Screws for Amal lift pump? 12-28, 12-40 unf

[Timleech]

A bit of a long shot this.

I'm trying to put together a spare Amal lift pump for my 4LW. I've collected all the bits I need, including an overhaul kit, except that I didn't have the longer screws/bolts and nuts which pass right through the two castings to hold them together, only the short type which tap into one casting (I need the longer ones).

I managed to scrounge some secondhand genuine screws from the local friendly reconditioners, but he didn't have any nuts. The screws he gave me are a mix of 12-28 and 12-40 UNF, and I can't find a UK source anywhere for these nuts.

Best I can come up with is to buy some 1BA socket cap screws, they're about the right diameter, have to go to two different suppliers, one for the screws & another for the nuts!. Could just bung in some M5 or 2BA but not very professional M5.5 would also be OK, but can't find any.

 

Anyone have any spare screws or recommend a source for the nuts?

 

 

Thanks

Tim

[matty40s]

I will ask my resident expert in the morning.

[5thHorseman]

UNF & UNC are the devil's own job to get hold of. I wanted one stainless 3/16 x1.25 inch unc screw and I tried everywhere. Was quoted £70.00 for a hundred and needed to wait while they brought them over from the USA, most enquires were met with sorry can't help.

 

Tried E-Bay and bought 10 for £3.50ish and they arrived by post the following day.

Edited October 8, 2014 by 5thHorseman

[Dalslandia]

are they 7/32" ?

[bizzard]

Just checked model engineers. Macc model engineering have 2BA with nuts in Cheese head, C/S and round head, but max length 1'' only.

[Timleech]

are they 7/32" ?

 

More or less, yes. I'm not sure exactly how those Unified number sizes are arrived at.

 

Edit to add that Unified size12 is nominally 0.216" diameter.

7/32" is 0.219". Close enough for ordinary mortals.

5.5mm, which is a recognised screw size but nobody seems to sell it, is 0.2165".

1BA is 5.30mm which is 0.209".

 

Tim

Edited October 8, 2014 by Timleech

[oldironsides]

Try someone who specialises in vintage Harley Davidsons, they are all UNC and UNF, I have a box full of them from my Harley days, maybe I could find it????

[Split Pin]

Tim

 

Measured a bolt removed from a pump to check it

 

OD is 0.207" pitch measured with thread gauges is 28 tpi

 

1BA is 0.2087" OD and 28.2 tpi

 

As the pumps were British made I would have expected it to be to a British Standard of its Time

 

Having said that the head size is 0.321" AF which corresponds to 2BA.

 

So using 2BA bolts wouldn't look out of place, neither would M5 as the head is pretty much the same size, (0.315")

 

Steve

[Timleech]

Tim

 

Measured a bolt removed from a pump to check it

 

OD is 0.207" pitch measured with thread gauges is 28 tpi

 

1BA is 0.2087" OD and 28.2 tpi

 

As the pumps were British made I would have expected it to be to a British Standard of its Time

 

Having said that the head size is 0.321" AF which corresponds to 2BA.

 

So using 2BA bolts wouldn't look out of place, neither would M5 as the head is pretty much the same size, (0.315")

 

Steve

 

 

Steve

 

Thanks for that. It's the fact that some of the screws are 40tpi which convinced me they're Unified.

I can get 1BA socket caps, which might look wrong but that doesn't really worry me, I'd rather they filled the holes properly

If I don't find any nuts, that's the route I'll take.

 

Tim

[rrt2]

Unimaster in Newbury have a superb range of unified, BA, BSP nuts bolts etc.

Only a short walk from the wooden bridge near the marina as you come into Newbury from the Reading direction

 

http://www.unimaster.co.uk

[RLWP]

 

 

Steve

 

Thanks for that. It's the fact that some of the screws are 40tpi which convinced me they're Unified.

I can get 1BA socket caps, which might look wrong but that doesn't really worry me, I'd rather they filled the holes properly

If I don't find any nuts, that's the route I'll take.

