Hi guys,

I need to buy a couple of 5/16 bolts. These are very unusual in Spain as here we use metric everywhere. I need to travel to the UK soon (Glasgow, for business) and I was hoping to get them there. I would like to have your advice on how common these are and where to get them.. Should I expect to find these in a place like say Halfords or do I need a more specific store?

Cheers,

Alex

The bolts in the pics are the original ones, thread is about 18mm long, I'm looking to replace them by longer ones, about 18-19mm long thread. The head is also "american" (do you call that "american" just like we do here or do you use a different name for that?) but any head would do, in fact an "european" one would allow me to use a normal spanner instead of an adjustable one which is nice, but I don't care much.


Motor with gear

These bolts fasten the thermostat housing to the engine on a Rover V8 engine with Edelbrock dress kit. Too short bolts have damaged the inner thread (aluminium) but there's plenty more thread further inside..

BTW, may be the case that the original Rover V8 engine uses the same arrangement for these than the Edelbrock one? In other words, maybe I can just order a couple original bolts from Range Rover?

Cheers,

Alex

[Edited on 11/7/07 by Alez]

[Edited on 11/7/07 by Alez]

Alex,

You won't be able to get that size off the shelf in somewhere like halfords or b&q, you'd need a specialist bolt stockist/shop. Your best bet is probably to source one through a land rover supplier if possible such as rimmer bros etc etc etc

Otherwise I have used namrick (www.namrick.co.uk) who can normally supply most things bolts related and do mail order.

all imho..

Ned.

ps just to be pedantic I think it's spelt whitworth and also known as BSW (British Standard Whitworth)

[Edited on 11/7/07 by ned]

I'd be surprised if it was Whitworth - surely it's a Unified thread, UNC or UNF. Looking at the picture, I would suggest UNC.

As the engine was originally designed in the US, you're talking about Edelbrock bits, and BSW hasn't been used since the 50's...

Hi mate,

there's loads on EBAY

CLICK ME FOR LOTS OF BOLTS

Good luck.

Whitworth and UNC are pretty similar its just the angle of the thread thats different - I was told. And they will fit

I had to use Whitworth on my old skool RS2000 alloy bellhousing as couldn't get any unf's or summit!

ISTR 5/16" is the only where UNC can't substuitute Withworth -- different tpi.


Looking at your engine I strongly suspect it is really 5/16" UNC you require.

Whitworth went out of automotive use in the UK before 1960

This URL will be able help by mailorder http://www.namrick.co.uk/browse.asp?PCID=6

[Edited on 11/7/07 by britishtrident]

To correct myself on this
1/2" not 5/16" is only size the TPi of Whitworth and UNC differ

From http://www.moreg.org.au/whitworth.htm

British Standard Whitworth (BSW)

These are the original, 19th Century, coarse-threaded industrial bolts designed to hold locomotives together. Because of their coarse pitch, they are more prone to vibrating loose, so are little used on motorcars. Except for threading into aluminum (e.g. crankcase studs), where a coarse thread is less prone to stripping than a fine one. It turns out that, except for 1/2" (where the British use 12 threads per inch (tpi) and Americans use 13 tpi) the thread pitches for the rest are the same as for American Unified Coarse (UNC). However, the thread form is different; Whitworth = 55 degrees; UNC = 60 degrees. In spite of this, mismatched nuts and bolts mate nicely, so you're likely to find UNC bolts or studs where BSW should have been.

Chaps, looking at the times for your posts I can't believe how quick you came with such useful posts. Very, very useful, thanks.

Btw, the helicoil option should be avoided if possible due to the position of the hole, I'm not sure it's possible at all to work that in at all, very tricky if at all possible (even with the distributor out of course, that was the case yesterday when I was looking at it).

Thanks everyone, I've learnt quite a lot today.. again!

Calvinx,

I'm only 2nd guessing, but when Alex says position of the hole maybe he means it's vicinity of the scuttle or other parts of the car it's fitted in (a fury iirc). Access with the tools without removing the engine might be an issue in a tight engine bay?
I do agree that helicoil would be another good option though.

cheers,

Ned.

Do you have any local breakers in your area that have an old type Mini in stock? If so the clutch housing bolts are 5/16UNC . IIRC , they are also a little longer than you need and could be cut to size

You could always buy two unc/unf manifold studs and locktite them in, the studs are cheap enough and I've more 5/16UNF nylocks than I know what to do with. If I can find some I might have some spare studs as well that you can have, let me have a poke around in the shed.........

How about these,






Let me know where to send them, no charge if you want them.

quote:

---

Originally posted by muzchap


I had to use Whitworth on my old skool RS2000 alloy bellhousing as couldn't get any unf's or summit!

---

Thank you all very much.

Yes, as Ned says I meant difficult to rework with the engine in place..

I finally have been able to get these bolts from a specialist, apparently it was my only bet in Madrid! The ones they have provided were long, so a friend had to cut them to length.. and that's how I now have a very nice set of custom bolts Oh, and the good thing as well is they have european hex head, so normal spanner!

Thanks everyone for the lesson