Jump to content

Oil Pressure Gauge


5thHorseman

Featured Posts

As a total noob to Gardner engines (2 weeks) I am the proud owner of a 1960's 2LW with a dicky oil pressure gauge. The Gauge reads 55psi (ie needle straight up) with the engine stopped and wiggles about a bit around the 55psi mark with the engine running (note my grasp of technical terms).

 

Is this a dustbin job or is there something simple that I can do to make it work properly.

 

Alister

Link to comment
Share on other sites

The fault is with the engine, so I suggest you donate it to a forum member who is looking for one, and seek a replacement for yourself!

Nice one. I did say noob not numpty.clapping.gif

 

After only two weeks I could not go back to the sound of a (dare I say it here) Isuzu

Link to comment
Share on other sites

Sorry, not much help but my 3LW has two oil pressure guages, one (4") mounted on the engine and the other via a small tube to a guage mounted on the pigeon box.

 

The previous owner's notes suggest that 35psi is normal. Apparently this is the pressure regulated by the bypass valve. On initial start the oil pressure goes to 40psi and immediately drops to 37psi. Worryingly, essential components are only lubricated by the bypass circuit so it is good to know that oil pressure is more than adequate.

 

If it were mine I would remove, clean and overhaul the guage or find a workshop that can do the same and calibrate it.

 

Alan

Link to comment
Share on other sites

I would look on ebay for a suitable replacement - search for:

 

  • vintage brass pressure gauge (the most hits)
  • or bourdon gauge (the type)
  • or Budenberg (the best make).

 

Look for one that goes from approx 0-60 psi. They polish up a treat if brass.

 

Gardners operate at either 45psi or IIRC some newer ones at 35 psi.

 

PS I presume you just bought your boat - it's a nice one I remember it being featured and seen it on the canal.

 

I put one for engine and one for gearbox in engine room. (6" size).

 

20140330_104841_zpsc9f5e99b.jpg

 

 

And 4" size on roof (you can add fittings to pipe to affix and bring away from Pigeon Box).

 

20140814_082743_zps79f94ea4.jpg

 

Oil pressure drops to zero obviously once engine is stopped, And takes about 15 seconds to rise when engine is on.

 

You can always slap on on the engine too.

 

IMAG2640_zps0d2b951a.jpg

 

Small point - the one on the roof will record less pressure (only about 1-2 psi) than the lowest one due to head of oil.

Edited by mark99
Link to comment
Share on other sites

The fault is with the engine, so I suggest you donate it to a forum member who is looking for one, and seek a replacement for yourself!

 

Alan,

 

Might do for 'Sickle' -- after seeing pics of you 'doing your bit for Global Warming' at Stoke B. recently..........

 

ATB

 

Mike.

Link to comment
Share on other sites

 

 

Gardners operate at either 45psi or IIRC some newer ones at 35 psi.

 

Mark,

 

Take care on this one - the manuals recommend the pressures you quote at fairly high engine revs and may not be attainable when the the engine is running at lower speeds - bear in mind Gardner's recommend a tickover speed of 320rpm.

 

It's best not to fiddle with the pressure relief screw without some advice, some have a number stamped on top - take care this cap may not come from the original engine.

 

Hope this helps, your engine room looks brill!.

 

Mike.

 

 

Link to comment
Share on other sites

 

 

I have a feeling that the only reason that it wiggles is because it is bolted to the engine

Alister

 

 

I've repaired/reset numerous bourdon gauges. Open the back and look at the linkage - its a bit fiddly (it may just be stuck) and to be honest you should calibrate it with a test gauge to get best results.

Edited by mark99
Link to comment
Share on other sites

I agree with mark99.

 

Bourdon gauges are fairly simplistic in their operation. Open the back up and gently see if the quadrant moves. They can stick on the spindle gear.

 

If there's anything come adrift inside it will be very obvious

 

http://www.marshallinstruments.com/faqs/detail.cfm?id=22

  • Greenie 1
Link to comment
Share on other sites

 

 

 

Gardners operate at either 45psi or IIRC some newer ones at 35 psi.

 

Mark,

 

Take care on this one - the manuals recommend the pressures you quote at fairly high engine revs and may not be attainable when the the engine is running at lower speeds - bear in mind Gardner's recommend a tickover speed of 320rpm.

 

It's best not to fiddle with the pressure relief screw without some advice, some have a number stamped on top - take care this cap may not come from the original engine.

 

Hope this helps, your engine room looks brill!.

 

Mike.

 

 

 

 

The older engines with white metal bearings were set to 45psi, later engines with thin wall shells to 35 psi. I'd be interested to know the reasoning behind this.

 

"Dear Marje

 

My Gardner engine has 'hybrid' bearings, with the original thick shells bored out to take thin wall shells.

