22 replies to this topic

[DeadSquare]

Austin, aka BMC, were so besotted about the torque / gallon ratio of the A series, that they were loth to fit anything other than their "All talk, no go" cams, which, although they had stood them in good stead in the post war horsepower taxation system and the mid 50s Suez oil crisis, were dier by the millennium.

 

Simply fitting the part number 948 cam from the 997 Cooper in a bog standard 848 Mini, made it go the way you felt a Mini ought to go.  It did use more fuel, but you got there quicker.

[miniGTS]

I had a chat with the engine builder about some options. He suggested a 731 cam but I've seen some comments that 731 isn't great. I'm thinking to keep the standard GTS cam. I don't know spec of the GTS cam but someone said it's similar to the MG metro cam. Anyone have any experience with a 731 cam in 1275 Or will the GTS cam, assuming it is similar to the MG metro cam, be a smoother cam with enough torque and fun driveability.

He also asked if I want some head porting done, would that be a worthwhile thing to do?

I want something that has power from low down and doesn't need to rev up to 2000 rpm before it shows sign of life. So stick with gts cam or get the 731?

[Cooperman]

The 731 is an old BMC rally cam. It was not well liked generally.
The MG Metro cam, which is very close to the Kent 266, is excellent, but the Mini Spares Evolution cam is great.
You can get very confused by the huge choice available, but in the end you may not notice the difference in normal road use, After all, you will not be using max revs and full throttle very often.
Of course, cam choice is important when you are looking to save a second or so per lap, but on the road it is different.
The big question is where do you want the torque and the max power. Look at the cam graphs if you can.

[whistler]

The 731 is an old BMC rally cam. It was not well liked generally.
The MG Metro cam, which is very close to the Kent 266, is excellent, but the Mini Spares Evolution cam is great.
You can get very confused by the huge choice available, but in the end you may not notice the difference in normal road use, After all, you will not be using max revs and full throttle very often.
Of course, cam choice is important when you are looking to save a second or so per lap, but on the road it is different.
The big question is where do you want the torque and the max power. Look at the cam graphs if you can.

For a road going engine the EVO001 cam from Minispares is excellent. I put one in my wife's 1330. The other cam that is recommended by some well known engine builders is the Piper 255. I have one in my 1220 (overbored 1098) and gives very good torque.

[stuart bowes]

is that still on the standard 1098 crank, and presumably the same block as the 998 (already stroked as 1098, and then bored out)

 

just asking because I have a 998 A+ and still debating what to do with it.  I like the idea of torque and not overly worried about revs.  I already have a 1098 crank on standby

 

and stupid question maybe, but re: the EVO cam, is that universal, as in can you use that in 998 as well as the bigger blocks.  or do you have to specify when ordering

 

(I may still just put it back together as a 998 and leave it to be honest, depends on budget when I get to it!)

Edited by stuart bowes, 01 August 2025 - 10:38 AM.

[Cooperman]

I put an Evo 001 cam in a 998 Cooper and it was superb. I also just put one in a 1293 MG Midget with a moderately d=ga-flowed head, a decent exhaust system and 10.0:1 CR running on twin HS2's. It's just very smooth and gives excellent torque all the way up the rev range with peak power coming at c.5600 rpm. It's possibly the best road cam out there.

What pistons are you using in the 1220 cc bored out 1098? Is the crank standard throw diameter or offset ground?

[miniGTS]

I have a cam that was a regrind and been marked as a 268. After some reading another cam I may consider is a 266 but will chat with the engine builder and see what else he suggests.

I should add that, even though the evo1 cam is a cost effective option in UK, in South Africa it's a special order item and together with an oil pump for it, ends up costing about 20 to 25% the cost of a complete engine and gearbox rebuild.

I'm waiting to hear if the gts cam that came out of the engine is still good to use or needs replacing.

Edited by miniGTS, 02 August 2025 - 07:13 AM.

[whistler]

is that still on the standard 1098 crank, and presumably the same block as the 998 (already stroked as 1098, and then bored out)

 

just asking because I have a 998 A+ and still debating what to do with it.  I like the idea of torque and not overly worried about revs.  I already have a 1098 crank on standby

 

and stupid question maybe, but re: the EVO cam, is that universal, as in can you use that in 998 as well as the bigger blocks.  or do you have to specify when ordering

 

(I may still just put it back together as a 998 and leave it to be honest, depends on budget when I get to it!)

Yes, standard crank but revs limited to 6000 max. I followed a template on Keith Calver's website for this build.