998cc automatic- tuning/reconditionig - (Stage 1/Stage 2)

[zaki]

Hi guys!

I just got my first classic Mini- 1991 Mayfair 998cc Automatic. It is an unfinished project with almost all the bodywork finished. It came from France with it's previous owner. It is now in Poland and that is where I live.

I have taken care of the subframes and suspension. I'll go for the EVO rubber cones + Bilstein b4 or KYB Gas-A-Just shocks.

When it comes to brakes I'll simply buy a ready set of calipers with 7,5'' discs that 10" wheels can clear easily.

The problem is the engine. I have absolutely no idea what could I do raise it's power from 42bhp to something around 55-65bhp.

I keep browsing forums like this one and theminiforum.co.uk, Facebook, Youtube and the more I know... the less I know .

The vast majority of tips about tuning Mini engines is about 1275cc and bigger units. I can hardly find any tips describing

tuning of a 998 and things get even worse when I add an automatic gearbox to this equation.

As I'm not a skilled car mechanic myself I'll have someone do all these things for me. I just have to point in the direction we should go with this project.

I have tons of question about, basically, everything when it comes to tuning of a 998.

• 1. Engine. I've read that changing rockers and a head is not necessarily something that I should go for as this may even cause degrease of power.
  
  I don't know how true this statement is but I'm not convinced that I should change that much as this is my first project.
  The other thing is that previous owner already has bought new pistons, crankshaft bearings and took care of engine's block resurfacing.
  So I really would not like to spend money on another set of pistons etc. (I'll check later what pistons and bearings these are)
  
  
  
  I was thinking about using one of these sets from Minisport. Do you think that it's worth something? Would custom air intake and exhaust do the trick?
  
  www.minisport.com/t-ktk01l-stage-1-tuning-kit-998-1275-hif38-carb-1990-on.html

• 2. Carburettor. Does changing this part help a lot in terms of gaining more power? I doubt that this engine would work better with two carbs but again- this is just my guess.
  I think that one but bigger carb would do the trick. Please correct me if I'm wrong. If yes- which one shall I go for.
  

• 3. Timing chain. Again- so many options as forum users writing about it. After studying this topic for a few hours I came to conclusion that  I have two options:
  
  
  a. Simplex timing chain of good quality (EVO) and maybe lighter timing gear and a tensioner (I don't know if this is needed).
  b. Duplex timing chain of good quality (EVO), lighter timing gear. I know about these 2 screws and possible cover fitting problems.
  
  
  I' pretty sure that I don't need any advanced solutions like MED's duplex as this is not that sophisticated/demanding tuning that I aim for.

• 4. Gearbox. I know that since the engine is stripped down reconditioning it is absolutely worth it.  I've visited ap2.world/ (Owner of the #ClassicMiniCulture Youtube channel helped me here- real Mini automatic lover . Thank you!).
  
  I was thinking about using this service kit but from what I can see there is a set of tools that I would have to buy as well in order to rebuild this gearbox.
  I've already sent an email or two to Martin (mra-minis ) and I am really considering sending him this unit as I'm not sure if my mechanic will be able to deal with it without ale the special tools and Martin's knowledge.

• 5. Cooling. I read that I have to use a proper motor oil and I thought about Millers ZFS 10w40 JASO MA2. What about additional oil cooler? Do I need one? Some say that tuned, automatic engine has tendency to overheating
  and some say it doesn't if you change the oil every 2000-3000 miles. I'm confused here. Won't 2 hour long highway trip cause engine to overheat? What about the air cooler? Do I need one? I was thinking about this Fletcher.
  

As you can see there's dozen of topics to cover and I'm sure that I can count on your vast knowledge. Specialists, and Mini lovers, that had to deal with all of similar problems not once, not twice .

Maciej (Mike if you prefer

[notamini]

I have a 4-core radiator which comes standard in the automatic 1100/1300. Maybe you can find one.

[zaki]

Nov 17, 2022 0:34:16 GMT notamini said:

I have a 4-core radiator which comes standard in the automatic 1100/1300. Maybe you can find one.

I have a refurbished one for this 998. I was thinking about Fletcher as it seems to work fine and looks so cool in chrome. It would fit other chrome parts like rocker cover.

I assume that your radiator needs different mounting and hoses or are these parts the same?

[jockduck]

Hi, the standard auto engine is slightly tuned over the manual engine, my own 998 mini is 0.040 over standard bore, when I had the exhaust valve seats changed for unleaded I gas flowed the cylinder head as per David Visard to stage 1, the rest is stock, I did have overheating and knocking issues in hot weather( Australia, up to 40 deg days), I discovered that the ignition timing was very bad with the stock distributor and have fitted a programmable ignition system and now the car flies and handles the hot weather with no knocking.
Jock

[zaki]

Hi! jockduck I'm not sure if I'm thinking about the same. Does this video cover the topic? No mention about "programmable ignition" though.

www.youtube.com/watch?v=Ziudc--90Ns

I don't have my car around so I'm not able to check what type of distributor I have.

