18 replies to this topic

[lawrence]

So people as the title suggests I am trying to make my mind up about doing the k11 engine transplant for my mini (Micra engine)

My mini seems to be having a recurrent headgasket issues, recently changed it yet again on New Year's Day and it went again about a week ago, seniors got a relatively high compression metro gta engine which probably isn't helping me on the hg front.

At the same time the hg went last week I bought a new verto clutch kit for her and exhaust system as the old manifold was full of pin holes

Now I've been struggling for the last week to remove the flywheel to no avail (separate post on this topic) and last night the pullers head broke off and I nearly bashed a hammer throught the windscreen I was so annoyed

One of my friends said I should try the Micra engine conversion as the a series engine is the only thing that's letting my otherwise reliable mini down

I've looked into the conversion and from my research it's going to cost me about £500 depending on how cheap I can get the car (I can weld so no problems in that department)

Pros of the conversion are
>better economy, drivability and engine reliability
>plenty of parts available at scrap yards

Cons
>loss of a series engine so mini isn't so genuine
>lack of money for conversion at this time
>will take time to fit and given a proper shake down

Pros of keeping the a series engine
>simple mechanics
>cheap ish spares
>once clutch is fixed and hg changed she should be reliable touch wood

Cons
>rubbish mpg (20-30 how I drive)
>hg will blatantly go again once if not twice this year alone
>gearbox on the way out

Now money wise
> I've got £100 or so to spend now.
>Got the specialist components trigger wheel and sensor bracket I could sell for £100 maybe more?
>Cylinder head got refurbished a few years ago with new valves, guides, valve seats double cut if I remember correctly so that should we worth a few quid maybe
>hopefully could get a refund on the clutch kit and the megajolt conversion bits and bobs I bought from dsn so that's another £100
>no idea what the rest of the engine is worth but the bores are in good condition as well as the cylinders so maybe £50? Or a bit more
>also got a series engine spares like oil, oil filters, couple of hg sets (Payen ones) so that could fetch me another £50

So I have enough money available if I sell up first but I cannot make my mind up

What are people thoughts on this issue? Anything would be helpful, comment of the prices of my stuff etc.
Hopefully someone will help me get my head around this, sorry for the long post too!

Thankyou kindly
Lawrence

[Sam]

I think you have summed up the pros and cons pretty well there. Personally I think a lot of the Mini's character comes from the A series. I'm sure a Micra engine will be better in every way, but it won't make the right noises, the right smells, and will it be as fun?

[Ben_O]

Surey it's not normal for an A series HG to go that often?

 

Ben

[cradley-heathen]

if i was you i would stick with the A series and sort out the HG problem. the only reason the HG will fail that often is if something is wrong.

 

is the head warped? have you had it skimmed? check that the studs havnt stretched (i know its not something you hear of with minis, but my brotehr had a 998 a few years back that had a the HG fail twice in a short period, when he took it apart the second time he double checked everything and found one of the head studs had stretched. he did the job as normal and used some new studs and it was fine for years after that.

 

the micra conversion IMO (notice i say in my opinion) isnt worth the aggro. to do an engine transplant you have to adapt drive shafts, engine mounts, exhaust and fuel systems, tons of wiring etc etc, and for the power you get from the micra engine, it just doesnt seem worth it. you would be better fitting something more powerfull for all the hassle of doing it. like i say, thats just my opinion.

 

if mpg's are you concern, the micra engine is going to be just as thirsty if you drive it hard all the time as it sounds like your doing now? any engine will give poor fuel economy if thrashed constantly.

[wile e coyote]

Ok .... I've never done a micra conversion but it looks fun... that aside available budget is a bit on the light side - not impossible and micra's litter the diminishing number of scrappies in our green and pleasant land so sourcing  everything shouldn't  be too difficult.....

 

Very unusual to have repeated hg fail on the a series providing both mating surfaces are totally flat and cleaned obsessively, a decent hg set used and torqued down properly (and again a week later).... unless there's something else going on..... have you checked water pump & changed thermostat???

 

A couple of  oddball thoughts:

 

-  your head - that sounds like it's had work done may be cracked - giving symptoms of hg failure (really hard to spot by the way)

-  if the hg has been done a few times and had been over tightened its possible that the studs have started to pull out of the block check around their bases for any hint of deformation

 

My view (quite apart from agreeing that the a series makes a mini a mini) would be fix what you've got.....then  if the idea still appeals grab a micra, rip it to bits ready to donate - then you can sell your current lump as in full working order....in the meantime go easy!

