RichardW's Velocette rebuild

[Hell Razor5543]

While she needs work and TLC, she is getting both. Happy Registration Birthday, Velocette!

[xantia_v6]

As promised a while back, some pictures of a 1929 Velocette... Sadly not a model U, but I think that you may find some useful details anyway.

[RichardW]

Thanks,Mike - that's a 350cc 4 stroke, but many bits are similar. Odd that the gear change gate has only got 2 slots in it, perhaps that is a 2 speed box, whereas mine is 3.

Some progress has been made...

I've got the mudguards, stays, and number plates painted, and started on the engine rear mount plates

This means I can put those on, and the wheels, and we will have a rolling chassis

I bought some 1/4" BCY bolts hoping that they would be thread for the petrol tank mounts, but they weren't.... more measuring and cogitating convinced me they were probably 1/4 Whitworth. On looking, this is pretty much the same as 1/4 UNC - and then I found that that is the std thread in a camera tripod mount. Now a while back I bought a tripod that was missing its mount, and found that some aluminium greenhouse bolts I had were the correct thread, so off outside, found a bolt, and sure enough it fits in the threads - both in the bottom and the side (for the gear change mount) So, I ordered some 1/4 Whit bolts, which came today - actually I haven't got enough, 'cos I forgot about the change mount - but they are shorter, so I will need to order some for that as well.

I have been sizing up other bits I need, grips, foot rubbers, tank knee grips etc, so will get that ordered. I was going to use the original internal scroll throttle, but it's pretty worn and sticky, and a new one is only £12, so I'm going to fit a new one (not exactly true to original as it a rotational type, but better that I have control of the thing!).

I've also got the Magneto back this week!

Doesn't look much different outside, but inside the cover there are some modern bits (condenser and cut out - this stops the battery discharging itself via the coil when the engine is not running - originally it was a mechanical cut out on the armature, but these were unreliable - and the mag repairer reported that it was already bypassed (unsurprisingly!).

Something odd in the advance mech... the mag rotates clockwise when viewed from this, the non drive end, so this is full advance, being pushed by a spring. However, the hole in the end cover for an advance / retard cable is on the other side - i.e. it would need to push the points plate down, which isn't going to work! The cam plate does appear to be able to work with a spring in either direction, but it would need a different spring and end cover. Perhaps this is not the original end cover and Grandad has fitted a different spring to give full advance all the time - he was certainly running it without a mag lever when it came off the road, as it is not in evidence! So I think I will just try without to start with.

I'm pretty sure when I dismantled the engine there were no gudgeon pin clips, but I'm sure there should be some, so I need to measure those up and try and get some.

[RichardW]

Starting to look like a (motor)bike again!

I've rebuilt the rear wheel bearing, and put the brake in - had trouble with it catching which was the shoe retaining screws being a bit long. I've cut them down now and it seems to be OK. Need to get the wheels in, then can roll it out into the sunshine!

Found some info on the Maglita advance. You can see on the top RH (as you look at it) there is a bulge in the casing where a cable ought to go. However, the other side is solid and could be drilled to accept a cable. In this photo (from the Magento Guys)

You can clearly see the top left has been drilled / tapped to accept a cable. So it looks like it is possible. I suspect that the only problem with not having one is a possibility that it will be hard(er) to start and / or prone to backfiring when kicked over (I wonder if it will run backwards... quite possibly!!)

[xantia_v6]

The magneto (probably) won't spark if turned backwards, so the motor won't run that way.

It is my understanding that variable advance is much more important on a 4-stroke than a 2-stroke engine, so maybe it was never actually used on this machine?.

[RichardW]

You're right, Mike - a bit of searching suggests advance not that important on 2-stroke. All the other ones I have seen have an advance cable, but this has certainly run without.

I got the peg straightened out, and started painting. You can see that the peg from the other side has been re-made at some time!!

I've also fitted the bars - they're a bit squinty... I think becuase the mount is twisted and it's throwing it out. I think I will just leave it for now.

I got the lower mount on the front mudguard fitted as well. I've ordered a load of stuff the last couple of days, and this lot arrived today - finishing touches!!

