18 replies to this topic

[Sunbeam]

Hello all, I’m new to this forum and would like to ask members for their advice. I have just finished the restoration of my first mini which is a 850cc mk1. First time on the road was a bit disappointing as it struggled to go up hills and acceleration was not as I had hoped! Everything is as it should be,timing,carb set up etc. My question is,would members advise me to change the engine for a 998 and if so, would it fit onto my magic wand gearbox? Ive heard that tuning a 850 is not ideal as the camshaft bearings are part of the block in one journal and are not ideal to tuning.Also what diff ratios are advised ?many thanks.

[DeanP]

If it’s the original engine that was fitted to the car when new, keep as it is. Changing it will wipe lots of value off your car.

[Shooter63]

I have exactly the same mini as you and yup the power is pretty poor to put it mildly, in fact in today's road conditions verging on dangerous, as a stop gap I'm going to do a 998 conversion. You will gain an extra 8ftlb of torque minimum which doesn't sound a lot but will make the world of difference, I would also change the diff ratio to 3.44 which will make 1st gear more usable. I would keep the 850 engine in case you ever wanted to put it back to original
The problem with trying to tune the 850 is lack of tuning parts available, I'm not sure if O/S pistons are even about any more

Shooter

[ACDodd]

850 engine tuning is easy, just make it bigger! I have machined a couple of 850 blocks now, one at 998 and one at 1150cc. It looks like and 850, but the 1150cc goes like a stock 1275 when fitted out with all the right bits.

Ac

[greenwheels]

Don't touch it - leave it as it is. That's a piece of history, learn to love it for what it is, it's a fun car. The more you drive it the more you will appreciate it's roadholding features.

If you want to zoom about get another car.

Edited by greenwheels, 18 April 2020 - 08:42 AM.

[absx2]

I`ve had a few 850`s and some were livelier than others but they were all capable of pulling up the hills without issues and there are some big hills around me. The diff ratio is low and the engines are smooth and quite capable of having the guts revved out of them so don`t be afraid to get 60 mph out of third gear.

There are a few things you can do to help it along a bit whilst keeping it original all of can be found in Vizards book.

Have you done a compression check, how old is the exhaust as I had a clogged one once, have you reconditioned the head as the valve seat area will be non existent if you haven`t ??

 

I don`t think an 850 is any worse than a 988 with a 2.95 diff and I have both to compare

Edited by absx2, 18 April 2020 - 08:52 AM.

[DeadSquare]

What you have to bear in mind, is that the 848cc engine was intended to deal with a fuel shortage, and mingle with cars whose drivers were proud to get the speedo needle in the upper 60s.

 

As much of today's traffic trundles in the upper 50s, I find that there is a definite period charm about 850 / 1960s driving  (in moderate doses)

[pusb]

Never had any issues with mine. It wasn't fast by any means, but could keep up with city traffic and would reach 70 on the motorway 

[ads7]

I'd echo the input from absx2.

I've had three engines in mine so far, 998 city with high 2.9 FD gearing, then 1293 mg metro, now 850 with a stage one inlet/exhaust fitted.

You've got to remember that the fun factor is what makes the Mini stand out. The 998 was a little livelier than the 850, the 1293 very nippy, surprisingly economical but a load of vibration which was really unpleasant.

Now the 850 runs so smoothly, you have to put your foot right down on occassions but it's just massive fun to drive with the exhaust and air filter snorting away.

So maximum drama from minimal speeds. Really relevant in today's financial/environmental situation.

I'd run your 850 til it can't run any more, good cheap fun in the spirit of Issigonis' original vision.

[Sunbeam]

Many thanks to you all for your input,a lot of sense there to consider,stay safe everyone.

[malynch27]

For a bit more oomph, do a mild tune with a few stage 1 bits, better air filter etc. It will never keep up with today's cars but find a good A or B road and you wont be able to stop smiling.

[cal844]

What I would do is to get a larger engine to fit, so you can keep the 850 to fit if you decide to sell.

[Sunbeam]

Does anyone know if a 998 engine will bolt onto a 850 magic wand gearbox? If I decide to upgrade the engine, I would like to keep the original gearbox. Thanks,

[DeadSquare]

Yes, it will.

[Algordo1100]

We have a 1964 mk1 850 back home in Queensland. It is totally standard and it's a hoot. Bumbling along down the esplanade and around quiet towns.

It's not so good on a motorway but it wasn't really designed for that.

I've said before I wouldn't really want it to have much more power than it does. Not on those brakes, not on those tyres, not sitting in those seats, not holding that steering wheel. I don't want to detract from it's originality. It is what it is and it's better for it in my opinion. A lovely peice of motoring history.

My 1996 Spi is a totally different beast. To get the 1964 to go something like that you'd end up nearly having a mk1 cooper S. But it's not a mk1 cooper S, it's a Morris 850 delux.