Cooper S Conversion Power
Discussion
Just had littlereds Mini given the Vmaxscart Rolling road tune.
Number (these are at the wheels)
Tuned - 85.4 bhp was the peak@6000 rpm with 89 lbs ft @4000 rpm (before adjustments first run was 70 bhp ) @ the fly!.
How does this sound - I think it may have had some head works as I had heard these "90 bhp" S conversions really only make about 78 - 80bhp at the fly. Happy with it anyway - may need valve guides over winter - but no big deal.
>> Edited by jellison on Friday 29th July 14:26
>> Edited by jellison on Friday 29th July 14:52
Number (these are at the wheels)
Tuned - 85.4 bhp was the peak@6000 rpm with 89 lbs ft @4000 rpm (before adjustments first run was 70 bhp ) @ the fly!.
How does this sound - I think it may have had some head works as I had heard these "90 bhp" S conversions really only make about 78 - 80bhp at the fly. Happy with it anyway - may need valve guides over winter - but no big deal.
>> Edited by jellison on Friday 29th July 14:26
>> Edited by jellison on Friday 29th July 14:52
85hp at the wheels! that is impressive! 
just had my mini RR's and it made 56hp at the wheels (about 88 at the flywheel) and i'm pretty smug about that! I've got a 1275 with ported MG metro head, metro inlet and LCB outlet into an RC40, also got a 286 kent scatter cam and a 1.75" carb
be interesting to see your spec
just had my mini RR's and it made 56hp at the wheels (about 88 at the flywheel) and i'm pretty smug about that! I've got a 1275 with ported MG metro head, metro inlet and LCB outlet into an RC40, also got a 286 kent scatter cam and a 1.75" carb
be interesting to see your spec
minimax said:Correction littlered numbers not at the wheels but @ the fly.
85hp at the wheels! that is impressive!
just had my mini RR's and it made 56hp at the wheels (about 88 at the flywheel) and i'm pretty smug about that! I've got a 1275 with ported MG metro head, metro inlet and LCB outlet into an RC40, also got a 286 kent scatter cam and a 1.75" carb
be interesting to see your spec
Which I am still pretty chucffed with - most of these S (90bhp ya right!) conversion make about 78 - mid 80's bhp at the fly - and exceptional one maybe on a very good day might get 90 but doubt it.
Hmm - I'd have expected a bit more at the wheels (that woul still only be mid to high 60's at the fly).
Engine is 80+k miles on Twin HS2's (S spec) carbs, Cooper head what ever that means - stamped on it when modded (but myunderstnading was the head was not touched in the S conversion - although why stamp the head if not! LC30 exhaust (beleive cam std - but power is pretty high up - 85.4 at 6k ad still 80 at 7k! but might not be).
Goes like stick on 3.44 diff.
Just had the head off this one and head faced new valves, new lcb and (looking like engine had gotten very hot at some point) re oxide on outside - but only ever gotten hot onve since we had it - fan switch failed. Stuart a Vmax found one sunken valve - head machine flat and new seat.
Back on rollers and same power give or take torque a bit better lower down 90ft/lbs at 3k!
Was going to have 1.5 roller rockers but got fed up waiting so had std put back - then when I come to get it MiniSpeed phone to say now in!
Quiter now though - which is nice.
How much are these likley to add - heard 5+ on a 70+bhp engine?
Back on rollers and same power give or take torque a bit better lower down 90ft/lbs at 3k!
Was going to have 1.5 roller rockers but got fed up waiting so had std put back - then when I come to get it MiniSpeed phone to say now in!
Quiter now though - which is nice.
How much are these likley to add - heard 5+ on a 70+bhp engine?
1.5 Ratio Rocker will add about 8 brake at the flywheel. I run 1.5 ratio rockers/well ported BV head on a 1275cc with standard cam and my little motor makes 64bhp at the wheels (around 85 at flywheel corrected). Bearing in mind your car has a hotter cam profile Cam as standard (I take it is an early carbed cooper (CAM 6648)?) it should crack the 90 brake mark (flywheel), albeit with a slight loss in mid range torque. That could be a good thing, it might save your standard gearbox!
The Cooper head was modded as part of the original John Cooper packs. Compression upped and ported.
Take those pee shooters off and put a proper carb (HIF44) or set of carbs (HS4's) on it! Let the little monster breathe.....
>> Edited by fwdracer on Tuesday 6th December 14:49
The Cooper head was modded as part of the original John Cooper packs. Compression upped and ported.
Take those pee shooters off and put a proper carb (HIF44) or set of carbs (HS4's) on it! Let the little monster breathe.....
>> Edited by fwdracer on Tuesday 6th December 14:49
Yep one of the early Cooper twin carb conversion - no 211S I think. Stuart said compression aroun 10.5 and well flowed head on std valve sizes. What about a set of 1" 3/4 SU's (I have a set of these from my TR racer) - not used in years as went to twin 2"'s and now Twin 50 Webbers. Too big? Think these are HS6, HS2 = 1.25, HS4 = 1.5's and HS6=1 3/4's. Yep think 90bhp (fly) will be on. At least a bit quiter know as 3.44 great for hooning around but not for long trips!
Thought so - you do wonder why they advertise them in the Mini Mags.
If I can add 8bhp to the 85 that will be a nice 10% an should be well noticable with 3.44 CR.
The surface area of 2x 1.25 HS2's is a good bit more than a single HS6 1.75 - this must be part of where the Cooper S power comes from.
>> Edited by jellison on Wednesday 7th December 11:13
If I can add 8bhp to the 85 that will be a nice 10% an should be well noticable with 3.44 CR.
The surface area of 2x 1.25 HS2's is a good bit more than a single HS6 1.75 - this must be part of where the Cooper S power comes from.
>> Edited by jellison on Wednesday 7th December 11:13
Ok - may be up for selling - have to seem if a TR racer is interested first (as had mentioned them on back of a gearbbox he is buy from me) - will know in a few days to a week. All specially rebuilt by burlin fuel systems - obviously different manifold for a mini (if that is what you want it for - need biggish engine mind). Will let you know.
Jon
Jon
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