I've now got some oil, and ordered a bore hone, gasket material to do the cylinder bottom and carb mount, and some felt to make the grease seals for the wheel bearings. Just chain, cables and exhaust to sort now. We will be short of chain cases, but that can wait as I will have to fabricate them, and I have no pattern at present!

[RichardW]

Finished off painting the brake rods / pegs etc. Cleaned up the tank ready for painting, will get a coat of rust converter on that first. Ordered clutch and throttle cables as they are available off the shelf from Grove Classics. Front brake has a special fitting on the end that will need to be changed over, and the decompressor cable was not available with the right fittings - hopeful I have found someone that can make those up, waiting on a reply. Rebuilt the front wheel bearing, fitted the brake assembly, and got that back in the frame. Looks at the rear, and decided I would refit the sprocket before putting the wheel in as that might avoid the need to take it out again (some hope!), stalled at first as I had painted the hub and it wouldn't fit on, so had to sand the paint back off. Got it on, however, I'm a bit stumped with the fixings. The sprocket is held on with 5 bolts (of which I only have 4, but that's not too much of a problem), but there are 2 triangular shaped washers (spacers? - they're about 1/8" thick) with each bolt - and I can't recall how it was fitted together. I wonder if the spacers allow the sprocket to be fitted in one of 3 positions to give better alignment of the gearbox and wheel sprockets.... although this pic from the one sold by Bonhams (what a useful resource those high def pics are!!) appears to show no spacers and the sprocket towards the outside of the hub...perhaps I didn't need to sand the paint off (or drift the sprocket into place.... ). Other pics of similar machines on their site also show no spacers on the outside.

Noted I don't have one of those springs on the rear brake either - presumably it is to soften the action.

Edit: Not having the spring is probably the equivalent of the spring mod on the Xantia brake pedal plunger

[xantia_v6]

That spring is to stop the rod rattling and the adjusting nut undoing itself at exactly the wrong time....

Although the (lock?)nut shown in the photo above does not look original to me.

[moizeau]

The spring also ensures the brake arm returns, without it it can snag on the adjuster's thread

[RichardW]

Progress...

Fitted the sprocket, with the spacers behind - until I get the gearbox in, won't be able to see if it lines up with the output sprocket. There's only just enough room to get the rear wheel in - with the tyre deflated it can be just squeezed in past the mudguard. Had a bit of fiddle with the nuts to get the wheel in the right place, and had to file the paint off the frame where the spindle fits as it was too tight. Tyre is just scraping on the mudguard on the front off side, it might need to be relieved a bit...

Note the clamp to hold it down to the bench - without the engine in the centre of gravity is above the centre line, so if you pick it up it just falls over - my original idea of hanging it off the rafters wouldn't work...

Next job was to clean the bore, this is the inside as it came off the shelf

After giving it a good hone, and wash, it needed to be dried

This is the bore once cleaned up....

Hmm, still a rusty band at the top , which is not a good sign. Not sure what to do.... I can't get my hand in to feel if it is rough in there, but Mrs W might be able to! i presume this is the bit that was above the piston when it was stood - the piston was stuck in the bore when I got it. I could just stick the piston in and run it to see what happens - oil control is not too much of an issue, given it's a 2 stroke!! If there's enough to get compression then it might bed in - or it might just wreck the rings. Interestingly (well to me anyway!) the piston is not original - this should have had a cast iron piston so it has been replaced at some time. The piston is a Heppolite one, and I can see the number on it, 2223, which shows it is from the later version of the engine in the GTP model. Oversize pistons appear to be available: http://www.classic-motorcycles.co.uk/cg ... b_pid=5251 also available in +040 thou, so a re-bore is a possibility. I've yet to determine if the current piston is an oversize item. I tried to fit the gudgeon pin clips I have bought, but they are too small, will need to get some bigger ones if I go with the current piston.

So I shoved the crankcase in the frame...

Looks almost like a motorbike

Another thing to sort out is the exhaust ring - one of them is broken. I had assumed it was just split, but after cutting the exhaust to get the good one off, it's apparent that a bit the length of one of the indents is missing:

The broken one is probably original, as it shows signs of being plated - however, the other one is homemade - it's heavier, and the indents are not equally spaced... I've got some brass and silver solder, so will have a go at getting a bridge on it, think the exhaust will seal with a bit of paste on it, even with a bit missing.

