As other have said the major limiting part is the head. Decide if you're willing to take the engine out/apart. If you don't want to take the engine out then I'd choose a valve size and compression ratio to suit the cam. LCB & air filter will help any engine breath and the gains improve the better the head flows. As for brands don't be fooled into thinking more money equals better. MiniSpares heads are excellent value.

 

From what Wazzah says you have a high compression Cooper. 'High' compression 21253 pistons are good for about ~10.5:1 NA. 

 

However the ECU will frustrate you in achieving the best from a new head. Depending on your budget there are bolt on kits which include a new ECU.

[fox815]

As other have said the major limiting part is the head. Decide if you're willing to take the engine out/apart. If you don't want to take the engine out then I'd choose a valve size and compression ratio to suit the cam. LCB & air filter will help any engine breath and the gains improve the better the head flows. As for brands don't be fooled into thinking more money equals better. MiniSpares heads are excellent value.

 

From what Wazzah says you have a high compression Cooper. 'High' compression 21253 pistons are good for about ~10.5:1 NA. 

 

However the ECU will frustrate you in achieving the best from a new head. Depending on your budget there are bolt on kits which include a new ECU.

what brand of aftermarket ecu is the best?

 

thanks

[Wazzah]

I'm looking at a Haltech Elite 1000 at the moment.

It can drive a 4 wire stepper motor.

It has an inbuilt map sensor like our Rover MEMS.

It can handle the JDM SPI and MPI 36-4 trigger pattern.

Haltech have been super helpful and I haven't even bought one yet.

I am making up an adaptor loom at the moment.

I have written a map for my car using their volumetric efficiency method and Haltech have confirmed trigger pattern, injection sequence and made suggestions in regards to the wasted spark ignition settings.

It has wideband add ons and is fully learning against target lambda in both closed and open loop.

I have just rebuilt my engine and will run it in on the Rover MEMS gear ( with sidedraught throttle body of course).

Once run in I'll get a horsepower reading then upgrade to the Haltech.

If you care to wait I'll write it up on this forum when done.