 

Tim

 

I may have got lost in the pitches and diameters - just in case - 7/32" x 40 tpi is a model engineering thread: http://www.ebay.co.uk/itm/like/231143366370?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=108&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0-L&ff12=67&ff13=80&ff14=108&ff19=0

 

Richard

[Timleech]

 

I may have got lost in the pitches and diameters - just in case - 7/32" x 40 tpi is a model engineering thread: http://www.ebay.co.uk/itm/like/231143366370?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=108&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0-L&ff12=67&ff13=80&ff14=108&ff19=0

 

Richard

 

Right, I've now decided that the coarser bolts are 1BA, they are a slightly different diameter from the finer ones. The diameter of those is a closer fit for 12 unf than 7/32, being between .212 and .215", but manufactured bolts do often vary wildly from official specs so they could possibly be 7/32 x 40. Hard to be sure without a shadowgraph to check thread forms! I'll try making a couple of 7/32 x 40 ME nuts to see how they fit. Probably have to make some 1BA nuts as well, as they should have a smaller than standard hex size. I've got some small hex bar, haven't checked sizes yet.

 

Thanks

Tim

[matty40s]

Danetre workshop supplies,

01327 877577,

If they don't have them, they will be able to get them.

[p6rob]

Have you tried www.namrick.co.uk? They usually have a stand at the National Restoration Show which is on 26th October at the NAC, Stoneleigh. I'll be on the Rover P6 Club stand playing with suspension bits.

Rob

[Split Pin]

If you fancy spending a few pennies then new pumps available http://amalcarb.co.uk/other-amal-products/amal-fuel-pumps/gardner-fuel-pump.html.

 

Unfortunately they don't do spares for some reason, I tried to get a discharge valve some time ago with no luck

 

Steve

[Timleech]

If you fancy spending a few pennies then new pumps available http://amalcarb.co.uk/other-amal-products/amal-fuel-pumps/gardner-fuel-pump.html.

 

Unfortunately they don't do spares for some reason, I tried to get a discharge valve some time ago with no luck

 

Steve

 

Yes, I'd seen that. May just be old stock? Last pump I had overhauled for a customer cost me nearly 100 quid to have done which puts that price into perspective. I had actually emailed them to ask about screws, no reply as yet. Not certain whether that has the right operating arm, but that can always be swapped.

Might have been cheaper in the end than messing about with what I have, if I counted my time. I've just spent an hour, while waiting for a boat to dry off, making up some 7/32 x 40 nuts, and thought I would make some matching bolts so that they would all be one size. Turns out that the die I have, HSS, never used before, bought in a set from a well know tool suppliers on the South coast about 12 years ago, is absolute carp. Even fully opened out, in a tailstock die holder, it's cutting a severely undersized thread, the thread in the die appears to be a long way out of line from the body. Can't really send it back after 12 years! I'll try a couple with a hand die holder, otherwise it'll be 1BA.

 

Tim

[J R ALSOP]

Just done a boat safety for a bloke who worked for Amal's, he is now 83, I will see him again next week I could ask him. By the way he has a clinker built boat which was built in the Orkneys in 1964, The railways delivered it to his house in Birmingham where he built a cabin on it, it was then delivered to to Tamworth Cruising Club, it is now at the Dunstable & District Boat Club, it is looking for a new home.

[Timleech]

Just done a boat safety for a bloke who worked for Amal's, he is now 83, I will see him again next week I could ask him. By the way he has a clinker built boat which was built in the Orkneys in 1964, The railways delivered it to his house in Birmingham where he built a cabin on it, it was then delivered to to Tamworth Cruising Club, it is now at the Dunstable & District Boat Club, it is looking for a new home.

 

It would be interesting to hear a definitive answer, although I think I'm sorted now.

For some reason I'd never even considered that my ME size taps & dies might include 7/32", I bought them some years ago when I started building a couple of models but they have lain untouched for at least 10 years. It turns out the the thread inside the 7/32" die is tapered, such that it will always cut an undersize thread except at the start

 

Just off to the workshop to make some 1BA screws with undersized heads. That is if I really do have a 1BA die.

 

Thanks

Tim

[The Pipe]

Try these people.

