Where would I look for a large gudgeon pin?

[Pete.]

I need a couple of small end gudgeon pins, from a fairly large engine. When I say large I mean about 5-6" long and perhaps 1.5" diameter hollow gudgeon. Size isn't critical but I need them on the hurry-up.

Any ideas?

 

[MCKDAVID]

a large gudgeon pin shop.....

ok I'll get my coat,

try the local farm / agricultural place, might get lucky, they usually have a fairly decent selection of pins etc..

 

[Jim Davey]

Anderson industrial engines, ask for Steve, I'm sure he'll know where to get something.

01264 336783

 

[CompoSimmonite]

Diesel railway engine ?

 

[Flathead_Dave]

https://www.google.co.uk/?gfe_rd=cr...rd=ssl#q=commercial+engine+rebuilding+in+kent

 

[awemawson]

Is this for a cylindrical square by any chance ? - (If so I could lend you one of those)

 

[I'm getting on a bit]

Well if it is, a gudgeon pin may be no good as they will be ground on a centreless grinder with the ends not being ground.

But good spot

 

[Shox Dr]

Well if it is, a gudgeon pin may be no good as they will be ground on a centreless grinder with the ends not being ground.

But good spot

I beleive Pete has. Surface grinder so that would not stop him.

 

[Pete.]

I do but it's being rebuilt.
No it's not for a cylindrical square, it's to make a base for a measuring tool. The main requirements are that it have a close-tolerance OD and be a good quality steel.

 

[mechman]

S

I do but it's being rebuilt.
No it's not for a cylindrical square, it's to make a base for a measuring tool. The main requirements are that it have a close-tolerance OD and be a good quality steel.

Sine bar ?

 

[I'm getting on a bit]

I beleive Pete has. Surface grinder so that would not stop him.

It would, you need a cylindrical grinder to grind the ends to make them square to the body.

 

[Shox Dr]

It would, you need a cylindrical grinder to grind the ends to make them square to the body.

Why is that?

Would a 'V' block on its side or flat, not work

 

[I'm getting on a bit]

Why is that?

Would a 'V' block on its side or flat, not work

Well you could grind it in a vee block but it may not have the precision for using it as a master measuring tool.

A cylindrical square with a dead parallel body with the end ground using the side of the wheel will be perfefctly square.

This will be done between centres on the grinder

 

[MattH]

I do but it's being rebuilt.
No it's not for a cylindrical square, it's to make a base for a measuring tool. The main requirements are that it have a close-tolerance OD and be a good quality steel.

Isn't silver steel ground to diameter?
A couple of lengths would be a lot less than a large gudgeon pin i'd of thought.

 

[awemawson]

If a 'perfect' cylinder is turned on a lathe so that the ends are concave, it will sit 'perfectly square' on a surface plate - it's not essential to grind the ends, and it you do then do it concaved

 

[I'm getting on a bit]

If a 'perfect' cylinder is turned on a lathe so that the ends are concave, it will sit 'perfectly square' on a surface plate - it's not essential to grind the ends, and it you do then do it concaved

All what you say is correct in theory, but can you get it parallel over 150mm to. 0002" TIR I'd say not

The reason for grinding is the square would be hardened for longevity.

My own square the end is counterbored so don't matter if concave or convex, although I agree concave is better

 

[Pete.]

My lathe could turn it parallel to 2 tenths between centres if I needed to make a square but all I actually need is a heavy-walled tube with parallel ground ID. I don't want it hardened because it requires further machining. I have a small one about 3.5" long from a bike but I want one that is slightly larger.

 

[graffian]

1-1/2" is pretty big, I have some pistons of maybe 8 inch bore and they have pins maybe 1-1/4".
Big block Chryslers have 1-1/32" pins around 3-1/2" long, I will have a look to
see if I have any spares, but they might well be hardened tool steel.

 

[Pete.]

1.25" would be fine if you got any spare mate. I will just modify the design a bit. I know they are going to be tough but I doubt they will be hard enough to resist carbide tooling, they would not cope with the combustion forces if they were I think.

 

[CKJDJK]

Try old time truck garages. They will probably have quite a few from engine rebuilds just kicking around.