Oil Pump Destruction

barry edwards · Post by **barry edwards** » Fri Jan 11, 2008 11:03 am

Having not rebuilt my machine G80 1949 for many years I forgot the rule regarding the guide pin and the oil plunger. Locked the plunger and stripped it on starting the engine. Has anyone any experience they could impart to me as to whether I will have knackered the half shaft on the crank, as you experts will be aware the half shaft worm is not visible without stripping the engine which I am trying to avoid.

Barry Edwards

Biscuit · Post by **Biscuit** » Fri Jan 11, 2008 11:47 am

I had this on a lightweight I looked at (same pump arrangement), the timing axle (half shaft) was undamaged, being hardened. The plunger (pump shaft) teeth were stripped and burred, which damaged the bore in the crankcase on withdrawal.

Result - new cases required. Sorry to be a pessimist, best of luck.

SPRIDDLER · Post by **SPRIDDLER** » Fri Jan 11, 2008 11:50 am

Oh, deary me, Barry. I think you know the answer to this but are still in denial!
I assume you have removed the oil pump plunger and found the 'splines' are stripped.

You've 3 options as far as I can see:

1) (A tempting cavalier, lazy and short term option) Get a replacement oil pump plunger, guide bolt and pin and 'feel' the plunger back into the housing in an endeavour to sense any scrunchyness, backlash, or nasty roughness, seeing if it even turns/reciprocates at all.
You'll need these new parts whatever you do but will never be confident about this 'fix'.

2) (The correct engineering option)
Strip and inspect/replace the damaged bits.

3) Offer it to ITMA for 50 quid. (That's a bit of an 'In' joke, sorry Barry!!).

In any case, and most significantly, there will almost certainly be bits of the old splines and steel dust inside (probably carried far and wide by the oil), which must be removed.

Look on the bright side: At least it's the right time of year for spending a couple of weekends holed up in a nice warm shed.

itma · Post by **itma** » Fri Jan 11, 2008 12:00 pm

There is no option and you know it really?
strip it and see.

Sprid is being over generous with my depleted funds. As a non runner i`m afraid my top bid is 20 quid, I can collect this weekend

SPRIDDLER · Post by **SPRIDDLER** » Fri Jan 11, 2008 4:40 pm

quote:
Sprid is being over generous with my depleted funds. As a non runner i`m afraid my top bid is 20 quid, I can collect this weekend

Generous gesture,Ken. I think you'd clinch it if you added yer Mum's dumplings recipe to the offer.

itma · Post by **itma** » Fri Jan 11, 2008 4:46 pm

Have you tried them yet?

SPRIDDLER · Post by **SPRIDDLER** » Fri Jan 11, 2008 5:03 pm

Made a dozen big 'uns last night and fed 'em to some visiting Aussie rellies. Wonderful!
They're taking the recipe back home entitled 'Mrs ITMA's Dumplings'.
Shame we don't have a 'Recipes' Forum.
Goin' to try making some doughnuts next. As Johnny Craddock famously said on his wife's cooking prog on the the box "I hope they all turn out like Fanny's". Edited by - SPRIDDLER on 11 Jan 2008 5:15:59 PM

itma · Post by **itma** » Fri Jan 11, 2008 5:22 pm

Watch out for hot jam I'd say.

Ought to be Old Ma Itmas dumplings tho?

SPRIDDLER · Post by **SPRIDDLER** » Fri Jan 11, 2008 5:35 pm

quote:
Ought to be Old Ma Itma's dumplings tho?

Quite so. I'll issue a correction.
The Aussies reckon they're just what they need after a hard day's 'Roo shearing.

'Hot jam'? 'Jamhot'?- not really the wrong Forum then.

crawsue · Post by **crawsue** » Fri Jan 11, 2008 6:29 pm

You must have some pictures of your "dumplings" somewhere Ken,not to mention Fanny's......Admin,check the apostrophe!