TR4 Oil Pressure

[geofjag3A]

The newly rebuilt engine of my  TR4 reaches 70psi at 2000rpm but is slow to rise. Is this a known issue and what is the cause It has not yet been run up to temperature so the results are 

at cold start. I can see no obvious fault but I am sure all is not well. Any thoughts?

[RogerH]

Hi Geoff

the fact that it gets 70psi suggests that the machinery can hold the oil.

Could it be the gauge/pipe work.  Have you tried another gauge or attached to a different position?

Whilst it is slowly climbing are there any expensive noises !!

The oil pipe from the gallery to the gauge may not be full of oil  (which would give a rapid reaction.)

If it is full of air then that air needs to get compressed to make the gauge read. This is much slower than the oil which is effectively a solid.

Keep listening to what is going on in the engine.

Roger

 

[Lebro]

How slow is slow ?  2 to 3 seconds would be quite normal.

Bob

[Ralph Whitaker]

Where the banjo for the oil pressure pipe fits on to the filter head there should be two different sizes copper washers, the one with the larger hole goes against the filter head so as not to obstruct the small passageway that allows the oil through to the gauge pipe. If two of the smaller hole washers have been used, or fibre washers, this would obstruct the flow of oil into the pipe and would cause your symptoms.

Ralph

 

[geofjag3A]

56 minutes ago, Ralph Whitaker said:

Where the banjo for the oil pressure pipe fits on to the filter head there should be two different sizes copper washers, the one with the larger hole goes against the filter head so as not to obstruct the small passageway that allows the oil through to the gauge pipe. If two of the smaller hole washers have been used, or fibre washers, this would obstruct the flow of oil into the pipe and would cause your symptoms.

Ralph

 

Thanks for your ideas. Seems likely. the gauge is a Snap On test gauge with a banjo fitting But I left the washers as before, so Hopefully.........

Sorry to see your opinion of BSA bikes. I love 'em. Down to my last two  350 Gold Star with 650 A10 engine and 1929 Sloper.

[geofjag3A]

2 hours ago, RogerH said:

Hi Geoff

the fact that it gets 70psi suggests that the machinery can hold the oil.

Could it be the gauge/pipe work.  Have you tried another gauge or attached to a different position?

Whilst it is slowly climbing are there any expensive noises !!

The oil pipe from the gallery to the gauge may not be full of oil  (which would give a rapid reaction.)

If it is full of air then that air needs to get compressed to make the gauge read. This is much slower than the oil which is effectively a solid.

Keep listening to what is going on in the engine.

Roger

 

Thanks for your thoughts. I changed to my Snap On test gauge but left the washers as I had them with the dash gauge. These are just 5/16"copper washers out of a selection box so could well be be the cause. I will report after the weekend.

[Ralph Whitaker]

5 hours ago, geofjag3A said:

Sorry to see your opinion of BSA bikes. I love 'em. Down to my last two  350 Gold Star with 650 A10 engine and 1929 Sloper.

Ah, different kettle of fish, mine are mainly Bantams and a C11G 250.

Ralph

[geofjag3A]

On 11/11/2023 at 10:47 AM, geofjag3A said:

Thanks for your ideas. Seems likely. the gauge is a Snap On test gauge with a banjo fitting But I left the washers as before, so Hopefully.........

Sorry to see your opinion of BSA bikes. I love 'em. Down to my last two  350 Gold Star with 650 A10 engine and 1929 Sloper.

You were spot on, thanks. So obvious I feel a bit sheepish. A shame the manual is not clearer.

[Ralph Whitaker]

13 hours ago, geofjag3A said:

You were spot on, thanks. So obvious I feel a bit sheepish. A shame the manual is not clearer.

Glad it was a simple fix for you,

Ralph