Bolt

[Timx]

Hi

I have a BMC 1.5L on a GRP the bolt that holds the small belt wheel[which connects the belt to the larger belt]which drives the pump to cool the engine with canal water has lost its thread, I took the washer off which gave me a couple of mm to get it back on to take it back to mooring, I left the boat at mooring and never brought the bolt with me to compare it at a shop. So my question is, as it will be an imperial thread / bolt anyone know what size I am probably looking at to try and buy off e bay rather than having to retrieve bolt and take to a engineering shop. I am a nurse, not an engineer and new to boating so forgive my ignorance. Any advice welcomed. I don't mind buying a few probables.

[bigste]

I am not familiar with what you mention but it will I think be a UNC fine thread. They will only cost you 10 pence in an ironmongers or engineering stockists. If not sure of the diameter just buy half a dozen, 3/16, 1/4, 5/16, 3/8 etc. UNC also do a coarse thread but I doubt it's that. Ask the stockist to show you one of each, there is a big difference and it should be easy to spot.

Maybe someone on here can confirm they did not use metric threads or better still the exact thread you need.

[magnetman]

When you say UNC fine do you mean UNF?

[Tony Brooks]

I think the OP is talking about the crankshaft pulley bolt and it may be longer one than those used on keel/tank cooled boats and vehicles. It is probably UNF but 1.5s were in production a long time and if its an early one it might be BSF, but I doubt it. If the starter motor is held on by just two bolts don't take the risk, wait until you have the pattern. Regrettably I can not remember the diameter but have a feeling it may be 3/8 or 1/2"

[wullie]

If the washer you removed was enough to give you a couple threads to get you back, then i would also say it will be UNF thread, still easy to get in many places, i would also check threads the bolt fits into, could be an idea to fit bolt with a spot lock tight, get this at same supplier of bolts, also can you remember size of spanner you used, that will give you size of bolt, even if it was in M.M. it will be a good indication of size of bolt, wont help identify thread but i still think it would be UNF.Should be a quick and easy fix.

[RLWP]

the bolt that holds the small belt wheel[which connects the belt to the larger belt]which drives the pump to cool the engine with canal water has lost its thread

 

I can't tell if that is part of the engine, or a separate pump

 

If it's part of the engine, it's probably UNF. If it's an aftermarket pump, it could be anything

 

Richard

[Timx]

Thanks for the replies, I will go back to boat and get the bolt and stop being lazy,just there is not any ironmogers around here but should be able to size it then look on the net

[OldGoat]

Thanks for the replies, I will go back to boat and get the bolt and stop being lazy,just there is not any ironmogers around here but should be able to size it then look on the net

 

 

Once you know the size either eBay is your friend (??) or try these people who keep a stock of obsolete / obsolescent nuts, bolts, and accessories:-

http://www.namrick.co.uk/

 

Not cheap but convenient.

 

 

Once you know the size either eBay is your friend (??) or try these people who keep a stock of obsolete / obsolescent nuts, bolts, and accessories:-

http://www.namrick.co.uk/

 

Not cheap but convenient.

(Still can't edit posts)

 

If you pop the offending part in the post they'll match it for you. Ring them first. Don't play dumb, say you're a nurse and you may get top service. There's a Scottish gentleman there who doesn't 'take prisoners', but if you're clear and polite he'll go the extra mile!

[bigste]

Sorry my error, I did mean unf. Like it has bean said it could even be bsf.

[Timx]

That's helpful Thanks will keep that address

[Timx]

Post-bolt 004 by Timore3, on Flickr

This is the bolt can anyone describe it so I could possibly order one on line

[RLWP]

It's a three and a half inch long something thread hex head bolt

 

Richard

[Timx]

hmm yeah stupid question I know

[Tony Brooks]

Post-bolt 004 by Timore3, on Flickr

This is the bolt can anyone describe it so I could possibly order one on line

 

Its not Whiworth or UNC.

 

I very much doubt its metric so that leaves BSF of UNF. Now, this may well be complete ollox but if you look at the head and it has a sort of indented disk shape in the middle I seem to remember it identified it as a UNF thread.

 

Edited to add - or is it a little raised lines at the outside of three radii?

 

Stop messing about with online, go to your long established local garaged that deals with all makes and ask them to try a known nut for you. You may even get the bolt for 50p.

