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how to increase the performance out of an 850
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Author:  matt van'74 [ Tue Jan 24, 2006 11:30 am ]
Post subject:  how to increase the performance out of an 850
i have an 850 in my countryman and i want to keep the original engine as the numbers match. however i feel that a stock 850 is going to be a little sllllooooowwww and i still want to be able to go on cruises and not be left behind more so than i am already :oops: :lol: .

So after some thinking and reading i have come to a decision to make.

I am not going to do anything which isnt reversable apart from some head work.

should i replace the single 1.25 SU with Twin's and then do a some head work (bigger valves, port it and shave it) just so it breaths a little better. Then maybe some extractors?

OR

Get a 1.5 SU with the same mods as above?

OR

keep it stock

Feel free to comment :wink:
Author:  fuzzy-hair-man [ Tue Jan 24, 2006 11:48 am ]
Post subject: 
I think any smallbore head will give you a good improvement over the 850 head and are a bolt on mod and will give you bigger valves so a 12G202(1100 head) is an option

Carb wise I guess twin inch and a quarters or a inch and a half? I don't really know don't go too big though.

Extractors are a good idea same thing though don't go too big a bore extractors of you will loose power.

Vizard's yellow book has a list of good mods for the 850 good thing is as most parts offer better performance than 850 items (especially heads) it is relatively cheap to improve an 850. AFAIK anyway :D

<edit> Oh and improved air filters help too
Author:  poeee [ Tue Jan 24, 2006 12:01 pm ]
Post subject: 
12G202 head, worked if possible. Single 1.5" SU. LCB and RC40 exhaust system.
Author:  sports850 [ Tue Jan 24, 2006 12:07 pm ]
Post subject: 
I'd probably say the single 1 1/2" SU over the twins , less fiddling to keep running right and also it will still look pretty standard . As soon as people see twins the "experts" will have a shot at you whereas most of them wouldn't notice a single 1 1/2" . From memory the twins don't make that much of an improvement of airflow over a larger single , anyone know the figures ?
As for the rest , yeah , better breathing into and out of the motor would do wonders , 850's are fun motors and respond well to a little work .
Author:  Besser [ Tue Jan 24, 2006 12:53 pm ]
Post subject:  More CC
Go for larger CC and keep the 850 original.

The day will come when 850's are so rare that they are worth something. At the moment you have a lump of iron.

Dollar for Dollar look for a 998 or 1100 that will give you straight power increase. Then with mods you can far surpass a 850.

I bought a 998 for $59 with anciliaries, it was a bargain and will find a home more easily then an 850.

For $1000 you can get a 1275A+

I supose it comes down to how much $, skill and time you have.

Good Luck
Author:  Steve [ Tue Jan 24, 2006 1:16 pm ]
Post subject: 
Matt

If doing the work yourself I would remove the 850 leave the oil in it and wrap it up and put it aside for safe keeping.

Take an 1100 motor (mini K) 4 speed syncro box and paint it like your 850 motor. The mini K ran a stock 1 1/4 carbie and air filter but was visualy different because it ran an altenator. you can still run the generator with the 1100 if you like and most people will never know and it will look exactly the same as your 850.

Image

Image

Just remove the heater and there are basically the same.

In saying that the 1100 would run so much better with an 1 1/2 carbie & extractors (all minis need to breath better) and run a set up silimar to Bruizer with the mini matic larger carbie and metal air box. I used this as I didn't want to run twins and wanted to retain the standard mini look (matic) as I didn't want a sports filter.

Image

Bruizer also has the extra steady as it retains its original wand gear lever. If I didn't add the extra stabilizer the motor would go through engine mounts at a scary pace.

Larger head, bigger valves extractors and 1/1/2 matic set up nice

Any questions just PM.

steve
Author:  Angusdog [ Tue Jan 24, 2006 2:36 pm ]
Post subject: 
I vote in these polls without any knowledge, so I have skewed the results towards the hapless bodger end of the spectrum.

But I have an 850 which I intend to put 2 x 1.25 SUs, extractors and a worked head onto. Currently 850 engines are at scrap value, but the idea of tuning such a small motor appeals.

You could easily buy another engine to keep in the shed in case peak oil hits home and people trade their Ford Territories for Mini 850s...
Author:  mad-mk1 [ Tue Jan 24, 2006 2:46 pm ]
Post subject: 
i agree with steve, go the 1100, and keep the 850 for when ur old and grampa ish!!
Author:  Matt 848 [ Sat Jan 28, 2006 11:09 pm ]
Post subject: 
I'm with Angusdog on this one.

I am considering a delightful little 850 for sale here in sydney or a fantatstic clubman S up in Qld.
Make a decision in the next week but I think I'm leaning toward the 850. The idea of tweeking a little engine like that has amazing appeal.
Either way, both cars are beautifully presented so I'm not overly fussed which way I end up gong.
Bring on the 850 though.
Author:  marcello [ Sun Jan 29, 2006 12:48 am ]
Post subject:  850
im with what most other people are saying. keep the 850 in storage and dont touch it. go out and get your self a 998 or 1100 and work that, it would be a shame to take away from the cars originality, even if it is only a head that is copping the irreversable change. there is so much appeal to 850's, more so when they are all in original spec. dont do it dude. you will regret it when 850's are worth a bit. restore it as best you can. wouldnt it be nice to have an 850 that has not been ****ed with for a change? thats my opinion.
Author:  Steve [ Sun Jan 29, 2006 2:10 am ]
Post subject: 
Marcello

I can't wait for 850's to be worth a bit :oops: as mine are only insured for $12 500 whats your mini insured for? 8)
Author:  erin [ Sun Jan 29, 2006 7:45 am ]
Post subject: 
OK Matt, I am by no means an expert, but I agree with putting the 850 in storage, since you're keen on keeping that engine as stock as possible, and putting in a different engine - whether you decide on a 998 or 1098 (or maybe another 850, since the only reason you don't want to touch the other 850 is the matching numbers).
I'm looking at getting a 1275 right now, but I'm not sure if I want to keep the 1100 sitting around - I doubt I'd want to drop it in again at a later date.
It all really depends on what you want :)
(sorry if this makes no sense - I don't normally drink, I'm a little hungover, and I can't type on laptops)
Author:  supercharged 850 [ Sun Jan 29, 2006 10:18 pm ]
Post subject: 
Check this link for info....

http://www.niksula.cs.hut.fi/~mdobruck/siililand/mini/diy/10/850tune.htm

...or invest in a supercharger with a few other mods :wink:
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