11 replies to this topic

[cradley-heathen]

as it says, i have looked everywhere on the net and i cant find any info on what the mini se7en racers use?

what kind of power do they manage to make from the 998 engines?

[miniJJ]

Hi, you could try contacting someone from here:

http://www.mini7.co.uk/se7encar.asp

They only give bhp and 0-60 times on their site. Hope this helps.

JJ

[cradley-heathen]

thats some serious power, but how do they do it?

what cam do they use?

what kind of head mods must they have?

[Wil_h]

Hummm, not sure I believe that, much like the claims that Miglias make. To make that bhp in a 998 you're going to have to rev to over 8k, maybe up to 9k.

[jayare]

The technical regulations include all the details of modifications which can be made to the engine and can be downloaded from the downloads page on the Mini7 club website linked to above. As below:


MINI SEVEN ONLY.
i) A production Rover Cars ‘A’ series 5 port head casting must be fitted which may be modified by polishing and machining to
combustion chambers, ports and machined faces
ii) Exhaust manifolds are free
iii) Standard ‘A’ series 998cc cylinder block is mandatory
Bore 64.58mm x Stroke 76.2mm (2.543” x 3.00”)
iv) Maximum bore size permitted 65.08mm/2.563”
v) Any production Rover Cars crankshaft with standard stroke 76.20mm (3.00”) except Cooper “S” is permitted
vi) Camshaft. Either the unmodified M7 6648 camshaft (obtainable via Mike Garton) or the unmodified Rover camshaft part
number CAM6648 is permitted. Cam Lift: Inlet 0.250"/6.35mm, Exhaust 0.252"/ 6.40mm
Timing:
Inlet opens - 16° B.T.D.C. Inlet closes - 56° A.B.D.C.
Exhaust opens - 59° B.B.D.C. Exhaust closes - 29° A.T.D.C.
A: Inlet 27.66mm. Exhaust 27.93mm. B: 34.35mm.
Set valve clearance to 0.021”, clearance to check timing.
Set valve clearance to 0.015” 0.4mm to check lift.
It is permitted to weld reinforce pressed steel type rockers on the top surface to minimise flexing.
vii) Rocker assemblies are free but must conform to the maximum valve lift 0.330”/8.38mm.
viii) Pistons must be either Rover Cars
ix) ADU 4203 (Dished, floating pin).
x) TAM 2052 (Flat top interference pin).
xi) TAM 2054 (Dished, interference pin).
xii) AE/Hepolite 20773 dished (fully floating g/pin).
xiii) Omega 3780 dished, fully floating g/pin.
xiv) Omega 3780F flat top, fully floating g/pin.
These are standard bore size part numbers.
A maximum oversize of 0.020”/0.50mm is permitted.
Strongly recommended to replace the old pattern fully floating rods/piston with the latest interference type. During engine
rebuilds, pistons should always be discarded.
xv) Piston crown may be machined to suit block height a maximum 0.025”/0.63mm.
Minimum distance from crown to top land 0.270”/6.86mm.
xvi) Minimum unswept volume is 24.0cc.
For example
Cylinder Head Combustion Chamber. 12.2cc.
Cylinder Head Gasket. 3.8cc
Minimum piston dish and cylinder volume (at TDC) 8.0cc.
Total (minimum unswept volume) = 24.0cc.
i.e. if cylinder/piston volume is less, the combustion chamber must increase and vice versa.
xvii) Any single choke carburettor is permitted. A multi choke carburettor is permitted provided only one choke is operational.
xviii) A single restrictor of maximum bore 1.5”/38.1mm fitted between the carburettor and manifold is mandatory. The restrictor
must maintain the maximum bore over a minimum width of 3mm/0.12”. The restrictor must be made of non-porous material. Total
length is free.
xix) The ignition distributor must be mounted in its original position. Ignition advance/retard must only be controlled by ‘bob
weights’, spring, and/or vacuum means within the distributor. The low tension switching of the ignition system shall only be with a
contact breaker or contact less system (i.e. Hall effect or light sensitive system) housed within the distributor body.
xx) Further Modifications are free.
xxi) Only Rover Cars ferrous ‘A’ series con rods with original centres (5.75”/146.06mm) are permitted (includes Cooper S).
Titanium is prohibited.


JR

[Wil_h]

MG metro cam and 115bhp, good luck.

[cradley-heathen]

very interesting reading, i am amazed at the fairly standard spec of all this, i have been told before about how they rev to 9k or whatever, but i didnt think a stock mg metro cam would allow for that?

i did here about one guy who made a titanium crank a fdew years back, i was told that was to go in a se7en but obvuiosly not legally with the rules here

im also quite shocked by the restrictor plate, didnt expect that!

[MiniMonty]

MG metro cam and 115bhp, good luck.

115 BHP = HUGE GRIN...

I'd luuuuurve to check that out along some A roads I know....

[cradley-heathen]

as already stated though i just dont see how you can make that kinda power with such a basic spec

[Wil_h]

See my post above, you can't. I know some very special small bores with nowhere near that power.

Much like the claimed 4.5 seconds to 60 of a Miglia, it's not true, but it promotes the series nicely.

[cradley-heathen]

my brother built my dads engine to a spec more crazy than that, and we were trying to keep it simple and drivable so it would be ok for dad to play with but not be undrivable in town, and it certainly didnt make that power

[icklemini]

Anyone here driven one?, or maintain one?
They do rev up to 9k, and they certainly go like a scalded cat.

The heads are full on spec - thats where a lot of the money goes...

Edited by icklemini, 05 June 2010 - 11:00 PM.