13 replies to this topic

[clubbie 1972]

Ive just bought a 1972 mini clubman with a 1990 metro 1275 engine in it (carb)

What bhp would it be standard and now say with a stage 1 kit?

Also whats the easiest way i can acheive that magic 100 bhp?

I'm guessing a stage 3 head with 1.5 rockers or twin SU 1.5 carbs? I don't actually know much about
it just what ive read in various mags but its all become so confusing

Money not much object here by the way, i hav up to 2k to spend on it if required but obviously the cheaper the better lol, could i whack on a turbo lol, presumably economy not be too bad wen i drove it below the spool up range hehe

Thanks in advance

Edited by clubbie 1972, 29 March 2008 - 12:17 AM.

[Sam Walters]

the easiest way to increase power is to increase the capacity.

so 1380 with roughly 7 cc dishes pistons, omega pistons maybe.
a 21 cc fully worked head.
skim the block 1mm
tuftrided and balanced crank/rods.
deplex venier timeing gear.
steel main centre strap.
good quality vandervell bearings through out
block and head drilled for 11 bolts.
arp con rod bolts and head stud set.
for the cam shaft a sw5 will do okay however a kent cams 266 i think it is has more punch
1.5:1 ratio roller tipped rockers.
orange diaphram clutch
new steel fly wheel.
a hif44 will supply the fuel/airflow for 100bhp

the gear box needs abit of attention, a quick rebuild doesn't cost much guess works will do this for you for reasonable prices.
aslong as it is in good condition it should be fine to use standard components. but your on the very limit. you should at least change the diff to something abit more sturdy.

ill be honest it wont be very cheap to do well i suppose you could do it on a budget and save yourself money such as not using omega pistons and things like that but id be worried about it all coming apart

Edited by flyingears2002, 29 March 2008 - 12:19 AM.

[clubbie 1972]

Would having a greater capacity mean my fuel economy wouldn't be as bad as done the other way with the 1275

[Guess-Works.com]

Supercharge it...

[biggav]

Spend £10 on "Tuning the A-series engine" by David Vizard.

Sure up the gearbox.

Strap on a Jonspeed or Vmax Supercharger

Grit yer teeth.

[Minicross498]

Nitrous oxide! Easy power. Some would say its cheating. But it works. Car stays drivable. Off and on-able power. And before someone jumps in and says Nitrous blows ya engine up. It does not! Incorrect set up and people getting greedy with it does. But the same would go for more boost on a turbo

[Sam Walters]

well, fuel economy should be good with that setup, id say around the 30-40 mark but thats just an estimate.#

as for that engine spec

do that but super charge it and do below change it to that.

don't get the block skimmed and have a 28 cc head instead! this should bring the static compression ratio to about 9.3:1

when its having 12psi of extra air pressure being slapped through the static compression ratio is just shy of 17:1 however! the dynamic compression ratio (the one that really matters) is around 15. with good fuel this should not be a problem and correct timing.

absolote minimum of 120 pounds per foot of torque and 140 bhp.

Edited by flyingears2002, 29 March 2008 - 02:37 PM.

[Ethel]

Where are you going to drive it? What variant of 1275 is it and what condition is it in?

A 1275 will produce 60-75hp depending on exactly what it is.

To make more power it has to consume more air, so make it breath better; turn faster; bigger; use auxilliary air stuffer inner (turbo or 'charger).

Improving breathing is way to have your cake and eat it as it will make the engine more efficient and improve economy. If the engine is on its last legs then a similar argument could be applied to boring it bigger.

[Sprocket]

If you are looking for 100bhp you will be disapointed with the SW5

[ginigwunkle]

bore it and stroke it! what ever you want......

lighten balance everything, get steel where you can afford (AT LEAST FLYWHEEL)

get a very good head, i have 21cc chambers in mine

a kent 276 or higher cam, lumpy but what you need for the 100 mark

1.5 rockers maybe

x pin diff at least, maybe sc gearset for long life!

[SMITHY2]

Hi there mate don't know what bhp my engine was before fitting head,rockers,
will have to have it rolling roaded later to find true bhp.Got twin su's to go on
still,Good luck with yours.

[Sam Walters]

If you are looking for 100bhp you will be disapointed with the SW5

it will kick out 100bhp/100 pounds per foot of torque from the modifications i listed.
but id still go with something with a little more kick. no point in spending al this money boreing it out to put a fairly mild cam in it.

[Sprocket]

Really?

I own a 100bhp 1400 with the Kent 274 cam which is a little hotter on the exhaust duration and comparable lift, 1.5 ratio rockers fully worked head fully lightened bottom end.

And for the result of a comparable engine build have a look at this from a man that knows what he is talking about.

I have nothing against the SW5 cam, its just not the wonder cam that everyone thinks it is

AC Dodd said....................

http://www.mlmotorsp...opic,124.0.html

This one is a 1380 as built by Swiftune racing its one of there classics, big engine mild cam(SW5) nice head, 1.5 Roller tip rockers, Twin HS4 SU carbs, cone filters/stub stacks, Carbs was fitted with a Custom ACDodd needles and RED springs.

Produced figures of 90.5bhp@ flywheel, and 86.7lbft @ 3500rpm respectively.

Here are the exact figures if anybody want to plot them, runs taken in 3rd gear, power at wheels was 81bhp peak.


Rpm Bhp Lbft
1500 20.41 71.46
2000 27.89 73.24
2500 35.71 75.03
3000 49.32 86.34
3500 57.82 86.77
4000 65.31 85.75
4500 73.47 85.75
5000 81.29 85.39
5500 87.41 83.47
6000 90.48 79.20

This engine also had leak down figures of 15%, 23%, 25% and 14%.

This was also the most powerful SW5 equipped car I have tested to date, though it should be it has the spec!!

Good luck getting 100bhp with the SW5 cam, Swiftune recon they can do it, so it must be achieveble, I doubt very much they would tell fibs, they are just not the sort of company/ people that would do such a thing, unlike another company I wont mention.

[Guess-Works.com]

I don't even think 1380 is necessary.... bearing in mind my 1330 is putting out 85 at the wheels, and there's nothing really special about it... well apart from the 290 scatter cam

Edited by GuessWorks.co.uk, 18 April 2008 - 07:40 AM.