Japanese inch bearings

[ausrobg]

I am completely confused.

JAF and KSM supplied RLS8 and RMS8 bearings are 0.025mm larger on the OD than Skefco, Hoffman and RHP.

Not surprisingly, this causes the Japanese bearings to bind up in my old Matchless crankcases.

What is the reason for different standard sizes between Japanese and English bearing manufacturers ?

Cheers,

Rob

[RohanB-3]

Have you looked at the (size) specs for the bearings ?
Something lost in the inch to mm translation. ?

It used to be that if English bits weren't the right size, its because the
usual operator wasn't there that day, and the temporary operator didn't
know about putting the wooden wedge under the worn out machinery to still
get the correct sizes out of it.

With the proviso that in some Matchy single engines, the 2 main bearings on
the drive side of the crank are actually 2 different sizes. If you don't
have one of each size, and put them on in the correct order, then you are
fucked - to put it mildly. Maybe we should enquire what motor this is,
before pursuing this line.... ?

hth !?

----------
From: ausrobg <ausrobg@...>
To: mc-engine@...
Subject: Japanese inch bearings
Date: Tuesday, October 27, 2009 5:43 PM

I am completely confused.

JAF and KSM supplied RLS8 and RMS8 bearings are 0.025mm larger on the OD
than Skefco, Hoffman and RHP.

Not surprisingly, this causes the Japanese bearings to bind up in my old
Matchless crankcases.

What is the reason for different standard sizes between Japanese and
English bearing manufacturers ?

Cheers,

Rob



------------------------------------

Yahoo! Groups Links

[RohanB-3]

P.S. Bearings have to be fitted into alloy crankcases that are HOT - or
there is no chance of getting them in there with everything still intact.
The cases have to cool down and really clamp down on them. Tell us about
the cooking you gave them...?

[Ian D-2]

>JAF and KSM supplied RLS8 and RMS8 bearings are 0.025mm larger on
>the OD than Skefco, Hoffman and RHP.


Doesn't sound right to me ???


Cheers          IAN


See www.drysdalev8.com for :
- Drysdale 750-V8 Sports & 1000-V8 Cruiser
- DRYVTECH 2x2x2 Experimental
- Carberry Enfield 1000cc V-Twin
- Drysdale Hillclimb Open Wheeler

[JOHN MEAD]

Bearings are available with the race being oversize to be used in worn housings.  Maybe you got some of those.

John Mead

--- On Tue, 10/27/09, ausrobg <ausrobg@...> wrote:

> From: ausrobg <ausrobg@...>
> Subject: Japanese inch bearings
> To: mc-engine@...
> Date: Tuesday, October 27, 2009, 3:43 AM
> I am completely confused.
>
> JAF and KSM supplied RLS8 and RMS8 bearings are 0.025mm
> larger on the OD than Skefco, Hoffman and RHP.
>
> Not surprisingly, this causes the Japanese bearings to bind
> up in my old Matchless crankcases.
>
> What is the reason for different standard sizes between
> Japanese and English bearing manufacturers ?
>
> Cheers,
>
> Rob
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>     mailto:mc-engine-fullfeatured@...
>
>
>

[Ian D-2]

>Bearings are available with the race being oversize to be used in
>worn housings.


But they won't have the original part number on them - or at
least have additional numbers after the part number.



Cheers       IAN


See www.drysdalev8.com for :
- Drysdale 750-V8 Sports & 1000-V8 Cruiser
- DRYVTECH 2x2x2 Experimental
- Carberry Enfield 1000cc V-Twin
- Drysdale Hillclimb Open Wheeler

[JOHN MEAD]

And those follow on numbers are easily ignored if the first ones are correct.

John Mead

--- On Tue, 10/27/09, Ian <iwd@...> wrote:

> From: Ian <iwd@...>
> Subject: Re: Japanese inch bearings
> To: mc-engine@...
> Date: Tuesday, October 27, 2009, 11:58 AM
>
> >Bearings are available with the race being oversize to
> be used in
> >worn housings.
>
>
> But they won't have the original part number on them - or
> at
> least have additional numbers after the part number.
>
>
>
> Cheers       IAN
>
>
> See www.drysdalev8.com for :
> - Drysdale 750-V8 Sports & 1000-V8 Cruiser
> - DRYVTECH 2x2x2 Experimental
> - Carberry Enfield 1000cc V-Twin
> - Drysdale Hillclimb Open Wheeler
>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>     mailto:mc-engine-fullfeatured@...
>
>
>

[RohanB-3]

On the chance that this is a Matchy single of the early 1950s, the parts
book makes a note about 2 different version of spacers - one type to be
used with Skefco and another type with Hoffman bearings - and which and how
to use if bearings are not paired. The bearings could well bind up if these
instructions are not followed, by the sound of it...

The UK AJS Matchless Owners Club can supply suitable bearings and spacers
in matched sets.

Opethiselps.

