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Cooper S MK2 redline
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Author:  GundyGuy [ Fri Nov 27, 2015 4:16 pm ]
Post subject:  Cooper S MK2 redline

Just wondering what would be a safe redline RPM for a 1970 Cooper S
Mine has had the engine rebuilt a few years ago and runs very strong
Dont know what was done to it
Does anyone have Rodney Hansen's phone number up in Toowoomba as he rebuilt the engine
Thanks
Marc

Author:  1018cc [ Fri Nov 27, 2015 4:42 pm ]
Post subject:  Re: Cooper S MK2 redline

Hi Marc,

You should be able to reach Rodney on 4634 3259 @ Hansens Automotive & Gas. You'd have to ring quickly as he is probably wanting to just about head home.

Cheers, Nick

Author:  Bubbacluby [ Fri Nov 27, 2015 9:02 pm ]
Post subject:  Re: Cooper S MK2 redline

6.5k would be the minimum safe limit. As they are essentially the same as a mini Clubman GT and these redline at 6.5k

Author:  winabbey [ Fri Nov 27, 2015 9:49 pm ]
Post subject:  Re: Cooper S MK2 redline

In case it helps the modified Mark 2 Cooper S's used by NSW Police had the tachometer redlined at 6,000 rpm, although of course there was nothing preventing the drivers from exceeding that. They did have to complete a Cooper S specific training course at St. Ives to be qualified to drive the car so there may have been a directive on rev limits.

Author:  drmini in aust [ Fri Nov 27, 2015 10:00 pm ]
Post subject:  Re: Cooper S MK2 redline

I've run the same EN40B S crank and S rods in 3 motors for the last 25 years. I used to redline at 8000 on track days, now I use 7500 max with rev limiter.
Crank is still -.010" (never ground since I've had it) and still not worn.
I'd say redline in a stock S would depend more on cam grind and valve springs than other engine internals, 7000 wouldn't hurt the bottom end.

Author:  Morbo28 [ Sun Jul 02, 2017 8:59 pm ]
Post subject:  Re: Cooper S MK2 redline

Thread revival! I'm just after some opinions about an appropriate redline on my engine. Drmini by the sounds of your post the answer might be 7000-7500rpm...

I have the electronic rev limiter set to 6500rpm. But I find at full throttle - pulling onto a highway for example - the engine seems to want to pull beyond that rpm and the limiter feels like it kicks too soon. (I should also say I don't spend a lot of time up there as it has a nice low and mid range and 2.9 diff).

I note you mention cam and springs in your post. My cam was ground specifically to match the supercharger and the thick linear torque and driveability. So it wouldn't be considered wild like a performance NA cam. Running double valve springs and 1.5:1 Yella Terra roller rockers.

Here's what the curve looks like so you can see what it does up that end of the rev range. The drop off would either be the dyno operator getting out of the throttle or the ignition rev limiter dropping cylinders.

Image

[Other info if you need it - 1100S 1275 block with +.040 forged pistons, I/H beam rods, std crank with a few little things done (but no major wedging), lightened flywheel, rotating assembly dynamically balanced together. Electronic ignition, but timing set by the dizzy curve and the points are used to send a low-level signal to the ignition module. 8.6:1 compression, running measured 7psi boost from charger, water injection used to cool charge. Okay that probably more than covers it.]

Author:  drmini in aust [ Sun Jul 02, 2017 9:05 pm ]
Post subject:  Re: Cooper S MK2 redline

If you want it to last I would say 7000. Bearings wear faster at higher rpm. Mine is redlined at 7500 but seldom sees it in road use.

Author:  Morbo28 [ Sun Jul 02, 2017 9:21 pm ]
Post subject:  Re: Cooper S MK2 redline

Yes I certainly do want it to last! No worries, 7000 rpm seems the go then. I won't see it that often anyway, but good to know. I'll set the limiter to that, thanks Dr Mini.

Author:  simon k [ Sun Jul 02, 2017 9:25 pm ]
Post subject:  Re: Cooper S MK2 redline

by that dyno sheet, you're already dropping off on torque, it's all over by 6500rpm... mine was like that, the cam was (is still) meant for pulling torque not screaming revs

except I had 13psi and was making 90-something bhp at about 5500, so a bit of a different animal

Author:  Minicooper4me [ Sun Jul 02, 2017 9:28 pm ]
Post subject:  Re: Cooper S MK2 redline

I gather you're talking 7000 rpm through the gears. What revs are you pulling in 4th.

Author:  slacko [ Sun Jul 02, 2017 9:30 pm ]
Post subject:  Re: Cooper S MK2 redline

mine is set at 5500 rpm
makes max hp at 6000 rpm , max torque at 5000 rpm
engine is quite happy to rev to 6500 rpm all day , but what for ?

Author:  Minicooper4me [ Sun Jul 02, 2017 9:50 pm ]
Post subject:  Re: Cooper S MK2 redline

So what speed are we talking about at 5500 rpm, and diff ratio.

Author:  slacko [ Sun Jul 02, 2017 10:09 pm ]
Post subject:  Re: Cooper S MK2 redline

just under 4000 rpm = 100 km/ph
3.44 diff on 10 inch wheels
25.7 km/ph per 1000 rpm
5.5 rpm x 25.7 = 141.35 km/ph

Author:  Minicooper4me [ Sun Jul 02, 2017 10:32 pm ]
Post subject:  Re: Cooper S MK2 redline

Thanks Slacko. So with these specs which mine is, my speedo is a bit out, sticking to 4000 on normal open roads, or around 4300 on freeways, I'm on the speed limit. Any more than this the cops are gunna say hello. How do the high rev guys get away with it ?

Author:  slacko [ Sun Jul 02, 2017 10:45 pm ]
Post subject:  Re: Cooper S MK2 redline

mk1 3 syncro box with 3.44 diff in top gear
I work on 2200rpm = 60 , 3100 = 80 , 4000 = 100 , 4300 = 110

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