 

Stones Brothers
Garrett Street, Brierley Hill, West Midlands, DY5 1JU
Tel: 01384 79888 Fax: 01384 77966
Stones specialise in all Imperial size fasteners.

Acclaim Fasteners
Unit 14 Premier Park Estate. Leys Road Brierley Hill DY5 3UP
Tel: 01384 76263
George at Acclaim put me on to Stones and he also stocks a good range of fasteners including Imperial sizes.

[Sir Nibble]

Wonder if the float bowl screw from a Mk 1 concentric carb would fit?

[Timleech]

This job developed well beyond the point of economic reality, if I kept any sort of account of my time, but 'I started so I'll finish' ! It would probably have made more sense to buy another pump.

I've realised that the body clamping screws should be 1BA, with 2BA hexagons. The 7/32" (or numbered UNF) screws are the ones which hold the centre of the diaphragm, they just happen to be almost exactly the same length and diameter as the 1BA screws, and I was given a mix of the two when I asked for some body screws from the local injection service guy.

I ended up having to make screws & nuts - yes, I could have got away with using M5 I suppose but they are very sloppy in the holes and incidentally would look all wrong because the heads are very thin. Having done that, realised that the inlet fitting I had was the wrong one for my job so had to make one of those as well. I've always been a bit nervous of the strength of the thread for the brass cap nut on these, so gave stud and nut extra thread. They are 1/8" BSP, but the thread into the body is 1/2" x 26 tpi.

 

 

One problem left, though. The operating lever arm that I thought was right, I've realised is not now that I've taken the in-use pump from the engine.

 

 

Engine pump lever on left, spare on right.

The cast one in the first picture came from a 2L2, and the geometry between pivot and pressure point on the arm is about right, but I'm pretty sure that it won't fit through the mounting bracket.

 

I know it's not a huge job to swap the arms over, if I did need to fit the spare pump, but I'd feel the exercise was properly complete if I had the right arm.

I don't suppose anyone reading this has an arm of that type they are willing to part with?

The alternative is to fabricate something, using the straight arm as a basis. The friction surface where it rubs on the camshaft is flashed with white metal.

 

Tim

 

[Split Pin]

Hi Tim

 

Nice piece of work making the 1BA screws and nuts

 

Looking through the Amal parts list the lever arm on your pump is part no 120/050 and is only used on the 4-5-6 LW crankcase mounted pumps

 

For LW cam box mounting the part no is 120/054 which looks like a shorter L3 version

 

The L2 one in your first pic is part no 120/055 and only used on the L2,

 

The one in the other pump looks like part no 120/086 fitted to L3 engines,

 

so looks like you need the one specific to the 4-6LW crankcase mounting

 

Steve

Edited November 14, 2014 by Split Pin

[Dinz]

http://burlen.co.uk/

 

Maybe?

[Timleech]

Hi Tim

 

Nice piece of work making the 1BA screws and nuts

 

Looking through the Amal parts list the lever arm on your pump is part no 120/050 and is only used on the 4-5-6 LW crankcase mounted pumps

 

For LW cam box mounting the part no is 120/054 which looks like a shorter L3 version

 

The L2 one in your first pic is part no 120/055 and only used on the L2,

 

The one in the other pump looks like part no 120/086 fitted to L3 engines,

 

so looks like you need the one specific to the 4-6LW crankcase mounting

 

Steve

 

Thanks for that.

 

http://burlen.co.uk/

 

Maybe?

 

Well, they haven't answered my email asking about buying some body clamping screws, my guess is that they have a bit of old stock of pumps for Gardner L3s and when they're gone they're gone, but I shall try contacting them again now that I know the part number for the lever.

 

Tim

[Split Pin]

Tim

 

Parts list can be found here http://www.bristolkandl.co.uk/amal.htm it is an earlier version than the one that I have, the part numbers are the same thought, just a different layout.

 

As I mentioned in an earlier post,I phoned them looking for a replacement discharge valve and quoted them the part number to no avail looks like they only do a repair kit now, plus maybe that one pump as N.O.S

 

Steve

Edited November 15, 2014 by Split Pin