[The Matt]

Don't convert. Take it from someone who knows! You'll regret it in the long run.

I'm converting back from a Vauxhall conversion at the moment. :)

[gazza01]

Just keep researching HG failures until you suss it. Stick with the A series if you can. Once you have the HG under control it's
all fun again.

[gazza01]

Don't convert. Take it from someone who knows! You'll regret it in the long run.

I'm converting back from a Vauxhall conversion at the moment. :)

Hey Matt. I remember you mentioning this on the facebook forum a while back. What are you're reasons for going back?
Might help with the OP too

[Broomer]

Don't convert. Take it from someone who knows! You'll regret it in the long run.
I'm converting back from a Vauxhall conversion at the moment. :)

Are you mental ?

[Cooperman]

A classic Mini has the A-series engine it was born with. The pleasure in owning a classic is that you are driving a piece of history which will appreciate with time and be valuable eventually. However, with an engine change to a non-A-series, it is not a true classic car anymore and the value will drop. Very few people want a classic car with the wrong engine. This applies to all classics such as Anglias, Cortinas, Jag E-Types, etc. I mean, would you buy an E-Type with a Mustang engine for what you would pay for one with the correct engine?

Head gaskets should last a very long time and if yours keeps going there is a basic problem which it will not be difficult to sort out.

Skim the head, fit new studs & nuts and use a top quality head gasket. Fit it carefully, torque it accurately with a torque wrench which is properly calibrated and accurate and re-torque after 2 or 3 heat cycles. to re-torque, slacken each head nut half-a-turn in the correct sequence and re-torque. Then re-set the valve clearances accurately.

Make sure the timing and mixture are correct.

[ibrooks]

Depends on what YOU want from your Mini. If it's a daily drive and all else is equal (i.e. there isn't something like money or lack of skill preventing the Micra conversion) then the Micra wins hands down. If you want to keep it original then sort the A-Series (I agree that there is something else going on if you are getting repeated head gasket failures and if you get to the bottom of it then the A-Series should be reliable at least).

 

With a little extra effort the Micra lump will go in without modification to the body so converting back to an A-Series at a later date is not a problem if resale value is a worry. V-Tecs and Vauxhalls are a different kettle of fish as much more needs to be changed.

 

Iain

[Rog46]

One other point, how long will spares be available for the micro engine?

[nigel5764]

_Hi

_{I agree with the other guys ,once you remove the a-series and a bit of the classic disappears so I guess its all down to what you want  out of it personally I,d stick with the a-series and sort out problem ,check head and get it skimmed and put on  a good gasket.}

Edited by nigel5764, 04 March 2014 - 07:53 PM.

[tiger99]

What about the diff ratio for the Micra? I assume that the Micra wheels have a larger rolling radius than any Mini wheel and tyre combination. The Mini will be lighter, so you would ideally want lower (numerically) gearing, as you could use less torque, more speed than in a Micra. I am thinking that with standard Micra gearing, the Mini might accelerate like a rocket, but be seriously limited on top speed and economy.

 

Basically, what I am saying is that you may have need of a different final drive ratio. Are they available? Is there room in the casing for a different pair of gears? There are companies such as Jack Knight who can make them, at a price, if it is possible.

 

That would be my only major concern with such a conversion, as long as the subframe was properly engineered. But I really would not want to butcher the shell in any way. If it will squeeze in without that, there is no possibility of needing an IVA test, with the very serious mods that would need.

 

I would not dream of converting any rare model of Mini, especially any kind of Cooper, but would not worry about a City E or something basic, as there are plenty of those still around. But even one of those would lose value. Probably worth it, but that is down to personal preference, i.e. how much do you value having a modern engine?

[Icey]

We got quite a way down the Vauxhall conversion route and I'll say one thing - if you think it's going to save you money compared to fixing/using an A-series, forget it!

You'll find that a lot of simple off-the-shelf items no longer fit (be it Mini or from the donor car) and have to be fabricated. Nothing is ever straight forwards. Everything costs money (and usually a lot more than you'd think).

 

If you are going to do it as an engineering exercise, go for it, why the hell not! If you are doing it just because your current engine is a bit ropey, really think about it as you'll soon burn through the same amount of cash as it would have taken to just repair rather than replace.

 

As for the 'is it still a Mini' question, that's just opinion (and we all know what opinions are like!).

 

Personally, after our experience with an attempted engine swap, nah! Not worth it unless you're going all out. The A-series is dated but it's easy and cheap to work on. I'd sooner keep a spare engine in the garage ready to drop in than try and graft a 'modern' engine in if I was using a Mini as a daily driver again.