74 replies to this topic

[Ethel]

Torque does make acceleration, but BHP is only torque x revs. so if you have 1 litre bike engine geared to 6000rpm at 50mph it will go just as well as 2 litre car engine with twice the torque but 3000rpm at 50mph. They'll both be consuming about the same amount of air and making the same bhp. What makes for a torquey driving car is having plenty of throttle left so you get a rapid hit of power when you put your foot down & allow the cylinders to fill.

Lightweights, like Minis, are potential flyers because they need less torque to accelerate which means the revs increase faster creating more power faster, which leads to faster acceleration, which.....

[CooperMad93]

Thanks for the link Brams86 found it very interesting, A stage kit is sounding more probable

[mk3 Cooper S]

oltonlad, have you ever been in a bike-engined car? I have an R1 powered kitcar, probobly about 100kgs lighter than an R1 mini would be, its about 450 kgs . Scaling it up, it's equivalent to a 1 tonne car with 190lb/ft of torque. or an impreza with 270lb/ft. Contrary to belief they are not bad low down, its all relative, they are quick enough low down, f****** quick between 7 -12,000rpm. If you do feel you are lacking a little "torque" all you do is whack the sequential gearstick forwards 1/2" once and floor it, you are gone. If I coast at 1,000 rpm in second and open the taps hard it will spin its wheels up no problem , smooth as silk from tickover to red-line. It certainly does not cough, splutter and struggle wheezing until it comes "on cam" like my (expensive) Swiftune 1380 would if I tried the same trick.... They are not ideal granted, not for everybody and can be too loud tiresome for some folk. But they are also exciting as hell to drive and certainly not slow. And I have been lucky enough to drive "the daddy" Caterham R500 250 miles home from Belgium after a trackday at Zolder. The Caterham was quicker granted but not as much as you would expect from £10,000 of K-series and £1,000 of Yamaha! Just don't believe the internet torque stories written by folk who have never tried one, it all bull. I have had bike-engined cars since 2002, building one of the very first Fury Fireblades, and done over 35,000 road and track miles in them.

I have driven allsorts, It is what ever floats your boat really
Ultralight kitcars suffer less from low speed/pull away lack of torque and the need to keep the rev's up or toggling down the gearbox when you want it to fly.
Lack of flywheel weight can annoy some people with the lack of overun.

No doubt bike engines can fly when you work them but the question was as a daily driver - not everyone could live with them

[Brams96]

Coopermad93 - What current engine do you have & what mods have you done to your engine & car so far, if any?

[CooperMad93]

standard metro engine in a mini, got an airfilter and an exhaust thats about it

[t@z]

i'd swing a nice torquey cam in there, not to lumpy....get a MJ on it and save for a decent head.

[tom1234177]

Anyone who's got a mini N/A running near 100 ponies, could they post up their spec, I'm near completion on my new engine, be nice to get an idea

[CooperMad93]

http://www.minisport..._KENMD266K.html would this one be a good choice? followed by one of these > http://www.minisport...nder_Heads.html

...whats an MJ by the way? lol

[Bungle]

megajolt

[Joseph-C]

http://www.minisport..._KENMD266K.html would this one be a good choice? followed by one of these > http://www.minisport...nder_Heads.html

...whats an MJ by the way? lol

I think the standard MG metro cam is very similar to the 266, so it wouldn't be worth the trouble swapping if you have an mg metro engine.
If not the 266 seems to be the choice cam for a daily driver.

I saved this when I was searching for info on a good spec head:

"Best thing to get is a gas-flowed head with 35.6 mm inlet and 30.5 mm exhaust valves and c.10.5:1 compression ratio and an MG Metro or Kent 266 cam with an LCB exhaust manifold, RC40 exhaust of 1.75" internal diameter, plus an HIF 44 carb on an MG Metro alloy inlet manifold."

I think it's better to get a good head first before a cam.

Edited by Joseph-C, 04 April 2012 - 04:57 PM.

[Timinichelsea]

Anyone who's got a mini N/A running near 100 ponies, could they post up their spec, I'm near completion on my new engine, be nice to get an idea

1293
Swiftune miglia head & block
forged omeags
steel crank & rods
sw5 cam
Fuel injection

Should be good for 100+ when its finished.

With the a more racy cam it'll probably make more like 120 :)

[blacktulip]

i think you just need to use what you have and add some goodies. i have a 1275 A-series, v max 2 head, sw5-07 cam, stage 1 kit, hif44, k+n element filter returning 72bhp 78lbs/ft torque at T+M electricals rollers in colchester. it is very quick compared to my old 998cc and its reliable. it goes up to 70 in no time. you dont need to worry about 0-60 times as you wont be hammering it everytime you drive it. what you want is a decent flat torque curve on the rollers.

[eden7842]

100bhp = still too slow

[oltonlad]

oltonlad, have you ever been in a bike-engined car? I have an R1 powered kitcar, probobly about 100kgs lighter than an R1 mini would be, its about 450 kgs . Scaling it up, it's equivalent to a 1 tonne car with 190lb/ft of torque. or an impreza with 270lb/ft. Contrary to belief they are not bad low down, its all relative, they are quick enough low down, f****** quick between 7 -12,000rpm. If you do feel you are lacking a little "torque" all you do is whack the sequential gearstick forwards 1/2" once and floor it, you are gone. If I coast at 1,000 rpm in second and open the taps hard it will spin its wheels up no problem , smooth as silk from tickover to red-line. It certainly does not cough, splutter and struggle wheezing until it comes "on cam" like my (expensive) Swiftune 1380 would if I tried the same trick.... They are not ideal granted, not for everybody and can be too loud tiresome for some folk. But they are also exciting as hell to drive and certainly not slow. And I have been lucky enough to drive "the daddy" Caterham R500 250 miles home from Belgium after a trackday at Zolder. The Caterham was quicker granted but not as much as you would expect from £10,000 of K-series and £1,000 of Yamaha! Just don't believe the internet torque stories written by folk who have never tried one, it all bull. I have had bike-engined cars since 2002, building one of the very first Fury Fireblades, and done over 35,000 road and track miles in them.

yeah, i drove my boss's twin R1 engined mini grasser (400bhp) and it scared the **** out of me.......

[Turbo Phil]

If it's for an everyday, useable road car a basic spec 100hp Turbo will be nicer to drive than a NA motor of the same power & the Turbo will produce more Torque.
When I had a standard Metty Turbo lump many years ago it was great to drive. It drove like a standard 1275 off boost, pulled from low down, was good on fuel & had bags of Torque under boost when you put your foot down for overtaking.
It would go just as well up pretty steep hills as it did on the flat. A great motor.
Once you start tuning the Turbo lumps you lose some of this driveability in exchange for more power. But the NA lumps are even worse the further you tune due to the need for more aggressive cam profiles etc