9 replies to this topic

[Patriot]

Right then,

 

I am just about to start mods to my 1977 1098 Clubman engine in the quest for more BHP and I wondered if anyone has completed the same work and had the car on the rolling road.

I would be very interested in the actual BHP output from a similar set up.

 

The modifications are, everything else is standard.

1098 Engine (Dished pistons)

12G295 Head (Double Springs) Skimmed for 1098.

Twin 1 ¼” SU Carbs.

Twin K & N Filters

266 Cam

Cooper 3 into 1 – Manifold

RC40 Twin Box Exhaust

 

Thanks,

 

Mark

 

[KernowCooper]

This chap went into Hi-Tech RR with almost the same spec as yours worth watching

 

1098 A series engine,
cooper 295 cylinder head,
kent 266 camshaft,
kent VS2 double valve springs,
1275GT gearbox,
central oil pick up,
straight cut drop gears,
3:44 diff

Build thread here

http://www.minifinit...p?f=186&t=91300

 

Edited by KernowCooper, 01 August 2013 - 05:06 PM.

[Vipernoir]

My 1098 with a 12G295 and an MG Metro cam (timed in woefully wrong on purpose as an experiment) chucked out about 66 lb/ft and 63 bhp.

 

If you use flat top pistons instead of dished, you may not need to have very much taken off the head - pistons are easier to find than an unmolested head...

[bmcecosse]

940 head is much better!  Problem with 1098 is 6000 rpm rev limit - so not much point in double valve springs......  About 65 bhp at fly is good going considering the rev limit.  

[bmcecosse]

And I found a terrific improvement by changing my 295 for a 940.....at ALL revs.  

[Vipernoir]

Did your 940 have the same size combustion chambers as the 295 ?

[Cooperman]

Best to go for flat top pistons. Dished pistons with a 12G295 mean that a lot has to be skimmed off it.

Remember the original engines with 295 heads used raised D-top pistons.

The 1098 engine is great for torque, but poor for bhp due, as Roy has said, to the 6000 rpm rev limit. With some good crank work you can go slightly higher, but crank snapping is always the risk when you do that.

[Rob Gavin]

Didn't have rolling road figures but i ran a similar spec a few years back (mg metro cam, 295 head, lcb, hif44, rc40). The engine was subsequently changed for an mg metro unit. While i got more torque, i noted no difference in the 'performance' on the road.

[bmcecosse]

My 295 had been well skimmed and generally 'worked over' - the 940 was only cleaned up - and some work on the exhaust throats where they are very tight at the bend - and the exhaust valves sunk down by 40 thou.  Straight swap - and very considerable improvement - let's face it - hard not to be  - both valves are larger than the 295 valves.   It pulls really well from any revs I ask - it's in a heavy car (non Mini)  with 14" wheels and a 3.7 final drive - and has been utterly reliable for 6 years now - although it doesn't do huge mileage, it is driven hard when it is used! 

[Patriot]

Thanks for feedback, would be nice to see about 55bhp.