MG midget 5 speed conversion.

[jamesatherton]

I was reading through some past topics and came across a toyota celica 5 speed conversion fo a 1275 midget. I was wondering if anybody could give any more information on this. What modifacations to the engine? What model/year the gearbox is from. Thanks james

[niva441]

Can't give any really useful details, but I've also heard of it being applied to Minors with 1275 engines. Perhaps someone with one of those can help.

[jamesatherton]

Thanks, i think that it was member boredpilot who gave precise details. Was hoping that there were no major modifacations to the engine/gearbox joinings.

[wildoliver]

It will be much like the sierra conversion requiring either a modified back plate or a modified bell housing, plus any modifications to spigot bearing, clutch plate, possibly flywheel, clutch system, accelerator cable etc.

I will however have an overdrive gearbox kit up for sale in a couple of days which fits almost straight in.

[george 500]

I may be wrong but I remember reading a while back that a sierra five speed gearbox slotted straight in (with modified bellhousng).

[wadgebeast]

Thought the sierra gearbox was for the B series rather than the A series. Might be better off changing the whole lot; stick a K series in it with a 5 speed as standard.

[wildoliver]

The sierra box can be fitted to a or b series.

Also starlet gearbox or celica can be used.

To be honest it depends what the car is going to be used for, if it is going to be a first car then there is no need for a 5 speed conversion, the best advice I have is if it's your only car and you find yourself wanting a more relaxed cruiser sell it and buy an mgb.

[bikemonster]

Have a look at the archived Sprite and Midget Technical BBS over at www.british-cars.co.uk under "MG" unsurprisingly.

You will need to sign up as a member to get to the archive, and it's worthwhile. There are some very knowledgeable guys who post there.

The topic of 5 speed conversions for Spridgets comes up every 20 minutes or so.

[coco h]

wildoliver said:

The sierra box can be fitted to a or b series.

Also starlet gearbox or celica can be used.

To be honest it depends what the car is going to be used for, if it is going to be a first car then there is no need for a 5 speed conversion, the best advice I have is if it's your only car and you find yourself wanting a more relaxed cruiser sell it and buy an mgb.

Agree - I've seen most varientsof midgets around. Just depends what you want to do. I need to keep mine as 4 speed which is a nightmare given the punishment it gets as the box needs rebuilding periodically.

[moosetvr]

Hi, Frontline down in Bath do a good conversion to fit a Ford type 9 into the spridgets. Helped a friend fit this kit to his AH sprite, and was quite straighforward. Ratios of the Type 9 suited the car well, fun up to 3rd and then 4 and 5 for cruising and motorways.

[wildoliver]

Coco guess you autotest yours too?

Frontline stuff is good, not the best but as a one stop shop they are great, they are however very very expensive.

[coco h]

wildoliver said:

Coco guess you autotest yours too?

Frontline stuff is good, not the best but as a one stop shop they are great, they are however very very expensive.

It's for hillclimbs and sprints - something to do with the class regs. A pain really as five speed would be better in some respects

[wildoliver]

Hmmm, must admit I know where your coming from, although I always found the problem with the standard box for hill climbs was it wasn't close enough ratio'd, although a good 5 speed would solve that if correctly ratio'd up you have to think that equals more gearchanging which equals more time off power.

Sometimes playing with diff ratio's is easier and works better.

Are you allowed any 4 speed box or does it have to be original? I ended up moving to a 1500 box on marina bell housing as they are virtually indestructable, unlike the 1275 box which is slightly beyond its power brief on a mild tune 1275.

[coco h]

I need to check but I think it is the housing that needs to remain the same. I changed to starit cut last year. I have 3 diffs for the car and that seems to solve the ratio issues. I am always concerned that given the car's power it will break the gearbox (highly non-standard bhp!!). But we are not the most powerfull in our class so I can only think we are all facing the same problem.

[coco h]

coco h said:

I need to check but I think it is the housing that needs to remain the same. I have 3 diffs for the car and that seems to solve the ratio issues. I am always concerned that given the car's power it will break the gearbox (highly non-standard bhp!!). But we are not the most powerfull in our class so I can only think we are all facing the same problem.

[wildoliver]

Is it Jack knight that used to make very strong internals for those boxes?

I always used to end up ripping the layshaft out of mine, hence my change to the marina/triumph box, but then again I wasn't limited to type.

You might find if the regs allow 1500 midgets you may be able to get away with the fact the gearbox is a standard 1500 item!