Hi - I'm sure this has reared its head sometime before.
I'm learning heaps about the 1275 Cooper S motor as we get further and further into the rebuild. I have learnt that the current oil pump on it is the original (going by the maker and the part # - it is branded Concentric 5367-C) and is a pin drive. I have also just learnt that they are no longer available, as the pin drive new ones are for the 850-1100, and don't fit the 1275 cos the pin isn't long enough.
So what are 1275 Cooper S engine rebuilders using now? My old pump could probably go back in, but with everything else being replaced/refreshed it seems a shame.
I don't really want to have to change the cam at big $s to suit a $60 new pump (if that's possible anyway) - so what are my other options? Can the pin be taken from the old pump and put into a new pump? Sorry if that sounds a bit simplistic - but I'm not a mechanic
Thanks in advance.
Peter

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1969 Mini Cooper S MKII (1330)
1972 Honda 750/4 (his),1976 Honda 400/4 (hers)
1982 Honda CB1100RC (ours)

You can still get pin drive S pumps made by/for MSC in UK, Karcraft sells them here. p/no AEG410.
But beware, racers have been breaking the ears off the shafts in these particular pumps when oil is cold, so they are not real strong.
<edit> although I ran one 50,000 miles in the 1310S it was still OK, and I have one in my 1360 as well.

Alternatives are use a slot drive pump (as used on late 1275s) and either a slot drive cam, or get Russell Engineering to modify your cam from pin drive to slot drive.
You will need to tap 1 more hole in the block for this pump, no big deal.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Thanks Doc - I knew there had to be an answer.
I'll get in touch with Karcraft for a price. Sounds like the easier of the alternatives - mine is just going to be kept as a basic stock road car.
Cheers!
Peter

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1969 Mini Cooper S MKII (1330)
1972 Honda 750/4 (his),1976 Honda 400/4 (hers)
1982 Honda CB1100RC (ours)

From their latest price list;
Oil Pump- Mini Cooper S (pin drive) AEG 410 $97.94.
Cheer Pete

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A recent study found the average Aussie walks about 900 miles a year
Another study found Aussies drink, on average, 22 gallons of alcohol a year
That means, on average, Australians get about 41 miles per gallon

Kind of makes you proud to be an AUSSIE

Just to throw this in from the side - they are available,this is only a moot point for consideration.
I had a problem ten years ago sourcing a 1275 pin drive oil pump at the double.
(Can't remember his name, was it Steve?) at Tovon Automotive made the suggestion of simply pressing the pin drive shaft from the old pump out of the impellor and pressing it back in the place of the shorter one in the new pump. I was sceptical, but it pressed stright out and pressed stright in on the new one. It has done ten easy years so far.....

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Mick - I had heard that too mate, but my mail is that the standard (850-1100) pin drive pumps they are now supplying won't fit the Cooper S at all, so this trick doesn't work any more. So I am told anyway.
Cheers
peter

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1969 Mini Cooper S MKII (1330)
1972 Honda 750/4 (his),1976 Honda 400/4 (hers)
1982 Honda CB1100RC (ours)

I thought that was only because the block is longer and therefor the pin drive shaft is as well?

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Mick, we all did that trick in the old days when the rotors were keyed on and the S pump had a wider rotor. Now, they are not keyed- the MSC `Sureflow' Cooper S ones are knurled or swaged or something.

Talking pumps still, I've been told re the star drive pumps on 1100S etc that the `star' is NLA now, so don't throw `em away if changing pumps.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Well it seems that Karcraft can't actually supply these pin drive pumps any more, and I'm struggling to find anyone that can.
Anybody got a good second hand one they are willing to part with?

Looks like I might have to resort to the Dr's mod recommendation, or just re-use the old pump. The car was actually holding reasonable oil pressure before the strip, about 60 at cruise, but was dropping off a bit at idle as they do.

Ah the fun and games......
Peter.

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1969 Mini Cooper S MKII (1330)
1972 Honda 750/4 (his),1976 Honda 400/4 (hers)
1982 Honda CB1100RC (ours)

Before you read the rest I must advise that I always change pumps when I build engines that require overbore, have bearings go or have other signs of neglect. This basically means all except my own

After disassembling the pump, make sure you remember where everthing goes, including the direction. Then check the pump for wear, refer to the black book:-

Side clearance of rotor to pump housing no more than 0.005" (0.127mm). This can be corrected by lapping the pump face but I doubt if this is worn bad that the rest will be within spec.

Clearance between the rotor lobes must be less than 0.006" (0.152mm). This is best measured in a couple of places of the assembly, they don't wear that evenly. In the black book it shows where each one should be measured.

The book doesn't mention anything about deep scoring but I would check this as well. It is much more important though for the clearances to be good than to worry about a couple of small score marks. Deep scoring, esp on the tips of the rotor/s is throwaway.

My advice would be to get a slot or spider drive cam and ground to a mild spec with a new pump, pins have been known to come loose (I have one atm like this). Short of that, the next option I would take is to get an adaptor made for the slot drive pump and use the original cam with a new pump. I would only use the old pump as last resort.

Regards

Daniel

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Videos - Turbocharged A-Series on Dyno & at Wakefield
Mafs waz not my strong subgeckt at skkol

Hmmm, the AEG410 `S' pump is still in the Karcraft catalog I got last week....

When I assemble the 1412 stroker soon it's getting an A+ slot drive pump, the cam will be an 1100S spider drive one converted to slot drive.
This involves machining up a slotted steel insert for the back of the camshaft, and carefully TIG welding it in 3 places.
This mod can be done with pin drive cams too, after the pin is removed. Talk to Graham Russell.

re. using S/H pumps- too much end float can often be fixed by machining the housing, but if the rotor and annulus are scored by debris, I'd bin it.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Yes Dr - Apparently they haven't had them for quite some time. Perhaps they could be removed from the catalogue
Anyway, took the old pump apart tonight, and the verdict is that it's really not too bad, with no scoring on the lobes to speak of, so we have made the executive decision to re-install it. Some might shake their head at that decision, but we are quite confident that there's a lot of life left in it, and my mechanic has had a lot of experience with them so I trust his judgement. And when we considered the hassle (not to mention $$) of adapting the cam, or pin, or getting a new cam etc etc, the decision was pretty easy.
If it proves to be the wrong decision, I'll be a big boy and deal with it when I have to.
Thanks again for all the input - the help, interest and advice on here is really awesome.
Cheers
Peter

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1969 Mini Cooper S MKII (1330)
1972 Honda 750/4 (his),1976 Honda 400/4 (hers)
1982 Honda CB1100RC (ours)

Peter,
My English S motor has the symptoms you describe, low pressure at idle, but leaps up the guage when the throttle is blipped, at cruising speeds over 2000rpm I have a solid 55-60 psi (hot) on the dial.

It has been like this for 8 years to my knowledge, I have raced, rallied and hillclimbed with that engine and it still keeps going!

I have always assumed it was just a bit of slack in the pump clearances, I don't think it's bearings

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Sir Alec! we are not worthy!

Yes Graham, my MG is the same too - I think it's a case of "that's the way it is", so it's of no real concern. My worry with the mini was putting the old pump back in - but I'm confident that it won't be an issue in this case. (takes deep breath).
BTW, your diagnosis of the gearbox noise being the layshaft was spot on - it was knackered, along with its bearings, and I'm even replacing the laygear itself as there was some wear on many of the teeth.
All good fun and lots of learning - she'll be sweet when done.
Cheers
Peter

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1969 Mini Cooper S MKII (1330)
1972 Honda 750/4 (his),1976 Honda 400/4 (hers)
1982 Honda CB1100RC (ours)