Tomorrow on with cleaning up the rear engine mount bolts so I can fit that, and then I can start building up the bottom end of the engine.

[moizeau]

Looking good. Regarding the rust in the cylinder, it's quite possibly the area that doesn't get touched by the rings. I'd just buff it with a dremel. The rust will need to be removed to stop it getting in the piston ring grooves but it possibly won't matter if that area is a little proud. It's normal on used engines to have a raised area near the top. Smaller engines with integrated heads are a pain.
Bonne continuation.

[Gibbo2286]

If you're worried about the ridge can you not get a stepped top ring? That's what we did when we did the old car engines with 'Cord' rings.

[RichardW]

Bit more measuring and I'm sure the piston is already oversize. No 1 Son's hand was small enough to go down the bore, a quick wipe round with 0000 wire wool and the rust is gone, leaving a shiny area instead. So I'm just going to re-build it as is and see what happens.

Rebuilt and fitted the clutch today. I had forgotten about the release bearing, don't make them like this anymore!

Then it was just the matter of placing the 16 release springs, and 47(!!) loose balls that the centre plate runs on!! Actually not that hard when done flat on the bench. Once the 3 parts of the clutch are sandwiched together it's easy enough to slide it onto the splines on the box, and then fit the sleeve nut to hold it in place.

Yes, those are cork friction elements. Not sure how much life there is left in them, but they will do for now I think. The three small pins in the tub are the release pins - they pass through the inner plate, and push the outer plate out against the springs, and hence release the clamp on the centre plate. The release lever has 3 angled lugs on the back of it that engage with matching lugs on the back of the box that make it move out as it rotates when the cable is pulled. You can see one of the pins is home made, being part of a bolt, rather than the (presumably hardened) original. Close up of the ball race

The clutch cable I have got doesn't quite match the fittings on the bike, but not that hard to make it fit with a bit of fettling....

[myglaren]

Time to step up your game Richard.

[RichardW]

That's some serious Heath-Robinson engineering there. Would you try and take off in that thing?????

I found the decompressor, and it looks to be complete - there is a tiny brass bolt which is broken, and I've written on the tag on the bag "note broken brass location bolt" - but I can't recall where it came from, and I can't see what it would do....

Yesterday I cleaned and reassembled the decompressor - parts of which I am sure are home made!! However still no sign of a location for that bolt - here it is in all its tiny glory, pretty amazed this has not disappeared over the years...

Then later on I was looking at the crankcase as I was washing the oil tank out with white spirit, and I spied this hole

Hmm, what's that all about, surely that will just blow petrol mix out when it's running? Then I remembered there is this insert to go into the end of the crankcase to reduce the free volume

Oh look, it's got a slot in the bottom! And a close look shows a witness mark that exactly matches the head of the broken bolt - so that's where it came from. Presumably I broke it trying to undo it - and in fact the label on the bag says (+ broken locating bolt) - so it was just coincidence that it was in the decompressor bag.

I've ordered some brass bolts to refit the saddle cover, so hopefully one of these can be adapted to fit in there.

Yesterday I played with the kickstart and got it to work - the spring wants to cross over itself, but there are marks to show that is how it was running, so I will put it back like that. I also mocked up the gear change, and straightened out the bent bits so the end is in about the right place next to the tank. I've re-tapped the pivot thread in the frame, but it is not great, I think I will need a longer bolt I can thread lock in, then fit the change with a bevel washer which I can adjust the tension on by a pair of lock nuts, otherwise it's just going to fall off in the first 2 miles! It never ceases to amaze me how parts on this machine come apart. There is a pivot on the change which looked a rusty mess, but gave up easily, and there is a ring joint screwed on the end of the vertical arm - possibly never been moved in 90 years, but it just unscrewed like it was put in there yesterday!!

Been thinking about the saddle - the front mount is missing, but it seems to me that this needs to pivot otherwise the springs at the back will do nothing. So I need to invent something that will allow that.

Once the new piston clips arrive I can rebuild the engine and then it is tantilisingly close to trying a start....