Bmc 1.8

[Paul Corbett]

I have a bmc 1.8, and this is my oil pressure, but when I start the engine, the gauge goes all the way, so it can't go no more, does anyone know if this is the wrong gauge, 

[MtB]

I'm no expert but I'd say wrong gauge, as a BMC 1.8 will probably produce 30 or 40PSI oil pressure when running.

 

Others will confirm this I suspect.

 

 

I'd suggest a gauge that goes up to 60PSI at least. 

 

 

[alan_fincher]

l normal running I would expect the pressure on a BMC 1.8 in good order to be a fair bit higher than 20 psi - it could easily be twice that.

 

So I can't see how that gauge can be right for this engine, if it only has indicated pressure up to 20 psi.

[beerbeerbeerbeerbeer]

I think mine runs at 50-55,

Id have to check mind 

[MtB]

3 hours ago, alan_fincher said:

l normal running I would expect the pressure on a BMC 1.8 in good order to be a fair bit higher than 20 psi - it could easily be twice that.

 

So I can't see how that gauge can be right for this engine, if it only has indicated pressure up to 20 psi.

 

 

Hey I just said that, one post before yours!

 

 

[Quattrodave]

IIRC my 2.2 bmc runs around 40 psi but when cold up around the 60psi mark...

[David Mack]

On 09/06/2024 at 17:08, MtB said:

I'm no expert but I'd say wrong gauge, as a BMC 1.8 will probably produce 30 or 40PSI oil pressure when running.

I agree.

But I'm curious what engine Lancing Marine would have supplied with a maximum oil pressure of 20psi which this gauge was intended for.

[Paul Corbett]

I also have this gauge what goes to my gearbox, 

[agg221]

What pressure does your gearbox reach?

 

I am wondering whether they have simply been swapped around at some point?

 

Alec

[Tony Brooks]

9 minutes ago, agg221 said:

What pressure does your gearbox reach?

 

I am wondering whether they have simply been swapped around at some point?

 

Alec

 

Before we can look up data to check that, we need to know the gearbox make and possibly model. If it has a pressure gauge, it will be hydraulic, so probably PRM or Velvetdrive. If it was a 1.5 I would add TMP, but that is an older box design.

[agg221]

2 minutes ago, Tony Brooks said:

 

Before we can look up data to check that, we need to know the gearbox make and possibly model. If it has a pressure gauge, it will be hydraulic, so probably PRM or Velvetdrive. If it was a 1.5 I would add TMP, but that is an older box design.

I was thinking of a more basic approach. There appears to be a 0 to 100psi gauge attached to the gearbox. If the pressure readout on it never exceeds 20psi then simply swapping the two gauges might solve it?

 

Alec

[Tony Brooks]

5 minutes ago, agg221 said:

I was thinking of a more basic approach. There appears to be a 0 to 100psi gauge attached to the gearbox. If the pressure readout on it never exceeds 20psi then simply swapping the two gauges might solve it?

 

Alec

 

I have just done a quick Google and all three boxed I mentioned seem to require a far higher pressure than 20 psi. well over 100 for PRM and Velvetdrive

 

I think the practical answer is either put up with it and rely upon the warning lamp or buy another gauge. I think the PRM page I looked at gave a pressure of 300 psi and I would not like to stick that into a 20 psi gauge. I can see the bourdon tube bursting.

Edited June 10, 2024 by Tony Brooks

[Paul Corbett]

This is my gearbox

[Tony Brooks]

44 minutes ago, Paul Corbett said:

This is my gearbox

 

A blast from the past, it looks like a TMP (Tideways Marine) gearbox. The operating pressure (Google) is 95 to 100 PSI), so I would not put the 20PSI gauge on it.

[Paul Corbett]

Thank you all for your help

[Paul Corbett]

Anyone got a link for the correct oil pressure gauge for my 1.8 please

[Tony Brooks]

5 minutes ago, Paul Corbett said:

Anyone got a link for the correct oil pressure gauge for my 1.8 please

 

Just Google "mechanical oil pressure gauge". 0 to 100PSI will be fine, 0 to 80 psi better.

 

The problem you have is to ensure the thread and fitting on the back of the gauge matches those on your tube.

[beerbeerbeerbeerbeer]

How would the OP know if the sender is correct too?

The senders vary too don’t they?

 

my gauge reads to 80,

and the oil sits at a steady 50 when under way. 
 

 

[Tony Brooks]

46 minutes ago, beerbeerbeerbeerbeer said:

How would the OP know if the sender is correct too?

The senders vary too don’t they?

 

my gauge reads to 80,

and the oil sits at a steady 50 when under way. 
 

 

Look at the photo he posted, since when did gauges connected by pipes use senders.

[beerbeerbeerbeerbeer]

35 minutes ago, Tony Brooks said:

 

Look at the photo he posted, since when did gauges connected by pipes use senders.

I have no experience of dealing with gauges. Hence the error of not seeing/understanding the pipe.

Is there an advantage of pipe over sender?

 

[Tony Brooks]

5 minutes ago, beerbeerbeerbeerbeer said:

I have no experience of dealing with gauges. Hence the error of not seeing/understanding the pipe.

Is there an advantage of pipe over sender?

 

 

Ah, that depends upon who you ask. Electrical gauges are not the most reliable, it is usually the sender that plays up. Mechanical gauges are very reliable, but the pipe connecting them to the engine is vulnerable to damage and if it fails can empty the engine oil into the bilge or worse. On balance i would go for an electric gauge, but the pipe on the OP's looks sturdy so no reason he can't carry on with it.

 

You are correct that there are two standards for electric gauges and senders, so they must be matched.

 

If I was in the OP's shoes, I would blank the gearbox oil pressure outlet and fit the gearbox gauge to the engine.

[Paul Corbett]

I've ordered this one of ebay, thank you everyone who's helped me