I've seen plenty of talk about the big motors, but what about the 850? Can I keep my original motor and still be able to drive on the interstate? What can be done to pep up the little guy?

 

Install a second one in the rear...

Fast 850 is an oxymoron.

Better to trade up to a good A+ 998, at minimum. A 998 starts with the HP you need to add to the 850. A 1098 isn't bad by comparison, either. A 1275 is better, yet.

An 850 is not worth sinking much money in. But, if you're set on doing it, get a better head (12G295 off 998 Cooper or 1098 Midget, or a 12G202 off a 1098 Mini), add a 1 1/2" SU, small bore header & freeflow exhaust. You might break 42 scream'n HP . Then stop....no replacement for displacement....

 

Seriously, don't bother trying. Start saving for a replacement. Go straight for a 1275 because you'll go there eventually anyway.

 

I looked at buying a classic with the 850. Because the car was completely original and in great shape, I would have kept the 850 just to keep the car original and correct.

Otherwise I'd go for the biggest engine I could find/afford.

 

ohhhh you guys ... why does everyone think that displacement will make them better drivers or somehow allow them to have more fun? You should know that it is not the size of your motor that counts, but what you can do with it that does.

ok, a few random thoughts on fast 848's (and only a moron would think there is anything 'oxy' about that) :

The 848 came about because the factory thought its most popular motor, the 948 (used in Minor's and Sprites and everything else at the time) was too much for the new little crate Issigonis was designing - so they de-stroked it (same bore, shorter stroke). You gearheads know that, as a general rule, shorther stroke means faster acceleration (even moreso if the motor is under-square) and the 850 has the potential to rev all day long, freely, past redline in top gear (unlike alot of cars), and the only things allowing it to destroy itself are in a cheap pile of factory bits that we all so enjoy upgrading and replacing; give it valve springs that won't bounce, a duplex timing chain instead of the single row it started with, and let the Machine Shop balance the moving stuff, and you can start to see that around-town performance isn't that far away... if you can convince the Software to use the entire rev range and put the foot in it once in awhile ...
The 850's I built also had the head and cam treatment mentioned earlier and a couple had final drive gears from 1100's (that being 3.65's instead of 3.76's but not over-gearing by doing the 'S'-type 3.44's) so road speed was good for all-day interstate weaving as well as stoplight launches. Even though peak power was a ways lower than redline, passing other cars that thought they were fast only meant dropping to third and stepping on the loud pedal.
You can't (for the most part) put the trick Cooper 'S' goodies on a small-bore motor anyway, so the stuff you are left with is easily scrounged and relatively inexpensive - 'cause no one else wants it! - so piecing together a screaming 850 really doesn't cost that much.

... and then there is the Milage; in this $3/gallon age, 50+mpg (road) from an 850 hot rod that's tons-o-fun to drive flat out is very satisfying - just don't cripple yourself by putting fat tyres on it (4 1/2 inch Cooper 'S' wheels are plenty wide and the rolling resistance isn't too much for your motor to have to push).

... I'm done for now but just think that all those great racing victories that the Mini is famous for started with 850's beating bigger established competition before any 1275 had even been dreamed of ...

 

What the hell is that about? Neither "ideas" were mentioned?


8ball, no need to be insulting to other opinions. You are not the only one who's ever rebuilt an 850. You can believe what you wish, as others can. Who gives a fly'n fig?

MOST Mini owners, and tuners, feel that expenditures on an 850 are unwise investment in a $ spent/HP return. BUT, (and that's what I said) it all depends on what the owner wants. With the parts, labor & machine work 8ball mentioned you can buy yourself a nice 1275 to swap and have a car that's has a wider sale appeal when done. Its your personal decision on how to spend your money.

 

850s are cool. However on the freeway they can be a bit tiresome or downright hazardous. The economy is great, but put your foot down and there's not too much left by todays standards. I ran a mini scamp kit car with an 850, granted it weighed about 1000 pounds, and a got well over 50 miles to the imperial gallon. On making them perform, 8 ball is right. Properly done they can be comparable to a stockish 998 Cooper. People who I know that have built performance 850s are more proud of their 850s than their 1275s due to the "you can't make it do that" factor.

Of course for the same amount of money/work a 998 can be improved significantly more to the point of beating a stock 1275 rather easily.

dr dave

 

Hey Dr Dave, haven't seen you around here before. Ah yes the 850. Always talked of using one as a boat anchor but never got around to it. I did have a new tuftrided Mountune crank for one a while back and can't think of where it went. I guess for something different a person could play with one but in the end it will still get you nowhere fast (or somewhere slow). A 998 has way more ability and although a longer stroke is still as smooth as silk. I would still only build a 1275 as it will crush a small bore dollar for dollar. It's funny how one can talk about a 1275cc motor as a big bore

Dennis

 

Den,

We should build a firebreathing 998 like the one I had in high school .

Just waiting here online, for the contractions to hit 5 minutes apart, then, off to the hospital. We're at 9 minutes right now.

Did you see ***/tuck?? Absolutely brutal!!!

dr dave