[mra-minis]

Nov 17, 2022 12:24:34 GMT zaki said:

Hi! jockduck I'm not sure if I'm thinking about the same. Does this video cover the topic? No mention about "programmable ignition" though.

www.youtube.com/watch?v=Ziudc--90Ns

I don't have my car around so I'm not able to check what type of distributor I have.

I can be contacted on [e-mail]

Your standard distributor will not cope with tuning and a programmable ECU is by far the best option, followed by a programmable distributor, at the bottom of the list is the standard distributor with no modifications.

Oil cooler would only be required in a mini when you go over about 80BHP if you have less than this and it still overheats, look at things like brakes, and inside at the adjustment of the brake bands, I often find these are at fault because people often over adjust them.

998 ? ideal for a turbo, nothing super high in power but easily 80bhp and loads more driveable

[mra-minis]

Nov 17, 2022 4:31:00 GMT zaki said:

Nov 17, 2022 0:34:16 GMT notamini said:

I have a 4-core radiator which comes standard in the automatic 1100/1300. Maybe you can find one.

I have a refurbished one for this 998. I was thinking about Fletcher as it seems to work fine and looks so cool in chrome. It would fit other chrome parts like rocker cover.

I assume that your radiator needs different mounting and hoses or are these parts the same?

I can be contacted on [e-mail]

The ADO16 radiator won't fit in most Minis, may fit in a Clubman shell

[notamini]

Thanks Kock. Good to know.

[mra-minis]

Nov 17, 2022 21:16:07 GMT notamini said:

Thanks Kock. Good to know.

I can be contacted on [e-mail]

Did you mean "kock" ?

[zaki]

"Your standard distributor will not cope with tuning and a programmable ECU is by far the best option, followed by a programmable distributor"

     Martin- that sounds interesting. I assume that is something that many of you have in your cars. Are there any ready sets that I can buy or is it a bit more complex solution?

    Something like this? www.youtube.com/watch?v=6Q_yST97xWo

[notamini]

Sorry Jock. Slip of the fingers.

[mra-minis]

Nov 18, 2022 7:35:28 GMT zaki said:

"Your standard distributor will not cope with tuning and a programmable ECU is by far the best option, followed by a programmable distributor"

     Martin- that sounds interesting. I assume that is something that many of you have in your cars. Are there any ready sets that I can buy or is it a bit more complex solution?

    Something like this? www.youtube.com/watch?v=6Q_yST97xWo

I can be contacted on [e-mail]

I did put together a kit of parts for adding an ECU to a NON ECU Automatic Mini a manual kit just won't work.

The kit works out at about £1300 but a requote would be needed, anyone that has fitted one will tell you how much better it is to any distributor based system

[mra-minis]

Nov 18, 2022 12:23:19 GMT notamini said:

Sorry Jock. Slip of the fingers.

I can be contacted on [e-mail]

[zaki]

First inspection of my gearbox' and I'm amazed how many various grind marks it has.

What I'm even more worried about is a small crack that we've found. I've seen both- the marks and this kind of cracks in a few other geraboxes

but is it normal or is it something that I shall be concerned about?  (This is my first classic Mini).

EDIT- I've seen that many of these gearboxes have similar marks. I assume that's the way these parts were built.

[mra-minis]

Nov 19, 2022 15:24:25 GMT zaki said:

First inspection of my gearbox' and I'm amazed how many various grind marks it has.

What I'm even more worried about is a small crack that we've found. I've seen both- the marks and this kind of cracks in a few other geraboxes

but is it normal or is it something that I shall be concerned about?  (This is my first classic Mini).

EDIT- I've seen that many of these gearboxes have similar marks. I assume that's the way these parts were build.

View Attachment

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I can be contacted on [e-mail]

The grind marks are fine the crack I couldn't see

[zaki]

I was talking about this one.

[zaki]

notamini mra-minis Can I ask you guys to move this thread to "Mini projects" section?

I thank you in advance.

[mra-minis]

Nov 21, 2022 7:20:49 GMT zaki said:

notamini mra-minis Can I ask you guys to move this thread to "Mini projects" section?

I thank you in advance.

I can be contacted on [e-mail]

It is done

[mra-minis]

Nov 19, 2022 19:38:16 GMT zaki said:

I was talking about this one.

View Attachment

I can be contacted on [e-mail]

That "crack" looks more like a cooling fault from casting and being cooled too quickly, it is doubtful to propagate any further as these cases are far stronger than they need to be.

[mra-minis]

Nov 21, 2022 11:28:52 GMT mra-minis said:

Nov 19, 2022 19:38:16 GMT zaki said:

I was talking about this one.

