15 replies to this topic

[JonnyAlpha]

A question that has been asked a thousand times no doubt but please bear with me.

 

I have an 1982 Austin HLE 1000 which is running OK albeit underpowered.

The car has been under a major restoration over the past 5 years (see my project build). Apart from renewing flexi hoses, Engine Mounts, Subframe Mounts, Adjustable Tie Bars in situ (very difficult) I never got around to lifting the engine or dropping the front subframe.

 

At some point in the future to compliment the restoration I would like to tidy up the Engine and take an opportunity to improve it.

 

I am not looking a Race Spec but just what would be possible within a reasonable budget. I also understand that there are hundreds of options and would just like some advice on best value for money. I also understand that improving the output of the Engine will lead to additional stress on other parts, as such what else should be considered in carrying out some of the options below.

 

First question though - is there a guide / book on performance enhancements covering all of the various options  

 

Based on my research so far some of the options / mix of options are:

 

1. Remove Engine, clean up existing head, hone out cylinders and fit next sze pistons? What other items should be considered here (bearings / clutch / Flywheel / Ignition / Carb / Filter etc.

2. Replace the HS4 (I think that's what I have) with an HIF38 (Which I think I have in the garage, but needs a refurb) and fit a better Manifold / Filter (I also understand that there is little if no improvement in replacing the HS4 with an HIF 38 apart from fast cornering fuel starvation problem improvement).

3. Fit a Stage 1 kit.

4. Fit a Cooper 998 Head? Do I need to change the Pistons?

5. Fit a 1275 Head - benefits / what type of head.

6. Buy an old 1275 carb fed engine and refurbish it.

7. Convert the Subframe to 7.5 Disc (remain on 10 Inch Wheel), needed with any increase in power I guess.

 

Many thanks for looking

 

 

 

[Mrpeanut]

I've owned several mini's over recent years, from basic 998's through a basic 1275 and a well sorted 1330. Currently I'm running a 1981 998 HL so same engine as yours. I've added a stage 1 kit and had it rolling roaded to give its best. I've sorted the suspension and steering. I have to say it's as much fun as the 1330, but obviously much slower. My view is that unless you really want to spend mega bucks, and assuming your engine is decent, then stage 1 it and sort your suspension. I wouldn't waste your time with 12g295 head on your engine for the same reason I was advised not to do the same to mine, namely that the camshaft holds it back.

[Cooperman]

That is good advice.
The A-series engine is limited by both head and cam and it is expensive to get a big increase in power and torque.
The 998 is a fine engine and there is little point in spending a lot on a fully rebuilt 1275.
A so-called 'Stage 1' kit will give a modest improvement so long as you buy from a good source.
You have a classic car with the limitations that implies. Enjoy it for what it is.

[ACDodd]

Seeing as they both cost similar to build, and in road trim about 70lbft/litre, the bigger 1275 based engine wins everytime. Its torque that puts are arse in the seat when you put your foot down. Therefore the 1275 wins everytime.

Ac

[JonnyAlpha]

I've owned several mini's over recent years, from basic 998's through a basic 1275 and a well sorted 1330. Currently I'm running a 1981 998 HL so same engine as yours. I've added a stage 1 kit and had it rolling roaded to give its best. I've sorted the suspension and steering. I have to say it's as much fun as the 1330, but obviously much slower. My view is that unless you really want to spend mega bucks, and assuming your engine is decent, then stage 1 it and sort your suspension. I wouldn't waste your time with 12g295 head on your engine for the same reason I was advised not to do the same to mine, namely that the camshaft holds it back.

 

Can you expand on "sort your suspension"?

[Spider]

Seeing as they both cost similar to build, and in road trim about 70lbft/litre, the bigger 1275 based engine wins everytime. Its torque that puts are arse in the seat when you put your foot down. Therefore the 1275 wins everytime.

Ac

 

Agree with this 100%.

 

While a 998 can be modified to make as much peak power or more than a 1275, the way it makes and delivers it is considerably different and will never be as easy to drive as a 1275.

 

And as AC has mentioned, costs of overhaul are similar for any engine.

[nicklouse]

you cant beat CCs.

[tb205gti]

I have been in the same boat. I fitted a small valve 940 head with increased compression, pocketed the block, fitted 2xHS2 on a good manifold and a CooperFreeflow manifold with RC40.

It goes really well - but going any further will start to cost too much. I decided to go the 1275 route. I'm building a 1275 with a 276 cam, 2xHS2, same manifolds and exhaust now. Should give me much more torque and a bit more top end as well.

 

..Nothing beats cubic capacity :)

[JonnyAlpha]

OK you have all sold me

 

I will look out for a 1275 head (or similar).

 

Incidentally at a local car show yesterday where my Mini was getting lots of nice comments and interest I spoke to several people about performance upgrades with some interesting results.

 

I am planning on sticking with 10 inch wheels (even with a larger engine) and was going to convert to 7.5 discs due to the need for increased braking capacity. One gentleman (who seemed to know his stuff?) suggested that if I fitted an extra servo on the front brake lines I would get the same if not better braking by retaining the twin leading shoe drums as opposed to fitting 7.5 discs?

 

Also since posting this I may have found some suitable donor engines TBC

[dyshipfakta]

Ditch the drums on the front no brainier there.

[carbon]

+1 for being wary using twin leading shoe front brakes with servo instead of discs.

 

With standard brake shoes fitted a servo would give you nice braking feel until the linings get hot. They then fade and you will lose most of the braking effort and even the servo assist won't make up for this. And this will probably happen in a situation when you need all of the braking you can get... You can reduce this effect by 1 fitting minifins and 2 using much harder linings which are less prone to fade, but discs are much better than drums in this respect.

 

Probably easier to fit 7.5 inch discs unless you are planning to stick with original brakes. Suitable disc sets are readily available, which is not the case for 'std' minifins and fade resistant TLS brake shoes.

[Cooperman]

The order for doing modifications to any car should be:

 

Improve braking system (and, no, servo assisted drum brakes are no-where near as good as 7.5" drums with Carbon-Metallic pads)..

Set/improve suspension to give optimum road-holding and good handling.

Increase power and torque.

 

There is little point in having more power and torque if the car still has to be slowed a lot for corners and be slowed by poor brakes. That seriously compromises any power/torque increases you may have. You are better off with 50 bhp and the very best braking, road-holding and handling, than 80 bhp with indifferent brakes and suspension/tyres.

 

If you can brake later, go around the corners quicker and start the next straight bit faster, that in itself is a big performance increase in itself.

[JonnyAlpha]

OK 7.5 brakes setup it will be then

 

What / how to setup the suspension? Geometry check?

[Cooperman]

There are lots of details on here with the optimum suspension settings for road use on here. Do a  search and if you can't find what you need come back on here and I'll re-enter the details.

 

On the original topic, the 998 has a special charm and is more in the original spirit of the classic Mini. It is smoother than a 1275 and it will really rev if you want it to. Once you get a 998 mildly modified with better suspension and disc brakes the overall performance will not disappoint and with a sensible final drive ratio, say a 3.44:1, it will be super to drive.

 

The original 998 Cooper was a lovely car to own and drive. I had a new one in 1964 and did over 20,000 miles per annum in it plus a lot of club motor-sport. It was a pleasure to own and although it had a 3.76:1 FDR I used to cruise it at around 75+ mph  (no 70 limit back then!).

 

Don't dismiss the 998 engine - it is a fine bit of kit. 

[mini_matt_106]

One option for the 998 is a turbo setup which can give you 100bhp without too much trouble