12 replies to this topic

[shed]

ive got a 1993 1275 sprite. plan on turbo'ing it at one point but looks like im gonna need to save a few pennies first.....

along with a stage 1, as a change of cam ive read the 649 cam is 'sporty'. whats it like with a stage 1'd 1275?

thanks

[MRA]

better off with a 276 or 286... unless the 649 is new and unused.

[Cooperman]

It rather depends on what you mean by the vague term 'Stage 1'. It's best to talk in engineering terms not a sales expression.
The 649 is the old BMC race cam and for it to work well you need a big-valve gas-flowed head, higher compression ratio, twin 1.5" SU carbs (or the equivalent), the ability to rev to a sustained 6500 rpm, a really good exhaust system and probably lower final drive ratio. There will be little power below about 3000 rpm. In fact a 1071 Cooper 'S' I built with a 649 would not pull cleanly below 3200 rpm, spitting back through the carbs below that figure. It's an olds design and modern cams are much better really.
Really it's not a road cam and, as Martin says, a 276 would be better.

[maggies_minder]

i was thinking the very same as the OP, i even have the same year and model mini.

is a 276 cam, just something you can put in and have RR'd and your away or do other components need to be changed aswell?
i dont want a race mini, just something to make my smile a little wider

[maggies_minder]

i was told by the previous owner (the chap that done the change) my mini has a metro engine, my car used used to be an auto.

[maggies_minder]

no idea, all i no for certain is its a 1275, he could have been telling porkies about the metro bit, it did RR at 66BHP though,
can you do it with the engine in?

otherwise this will wait until something serious happens and the car has to come off the road.

[samsfern]

no idea, all i no for certain is its a 1275, he could have been telling porkies about the metro bit, it did RR at 66BHP though,
can you do it with the engine in?

otherwise this will wait until something serious happens and the car has to come off the road.

you need the engine out, and virtually stripped down, gearbox off, head off, to change the cam, then you need to time it in properly with a vernier.

i run piper cams version of the 649, the 649+ race, supposebly gives more power up top end then the original. its a 1330, compression ratio is 12.5:1, 3.65 final drive, straight cut drops. theres not much power at all below 3k, sort of tries to idle, lumpy, but you know about it when you get it on cam. i use the mini everyday, just have to drive it differently.

the 276 is quite a nice cam as well, had one in my old mini.

Edited by samsfern, 25 November 2010 - 08:20 PM.

[maggies_minder]

no idea, all i no for certain is its a 1275, he could have been telling porkies about the metro bit, it did RR at 66BHP though,
can you do it with the engine in?

otherwise this will wait until something serious happens and the car has to come off the road.

you need the engine out, and virtually stripped down, gearbox off, head off, to change the cam, then you need to time it in properly with a vernier.

i run piper cams version of the 649, the 649+ race, supposebly gives more power up top end then the original. its a 1330, compression ratio is 12.5:1, 3.65 final drive, straight cut drops. theres not much power at all below 3k, sort of tries to idle, lumpy, but you know about it when you get it on cam. i use the mini everyday, just have to drive it differently.

the 276 is quite a nice cam as well, had one in my old mini.

cheers sam in that case this is one "mod" that can wait until i can afford to be carless.

[1984mini25]

no idea, all i no for certain is its a 1275, he could have been telling porkies about the metro bit, it did RR at 66BHP though,
can you do it with the engine in?

otherwise this will wait until something serious happens and the car has to come off the road.

I’d always been under the impression all A plus a-series were metro engines; it’s just the MG versions that are the really special ones.

[samsfern]

or buy another engine and box, and rebuild it, rebore, crank grind, maybe balance and lighten if funds allow, do a dry build to calculate the compression ratio, i had 11:1 when i had the 276 in my old mini, then get the block skimmed the required amount, and build it in your spare time, carry on using the mini, then fit it one weekend.

Edited by samsfern, 25 November 2010 - 08:28 PM.

[maggies_minder]

nah id rather buy a fast car than spend a fortune on an engine build for my mini.

[bmcecosse]

649 is a great camshaft - just not suitable for 'stage 1' use! I'll second the MG Metro cam for general road use. the '276' is a bit like the old BMC 731 - which was useless. But the BMC 544 was excellent! Still a bit adventurous for a 'stage 1' engine.

Edited by bmcecosse, 25 November 2010 - 10:19 PM.

[Cooperman]

I built an engine for a 1965 Cooper 'S at 1293 with a 276 and an original Downton head and it gave 94 bhp at 6100 rpm. Another into which I put the 276 with a Rob Walker head on a 1275 A+ block with 10.6 CR gave 92 bhp. Both were very good to drive and pulled from around 2600 rpm. The 544 is very similar to the 286 and almost as good, but as said, needs more mods than a so-called 'Stage 1' kit.

Edited by Cooperman, 26 November 2010 - 12:07 AM.