Turbo mini metro new build help.
Turbo Mini Forums

So I am restoring a mg metro 1300 and wish to have an a series turbo in it.

So firstly I have had no history with a series, so learning a lot here. I've 9 mg rovers but all k series or t series engines.

I am aiming for about 8 to 10psi and hopefully about 120bhp which would be a nice reliable fast road setup in the metro.

I've bought 2 engines for the project
1) metro 998 a+ series std fully complete with subframe, carb manifold etc.

2) 1275 metro turbo a+ series std just engine and box.

Also I've bought;
omega pistons 15cc +20
Metro 1300 nasp cam shaft for better lift than the std turbo.

I would like to know as the omega pistons require boring out the block to plus 20 on a 1275 would I be able to do this on the 998 a plus series block just to the same amount. As long as the block doesn't differ in any other way between the 1275 and 998 is this OK?
Are all journals the same size etc?

I am wondering as this would leave me with a std metro turbo a series and a second modded setup with the pistons and changed cam shaft in it.

Is there any block differences I need to know about?
Is crank difference between the 1275 turbo and 998?
If crank is different I wonder is the standard one ok, is turbo crank same as 1275? Just so I can get one if needed.

The head will be getting dry deck conversion and new tri angle seats etc and some porting. Again I wonder if I should send off the 998 head instead of the 1275.
Giving me a modded turbo and a standard turbo engine.

Any help or advice appreciated.

Also I read on here that I can convert my hif44 nasp carb to be a turbo one with the turbo carb service kit. Is this correct?

Does anyone have any info on what to use for boost controller. The original turbo in the metro was limited to 4psi in the wastegate and the a leak off valve allowed it to boost up to 7psi above 4500 rpm. I would like to run 8 or 10psi top. But should I keep it variable like this and if so has anyone suggestions for this rpm based control? Or do you all just run a flat value boost?

I will need a turbo inlet plenum to fit the hif44 has anyone suggestions where I should look for one even one needing restored. ?


Many many thanks for all your time and advice... trev.

If you don't own one you will never understand....

998 and 1275 block are totally different, so no.

Turbo cam is a standard n/a cam. MG metro n/a cam is a little better though...but just a little.

998 and 1275 crank are also different.

If you're doing a 1275, you've wasted your money buying a 998.

And no, a n/a SU cannot easily be converted to the same as a turbo spec carb. That isn't to say you may not be able to make use of a n/a carb for a low boost setup.

Yes you will need an OE type inlet plenum, as internally it is designed to help lift additional fuel from the carb.

Edited by stevieturbo on 15th May, 2021.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Sell the 998 engine, you're not going to be using it on this build.

Thanks for the info. I'll sell the 998 then its all standard.
And I'll get the inlet plenum.

Any help on the boost controller setup appreciated.

As for the carb ..

There is a full link on here about how to setup your hiff44 na to use in a boost setup.
Is this information incorrect seems its being used by people on this group

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=2103

If you don't own one you will never understand....

As already said, a n/a carb can be adapted for boosted use, however that does not make it the same as a turbo SU, which also has additional sealing aspects which would be impractical or impossible for mere mortals to achieve on a n/a carb without some damn good machining abilities

Will it work ? usually yes, will it be the same as a proper carb ? No.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Stevie. I am wanting to know will it work reliably?
So ive just bought a 1275 maestro a series n.a. to do my mods to and keep the other engine std.
So if it comes down to it I want a reliable modded carb for the modded car and full original for the std turbo setup.

So really my questions now are.
what is the best place to get a turbo su carb for the std turbo setup
And if I use the normal su carb and change it as per post is it reliable with increased boost. Would love to know anyone here that is using this setup and if it's been reliable or not.

Finally for boost control is anyone using a variable setup or do u just use a flat boost value.

Thanks. Trev.

If you don't own one you will never understand....

Stevie. I am wanting to know will it work reliably?
So ive just bought a 1275 maestro a series n.a. to do my mods to and keep the other engine std.
So if it comes down to it I want a reliable modded carb for the modded car and full original for the std turbo setup.

So really my questions now are.
what is the best place to get a turbo su carb for the std turbo setup
And if I use the normal su carb and change it as per post is it reliable with increased boost. Would love to know anyone here that is using this setup and if it's been reliable or not.

Finally for boost control is anyone using a variable setup or do u just use a flat boost value.

Thanks. Trev.

If you don't own one you will never understand....

