803cc to 1098cc Swap

[Andymoor94]

Hello!

This has likely been covered but from the information I've found, it's hard to jigsaw from that info what's actually needed, when it should be done and the actual benefits.

So I have a 1963 4 door with the 1098cc engine. I disassembled it to begin welding before hopelessly falling into the pit of "Oh god it's worse than I thought". I couldn't wait as long as would be needed to get back in a Moggy, so I bought a well looked after 1954 Split screen Series II, featuring an 803cc engine and what is definitely not the original carb.

The 1098 could do with some tinkering to run it's best, whilst the 803 purrs from the start. The gear range is annoying and I live on top of a hill, so any journey is a little bit of a huff. You can begin to see why I want the 1098 in.

So firstly, would I see a large enough beneficial difference to warrant the swap? And if so, are there any major modifications needed (or cutting) in order to fit the 1098 into the '54 body? I'm aware of the need to use the 1098 gearbox floor cover and swap the carb too, but what else is generally needed?

[jagnut66]

Hi,
Assuming you have all the following in your Minor 1000, you will need to transfer over the rear axle and diff, prop, gearbox and (obviously ) the engine.
You will also need the 1098 gearbox tunnel cover and will have to remove a section of the transmission tunnel to accomodate the 1098 box.
You will then have to swap over handbrake levers, as the original handbrake in the splitscreen will be too long and will interfere with the 1098 gearlever.
Obviously engine and gearbox mounting rubbers, heater hoses, fuel hose and all other 'consumables' should be examined to decide whether they are still 'fit for purpose' at the same time, they are not expensive, so if in doubt replace.
Apart from the transmission tunnel 'surgery' it will be a fairly straight forward swap.
You may then want to look at upgrading the front brakes, however the existing set up should be adequate, so long as it is in good order, the last bit and any other 'upgrades' are down to personal preference and are subject to arguments / discussions elsewhere on this forum. Basically it is your car and your choice.
(The rest of us reserve the right to 'groan' as appropriate...... )
The 1098 set up will be far less breathless than a 803, it will climb hills better and in conjunction with its 4.22 diff, is far better suited for modern day to day driving / long journeys / motorway driving. Also, if anything does go wrong, parts are more readily available.
Best wishes,
Mike.

[philthehill]

I had a 1098cc engine and gearbox fitted in my Ser 2 and it was a good and beneficial swop especially as I was doing in excess of 700miles per week and that was mostly up and down the M6.

The 1098cc (or 948cc) gearbox cross member needs to be fitted as the 803cc gearbox mount is different.

Whilst you are at it change the 803cc rear axle for the 1098cc rear axle unit. Use the 1098cc speedo to keep the indicated speed correct.

Use the 1098cc carb/manifold and ancillaries.

Only the floor inside the car needs to be cut back to accommodate the 1098cc remote gearchange.

I have not done it myself but I understand that some fit the gear change housing from the 803cc gearbox to the 1098cc gearbox so as to keep the inside of the car looking original. I have to say that the 1098cc remote is a much nicer way of changing gear and the removed section of floor can always be welded back in place if required at a later date.

[ampwhu]

all you need to do is:

remove the 803 engine. take the flywheel, clutch and backplate off and fit these to the 1098 engine. fit the 1098 back in the Series 2 car. You'll then have a 803 box mated to a 1098 engine. No sodding about with floor change panels etc.

I would also swap the 4.2 diff and put that in the series 2. Drive moderately and you'll be fine.

I have in my series 2 a 1098 fitted to a 803 box (but have 948 internals in the box) and have driven it for maybe 10 years and have no problems at all.

[jagnut66]

I have in my series 2 a 1098 fitted to a 803 box (but have 948 internals in the box) and have driven it for maybe 10 years and have no problems at all.

And therein lies the rub in that approach, the 803 gearbox is not strong enough to cope with a 1098 engine. For the sake of some time spent with the angle grinder, it will cost him allot less than having his 803 box rebuilt with 948 internals.
He may also not just want to be limited to driving his car 'moderately'.........

The 1098cc (or 948cc) gearbox cross member needs to be fitted as the 803cc gearbox mount is different.

Thanks Phil, I missed out that bit.
Best wishes,
Mike.

[ampwhu]

really? a friend drives a MM daily with a 1275 engine and an 803 box. he drives the car with consideration. Don't make it out to be a problem when it isn't.

[ampwhu]

really? a friend drives a MM daily with a 1275 engine and an 803 box. he drives the car with consideration. Don't make it out to be a problem when it isn't.

[jagnut66]

really? a friend drives a MM daily with a 1275 engine and an 803 box. he drives the car with consideration. Don't make it out to be a problem when it isn't.

There is a problem with a lack of spares to rebuild these boxes and they are weaker than the later ones. You underlined this yourself when you stated:

a 803 box (but have 948 internals in the box)

And here you mention your friend drives his car with 'consideration', which suggests he realises this too.