[RohanB-3]

Are these C3 clearance bearings ?

Perhaps you need the extra bigger clearance ....

[RohanB-3]

P.S. that is only 0.001" = barely measurable ?
A trace of oil  ??

Your problems lie elsewhere ?

----------
>>>
From: ausrobg <ausrobg@...>
To: mc-engine@...
Subject: Japanese inch bearings
Date: Tuesday, October 27, 2009 5:43 PM

I am completely confused.

JAF and KSM supplied RLS8 and RMS8 bearings are 0.025mm larger on the OD
than Skefco, Hoffman and RHP.

Not surprisingly, this causes the Japanese bearings to bind up in my old
Matchless crankcases.

What is the reason for different standard sizes between Japanese and
English bearing manufacturers ?

Cheers,

Rob



------------------------------------

Yahoo! Groups Links

[ausrobg]

Matchy G80CS 1961

Outer drive bearing is a RLS8 C3

Inner is a RMS8

The old Skefco ones that came out are exactly the same OD as some NOS Hoffman, and some new RHP.

The JAF and KSM are both 0.025mm larger on the OD. (Note you can't get C3 for inch bearings from most Japanese manufacturers).

If you don't grid the OD, the bearings will bind and the cases might yield as well !!

Cheers,

Rob

--- In mc-engine@..., "RohanB" <newboltz333@...> wrote:

>
> Have you looked at the (size) specs for the bearings ?
> Something lost in the inch to mm translation. ?
>
> It used to be that if English bits weren't the right size, its because the
> usual operator wasn't there that day, and the temporary operator didn't
> know about putting the wooden wedge under the worn out machinery to still
> get the correct sizes out of it.
>
> With the proviso that in some Matchy single engines, the 2 main bearings on
> the drive side of the crank are actually 2 different sizes. If you don't
> have one of each size, and put them on in the correct order, then you are
> fucked - to put it mildly. Maybe we should enquire what motor this is,
> before pursuing this line.... ?
>
> hth !?
>
> ----------
> From: ausrobg <ausrobg@...>
> To: mc-engine@...
> Subject: Japanese inch bearings
> Date: Tuesday, October 27, 2009 5:43 PM
>
> I am completely confused.
>
> JAF and KSM supplied RLS8 and RMS8 bearings are 0.025mm larger on the OD
> than Skefco, Hoffman and RHP.
>
> Not surprisingly, this causes the Japanese bearings to bind up in my old
> Matchless crankcases.
>
> What is the reason for different standard sizes between Japanese and
> English bearing manufacturers ?
>
> Cheers,
>
> Rob
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>

[ausrobg]

C3 is merely a slacker internal clearance for squeezing into tighter holes.

Cheers,

Rob

--- In mc-engine@..., "RohanB" <newboltz333@...> wrote:
>
> Are these C3 clearance bearings ?
>
> Perhaps you need the extra bigger clearance ....
>

[ausrobg]

The JAF came from Bearing Services.

The KSM cane from CBC Bearings.

Unless they are all made by the same mob, I would be pretty unlucky to end up with a special oversize order that went unused so they chucked in the standard parts bin !!!

I ended up using the RHP bearings ... no dramas.

Cheers,

Rob

--- In mc-engine@..., "RohanB" <newboltz333@...> wrote:

>
> P.S. that is only 0.001" = barely measurable ?
> A trace of oil  ??
>
> Your problems lie elsewhere ?
>
> ----------
> >>>
> From: ausrobg <ausrobg@...>
> To: mc-engine@...
> Subject: Japanese inch bearings
> Date: Tuesday, October 27, 2009 5:43 PM
>
> I am completely confused.
>
> JAF and KSM supplied RLS8 and RMS8 bearings are 0.025mm larger on the OD
> than Skefco, Hoffman and RHP.
>
> Not surprisingly, this causes the Japanese bearings to bind up in my old
> Matchless crankcases.
>
> What is the reason for different standard sizes between Japanese and
> English bearing manufacturers ?
>
> Cheers,
>
> Rob
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>

[Ian D-2]

>P.S. that is only 0.001" = barely measurable ?


Don't say that to a toolmaker !!   0.001mm maybe, but a toolie
can find 0.001" with a wooden ruler. :-)

BTW - on a hardened ground shaft, you can pick up a 0.0002"
( 2 tenths thou ) step by running your finger over it, even less
with practice.


Cheers            IAN


See www.drysdalev8.com for :
- Drysdale 750-V8 Sports & 1000-V8 Cruiser
- DRYVTECH 2x2x2 Experimental
- Carberry Enfield 1000cc V-Twin
- Drysdale Hillclimb Open Wheeler

[Ian D-2]

>>P.S. that is only 0.001" = barely measurable ?


True story........

