Hi all,
I bought GLP142 from Minispares because it was the only pin drive pump they have, however the shaft is 1cm too short and the impeller has 4 lobes instead of 5 like my old original S pump. I can easily press out the shaft off my old pump and swap them, but I want' to make sure the new 4 lobe pump will push enough oil. As said in the title, it is an original Cooper S 1275 from 1965 with pin drive cam.

The Minispares description for GLP142 is:

original short pin drive oil pump for all Pre a Plus minis with 850/998/1100ccc engines except autos and others with star drive or the later slot drive pumps as found on A Plus blocks

Thanks!

_________________

I haven't seen a 5 lobe pump for yonks. They maybe out there, but I doubt it.

You can get Replacement Cooper S Oil Pumps from APT, just bolt on, no shaft changing or mods.

http://www.aptfast.com/

Go to APT Parts, then select A Series Parts, then Engine Components & Misc.

I have used a few of these and quite happy with them.

_________________

you can get a spade drive adapter welded into your cam, then you have a heap of options for pumps

talk to Dr Mini about the adapter

I had problems two and a half years ago sourcing one, they were out of stock all over. But they seem to not be a problem anymore.

http://www.minisport.com.au/prod1766.htm

_________________
SooperDooperMiniCooperExpertEngineering

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

It looks like the only difference is the length of the shaft. Aside from the original pump having 5 lobes and my new one with the 1cm shorter shaft having 4 lobes, they both have the same inside dimensions.

Can anyone confirm that the volume of oil moved by the small bore (shorter shaft) and Cooper S (long shaft) pin drive pumps is the same?

If so, I can swap the shafts in about 10 minutes and save having to spend another $60 plus shipping for a long shaft pin drive pump. Still a lot easier than removing the cam and welding a fitting on the end too.

_________________

The old pumps were keyed in, but are new pumps still done this way or swaged? You might have problems if this is the case, no harm in trying however.

_________________
SooperDooperMiniCooperExpertEngineering

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

The pumps are the same as far as volume of oil goes, however as Mick has pointed out ^ you can't change the shaft in most new pumps.

_________________

a fella in SA found that the shaft was only pressed in, no knurling or anything - so it slipped

Well, I suppose that is another way of doing oil pressure relief, an oil pump with a clutch of the shaft

_________________

As said you can convert a pin drive pump into slot drive by TIG welding my adaptor into it. Lots have been done this way recently.
See http://www.ausmini.com/forums/viewtopic.php?t=39787

Also, Minisport SA was going to retrofit some 998 drive pumps with a longer Oz made S length shaft. I spoke with Andrew at the time, but not sure if it has happened.

_________________
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.

The good news is that the old longer shaft is 0.001" larger diameter than the new pump's shaft. Once I pressed both shafts out, the long shaft pressed into the 4 lobed spider nice and firm. The short shaft slips right in and out of the old 5 lobe spider.

All done and fitted.

Kevin, maybe the next time round I'll give your adaptor a go!

_________________