See this earlier post: viewtopic.php?f=4&t=30075

Plus, (and here's the biggest point for the OP when considering what to do next, certainly financially), the OP stated that he has a Minor 1000 ready to strip, which means he has a 1098 gearbox and ancillaries ready to hand, which will cost him nothing, except the time and effort involved in fitting them.
Best wishes,
Mike.

[ampwhu]

the reason why I fitted 948 internals was because I had new spares and knew someone who would do it for me.

I doubt the person asking the question would have been 'hacking' about in a 803 engine car to begin with so fitting a 1098 to a car with an 803 box is more than sufficient. As I said further up, it works as it has been done by plenty of people for years with the proof to go with it.

if you go ahead with the 1098 engine, i'd look at the brakes. you want to be able to stop with that little bit more power.

[Andymoor94]

Hi,
Assuming you have all the following in your Minor 1000, you will need to transfer over the rear axle and diff, prop, gearbox and (obviously ) the engine.
You will also need the 1098 gearbox tunnel cover and will have to remove a section of the transmission tunnel to accomodate the 1098 box.
You will then have to swap over handbrake levers, as the original handbrake in the splitscreen will be too long and will interfere with the 1098 gearlever.
Obviously engine and gearbox mounting rubbers, heater hoses, fuel hose and all other 'consumables' should be examined to decide whether they are still 'fit for purpose' at the same time, they are not expensive, so if in doubt replace.
Apart from the transmission tunnel 'surgery' it will be a fairly straight forward swap.
You may then want to look at upgrading the front brakes, however the existing set up should be adequate, so long as it is in good order, the last bit and any other 'upgrades' are down to personal preference and are subject to arguments / discussions elsewhere on this forum. Basically it is your car and your choice.
(The rest of us reserve the right to 'groan' as appropriate...... )
The 1098 set up will be far less breathless than a 803, it will climb hills better and in conjunction with its 4.22 diff, is far better suited for modern day to day driving / long journeys / motorway driving. Also, if anything does go wrong, parts are more readily available.
Best wishes,
Mike.

Absolutely fantastic breakdown, thank you!

I have everything, since it's coming from what was a complete Minor, so sourcing the parts won't be a problem. The only pain will be the axle - I've NEVER done any work with suspension and moving parts before, I'm actually coming from working on French mopeds. At least I am safe in the knowledge that I have a broken minor to practice removing bits from before attempting the rest!

I essentially want the running quality of my old minor in my new '54, so I'll be putting everything in that can go in, with the consideration that it makes a difference (i.e. if I can use the working starter from my 803 on the 1098, I'd keep that since I have a knackered starter than needs looking at for the 1098).

Thanks for all the help and suggestions.
I'll keep you guys posted as I work and learn then. *GULP*

[myoldjalopy]

It would seem a shame to brutally chop the floor of yet another old original. And in addition to Mike's comments, you will need a new carpet to cover the later transmission tunnel! A sympathetic approach would be to amalgamate the 803 and 1098 box so the interior remains original. However, its a bit complicated and I have never done it, but I found these instructions in an old 1989 copy of Minor Matters Tech Tips:

"The components are not immediately compatable because the rear ball race of the 1098 gearbox is of a larger outside diameter and positioned about 3/16" further back than on a SII box. Therefore, a spacer plate made from 3/16" aluminium must be fitted between the 1098 casing and the 803 rear extension (seems a shame to chop your 948 box), a gasket can be used to make a pattern for the plate, remembering to put all the oil holes and a hole for the locating peg on the steel bearing housing. A blind clearance hole needs to be drilled into the face of the 803 rear extension to take the end of the locating plate.
Unfortunately, the speedo drive pinion is now about 3/16" too far back and will mesh with the nut and washers on the main shaft instead of the speedo gear. This is overcome by by putting a 0.1" thick spacer between the speedo drive gear and the distance piece on the main shaft, the diameter of the spacer being identicle to the distance piece, and by chamfering the far end of the teeth of the speedo drive pinion.
With the whole thing together with a gasket either side of the spacer plate and 3/16" longer screws there then needs to be a small slug of steel welded into the bottom of the slot in the reverse selector rod to prevent accidental selection of reverse when selecting fourth. (This then retains the 'up and over' 803 reverse gear select mechanism).
Before assembly, a new combination of bearing packing washers for the rear cover will have to be selected, as detailed in section FF8 of the Workshop Manual.
To fit to the car, because of the additional 3/16" now added, the two slotted holes in the gearbox mounting cross member must be widened. Also, with a 1098 engine,bgearbox and 4.22 diff in a SII, the correct speedo head must be fitted to match the axle ratio. The 'works' from the large diameter later type speedo will fit into the casing of the small diameter head fitted to SII cars but the dials have to be interchnged and rescaled."

It all seems a bit of a faff. Much easier to 'marry' a 948 gearbox to the 803 - no engineering required - and fit a 948 engine. This I have (had) done. You can swap over the reverse gear selector and retain the 803 reverse gear selection method, reducing the risk of selecting reverse when trying to go into fourth at speed! .

