Oil Pressure For BMC 1800

[alan_fincher]

As part of further trying to sort out Chalice's engine, and to establish current health, I plan to put an oil pressure gauge on our BMC 1800.

 

I'm not sure yet if this will become a permanent feature, (relatively hard), or just temporary (quite a lot easier).

 

I'm sure I've seen the experts post their views on what the oil pressures should be, (idle/fast, cold/hot, etc), but the search facilities have let me down on this one.

 

Also, I don't think the BMC operation manual for the engine actually gives any numbers.

 

So what might I hope to be seeing ? And how much worse than that can it be before panic should set in ?

 

(I can't say I'm not nervous, because at the moment I have genuinely no idea what this might reveal).

 

Alan

[denboy]

Pure guestimate would think around 30psi normally?

[Mick_B]

Hi Alan

 

Starting from cold pressure fro 60 to 70 psi is not uncommon. this will fall to 40 to 45 at tickover and 25 to 30 is fine at tickover with the engine hot. This should give about 40ish at cruising revs. Tickover pressure falling below 20 psi is when I would begin to plan ahead for some remedial work to restore pressure. A heavier oil will suffice as a stopgap but not long term.

 

I shall however await contradiction but this is my experience with bmc 1.5 and various Perkins also.

[RobinJ]

As part of further trying to sort out Chalice's engine, and to establish current health, I plan to put an oil pressure gauge on our BMC 1800.

 

I'm not sure yet if this will become a permanent feature, (relatively hard), or just temporary (quite a lot easier).

 

I'm sure I've seen the experts post their views on what the oil pressures should be, (idle/fast, cold/hot, etc), but the search facilities have let me down on this one.

 

Also, I don't think the BMC operation manual for the engine actually gives any numbers.

 

So what might I hope to be seeing ? And how much worse than that can it be before panic should set in ?

It will depend where it is measured!

On mine the gauge is connected to the high pressure side before the oil cooler and reads 80 at start up, the pressure relief valve kicks in at about 50 and after its been running for a while you can see the gauge bouncing as it opens and closes, when hot it settles down to between 40 and 60.

The pressure on the 1.5's seems to vary too and I think this is becuase some are measured after the pressure relief valve. My old one also read around 40 to 60 at normal running, but some sit on 25 and stay there.

[alan_fincher]

Thanks for the replies so far.

 

I hadn't really expected that different examples of the same engine spec might measure the oil pressure at different places.

 

I don't actually have an engine oil cooler on my 1800. I've been told that's not terribly clever, but must have been Calcutt's practice at the time they marinised this one. I don't really fancy the prospect of trying to retro-fit an engine oil cooler, to be honest.

 

I think it will be some days before I know the answer wrt my actual pressures. The oil pressure sensor that's arrived, (Faria from ASAP Supplies), plus a T piece adaptor, (separate e-Bay purchase), both seem to have a very much smaller thread on them that I remember as being on the engine itself, and hence on the existing oil pressure warning lamp sensor.

 

I think I'm about to get into a "what thread is that" and a "how do I adapt this to this" type debate.

[RobinJ]

I hadn't really expected that different examples of the same engine spec might measure the oil pressure at different places.

 

I don't actually have an engine oil cooler on my 1800. I've been told that's not terribly clever, but must have been Calcutt's practice at the time they marinised this one. I don't really fancy the prospect of trying to retro-fit an engine oil cooler, to be honest.

 

I think it will be some days before I know the answer wrt my actual pressures. The oil pressure sensor that's arrived, (Faria from ASAP Supplies), plus a T piece adaptor, (separate e-Bay purchase), both seem to have a very much smaller thread on them that I remember as being on the engine itself, and hence on the existing oil pressure warning lamp sensor.

 

I think I'm about to get into a "what thread is that" and a "how do I adapt this to this" type debate.

If it is the one just above the starter motor next to the oil filter, its quite large, I belive it could be a pipe/hydralic thread.

I had a long adapter made to get both the oil pressure switch and pressure sensor above the oil filter in order to screw them in and with a tee piece this is far easier to get at!

[RLWP]

I don't actually have an engine oil cooler on my 1800. I've been told that's not terribly clever, but must have been Calcutt's practice at the time they marinised this one. I don't really fancy the prospect of trying to retro-fit an engine oil cooler, to be honest.