What oil pressure should it run at?

 

Worried of Dutton."

 

Actually it's set to run at just over 40 psi, & I see no reason to change that (unless someone can offer a good reason for me to do so).

 

The standard tickover speed according to my book is 420 rpm, though I know they could be set significantly lower, especially with a heavy marine flywheel. My 4LW ticks over quite happily at about 380 rpm.

 

Tim

Link to comment
Share on other sites

 

The older engines with white metal bearings were set to 45psi, later engines with thin wall shells to 35 psi. I'd be interested to know the reasoning behind this.

 

"Dear Marje

 

My Gardner engine has 'hybrid' bearings, with the original thick shells bored out to take thin wall shells.

What oil pressure should it run at?

 

Worried of Dutton."

 

Actually it's set to run at just over 40 psi, & I see no reason to change that (unless someone can offer a good reason for me to do so).

 

The standard tickover speed according to my book is 420 rpm, though I know they could be set significantly lower, especially with a heavy marine flywheel. My 4LW ticks over quite happily at about 380 rpm.

 

Tim

The pressure differences is due to differing bearing clearances between the earlier white metal bearing types and the later pre finished bearings.

 

As for hybrid engines, the factory stated advice sheet states that oil pressure is to be set to the higher setting (45psi at 1000rpm) as the normal mod is white metal main bearings with modification for pre finished big ends. So you have a mix of both. Incidentally having a later engine set to the earlier higher pressure really doesnt make any difference.

 

As for Idle speeds, the standard is 420 rpm for most automotive applications but 330 rpm is a stated option for marine and rail traction (needs the heavier type flywheel for this lower speed) also incidentally states that the heavier type flywheels are only for engines upto a max speed of 1500rpm past that it should be the lightweight ones fitted.

Link to comment
Share on other sites

The pressure differences is due to differing bearing clearances between the earlier white metal bearing types and the later pre finished bearings.

 

As for hybrid engines, the factory stated advice sheet states that oil pressure is to be set to the higher setting (45psi at 1000rpm) as the normal mod is white metal main bearings with modification for pre finished big ends. So you have a mix of both. Incidentally having a later engine set to the earlier higher pressure really doesnt make any difference.

 

As for Idle speeds, the standard is 420 rpm for most automotive applications but 330 rpm is a stated option for marine and rail traction (needs the heavier type flywheel for this lower speed) also incidentally states that the heavier type flywheels are only for engines upto a max speed of 1500rpm past that it should be the lightweight ones fitted.

 

Mine has had the thick-walled mains line bored to take thin wall shells. It has the later type con rods.

 

I remember years ago, when converting a 4LW from open to enclosed flywheel arrangements for our Humber Keel I was in discussion with someone in Gardners technical department and they pointed out that I needed to know whether the (heavy) flywheel I was fitting was cast iron or steel, because of the speed limitation on a cast iron wheel. Luckily it was steel.

 

Tim

Link to comment
Share on other sites

Do you have a low pressure alarm/warning light and does it work as expected? The capillary may be blocked. Slacken the connection at the back of the gauge and check for oil flow. A new capillary can be obtained (e.g from ebay).

 

Edited to add:-

 

Also the gauge should have a 0.020" orifice in the pipe connection (Gardner part MA340) which could be blocked. I suggest you check this too.

Edited by jonesthenuke
Link to comment
Share on other sites

 

 

I have a feeling that the only reason that it wiggles is because it is bolted to the engine

Alister

 

 

I can't make out what the connection is on the bottom of the gauge. Does it have a shut off valve?

 

Richard

Link to comment
Share on other sites

 

Some hose linings are susceptible to the wrong fluid. One thing that can happen is that they swell up, blocking the bore of the hose

 

Richard

 

Or if the gauges connection flange connected directly to the engine head nut is not damped with rubber mountings (big rubber washers) the vibration of the engine could have caused the quadrant gear inside the gauge to jump and stick fast. Sounds more plausible as the needle is stuck at a high pressure?.

Edited by mark99
Link to comment
Share on other sites

Yes, it could be a lot of things. And one of the things to consider is does oil get to the gauge - why? - because there are a variety of mechanisms that could cause the gauge not to work, and even stick at a high pressure

 

And it could be the needle is stuck on the backplate too

 

or there's a bit of grit in the quadrant gear

 

or, oh loads of things

 

so... Best thing is to turn up with an open mind about what is wrong, carrying with you some knowledge of possible failure mechanisms including highly improbable ones that do actually occur, and find out by doing some simple tests

 

Richard

 

As an apprentice I once shoved around six thousand psi through a 200 psi gauge by accident. It didn't work after that as the needle was bent and had gone all limp

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.