[philthehill]

The point being missed here is that the OP appears to have all the spares/items readily available to fit the 1098cc engine/gearbox.

With all the parts to hand the 803cc engine and gearbox can be hauled out and the 1098cc engine and gearbox fitted with ease.

The total job can be done over one weekend. An axle change can be done at a later date.

What ever is cut out can be retained and welded back in at a later date if required. Most cars have had a amount of welding done so this small addition piece of welding will not be at odds with what has already been done.

[jagnut66]

One other thing I forgot to mention is that you will need to 'adapt' the 1098 gearbox tunnel cover to match the earlier clutch pedal position, which was inside the chassis leg, rather than outside, as on your later car. See picture below.

Gearbox tunnel cover pedal slot.JPG (1.3 MiB) Viewed 1691 times

A small patch piece can be made up to block the slot for the later pedal position out of the bit you cut out.

You mention wanting to use your good 803 starter motor on your replacement 1098 engine, I believe it is compatible, if so you can just bolt it in place, as physically it is the same and will fit.

For changing the rear axle over to the later one I simply put an builders plank under the car, supported on axle stands, just ahead of the rear wheelarch, this gave me complete access to the space I needed to work in.

DSCF3411.JPG (1.31 MiB) Viewed 1691 times

DSCF3413.JPG (1.32 MiB) Viewed 1691 times

Obviously the front is up on axle stands too, so it sits level. I left my trolley jack up in position but not not actually taking any weight at this point, just to be extra safe, though it never became an issue, the car remained stable and in position throughout the refit.
Now done and the axle stands are back under the axle itself.

you will need a new carpet to cover the later transmission tunnel

Indeed, I have bought a complete carpet set to suit, as the set in my car was past its best anyway, however the OP can use the one from his scrap Minor 1000 if its any good.
Best wishes,
Mike.

[myoldjalopy]

The point being missed here is that the OP appears to have all the spares/items readily available to fit the 1098cc engine/gearbox.

I'm not missing the point, Phil. I'm well ware of what the OP has and what his proposals are - hence my own comments! At least he will be able to make an informed choice as to the way forward. The 948 is generally held to be the 'sweeter' engine. Of course, there are other options - one of which would be to sell the 'unmolested' 803 with its 'purring' engine, buy a later model with the 1098 set-up, and keep the 1963 car for spares. No spanners required!

[jagnut66]

Of course, there are other options - one of which would be to sell the 'unmolested' 803 with its 'purring' engine

I think the other point of this post is that, like allot of us on here, he likes the look and period charm of a split screen but wants it to be as usable in all driving conditions as the later models. One of those being the hill climb to where he lives that he mentioned at the start. I don't think he wants to sell his split screen any more than I do.
Once he's done it will still look the same, except for the position of the gear lever. Plus as Phil said above, everything is completely reversible, should a future owner so wish.
Best wishes,
Mike.

[myoldjalopy]

"Once he's done it will still look the same, except for the position of the gear lever."
...and the type of lever - and the transmission tunnel - and the handbrake lever!

[jagnut66]

and the type of lever

Obviously.

and the transmission tunnel

Hidden by the carpet, so not on show...….

and the handbrake lever!

I've sprayed mine gold (rather than black) so it blends in better...…
It must just be me but I'm at a loss to see what the problem is...….
Best wishes,
Mike.

[myoldjalopy]

Transmission tunnel "Hidden by the carpet, so not on show...…." Not so - the later transmission tunnel is at once much bulkier and squarer in profile than the 803 type, as even a cursory inspection will reveal........hence the need for the later carpet to fit!
I don't see a problem in trying to ensure the OP has the most complete and accurate information before he can make an informed choice as to the way forward, what that entails - and what he ends up with. Its a good thing Phil added the info about the gearbox cross member/mount and that you subsequently remembered the issue with adapting the later transmission tunnel.....

[Andymoor94]

Of course, there are other options - one of which would be to sell the 'unmolested' 803 with its 'purring' engine

I think the other point of this post is that, like allot of us on here, he likes the look and period charm of a split screen but wants it to be as usable in all driving conditions as the later models. One of those being the hill climb to where he lives that he mentioned at the start. I don't think he wants to sell his split screen any more than I do.
Once he's done it will still look the same, except for the position of the gear lever. Plus as Phil said above, everything is completely reversible, should a future owner so wish.
Best wishes,
Mike.

Essentially hit the nail on the head there!

So progress, I have the axle out of the donor car, gonna clean it up and check everything is in good order (diff, brakes, etc). I've started taking bits from the gunky 1098 engine to clean, just a good old table top teardown!

Transmission will also be looked at, brought back to life etc.

All in good time, got some learning and work to do before I make the transition! Thanks for all of the help and advice, will no doubt be posting again in the near future (Hopefully not a "Morris minor bits for sale" post)

[SteveClem]

I’d be interested in a good 803, as a spare for my A30.
Parts are getting harder to find, so I’ve started hoarding..