View Attachment

I can be contacted on [e-mail]

That "crack" looks more like a cooling fault from casting and being cooled too quickly, it is doubtful to propagate any further as these cases are far stronger than they need to be.

I can be contacted on [e-mail]

yep that's the one

[zaki]

Guys,

Will that kind of camshaft (HT version) give anything without other modding of engine's cylinder head?

www.med-engineering.co.uk/engine-assembly/camshafts/road-camshafts-blanks

Or maybe this set:

www.med-engineering.co.uk/engine-assembly/camshafts/med-st1-camshaft-kit

[mra-minis]

Nov 24, 2022 21:37:26 GMT zaki said:

Guys,

Will that kind of camshaft (HT version) give anything without other modding of engine's cylinder head? (links removed)

I can be contacted on [e-mail]

I have a range of camshafts for the automatic, none of steves are designed with the automatic in mind

[zaki]

MED's won't work? Damn! Martin- I've sent you an email.

[mra-minis]

Nov 25, 2022 6:52:45 GMT zaki said:

MED's won't work? Damn! Martin- I've sent you an email.

I can be contacted on [e-mail]

Yes they will work but they are tuned for manual not automatic and there is a big difference on where the best place to ficus the torque curve is, this is to suit the converter stall speed, if you want I can quote on a modified stall speed TC to suit a different camshaft including full race cams

[notamini]

Nov 25, 2022 17:48:10 GMT mra-minis said:

Nov 25, 2022 6:52:45 GMT zaki said:

MED's won't work? Damn! Martin- I've sent you an email.

I can be contacted on [e-mail]

Yes they will work but they are tuned for manual not automatic and there is a big difference on where the best place to focus the torque curve is, this is to suit the converter stall speed, if you want I can quote on a modified stall speed TC to suit a different camshaft including full race cams

Martin it is my understanding that Stall speed is the point where the TC is fully engaged. Is this correct? What is the stall on a factory installed 1275 like mine? Could you explain the differences between higher and lower? Would higher help the auto box's initial shifting from N to N, 1 or D preventing 'squawking' during engagement? (assuming the idle speed is about 800 rpm)?

Also would the idle be less 'loaded' if the TC stall was higher?
I have many curiosities about the auto design.
Cheers,
Mark

[mra-minis]

Nov 26, 2022 1:17:16 GMT notamini said:

Nov 25, 2022 17:48:10 GMT mra-minis said:

I can be contacted on [e-mail]

Yes they will work but they are tuned for manual not automatic and there is a big difference on where the best place to focus the torque curve is, this is to suit the converter stall speed, if you want I can quote on a modified stall speed TC to suit a different camshaft including full race cams

Martin it is my understanding that Stall speed is the point where the TC is fully engaged. Is this correct? What is the stall on a factory installed 1275 like mine? Could you explain the differences between higher and lower? Would higher help the auto box's initial shifting from N to N, 1 or D preventing 'squawking' during engagement? (assuming the idle speed is about 800 rpm)?

Also would the idle be less 'loaded' if the TC stall was higher?
I have many curiosities about the auto design.
Cheers,
Mark

I can be contacted on [e-mail]

Hi Mark,

Yes that is correct, I think yours is 1400 rpm but I don't have my manuals in front of me.

The difference between a lower and higher stall speed is simply the point that the engine cannot move the stator against the converter body and will not rev any higher whilst in gear.

Why would you want a different stall speed ?

Well to accelerate the vehicle it needs to be able to supply more torque than is being resisted by friction, friction with the tyres on the road, the bearings in the hubs etc etc...
The more spare torque you have available the more acceleration you get, but lets just consider somebody fitting a 1275 INJ TC to their 998 Mini. what will happen ? well as the 998 won;t be able to pull the converter to its stall speed, the point of lock up will now be considerably lower down the rev range, this means that the available "spare" torque may not be sufficient to accelerate the vehicle but in actual fact it may be the case that the "spare" torque is in fact in the negative and will never be able to accelerate the car just like trying to pull away in a higher gear. now factor in a camshaft that is designed around certain performance gains and the torque curve can disappear at the area on the torque graph where it is most needed, even with a standard TC it may not be possible to get it off the ground, hence why a higher stall speed is needed, the problem with higher stall speeds they also mean the TC has more slippage when being driven normally, an excessive stall speed will only work on an engine that can rev above a certain amount to counteract the effects.


Would higher help the auto box's initial shifting from N to N, 1 or D preventing 'squawking' during engagement (assuming the idle speed is about 800 rpm)?

It could do if the squawk is caused my slippage due to low pressure but it's more often than not caused by other issues though.

Could the idle be less 'loaded' if the TC stall was higher? Yes certainly.

Regards Martin

[notamini]

Thanks Martin. This is quite informative.