 

I'm pretty sure we haven't got one either. The oil cooler that is fitted is for the gearbox.

 

Richard

[alan_fincher]

If it is the one just above the starter motor next to the oil filter, its quite large, I belive it could be a pipe/hydralic thread.

I had a long adapter made to get both the oil pressure switch and pressure sensor above the oil filter in order to screw them in and with a tee piece this is far easier to get at!

Sounds about right.

 

I'm just about to head to the boat to work out the shortfall between "bits I have" and "bits I actually need".

 

If I can screw the T-piece I have into the end of an existing extension, I might get away with it, but it's going to look awfully Heath Robinson.

 

I can't quite believe the size of the oil pressure sensor just received. Not quite bake bean tin sized, but getting there. (OK, I'm exaggerating a bit, but not what I was expecting....)

[Yoda]

I seem to remember that it has a tapered thread. Could be wrong.

 

As for oil pressure, it should be measured after the pressure relief valve. This ensures that the valve is working correctly. It is also useful to measure the oil temperature because of the type of installation. You do not want to get the oil too hot.

 

If you have low oil pressure, there are several causes. Wrong oil, oil too hot, main bearings worn out, oil pressure relief valve not working properly, blocked oil filter, low oil level, big ends worn out.

 

Hope this helps!

[David Schweizer]

Alan,

 

The workshop manual I have for the BMC 1.5 states that oil pressure (hot) should be 15lb per sq in at idle speed, and 50lb per sq in at normal running speed. I dont know whether that helps.

 

I got the manual as a free download from alink given on this site, but cannot find it yet, They also had a link for the BMC 1.8.

 

Edited to add :- From the Calcutt web site, workshop manual for BMC 1.8 :- http://www.calcuttboats.com/pdfs/Workshop%20Manual%201.8.pdf

 

Oil pressure, (They call it System Pressure) - Running - 50lb sq in, Idle - 15lb sq in. so the same as the 1.5

Edited June 11, 2009 by David Schweizer

[alan_fincher]

Thanks David,

 

I failed to find it in the on-line copy of the workshop manual, and my printed one was on the boat.

 

Whilst on the boat I finally managed to find the reference, and the numbers you have quoted.

 

Presumably the running pressure is not supposed to be higher than 50 psi, because that's what the relief valve is also quoted as running at.

 

I'm kind of surprised by only 15 psi at idle, but at least I now know I don't need to panic if I record a figure close to that.

 

Fitting a gauge is going to be a challenge, largely because the sensor that ASAP supplies have sent is huge. It's going to be very hard to get the relevant hole on a T piece pointed in a way that it will not be colliding with something.

 

It's certainly going to make changing the spin-on oil filters even harder than it already is.

 

Finding somewhere to mount the gauge is the next challenge.....

[Richard T]

I agree with the figures quoted above. The sensor is difficult to fit - on our boat it stopped working so got a replacement which was slightly bigger than the original - it wouldn't fit because the remote oil filter plate and pipes got in the way. So could have saved you a few quid Alan by letting you have our spare. The original worked when cleaned so presumably some crud had got into it.

[alan_fincher]

I'm pretty sure we haven't got one either. The oil cooler that is fitted is for the gearbox.

 

Richard

Sorry, missed this post, Richard.

 

I don't know if your's is a Calcutt, but they don't seem to think you need to cool the engine oil. Even the new Turkish versions I have seen have only a gearbox oil cooler.

 

The expert on BMCs that Baldock referred me to took a quick look at our engine as we were passing. He reckons engine oil coolers do much to preserve the life of the engine.

 

I've no idea how complicated it is to add one, nor what the cost might be - I have not investigated that. I'm guessing it's not trivial, knowing the pipe into which it would need to be introduced, and some of the clearances involved.

 

So could have saved you a few quid Alan by letting you have our spare.

Hi Richard,

 

The only complication I could see there might be that sensor and gauge were not matched.

 

I gather there is more than one standard.

 

I've deliberately sourced both together to try and avoid that pitfall.

[RLWP]

Sorry, missed this post, Richard.

 

I don't know if your's is a Calcutt, but they don't seem to think you need to cool the engine oil. Even the new Turkish versions I have seen have only a gearbox oil cooler.