 

Many hardware shops would do the same for you.

 

I think the female thread may well also be damaged so how long a new bolt will hold is open to question.

Edited May 23, 2014 by Tony Brooks

[RLWP]

What diameter is it in inches?

 

Richard

[bizzard]

 

Its not Whiworth or UNC.

 

I very much doubt its metric so that leaves BSF of UNF. Now, this may well be complete ollox but if you look at the head and it has a sort of indented disk shape in the middle I seem to remember it identified it as a UNF thread.

 

Stop messing about with online, go to your long established local garaged that deals with all makes and ask them to try a known nut for you. You may even get the bolt for 50p.

 

Many hardware shops would do the same for you.

 

I think the female thread may well also be damaged so how long a new bolt will hold is open to question.

Yes Tony UNF and I think UNC would normally have that dimple on the top, often with 'auto' in relief written around it.

[Pete & Helen]

Hi

I have a BMC 1.5L on a GRP the bolt that holds the small belt wheel[which connects the belt to the larger belt]which drives the pump to cool the engine with canal water has lost its thread, I took the washer off which gave me a couple of mm to get it back on to take it back to mooring, I left the boat at mooring and never brought the bolt with me to compare it at a shop. So my question is, as it will be an imperial thread / bolt anyone know what size I am probably looking at to try and buy off e bay rather than having to retrieve bolt and take to a engineering shop. I am a nurse, not an engineer and new to boating so forgive my ignorance. Any advice welcomed. I don't mind buying a few probables.

 

Had a quick google for you on 1/2inch unf bolt, liverpool and ended up on a forum where a likely local source of bolts was given. so as your in Merseyside hope its local to you and able to get what you need.

 

Express Tool & Fasteners Ltd

20-30 Derby Road

Liverpool

Merseyside L20 1AB

[jodansgang]

I guess this has nothing to do with the little super hero dog movie that I enjoyed so much......

[Iain_S]

If it's half inch diameter, UNF has 20 threads per inch: BSF has 16.

 

Iain

[Timx]

Thank you for your replies , I will take Tony Brookes advice, which I knew really, just wanted to do it the easy way which rarely works . Thank you Pete and Helen, that will be my first try . Bizzard,and Ian thank you but doesn't mean much to me ,I was a bit pissed last night and ordered some bolts off e bay around what was advised to try,only a few quid so may come in handy in the future.The comment about the female thread is also A point to consider,possibly the wrong bolt was used in fixing it initially.If I can change the belt by taking the other twirly thing off I could locktight it down.The history of the boat is a 27ft Norman with an engine as mentioned earlier, the boat was previously gutted and redone out by the owners,however they split up having re done it.When I spoke to the lady about the boat she told me they had both spent a lot of time together sorting it out,and internally you can see they had.However it hadf not been used for a couple of years when I bought it[,blind[no knowledge] and naïve as I had some money on the hip last year, so knew little problems I could sort by throwing cash at it. bought it in Bath way and my idea to sail it to scarisbrick soon became a laff and tony tug took it in the end ,so my idea of a holiday on a boat one way made no sense at all and cost me an extra 500 lol The woman who sold it to me was right up front and complained that after getting all sorted he would not take it out or go anywhere, that seemed reasonable excuse to me, but later on I realised the reason why was.probably, because he probably realised it had a few problems lol and wouldn't take cain hill,which it didn't lol.I bought it for 9k and since last year have spent about 5 hundred to RCR apart from there tariff,three new battteries, an internal charger, for hook up, a hook up, 1500inverter,New Morse wire.But I have gained knowledge so I have learnt lol,

Sorry for going off topic just wanted to explain.I love having the boat, as its moored only about twenty mins away so if im off and its sunny , great a boat for a pub crawl even if its just me for most of it.

I retire next year and will prob sell it yr later as I want a new narrowboat to travel the system from race track to race track, but that's another story.

[Tony Brooks]

Lest assume it is a "standard" Newage/Tempest type marinisation.

 

I think this is the drive pulley for the raw water pump and that is fixed to a bracket that is in turn bolted via slotted holes to the front engine mount. If you loosen the bolts in the slotted holes the bracket should drop and twist so you can take the belt off. The bolts will also allow you to tension the belt correctly but please rather slacker than the alternator belt because many of those pumps have no proper bearings and they wear easily.