What have you done today with your Austin Seven

[flywheel1935]

that looks a big gap! what size pistons are they?

Haven't posted the pic of the piece of broken ring yet !!!!!  :-(

May I suggest checking availability of new ones before chucking those in the hedge

Not even sure why there is a bottom ring ???? seen other pistons that only have 2 compression and 1 oil control ring.???

[Chris KC]

that looks a big gap! what size pistons are they?

Haven't posted the pic of the piece of broken ring yet !!!!!  :-(

May I suggest checking availability of new ones before chucking those in the hedge

Not even sure why there is a bottom ring ???? seen other pistons that only have 2 compression and 1 oil control ring.???

You may be in luck then!

[Dave Mann]

Two oil scraper rings with the lower one at the bottom of the skirt was the norm 50+ years ago even on seriously big engines of 16" bore or more. However it was found that if the lower scraper ring was too efficient it resulted in piston seizure due to oil starvation of the skirt so flats were cut on the running face which worked well till the ring wore down and he flats disappeared so notches were cut in the running face. Then in the 1970s the lower scraper ring was moved to above the gudgeon pin which resolved the problem giving low oil consumption without piston seizure.

[Bob Culver]

It always seems a miracle the way rings and pistons function on the merest trace of oil.esp those cars which consume none at all.
There is no risk of Seven bores running dry!
Some 1950s cars were supplied without the lower ring . It could be fitted later from below. (Minx)
It was always advised not to fit steel 4 piece rings in the lower groove
I vaguely recall a picture of Merlin engine with lower oil rings (used vast amount anyway)

[Hugh Barnes]

For this Mag engine newbie, getting this far has taken all day! What a palaver!! It took me an hour to remove the fiddly little nut and bolt that holds the bottom pulley on (an 1/8th of a turn at a time) and then, just as I thought my task was completeted, I realised I had to loosen offf all the engine bolts and jack it up to get the pulley past the front forging. 

Next step it get the seal housing machined out to take a modern lip seal. I am eternally optimistic in that it will just go back together in about 20 minutes...

   

[Reckless Rat]

20 minutes will be just fine as long as they are not consecutive...

[Hugh Barnes]

:o)

and carrying on with the research, it was clear that the nut and bolt holding the bottom pully in place wasn't quite right. Turns out it should be a taper pin. That would have made disassembly much easier and will certainly make reassembly a quicker process when I source the correct part...

[Hedd_Jones]

ill happily send you a taper pin Hugh. PM me your address

If you could do me a favour too? Just measure the gap between the starting handle bearing and the starter dog please.

[Hugh Barnes]

Thanks Hedd, very kind of you...

I've had a quick measure this evening and make it exactly 1" between the rear of the starting handle support and the leading edge of the 'pawl' of the dog. I'll take a photo of it in the morning so you can see exactly what I have measured. I'll also take photos and measurements of the starting handle, remembering your post from a while back...

[Bob Culver]

Hi Hugh

It may have seemed a pain but near everything on a Seven is way way more accessible and simple than anything on a modern. They are just not intended to be worked on.