Also I see ur local in n.i. stevie, are you far away. Would love a chat if ur free. I'm new to a series and pretty much using the yellow bible and this forum for my info

If you don't own one you will never understand....

Does anyone know if you must use the omega pistons rings with the 73.5 plus +20 15cc dish pistons. Ive got a new set but there are 2 rings missing. And most places only sell a full set.

Also does the cc now become 1293 at plus 20 or does the calculation change due to the 15cc dish? I just wish to know as its used later for carb setup I think. Thanks.t.

If you don't own one you will never understand....

Boost control is entirely up to you, there are many options these days from cheap, to expensive.

To limit torque to try and improve gearbox longevity, you might wish to ramp boost in, leaving it a little lower in the mid-range even if that doesn't feel as good.
Of course, if just a low boost setup, probably a waste of time, just keep it simple at first and see how it goes.

If it was me, I'd be trying to find a proper turbo carb.
But a regular SU could probably work ok.

A 1275 with +20 pistons will be 1293.

As for rings, various companies make rings and you might be able to get singles, just depends what dimensions they are etc.
Dave Powell at Performance Unlimited is a Total Seal dealer and very knowledgable man who might be able to help.
But you'd need exact measurements of what you need. Ring dimensions and groove dimensions in the piston etc.

or might just be handy to buy a full set from Omega in case you lose or damage some, unless they're asking a fortune

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

The omega ones are advertised as less slip or something and they are 120 quid. Which is a lot for rings. I will try dave so thanks for the suggestion.
I will also try to get a turbo carb as I need to spend money resto kit, higher boost needle etc I better make it for the correct carb.

I've got a digital controller by innovate which doubles with afr so I might try it. I cant remember if its got rpm based variable boost. I know its got boost cut on values will check boost gain based on rpm.

Many thanks for assistance so far.

If you don't own one you will never understand....

https://www.youtube.com/watch?v=1c5qsrl-fvw

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Bit weird someone having a K&N on it...but hey ho. Looks correct apart from that

https://www.facebook.com/commerce/listing/9...hare_attachment

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Turbo carb rebuild procedure is handy but doesn't tell anything about how to convert a hif44 for turbo

The last link above this list doesn't show anything.

Last wee question for a while.

I believe the ports and valves are bigger on the mg metro 1275 compared to 1275 turbo.
As ive both engines was thinking of putting the n.a. head in my turbo will is flow better?
Maybe they tried to limit power because it was chewing gearboxes lol.

Has anyone else played with this.
Is there anything else I would need to change? Like the valve springs are doubles on my turbo buy not on the n.a.
Maybe modern good springs forgo doing that but info would be great.
I'm using the metro cam for a bit more oomph.

Thanks.

If you don't own one you will never understand....

I ran metro turbo parts on an otherwise standard metro 1275engine (i think an LE or something) I still have the engine and the valves are bigger than standard pre A plus and i believe they are also bigger than the turbo version. Mine was back in the 90's when used engines were cheap, i bought the head with the turbo, but never used the turbo head. I ran 30k with about 8 or 9psi, so nothing special, and had no issues. I think the turbo head was mostly to improve long term reliability and reduce the possibility of cracking between valves. The sodium valves were maybe a little bit for the marketing dep't as well.

Jeff

Thanks Jeff just what I wanted to know

As for piston rings I've got mini spares to include a set of omega rings or mega rings I think they said plus20 for 48 quid - score..!!

There are lots of gaskets out there and timing chain upgrades....
Is it worth using vernier chain kits to dial it in or if I find out how much its off is an offset key enough in some occasions.
I do see most going double chain so I will do that but do the old ones give as much play as it suggests.?

Reliability wise I want a good gearbox so need a xpin diff if anyone has one one sale. Thanks t.

If you don't own one you will never understand....

I'm probably not the best person to recomend parts as I always used cheap standard parts. I have bought adjustable duplex for my 1275 tho (still in box...) and I am contemplating xpin diff. The cost of diff and flywheel/clutch are part of the reason the 1275 is still in bits. As a bit of a recomendation for the diff, when I got my original metro turbo setup, it came from a PYO yard, the selection I made was based on F@#k me the diff on this one is all over the engine bay. The turbo must be a good one!!! To avoid the diff casing on mine being destroyed, I just stuck with skinny tyres. Is that a normal budget fix??? I now have fat tyres and a 998.

Edited by Jd24-7 on 4th Jun, 2021.