12 replies to this topic

[andyt]

I'm in the process of putting together an mg metro engine standard bore new rings and all new bearings, i have a big valve ported and polished head (29/36), lightened flywheel and will be running 3.44 diff on 10" wheels. The car is for weekend blasts the odd show trip and maybe a track day or two would a 276 cam be ok to live with?

 

Andy. 

[Cooperman]

That should be fine for the uses you describe. 

Peak power will be at around 6100 rpm, so expect to have to 'rev it' to make it go at its best.

An alternative which gives better torque lower down and peak power at 5700 rpm would be the 266 (or the very similar MG Metro cam).

[andyt]

I like the sound of torque at lower revs is this what the swiftune sw5 or the minispares evo cam would provide rather than having to rev the nuts off of the thing all the time?

 

Andy.

[skoughi]

Kent 266 in my 1330 with the same cylinder head, 3.44 final drive, slightly lightened pre verto, slightly modified HIF44 with an MED stub and ITG filter. I love driving her as there is plenty of low down torque, my good woman even commented once why I didn't have to change down a gear when we were pottering up a steep hill behind a slow moving car doing about 1500 rpm in 4th! No need to rev the nuts off it so less stress on the engine.

[Cooperman]

I have no experience with the SW5, but I have used a Mini Spares EVO1 in a 998 to good effect.

Personally I like the Kent 266 and I built an endurance 1275 Cooper with a 266, a mildly flowed head, Better exhaust and a modified HIF44. It had a lightened pre-Verto flywheel and comp clutch. the FDR was 3.44 (my favourite) and it gave 84 bhp at 5700 rpm. I can't remember the torque, but it was excellent.

I didn't have to really rev it to get it to go, but it would rev to almost 7000 rpm with no problems.

For pistons I used 21253 at +0.060" oversize. The distributor was an Aldon Yellow. Comp ratio was 10.5:1. Valves were 35.6/29.5 In/Ex.

It was quite a competitive car, but against modern cars like the MG-ZR (or Rover 214 Si). the Peugeot 106/206, Citroen and small VW, all under 1400 cc (the limit for endurance rally cars) it was not going to win, although it was possible to get into the top 10. But I wanted to win, so I sold it and built a Rover 214 Si which was seriously quicker on gravel or tarmac.

Have a look at the cam graphs and choose one which gives best mid-range torque - that is much more important than top-end power, despite what the two 'comics' might have you believe.

Sounds like you'll have a nice engine.

[MrBounce]

I had a Kent 266 in my old Mayfair's 1302 engine. It had an MED Road Comp head with twin 1 1/4" SUs, Maniflow exhaust and K&Ns. That engine was almost a perfect balance of driveability and occasional blasting down the road. It was a blooming lovely thing to drive with oodles of torque. It had 79BHP at about 5200rpm and a similar torque figure with a very flat curve. 

 

So it's big Thumbs up for the 266 from me, but given your usage, I reckon that the 276 will do well too.

[Cooperman]

Of course the torque and power bands are narrower with the 276, but standard gear ratios are just about OK so long as the FDR is no higher than 3.44:1. A 3.76:1 is better, but means more revs at normal cruising speeds.

I always think the big step is from 276 to 286 because the 286 is very 'cammy' and only suitable for competition and then with SC CR ears and a low FDR (3.(;1 for example).

For road and occasional track use I would personally go for the 266 with a 3.44:1 FDR. Make sure the head is nicely gas flowed and set a good CR like about 10.3:1 for best results. A Maniflow twin-box exhaust with a 2.75" bore is good with an LCB exhaust manifold and an alloy inlet manifold with the nasty casting flash removed.

[nicklouse]

again i would disagree a 286 in a 1380 standard box etc was fine for going to work and doing the odd treasure hunt or 12 car. i was young

 

just done a 1380 with a minispares evo1 cam with a 3.1 diff in a Midas and that is great and more modern.

[Cooperman]

The 286 gives peak power at 6400 rpm and peak torque at 4200 rpm. I use one in my full-on historic rally Cooper 'S' and it is fine as I have a SC CR gearbox, 1:1 drop gears and a 3.9:1 FDR.

On gravel, ice or even in very wet conditions I have often thought that I might be better of with a 276 or even a 266. The BMC Comps dep't used to run a standard 510 for gravel to maximise mid-range torque and power.

There is always a lot of talk (and torque  ) regarding cam choice, but for a 286 you need to be using 6800 rpm as your change up point a lot of the time, whilst a 276 could be 6300 rpm at optimum change up. A 266 would give best performance with a change up at 5900 rpm in 1st & second and then use the fantastic mid-range torque to give good acceleration through 3rd and 4th gears.

Too many people who don't look at the cam graphs before making a decision tend to 'over-cam' their engines. For the vast majority of uses what is needed is optimum torque at between around 3200 rpm and 4500 rpm with peak power at between 5500 rpm and 5800 rpm.

That's just my view on it, but one of the nicest Minis I have ever owned was a 1973 Innocenti 1300 Export with a mildly improved head, 10:1 CR, 3.44:1 FDR and a BMC 510 cam. It was just so 'friendly' to drive on the road, unlike my 'S' which is noisy and has to be revved high to get it to go at its best.

I hope this helps.

[carbon]

I'm running a MD266 cam in 1293, and works well for me, but have found that it is short on valve lift with standard A+ rockers:

- with std A+ rockers (maybe 7.5mm lift at valve?) it ran out of steam above about 5000rpm

- went to 8.0mm valve lift and got much better mid-range and top end, only lost a little grunt at low rpm

- now with 10.5mm valve lift and it really comes to life at mid and high rpm. Low end still tractable but has less torque below about 2500rpm.

 

Would suggest CR of about 10:1 on 99 octane (with 82C thermostat). Also distributor advance curve needs more fettling with higher valve lift, bringing initial advance in sooner.

[Midas Mk1]

Got both 276 and sw5 with 1.5s in my current engines, and love them. Sw5 silky smooth idle and pulls like a trains to 6.6k , 276 pulls then kicks at 4.5k surging to 7k. 276 punches 10bhp more, but then harder to use.

[Cooperman]

Too many people read the 'comics' and convince themselves that they need a really 'hot' cam to make their car go fast. In fact what they really need is high torque to get good acceleration using between 2500 and 5500 rpm.

There is also a lot of nonsense about what is termed 'fast road'. With a classic car, including the Mini, we are talking 'not quite so slow road'. For a 'hot' cam to work in needs to be driven between max torque and max power for best (fastest) results. That means driving aggressively most of the time and accepting high engine wear rate. In practice very few people do drive like this.

When selecting a cam look at the cam graphs supplied by the cam grinders, then decide which one has the torque and power curves which best suit the application. Fitting a very hot cam can, in fact, make for a 'slower road' Mini than with a milder cam as it can 'bog down' at medium revs when an up-change is made.

[Racer_Pete]

276 is a very tame cam IMO, I had a 998 with a swiftune SW10 which is similar to a 286 and was a ******* cat to drive and extremely fun, with the slightly updated engine you have, the 276 will be a good cam all round. At the end of the day it all depends on your driving style, I have a 296 in a 1310 which will see 8500rpm (as long as you've got the bottom end to suit that is)