 

The expert on BMCs that Baldock referred me to took a quick look at our engine as we were passing. He reckons engine oil coolers do much to preserve the life of the engine.

 

I've no idea how complicated it is to add one, nor what the cost might be - I have not investigated that. I'm guessing it's not trivial, knowing the pipe into which it would need to be introduced, and some of the clearances involved.

 

Calcutt were the last people to work on our BMC. They were happy with the engine - apart from the hole ripped in the sump - but suggested we should have the gearbox cooler.

 

I can't see why an oil cooler should prolong the life of an engine. Are you really working the oil that hard?

 

My A-series Midget could do with an oil cooler but only because if I thrash it mercilessly the oil gets very hot and the pressure gets very low at idle. If I ever get around to it I'll fit an oil cooler with a thermostatic valve so that the oil gets a chance to get hot under normal conditions.

 

Richard

[alan_fincher]

I can't see why an oil cooler should prolong the life of an engine.

Dunno, I'm afraid.

 

Baldock reckons this is the man for BMCs down our way, and that's what he said.

 

I can't see it happening on ours - on the "too difficult" list, I'm thinking.

[churchward]

Dunno, I'm afraid.

 

Baldock reckons this is the man for BMCs down our way, and that's what he said.

 

I can't see it happening on ours - on the "too difficult" list, I'm thinking.

I would say fitting an oil cooler on the engine is completely unnecessary. You only really need one if you are pushing the temperature limits and running the engine hard for long periods. Which is why folk track racing their cars use them because there is a danger of the high rpms used over cooking the oil making it too thin and loosing its lubrication properties. This is hardly the case in a narrowboat, the engines are so little taxed. If we were thrashing the engines hard enough to need one you would be better off using a higher spec oil. After all one of the reasons many folk use low spec oils in these kind of engines is that they are only lightly loaded.

 

Save you pennies for more worthwhile things. An oil cooler on a PRM hydraulic box is a different matter of course.

[David Schweizer]

I am intrigued by all this talk about Engine oil coolers. As far as I am aware we do not have one on our BMC 1.5, what would it look like? Assuming that we do not have one, the engine has survived 28 years and over 20,000 hours without one.

 

The engineer who re-built our engine a few years ago also feels that unless you are going to bat up and down the Thames at breakneck speeds, the PRM 260 gearbox does not really need an oil cooler either. This view was born out last year, when one of the pipes failed and started to leak. Acting on the telephone advice of our engineer, we merely used the other one to by pass the cooler and ran the boat for several weeks without any problems, before a replacement could be obtained and fitted.

[RobinJ]

I would say fitting an oil cooler on the engine is completely unnecessary. You only really need one if you are pushing the temperature limits and running the engine hard for long periods. Which is why folk track racing their cars use them because there is a danger of the high rpms used over cooking the oil making it too thin and loosing its lubrication properties. This is hardly the case in a narrowboat, the engines are so little taxed. If we were thrashing the engines hard enough to need one you would be better off using a higher spec oil. After all one of the reasons many folk use low spec oils in these kind of engines is that they are only lightly loaded.

I don't think the 1.5 was ever fitted with one.

Most of the 1.8's seem to have one fitted?

Interestingly, using monograde oil the engines do get quite warm on long runs and I have noticed that the 1.8 does not overheat like the 1.5 did although it runs better on multigrade (possibly because the oil is cooler)?

I think most of the problems associated with oil coolers is connected to them being cooled from skin tanks, I know when my PRM was overheating the engine oil was getting heated by the gearbox!

If you are trolling about on canals, you probably won't notice any difference, but regular running on rivers etc., I feel maybe they do help?

[alan_fincher]

Thanks for everybody who has given advice.

 

After a bit of a struggle we got the whole set-up of oil pressure sensor and oil pressure gauge installed today.

 

It was too late to run the engine long on it's mooring, and certainly too late to go boating, but inital results look promising.

 

Despite it's age, the engine looks like it will record pressure values within the manufacturer's quoted range.

 

We will only know for certain when we take it out for a bit of a thrash, and see what the pressure looks like once the oil is fully hot.

 

So far, so good, though!

[alan_fincher]

We will only know for certain when we take it out for a bit of a thrash, and see what the pressure looks like once the oil is fully hot.

