MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - New oil pump is too big.

Before Christmas I bought a Kent cam kit from Minisport of Padiham Lancs. I also bought an oil pump as my previous one was pin drive whereas the new cam required a slot drive.

The operative I spoke to told me there was no need to pay £56 for the Kent oil pump as their in house one was just as good for a fraction of the price.
Great, I thought. That is until today when I came to fit it.

Cam fitted, end float sorted, pump gasket in, pump in. I had to shorten the three bolts to prevent them bottoming out because the new pump is slightly shallower than the old one.

All OK until,I tried to refit the backplate and tin can cover. No way would it go on. The pump is wider than the old one. It will fit under the cover, but with the cover in position in the back plate it won't fit. Even with the cover removed to trial fit the back plate, the play fouls the pump. It's just physically too big. ie.wide.
I will be contacting Minisport tomorrow, but I wondered if anyone else had encountered the same problems when changing cams.

1098 10CC engine.

Bernie.
b higginson

Yes. The slot-drive oil pump uses a common body for the small-bore and big-bore versions. The small-bore inline engine (948/1098) has a smaller tin cover which is slightly lower down than the 1275 version.

Two options are to either acquire a tin cover from a 1275 and modify your backplate, or acquire a 1275 backplate complete with cover.

I have a backplate available, if you need it.
Dave O'Neill 2

Pain, isn't it, Bernie? I shaved my backplate to fit, but luckily* the tin cup sits behind the backplate, so I could put it where I wanted.

*unless my soldering fails, and the tin cup falls into the bell housing, being mangled by the flywheel on the way.
Nick and Cherry Scoop

Nick

That's only an option on the 948 pressed steel backplate.
Dave O'Neill 2

I need to contact Minisport tomorrow to see what my options with them are, but I may need to take up your offer, Dave.

If you could let me know how much you need for the backplate, I can be contacted on:

b.higg41@gmail.com

Cheers.
Bernie.
b higginson

Good luck buddy, carp like this just eats my soul alive
1 Paper

I contacted Minisport and they apologised (they didn't realise there is a difference between 1275 and 1098, as they mostly deal with Minis), and offered to refund the pump price if I sent it back, which sounded OK until I did a bit more digging by contacting Kent Cams and others, only to find out that there is not an alternative pump to be had, so I will very likely take up Dave's offer and keep the Minisport pump.

I will report back when this PITA is sorted.

Bernie.
b higginson

I managed to source a 1275 backplate and pump cover from a MASC member local to me. The plate and cover are now fitted and it has solved the problem.

So many thanks to Dave O'Neill for his knowledge on the subject. I really was starting to get a bit stressed before Dave chimed in.

It's people like Dave and the many knowledgeable people on here that make the midget and Sprite BBS the liveliest and best car forum I've ever used.
b higginson

The pump is physically bigger because it has a bigger rotor, so higher capacity. It doesn't foul by much, and clearance can be gained by dressing a bit off the body at the offending point.
There are the original-sized 3 lobe pumps available, but IMHO the capacity of these was always marginal and it's better to go with the fettled 4 lobe pump.
Paul Walbran

This thread was discussed between 17/01/2018 and 22/01/2018

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.