I heard a very useful tip the other evening. Someone restoring a big engine 
was stuck for piston rings & skimmed up a brake disk, parting out at the 
appropriate diameter. Similarly, a brake drum might also be helpful.

What a good idea! Fine grain cast iron & annealed over a number of years by 
repeated cycles of heating & cooling and being allowed to rust from time to 
time...............

regards,

Kim Siddorn

On Sun, 14 Sep 2008 17:52:25 +0100, "Kim Siddorn" 
wrote:

>I heard a very useful tip the other evening. Someone restoring a big engine 
>was stuck for piston rings & skimmed up a brake disk, parting out at the 
>appropriate diameter. Similarly, a brake drum might also be helpful.
>
>What a good idea! Fine grain cast iron & annealed over a number of years by 
>repeated cycles of heating & cooling and being allowed to rust from time to 
>time...............
>
>regards,
>
>Kim Siddorn

But, most are ventilated now, at least the van ones are, and they are usually
surface cracked from heat when we get rid of ours.

The BMW discs used to have the same problem as well, they would start to crack
through the ventilation/drainage holes.

Looking through a big pile of truck discs at the scrapyard the other day, they
were almost exactly the same, just bigger. What you'd need is a new older type
non-ventilated disc perhaps, or a new drum, I'd be a bit cautious with anything
old and used.

Peter
--
Peter & Rita Forbes
Email: diesel@easynet.co.uk
http://www.oldengine.org/members/diesel
http://www.stationary-engine.co.uk
http://www.oldengine.co.uk

Heavy right foot is usually the big problem with cracking and not planning 
ahead, so I'm told. :-))

Martin P"Peter A Forbes"  wrote in message 
news:uihqc41dsmltu3dubbkolqpo21d25hlmvg@4ax.com...
> On Sun, 14 Sep 2008 17:52:25 +0100, "Kim Siddorn" 
> 
> wrote:
>
>>I heard a very useful tip the other evening. Someone restoring a big 
>>engine
>>was stuck for piston rings & skimmed up a brake disk, parting out at the
>>appropriate diameter. Similarly, a brake drum might also be helpful.
>>
>>What a good idea! Fine grain cast iron & annealed over a number of years 
>>by
>>repeated cycles of heating & cooling and being allowed to rust from time 
>>to
>>time...............
>>
>>regards,
>>
>>Kim Siddorn
>
> But, most are ventilated now, at least the van ones are, and they are 
> usually
> surface cracked from heat when we get rid of ours.
>
> The BMW discs used to have the same problem as well, they would start to 
> crack
> through the ventilation/drainage holes.
>
> Looking through a big pile of truck discs at the scrapyard the other day, 
> they
> were almost exactly the same, just bigger. What you'd need is a new older 
> type
> non-ventilated disc perhaps, or a new drum, I'd be a bit cautious with 
> anything
> old and used.
>
> Peter
> --
> Peter & Rita Forbes
> Email: diesel@easynet.co.uk
> http://www.oldengine.org/members/diesel
> http://www.stationary-engine.co.uk
> http://www.oldengine.co.uk

On Sun, 14 Sep 2008 18:24:20 +0100, "campingstoveman"
 wrote:

>Heavy right foot is usually the big problem with cracking and not planning 
>ahead, so I'm told. :-))

Where's your halo ? :-))

Some of the problems we have had were caused by towing the trailer fully loaded,
and insufficient braking on the trailer brakes.

Having said that, as most of our mileage is without the trailer (less than 2% of
mileage is with the trailer) and was almost all on motorways, it is difficult to
see why they should suffer from cracking at all.

It was less of a problem with the old asbestos/metal brake pads than with the
newer high-friction pads.

Peter
--
Peter & Rita Forbes
Email: diesel@easynet.co.uk
http://www.oldengine.org/members/diesel
http://www.stationary-engine.co.uk
http://www.oldengine.co.uk

My halo is where I usually keep it, on a hook in the van ready for 
emergencies :-))

Martin P

"Peter A Forbes"  wrote in message 
news:cbnqc4984ld8mmrg9g5qkk2rul3qi7ue6g@4ax.com...
> On Sun, 14 Sep 2008 18:24:20 +0100, "campingstoveman"
>  wrote:
>
>>Heavy right foot is usually the big problem with cracking and not planning
>>ahead, so I'm told. :-))
>
> Where's your halo ? :-))
>
> Some of the problems we have had were caused by towing the trailer fully 
> loaded,
> and insufficient braking on the trailer brakes.
>
> Having said that, as most of our mileage is without the trailer (less than 
> 2% of
> mileage is with the trailer) and was almost all on motorways, it is 
> difficult to
> see why they should suffer from cracking at all.
>
> It was less of a problem with the old asbestos/metal brake pads than with 
> the
> newer high-friction pads.
>
> Peter
> --
> Peter & Rita Forbes
> Email: diesel@easynet.co.uk
> http://www.oldengine.org/members/diesel
> http://www.stationary-engine.co.uk
> http://www.oldengine.co.uk

> But, most are ventilated now, at least the van ones are, and they are usually
> surface cracked from heat when we get rid of ours.

Look for rear discs. They're less likely to be ventilated, they do
less work and so don't get so hot.
I won't comment on heavy right feet!

John

On Sun, 14 Sep 2008 13:13:03 -0700 (PDT), John 
wrote:

>> But, most are ventilated now, at least the van ones are, and they are usually
>> surface cracked from heat when we get rid of ours.
>
>Look for rear discs. They're less likely to be ventilated, they do
>less work and so don't get so hot.
>I won't comment on heavy right feet!
>
>John

Backs are still ventilated on the vans.

Peter
--
Peter & Rita Forbes
Email: diesel@easynet.co.uk
http://www.oldengine.org/members/diesel
http://www.stationary-engine.co.uk
http://www.oldengine.co.uk

On 14 Sep, 21:33, Peter A Forbes  wrote:

> Backs are still ventilated on the vans.

Is that a problem? Even vented disks are still plenty thick enough for
making piston rings out of, unless it's some humongous scraper ring
with multiple lands.

Actually, a ventilated disk is just what you need for a scraper ring!

regards,

Kim Siddorn

"Andy Dingley"  wrote:
>
>> Backs are still ventilated on the vans.
>
> Is that a problem? Even vented disks are still plenty thick enough for
> making piston rings out of, unless it's some humongous scraper ring
> with multiple lands.

On 15 Sep, 13:15, "Kim Siddorn"  wrote:
> Actually, a ventilated disk is just what you need for a scraper ring!

Now that would be a fearsome engine!

The bore on the big Hornsby that we extracted from Niven's sawmill in 
Carlisle,( now installed at the Anson Museum,) was 22". IIRC.
"Andy Dingley"  wrote in message 
news:ad2e0d84-3f45-481f-b3f3-1aa93dece249@m3g2000hsc.googlegroups.com...
> On 15 Sep, 13:15, "Kim Siddorn"  wrote:
>> Actually, a ventilated disk is just what you need for a scraper ring!
>
> Now that would be a fearsome engine!