 

Update:

 

We took the boat out for a bit of a thrash to see what the new oil pressure gauge records once the oil is hot.

 

We added the Wendover arm, as it's quite shallow in places, making the engine work harder.

 

Broadly with the engine hot:

 

Idle (700 RPM): Just under 20 psi.

"Slow" (about 1100 RPM): Around 40 psi.

"Fast" (about 1800 RPM): Around 55 psi.

 

Unless someone says otherwise, these seem in line with numbers from the BMC manual, and suggestions by other posters.

 

This is an engine that has not been opened up in 14 years, (paint seals not broken), so I don't think these numbers are too bad at all, really.

 

I'll find something else to worry about.

 

(Oh, and it's using Lister Petter Oil, which at 10W/40 is perhaps thinner than some would recommend - obviously oil pressures could be higher with a 20W/50).

[NB Alnwick]

Broadly with the engine hot:

 

Idle (700 RPM): Just under 20 psi.

"Slow" (about 1100 RPM): Around 40 psi.

"Fast" (about 1800 RPM): Around 55 psi.

 

Nothing to worry about there!

[churchward]

Update:

 

We took the boat out for a bit of a thrash to see what the new oil pressure gauge records once the oil is hot.

 

We added the Wendover arm, as it's quite shallow in places, making the engine work harder.

 

Broadly with the engine hot:

 

Idle (700 RPM): Just under 20 psi.

"Slow" (about 1100 RPM): Around 40 psi.

"Fast" (about 1800 RPM): Around 55 psi.

 

Unless someone says otherwise, these seem in line with numbers from the BMC manual, and suggestions by other posters.

 

This is an engine that has not been opened up in 14 years, (paint seals not broken), so I don't think these numbers are too bad at all, really.

 

I'll find something else to worry about.

 

(Oh, and it's using Lister Petter Oil, which at 10W/40 is perhaps thinner than some would recommend - obviously oil pressures could be higher with a 20W/50).

Nothing wrong with those numbers I'd say you have a happy engine there. Despite what some people may think and tell you there is no reason why such engines can't have a very long life in a narrowboat context if properly looked after although a great deal depends on how well it was treated when new and the first few services.

 

At cold 20W/50 might get you some higher numbers (which can be counter productive as it is more difficult to get the oil into the bearings quickly enough)but it won't make much difference at operating temp. 10W/40 in terms if viscosity is not a bad spec for narrowboat installations particularly in the winter months for cold starting and getting some of the good stuff around the bearings quickly as the engines fires up. I am trying some of the Morris 10w/40 Golden film a the moment.

Edited June 14, 2009 by churchward

[David Schweizer]

Nothing wrong with those numbers I'd say you have a happy engine there. Despite what some people may think and tell you there is no reason why such engines can't have a very long life in a narrowboat context if properly looked after although a great deal depends on how well it was treated when new and the first few services.

 

At cold 20W/50 might get you some higher numbers (which can be counter productive as it is more difficult to get the oil into the bearings quickly enough)but it won't make much difference at operating temp. 10W/40 in terms if viscosity is not a bad spec for narrowboat installations particularly in the winter months for cold starting and getting some of the good stuff around the bearings quickly as the engines fires up. I am trying some of the Morris 10w/40 Golden film a the moment.

You can buy it on line from Morris Lubricants here :- http://www.morrislubricantsonline.co.uk/Sc...iew.asp?sku=CCO

 

I buy my oil direct from them in 25 litre drums.

Edited June 14, 2009 by David Schweizer

[churchward]

You can buy it on line from Morris Lubricants here :- http://www.morrislubricantsonline.co.uk/Sc...iew.asp?sku=CCO

 

I buy my oil direct from them in 25 litre drums.

Indeed that is where I got mine from. I think it works out between £17-£18 per 5 litres if you buy the 25ltr drum.

[alan_fincher]

I am trying some of the Morris 10w/40 Golden film a the moment.

I'm currently using the Lister Petter 10W/40 oil, (API-CC).

 

I'm led to believe, (but have not had confirmed), that Morris blend it, so it may be a very similar oil to the one you are listing.

 

Price has gone bloody stupid at our marina though - a shame I forgot to but any when passing Uxbridge Boat Centre, as they were very significantly cheaper the last time I looked.

 

Not quite sure I want to store 25 litres, though....