10 replies to this topic

[Ruth's Mini]

does anyone supply a higher capacity pin drive oil pump for an 850 Mini?

thanks in advance

[nicklouse]

sure you can get them but pin drive is not that strong and you dont really need a higher cap pump for anything other than a turbo.

 

what issue thinks you need one?

[mini13]

you can swap in the 1275 pin drive with a spacer plate, IIRC the early 850 pumps were smaller than what we have today.

 

if you cant get the 1275 pin drivemight be worth swapping to a later cam and drilling the extra holes for the later 4 bolt pump.

[Ruth's Mini]

sure you can get them but pin drive is not that strong and you dont really need a higher cap pump for anything other than a turbo.

 

what issue thinks you need one?

I've been told that the lubrication system has 2 inherent problems...

 

1) that an oil suitable for both engine & gearbox is a compromise but nothing can be done about that,

2) the oil pump is located too high resulting in poor pressure to some areas so thought a higher capacity pump might help

 

we're in the process of a complete rebuild

 

thanks for the replies 

[nicklouse]

1 yes you can but not worth it on a road car.

2 if as mini13 says the old 850 pumps were lower capacity than the standard pumps now then modify to a modern version.

[Cooperman]

Standard decent quality oil pumps have been working in the classic Mini for almost 60 years now.

If rebuilding an engine a new cam will be needed, so it will almost certainly require a slot-drive oil pump. The standard pump is fine for a modified 1275 engine revving at up to 7000 rpm, so it is certainly OK for a lower revving 850.

[Spider]

Put a New Standard Pump in it.

 

It won't need anything more than that and would be detrimental to go beyond that, in terms of Oil Pump capacity (ie, gph).

[Spider]

If you can't find a new Pin Drive Oil Pump, you can make an adaptor for the Cam, so it'll work with a Spade Pump

 

[mini13]

point 2 is bullsh*t, once the pump primed suction head will have no effect on output as the relief valve is there, and if it wasnt the difference would be in the order of half a psi.

[Cooperman]

If point 2 was correct one might wonder how the A-series engine has survived for almost 70 years, especially in all those race and rally A35', A40's, Sprites & Midgets, Coopers & Cooper 'S's, and usually all with the standard pin-drive OE oil pump.

The only problem with the pin-drive is that in really, really cold weather (like minus 10c)  when using the old 30 or 40 grade Castrol XL or XXL oil it was possible to snap the pin on a car with a 'cammy' engine due to the need to rev it from cold to get it to run. This didn't happen often, but it has been known a few times.

With the slot drive cam it is not an issue. 

[Ruth's Mini]

great discussion points

 

thanks everyone