Someone with winsu....

Post by **bmcecosse** » Mon Jan 14, 2008 8:11 pm

A 266 is not a 'lairy' cam PeeTee - so I think the Polo troubles must have been down to other factors - very possibly the Weber as Richard has pointed out. That's the beauty of the good old SU - variable choke geometry which allows it to work well at all airflow rates.

Post by **Peetee** » Mon Jan 14, 2008 8:48 pm

I know BMC. I had toyed with a 272 (between them they were about the only two options at the time) but I understood the advantages of the 266 especially with a long ratio box (21.4mph/1000rpm in top). It just didn't work out that way

It's a good example of how a holistic approach and good research/advice can save you wasting a lot of money.

Post by **bmcecosse** » Mon Jan 14, 2008 8:54 pm

Hmm - I'm toying with the idea of fitting a longer cam in my TR7 - comes with 252 as standard which in a 2 litre 4 pot is not exactly 'sporting'. It's easy enough to change - being OHC - but I really wonder if it will be worth the cost and effort!

Post by **IslipMinor** » Mon Jan 14, 2008 9:45 pm

Peetee,

Lost a little torque around 2,500/3,000 over the 266, which produced 100+ lbf. ft. all the way from 2,500 to 5,200 rpm - quite amazing. Max power (100 bhp) was at 5,700 and by 6,000 rpm the power was falling off quite quickly.

Was pleasantly surprised that the 276 did not need a huge increase in revs to get its power. After increasing the CR to 10.5, from 9.5, a small amount of 'Vizarding' on the HIF6 and changing to the 276, the increase was 4 bhp, which was a bit disappointing. BUT after removing the Metro airbox, with its K&N filter, the power shot up to 112 bhp - all in the same RR session. Note to self, get a new, higher flow air filter to get back the 'lost' 8 bhp!!

The top end is much more free revving with the 276, so overall, a small reduction in torque at low revs, but a big improvement from 3,500 onwards.

Post by **Matt** » Mon Jan 14, 2008 10:07 pm

Cheers for that dunketh.

Plans are afoot for the ignition *cough*megajolt*cough*

and its a freshly rebuilt engine so its definately not time for RR tuning yet, but it will happen.

Pete... you know a few people with tweaked 1275s, if carlo wont let you have a go you can have a go in mine when its a bit more sorted