Sunbeam S7 Deluxe

[Melvyn Best]

Saw a rather nice looking Sunbeam today parked outside a local shop , not sure of the model and didn’t take any pictures but will try next time I see it

 

[Shox Dr]

Made a start on pocketing one of the old pistons, first off 5/16" transfer punch slid down each stem guide with a light tap, marked the piston tops.



Piston clocked over 68*. Keeps rocking, so I’m going to make a shaft clamp for it. I need to pop round a mtes to blag some stock

 

[Shox Dr]

Glad I tested this on an old piston, couldn't get enough grip, the piston either rocked or grabbed.
Popped down a mates and blagged a bit of Aluminium, bored out, the bottom faced and then cut in half.






Ready for cutting the valve relief

 

[Shox Dr]

While cleaning the timing gear I noticed it had been machined off centre to the casting, that few grams spinning round at 6000rpm or even half that will cause vibration.

Could have clocked it in the4jaw, but turning up a mandrel in the 3jaw was far faster and guaranteed to be on axis.




Not far off everything been ready to rebuild now, got the seals this morning.

 

[Seadog]

I'd have had to true the centre boss as well

 

[Shox Dr]

I'd have had to true the centre boss as well

hehe, I left that on purpose .

 

[Seadog]

 

[Shox Dr]

You won’t catch anything, if you dont have a worm in the water



looks stepped because it is, I only took the bare minimum off where necessary.

 

[Seadog]

 

[Shox Dr]

...and at 40rpm it took long enough

quick turn down of the shoulder now gives me a drift to press the old oilite bearing out, and the new one in.

Very little play, but while you’re at it might as well, all helps oil pressure.
The replacement reamed


In the end it didn't escape the 4jaw, the bearing required rebating for oil supply

 

[Shox Dr]

The timing gear shaft had also worm on the underneath from too much tension on the cam chain. 69quid for a new one. So ordered a length of 3/4" Silver Steel £14. Only mod the oil gallery was blanked with a plug, I didn't like this so tapped for a m6 grubscrew, fitted to the other end it butts up against the block so cannot wind out, I dab of locklite will seal it. Also means it can be cleaned out if necessary in the future


Made the mistake of centre drilling first, and 2.2mm drill bit snapped when breaking through.


.and just to rub it in it broke into 3 pieces. Lucky I could get a scribe in the hoke to help it out, then lot and lots of tap tap tapping to get the bits out




All the fun jobs

 

[slim_boy_fat]

I need to pop round a mtes to blag some stock

No, you need to stay indoors - oh, I see from subsequent posts things have moved on.

 

[Shox Dr]

No, you need to stay indoors - oh, I see from subsequent posts things have moved on.

Keep up at the back.

Heat treated and light polish

 

[Shox Dr]

Grumble, that pushed in far too easy.



Even bigger grumble is I did think about taping out the oil gallery drilling to take a set screw, while that can still be done, the shaft has been hardened, I’ll have to grind a flat to stop it spinning/walking

 

[Shox Dr]

Well that was a mistake.

decided to case harden the timing shaft to see if the process would add to the diameter.

Noop. I can now push it in by hand

Supplied dia was 19.07
Hardened via quenching 19.05
After case hardening 19.03

Arrrrrrrh

 

[arther dailey]

some days the dog other days the lamp post ,have a cuppa then crack on you will sort it

 

[Shox Dr]

some days the dog other days the lamp post ,have a cuppa then crack on you will sort it

Cheers

And there’s me thinking that light coming from my head was divine

On wards and upwards

 

[arther dailey]

 

[Shox Dr]

Decision made, ordered 19.50mm I’ll not touch the bearing surface, reaming the bush to suit, turning down the rest to 19.10 (oversize by .03mm) hopefully it with shrink with heat treating to 19.07.


Edit; out of stock of 19.50mm

 

[Shox Dr]

Just spoken to the buyer at Drill Service, she said no problem, they’ll have stock before the weekend and send it out soon as.

You cant beat that for customer service

www.drill-service.co.uk