Exhausts - RC40, Millennium and others tested

The recent rolling road re-test of the 1275 engine build I did saw an opportunity to do some exhaust systems testing.

I had noticed a few years back that the RC40 was being manufactured by a different process than the originals - giving rise to a change in the shape of the bends applied to the system. I had wondered if they would be causing a restriction at all - but hadn't had the opportunity to test it. The lack of expected power from the aforementioned engine lead me to investigate all possible angles from the tyre contact patch to the carb mouth. I found nothing that explained the 14 or so bhp I was 'missing'. After some application of the old grey cells I mentally narrowed cause down to one of two things - either the piston oil control rings were still causing excessive drag (75% of all internal friction of an engine is generated by the piston rings) or perhaps these new bends in the venerable RC40 were indeed causing a power loss.

2003-08, Oil gallery plugs

Here's something unusual that cropped up a little while ago that I've never commented on before - main oil gallery plugs/bungs.

I'd been conversing via e-mail with a guy that was experiencing weird oil flow/supply problems with his performance street engine. Initially he'd been blaming it on the supposedly superior oil pump he'd bought. He sent it to me; I inspected it and found it to be in perfect health with no signs of causing the issues in hand. Firstly there was a claimed total oil drain down from the pump causing lack of initial supply on start-up for a few seconds, and then repeated crank bearing failures when used in anger (i.e. at high rpm for protracted periods). Unless there is something drastically wrong with the oil pump and fitment - cracked pump body, non-flat mounting surface, mounting bolts too long, split gasket, etc. - it will not drain down simply because the inlet and outlet ports are above the centerline, near the top of the pump as it is mounted to the block.

Lubrication - Temperature critical

The correct running temperature of the oil is perhaps even more important than the water/coolant temperatures - so let us consider how to control them.

Mainly because it seems to be the most misunderstood of the whole process, and oil cooler fitment almost a reflex when over-heating occurs where a tuned engine of any type is concerned. And in many cases on standard production road cars for that matter.

Almost since the appearance of the immortal Cooper S, fitting an oil cooler has been the essential thing to do to any tuned Mini without any comprehension why. The original fitment was necessary because oil and bearing technology wasn't too advanced. Asking an oil of yester-year to cope with lubricating an engine at racing speeds, and a gearbox pushed their performance to the edge of their all too narrow capability, so extreme control over their working environment was essential for reliability. Hence oil cooler fitment.

My own Twin point by Keith Dodd 1st June 2006

Having now covered 17000 miles in my twinpoint from new it developed bad oil leaks making it a true mini. The rocker cover seals perished along with a diff output shaft seal. The leaks now rectified, Duckhams oil was used to refill the engine.

My own Twin point by Keith Dodd 1st June 2006 making it a true Having now covered 17000 miles in my twinpoint from new it developed bad oil leaks mini.

My own Twin point by Keith Dodd 1st June 2006

Having now covered 17000 miles in my twinpoint from new it developed bad oil leaks making it a true mini. The rocker cover seals perished along with a diff output shaft seal. The leaks now rectified, Duckhams oil was used to refill the engine.

My own Twin point by Keith Dodd 1st June 2006 making it a true Having now covered 17000 miles in my twinpoint from new it developed bad oil leaks mini.

Mini Production dates

We have tried to get together as complete list as possible to show all the models made from 1985 onwards, hopefully this will help identify those cars that have been modified over the years. If you have any information that you know is correct or anything that you think is not right please let us know.

Historical Article-February 1995-Calver's Clinic

Calver's Clinic COOKING OIL This engine oil thing seems to have caught people's attention - which is good as there is nothing like awareness of what is good for your engine. Having done the 'Life Blood' article in Minitech News 6, and what oils to avoid in Mini Tech News 7.

Historical Article-February 1995-Calver's Clinic

Calver's Clinic COOKING OIL This engine oil thing seems to have caught people's attention - which is good as there is nothing like awareness of what is good for your engine. Having done the 'Life Blood' article in Minitech News 6, and what oils to avoid in Mini Tech News 7.