When I was an apprentice, we had a job setting up spiral bevel
gear cutting machines for the first cut where the only way to do
it was with 2 steel rulers side by side. ( OK, we could have
used an internal mic, but we didn't need that sort of accuracy )

It was in the days before metric was invented and we used the
1/64" scales on imperial rulers.  The old guys there could get
them within 5 thou ( 0.012mm ) - which I found amazing.  After
3 months in the SB department, I could get them within 5 thou
too, no micrometer, just 2 steel rulers.


Cheers       IAN


See www.drysdalev8.com for :
- Drysdale 750-V8 Sports & 1000-V8 Cruiser
- DRYVTECH 2x2x2 Experimental
- Carberry Enfield 1000cc V-Twin
- Drysdale Hillclimb Open Wheeler

[Ken Augustine]

At  AMOL where I was a rookie, one of the machinists could only work to .002" but he could do it with his eye from .up to 1.000".   We could hand him anything with a single diameter or thickness and he would call it from a glance andtouch.  

Ken A




________________________________
From: Ian <iwd@...>
To: mc-engine@...
Sent: Tue, October 27, 2009 9:30:27 PM
Subject: Re: Japanese inch bearings

 

>P.S. that is only 0.001" = barely measurable ?

Don't say that to a toolmaker !!   0.001mm maybe, but a toolie
can find 0.001" with a wooden ruler. :-)

BTW - on a hardened ground shaft, you can pick up a 0.0002"
( 2 tenths thou ) step by running your finger over it, even less
with practice.

Cheers            IAN

See www.drysdalev8. com for :
- Drysdale 750-V8 Sports & 1000-V8 Cruiser
- DRYVTECH 2x2x2 Experimental
- Carberry Enfield 1000cc V-Twin
- Drysdale Hillclimb Open Wheeler


   


     

[Ian D-2]

>At  AMOL where I was a rookie, one of the machinists could only work
>to .002" but he could do it with his eye from .up to 1.000".   We
>could hand him anything with a single diameter or thickness and he
>would call it from a glance and touch.


We had an old guy in our inspection department who was the
same; thing is, I was never able to work out if he was pulling
the wool over our eyes or not; I'm still not sure.

Similarly, we had another old guy who could tell you the
grade of steel by just holding it in his hand.  Like the guy above,
I was never able to work out if he was having us on, but I was
never able to fool him. ( Granted we mainly used 5 or 6 grades,
but it was still amazing )



Cheers            IAN


See www.drysdalev8.com for :
- Drysdale 750-V8 Sports & 1000-V8 Cruiser
- DRYVTECH 2x2x2 Experimental
- Carberry Enfield 1000cc V-Twin
- Drysdale Hillclimb Open Wheeler

[JOHN MEAD]

No, C3 is a running clearance.

John Mead

--- On Tue, 10/27/09, ausrobg <ausrobg@...> wrote:

> From: ausrobg <ausrobg@...>
> Subject: Re: Japanese inch bearings
> To: mc-engine@...
> Date: Tuesday, October 27, 2009, 10:02 PM
> C3 is merely a slacker internal
> clearance for squeezing into tighter holes.
>
> Cheers,
>
> Rob
>
> --- In mc-engine@...,
> "RohanB" <newboltz333@...> wrote:
> >
> > Are these C3 clearance bearings ?
> >
> > Perhaps you need the extra bigger clearance ....
> >
>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>     mailto:mc-engine-fullfeatured@...
>
>
>

[ausrobg]

That's what I said ...

Same dimensions, but has larger ball raceway clearance for a tighter press fit without binding up.

Cheers,

Rob

--- In mc-engine@..., John Mead <john.mead@...> wrote:

>
> No, C3 is a running clearance.
>
> John Mead
>
> --- On Tue, 10/27/09, ausrobg <ausrobg@...> wrote:
>
> > From: ausrobg <ausrobg@...>
> > Subject: Re: Japanese inch bearings
> > To: mc-engine@...
> > Date: Tuesday, October 27, 2009, 10:02 PM
> > C3 is merely a slacker internal
> > clearance for squeezing into tighter holes.
> >
> > Cheers,
> >
> > Rob
> >
> > --- In mc-engine@...,
> > "RohanB" <newboltz333@> wrote:
> > >
> > > Are these C3 clearance bearings ?
> > >
> > > Perhaps you need the extra bigger clearance ....
> > >
> >
> >
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >     mailto:mc-engine-fullfeatured@...
> >
> >
> >
>

[RohanB-3]

Maybe. Just polishing off whatever the anti-corrosive is they use would
remove 0.001"

??

----------
From: Ian <iwd@...>
To: mc-engine@...
Subject: Re: Japanese inch bearings
Date: Wednesday, October 28, 2009 2:30 PM


>P.S. that is only 0.001" = barely measurable ?


Don't say that to a toolmaker !!   0.001mm maybe, but a toolie
can find 0.001" with a wooden ruler. :-)

BTW - on a hardened ground shaft, you can pick up a 0.0002"
( 2 tenths thou ) step by running your finger over it, even less
with practice.


Cheers            IAN