Case "O" ring required?

Status
Not open for further replies.
Mofosheee

Mofosheee

VIP MEMBER
Joined
Aug 4, 2020
Messages
161
Hello Access
I'm about to put my cases together. Examining the cases it seems to me an oil "O" ring would be required at the location marked with a ? mark.
Would someone please advise me on this?
 

Attachments

  • Case "O" ring required?
    cases.jpg
    324.4 KB · Views: 286
As above, no o-ring. Apply a thin bead of jointing compound, such as Loctite 574 Multi-Gasket, to one face only of the crankcase joint. At the oil passage you marked, apply only to the outer edge, for bolts holes, apply full circle. Apply continuously but sparingly and smooth excess away to the outer edge. Doesn't matter if gasket compound is squeezed outwards, it easily wipes away. But take care it does not go to the inside, especially into oilways.
 
Mofosheee said:
Hello Access
I'm about to put my cases together. Examining the cases it seems to me an oil "O" ring would be required at the location marked with a ? mark.
Would someone please advise me on this?
Click to expand...
Whatever for?

When running the pressure at that point is negative and is the suction of the scavenge side of the oil pump.

At rest, the pressure is pretty close to zero, differing only with how much oil has accumulated in your sump!

Also note, here is nothing there to hold an O ring in position!

You will find elsewhere a recent discussion on jointing compounds. Try Threebond 1184! But seriously, do not put too much around this area, it is an oilway!
 
SteveA said:
Whatever for?

When running the pressure at that point is negative and is the suction of the scavenge side of the oil pump.

At rest, the pressure is pretty close to zero, differing only with how much oil has accumulated in your sump!

Also note, here is nothing there to hold an O ring in position!

You will find elsewhere a recent discussion on jointing compounds. Try Threebond 1184! But seriously, do not put too much around this area, it is an oilway!
Click to expand...
I can understand why recess gives that impression if you've never stripped one of these engines, but I guess its only there to ensure that the holes in each case will not misalign due to manufacturing variance.
 
cliffa said:
I can understand why recess gives that impression if you've never stripped one of these engines, but I guess its only there to ensure that the holes in each case will not misalign due to manufacturing variance.
Click to expand...
It's there to ensure some putz like me comes along and asks a stupid question. Yup, understand it's negitive pressure.
In other applications I've encountered, dowels have been used.
 
Mofosheee said:
It's there to ensure some putz like me comes along and asks a stupid question. Yup, understand it's negitive pressure.
In other applications I've encountered, dowels have been used.
Click to expand...
Ah yes, but dowels would make things too simple ;)
 
SteveA said:
Whatever for?

When running the pressure at that point is negative and is the suction of the scavenge side of the oil pump.

At rest, the pressure is pretty close to zero, differing only with how much oil has accumulated in your sump!

Also note, here is nothing there to hold an O ring in position!

You will find elsewhere a recent discussion on jointing compounds. Try Threebond 1184! But seriously, do not put too much around this area, it is an oilway!
Click to expand...
I've been waiting for an Amazon delivery of Yamabond3 for days. Heard that was the sheet to use.
 
It is worth putting a light countersink on all the holes (except that one) (imho) after checking the area is not raised around the holes by light lapping.
Any sealant in theory is only mircrons thick being two machined surfaces so any riser will increase that gap which can make the sealer work harder. (?)
That case joint is a one shot job.

Who knows what shape the case is in at running temperature and cooling off.
 
Time Warp said:
It is worth putting a light countersink on all the holes (except that one) (imho) after checking the area is not raised around the holes by light lapping.
Any sealant in theory is only mircrons thick being two machined surfaces so any riser will increase that gap which can make the sealer work harder. (?)
That case joint is a one shot job.

Who knows what shape the case is in at running temperature and cooling off.
Click to expand...
I ran a fine gunsmith stone lightly along the faces. Found them to be very "straight" with no high spots. I like the idea of light countersink.
It's all about doing it right the first time Warp
 
cliffa said:
I can understand why recess gives that impression if you've never stripped one of these engines, but I guess its only there to ensure that the holes in each case will not misalign due to manufacturing variance.
Click to expand...
It could have been machined there to locate the crankcase half on a fixture when it is flipped over to machine the other side
 
Mofosheee said:
It's all about doing it right the first time Warp
Click to expand...

I wish I had read that before trying to make a Jim Comstock spring under the engine device instead of a now paperweight. :)

The DR650 engine for one has a passage similar to that (one case to the other) and recessed for an O - Ring so not unusual.
Asking is better than not, then someone querying if you fit the case O-Ring (not that there is one) if the engine was back together.
 
This is sorta kinda relevant to my original post. Moving on, things weren't looking right at the oil pump.
The pump that came with my "73" is identical to the first attachment with numbers 16136 cast in it. Referencing Andover part; 06-3037 has the raised seal "retainer" or the dowel...................... like I was expecting to find at the case halves (post #1)

With zero confidence in and no intention of using this pump I will go with new. Who has seen this before?
I know someone has an answer. Thanks again!
 

Attachments

  • Case "O" ring required?
    oil pump My 73.jpg
    114.8 KB · Views: 164
  • Case "O" ring required?
    oil pump somebody elses.jpg
    231.2 KB · Views: 154
Mofosheee said:
This is sorta kinda relevant to my original post. Moving on, things weren't looking right at the oil pump.
The pump that came with my "73" is identical to the first attachment with numbers 16136 cast in it. Referencing Andover part; 06-3037 has the raised seal "retainer" or the dowel...................... like I was expecting to find at the case halves (post #1)

With zero confidence in and no intention of using this pump I will go with new. Who has seen this before?
I know someone has an answer. Thanks again!
Click to expand...
All pumps should have a spigot at the pump output, the MKIII is larger at the plate diameter to accommodate the larger MKIII seal that is used with the anti-wetsump :confused: valve...

However, new AN pumps only use a larger spigot, which works fine with both types of oil seal.

If in doubt use a new pump...according to AN they are about 5% more efficient than the older ones were....it's only money....

andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk
 
Last edited:
Pre-Mk3 spigot (feed bush)
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk
Mk3 (now on all new pumps as SteveA said)
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk
 
Status
Not open for further replies.
Back
Top