Advice on upgrades to 1961 850

[Mr Rusty850]

Hi,
I'm rebuilding a totally bog standard 1961 Morris Min 850 (coil spring clutch, magic wand gearchange etc). As a break from the usual weldathon I've split the engine and gearbox and stripped the engine down. I want to keep the car standard (at least externally) but I wondered what sensible upgrades you would suggest to the engine and the gearbox. My intention is to have the head converted for unleaded and to have it balanced, but wondered if there are other 'upgrades' I should consider.

Thanks,
Barry

[greyghost]

centre oil pick up, id never put a car together without one
I think it's the most undervalued mod out there.

[Peter Laidler]

Yep. Modify the rear radius arm by fitting grease nipples at each end. Think of future maintenance and survivability at every stage of the restoration

[111Robin]

Just buy a copy of Vizard's book and open your wallet. Plenty of mod's suitable for the 850, just depends how far you want to take it. Start with the head, camshaft, manifolds and carburation, all candidates for improving breathing or even consider going for a 998 block, it's an open book.

[iain1967s]

Assuming it’s a 363 or 145 gearbox, a Cone to Baulk ring conversion kit [8G718], if you can find one…

[Mini Mad Swede]

Had it been mine then a 'hotter' but still very mild camshaft, increase compression to 9,0-1 from the theoretical factory 8,3-1
Also a H4 SU has the same bolt pattern as the HS2, but dunno if it even needs changing to a bigger carb at that low stage of tuning?
Would also consider change of final drive to 3,44-1 instead of factory 3,765 that drives you (me at least..) nuts reving like mad.

But as the others suggested David Vizard's How to modify your Mini is still a really good guide to use.

And make sure all the wheels point in the same direction, something they rareley do. Dont want the little power it has being used up fighting to get it rolling.

[Peter Laidler]

I don't for one minute think that you've got any intention to even remotely flog the grand old lady in any way. Just updating the reliability that seemed to be missing in older mini's....., those made before 1999 (just a joke!). You could easily replace the brakes to the more efficient twin leading shoes. And an (almost) unnoticed simple upgrade too. But here's a bit of advice. Whatever original parts you DO take off and replace, make sure that you keep them in a box so that whoever buys it in the future can have them with the car and not use it as a bargaining ploy!

[Mr Rusty850]

Thank you to everyone for their replies; they are all really useful. I've checked the gearbox and its the 22A363 cone synchromesh box. I'm aware that quite a few boxes were changed to baulk ring synchro back in the day so was wondering if theres a quick visual check that can be made to see if it's been converted to baulk ring?
Assuming it's not, could a later magic wand gearbox be fitted to the current engine or is the cone synchromesh not too bad?

I'll buy a copy of David Vizard's book. Always enjoy the read even if I only keep it in a very mild state of tune. This whole project is a big nostagia trip for me as my first car was a 1963 Morris Mini Minor 850. I was still at school and so my chosen spares supplier was the local scrap yard. The Osselli catalogue was my dream read but totally out of reach.

Peter, I'd already read your technical papers which are great. The radius arms are stripped down and I'll modify as per your recommendations. One of the front backplates is badly corroded so I'd already decided to go to twin leading shoe.

If anyone has other advice/suggestions please post.

Thanks,
Barry

[cmiller]

Interesting to read ians comment on the 8G718 baulk ring conversion kit. I have two NOS ones. I am in the States but could ship to England. Get in touch with a PM for more info.

Chris Miller

[timmy201]

There’s lots of ways you can go depending on what you want and how much you have to spend

- Rebuilt stock 850 with hidden mods like: cam, head, updated gears
- Rebuilt 850 with period twin carbs or 1.5” single carb, head, cam & updated gearbox
- Extreme modified 850 with 1098 crank and different head. I guess this removes the option of returning the engine to “stock” in the future
- If you like the standard look you can make a 998 or 1098 look pretty much identical in the engine bay. A stock mini 1098 was 50hp, which is a huge improvement over an 850. You could keep the standard engine to the side if you ever wanted it in the future.

My 850 came without the original engine, so I chose to make a hybrid of small bore parts:
4 synchro gearbox with magic wand & pot joints
1098 engine bored out with flat top pistons
266 cam and modified 202 head