9 replies to this topic

[Richard_]

Hi - I am considering swapping my 998 block and head for a suitable 1275 set up if I can find one.

I'm in the 'research' phase at the moment but I have done engine swaps on a mini before (long time ago and I made several mistakes!)

The car has only done 25k miles so i'm thinking the manual gearbox is good to retain.

 

Am I right the job can be done leaving the gearbox in the car? 

But I would think it easier to take the whole lot out, then split it?

I am sure there must be a comprehensive guide to this swap somewhere in the forum but I'm struggling to find it. Any pointers anyone?

 

Many thanks.

 

 

[sonscar]

Take the entire engine and box out,change the motor(compatibility issues I am not qualified to comment on may arise)and refit as one.Much more accessible and civilised,Steve..
P.s I too have a Racing Green,yours looks nice shame to change the engine for what may be an unknown.

Edited by sonscar, 25 April 2022 - 04:09 PM.

[Compdoc]

Unfortunately, there is no way that you can remove the engine and leave the gearbox attached.

If you haven't got one, get a Haynes manual and do a search on this forum and on You Tube, for rebuilding a classic Mini engine. The 998 and 1275 are very similar but there are a few idiosyncrasies to get over depending mostly on the age difference and specification of the two engines.

There are lots of knowledgeable people on here that will help with any problem you might come across.

Good luck.

[Richard_]

Yes I must've mis-read a post re leaving the box in place. Apologies.
all this is in mind because I took the car out yesterday and found it a bit hesitant at low revs. I could probably regain a lot of performance with a straightforward tune up and save a load of hassle! Having run a 1300 mini back in the late 70s though, I can remember what fun it was.

Edited by Richard_, 25 April 2022 - 06:05 PM.

[nicklouse]

You can leave the box in the car but you are really making it harder than you need to.

 

haynes manual.

[Spider]

It's not a difficult job, just be aware though there are some ancillary parts that are different between the 998 and the 1275, some that some to mind are the Primary Gear, Top Radiator Bracket / Steady and Top Radiator Hose. Also, very few internal parts are interchangeable between the 998 and the 1275.

[mab01uk]

Yes I must've mis-read a post re leaving the box in place. Apologies.
all this is in mind because I took the car out yesterday and found it a bit hesitant at low revs. I could probably regain a lot of performance with a straightforward tune up and save a load of hassle! Having run a 1300 mini back in the late 70s though, I can remember what fun it was.

 

If you have a good 998cc in a nice original spec Mini on 25k miles why change it? If all it needs is a good tune up, they are much smoother revving, more robust/bomb proof and longer lived than most 1275 engines. If you can find one for a reasonable price it will almost certainly be much higher mileage and an unknown in need of an expensive rebuild. The only reason really for the hassle and expense would be for attaining ultimate power but with just some minor mods a good 998 will easily match the performance of a standard 1275.

Edited by mab01uk, 26 April 2022 - 07:27 AM.

[Aria Aradhea]

If and when you decide to swap the engine, don't forget to source a compatible speedometer as well. Your 998 speedo will only go to 90mph/140kmh while the 1275 will use a 120mph/180kmh one.

[nicklouse]

If and when you decide to swap the engine, don't forget to source a compatible speedometer as well. Your 998 speedo will only go to 90mph/140kmh while the 1275 will use a 120mph/180kmh one.

Not quite correct. As if you change the speedo you will also need to change the drive parts to match. But if you are not changing the gear box you don’t need to change anything. 

[Aria Aradhea]

Not quite correct. As if you change the speedo you will also need to change the drive parts to match. But if you are not changing the gear box you don’t need to change anything.

Ah, that's true. I swapped my 998 into a 1275 but I took the whole thing out to save time, money and headache.