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BMC 1500 diesel


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I don't think a reverse rotation BMC 1.5 was ever made, unlike some marine engines & Listers, but the gearbox may reverse the prop rotation. Being hydraulic, I don't think you can check the shaft rotation until you get oil pressure in the box so before too long I suggest you get the engine  running on the floor to see which way the coupling turns in ahead.

 

Also check with Borg Warner because I think they use epicyclic gears (like automotive auto boxes) so may very well run perfectly happily for long periods in nominal reverse, unlike many other boxes - especially those using sun and planet gears.

 

Once again Mr Morris (as you all Austin and then BMC) did not fit six mounts, the mariniser or Borg Warner did. It is true that when mated to the BMC B type gearbox with reduction box, a huge cast iron thing, an extra set of mounts was fitted. Before you can make an informed decision, you need to find out why and who fitted the extra mounts. The image I found made them look more like thrust mounts than weight supporting mounts, but that is only from a photo that only showed the top of the mounts.

 

If I were not to instal an instrument panel myself I would not be looking for an engineer, I would be looking for a small craft electrician. Not sure how a degree level  engineer used to massive engines  would take to working on a 1.5. I know they call themselves marine engineers, but they are really boatyard or small craft engineers.

 

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1 hour ago, Tony Brooks said:

I don't think a reverse rotation BMC 1.5 was ever made, unlike some marine engines & Listers, but the gearbox may reverse the prop rotation. Being hydraulic, I don't think you can check the shaft rotation until you get oil pressure in the box so before too long I suggest you get the engine  running on the floor to see which way the coupling turns in ahead.

 

Also check with Borg Warner because I think they use epicyclic gears (like automotive auto boxes) so may very well run perfectly happily for long periods in nominal reverse, unlike many other boxes - especially those using sun and planet gears.

 

Once again Mr Morris (as you all Austin and then BMC) did not fit six mounts, the mariniser or Borg Warner did. It is true that when mated to the BMC B type gearbox with reduction box, a huge cast iron thing, an extra set of mounts was fitted. Before you can make an informed decision, you need to find out why and who fitted the extra mounts. The image I found made them look more like thrust mounts than weight supporting mounts, but that is only from a photo that only showed the top of the mounts.

 

If I were not to instal an instrument panel myself I would not be looking for an engineer, I would be looking for a small craft electrician. Not sure how a degree level  engineer used to massive engines  would take to working on a 1.5. I know they call themselves marine engineers, but they are really boatyard or small craft engineers.

 

Thanks, no real chance of finding out who fitted the mounts as there is no nameplate and all the previous owner said is that it is a BW box. Can I presume that it is a 2:1 ratio as that seems to be the norm, although I read that the Velvet drive was available in other ratios. 

Not concerned about the panel as I can make one, although it might need new sensors. I need to sort out the paint and the rest of the installation parts like new mounts first.

 

Link to vid clip: 

(1) Facebook

 

As you can see, I could not see the mounts from that clip. At present I think it's a keeper and will only sell it if I'm offered silly money. Present plan is to replace the rocker cover and air filter units with Chrome jobs, then paint it Ferrari Red, as I don't think it's easy to see oil leaks on a black block.

Edited by TNLI
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6 minutes ago, TNLI said:

Thanks, no real chance of finding out who fitted the mounts as there is no nameplate and all the previous owner said is that it is a BW box. Can I presume that it is a 2:1 ratio as that seems to be the norm, although I read that the Velvet drive was available in other ratios. 

Not concerned about the panel as I can make one, although it might need new sensors. I need to sort out the paint and the rest of the installation parts like new mounts first.

 

Link to vid clip: 

(1) Facebook

 

And I can't see enough of the box to identify it. It looks like no BW box that is normally fitted to 1.5s - a 71 to 72.

 

If I had to guess, I would say that at present it looks more like a TMP hydraulic box. If it is then TMP is still in existence as far as I know (Tideway Marine Products) Kingston on Thames area. In their day they seemed to have a tendency to sheer pop rivets in the clutch assemblies.

 

I think some photos of the box would help identify it

 

Dredging my memory I think the control lever has some similarities to old PRM boxes but the rectangular section above the coupling goes against that.

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The control quadrant being placed on top of an up-stand seems similar to a PRM 100 (stopped production in 1973) but the bit above the coupling does not. It also seems that the box is mounted at an angle that is typical of PRM.

Edited by Tony Brooks
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11 hours ago, Alan de Enfield said:

 

It really doesn't matter which way it turns as long as the prop, the gearbox and the engine are all matched for rotation.

 

I have one engine / gearbox / prop that spins 'left handed' and one engine / gearbox / prop that spins right handed (both in the same boat)

 

 

21-10-19e.jpg

You have to have a contra pair or you end up going sideways!

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13 minutes ago, Tracy D'arth said:

You have to have a contra pair or you end up going sideways!

 

Not necessarily you can adjust the trim-tab on the rudder,

Increase the revs slightly on the engine that is on the side that the boat is turning into, or

You can even have contra-rotating props on the same shaft, (which is the normal way of ovecoming prop-walk on a single engine with an outdrive).

 

Counter-rotating propeller sterndrive - Bravo Three® - Mercury

 

 

 

Some years ago I had a fishing boat with twin 50hp outboards, they were both the same rotation but underneath the cavitation plate on all OBs there is a rudder trim tab, simply turn/adjust to offset the prop-walk.

 

Adjusting the trim tab fin on a 50 horse Mercury Tiller Drive - YouTube

 

 

Sea Bird 6001.jpg

 

Edited by Alan de Enfield
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2 hours ago, Tony Brooks said:

The control quadrant being placed on top of an up-stand seems similar to a PRM 100 (stopped production in 1973) but the bit above the coupling does not. It also seems that the box is mounted at an angle that is typical of PRM.

Thanks fot that and I will take some better pics of the box this afternoon. Hope it is a BW Velvet drive!

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14 minutes ago, TNLI said:

Thanks fot that and I will take some better pics of the box this afternoon. Hope it is a BW Velvet drive!

 

I am sure it is not but over the years BW have made other marine boxes but none I could find images of looked like this one. It is definitely not a 71C or 72C as far as I can see.

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21 minutes ago, Tony Brooks said:

 

I am sure it is not but over the years BW have made other marine boxes but none I could find images of looked like this one. It is definitely not a 71C or 72C as far as I can see.

I think you are correct, as this link shows a clear picture of the PRM selector that is identical to mine:

The step by step guide to dismantling a PRM 100 marine gearbox - Practical Boat Owner (pbo.co.uk)

 

There seems to be an emergency gear selector of some type, but that article does not mention it.

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If you look at the first image where the cover has been taken off the box, you will see a fork hanging down from the cover. This locates and secures a sliding dog clutch on the shaft below.  In an emergency you take the cover off, side the dog clutch into the centre of the clutch, and replace the cover. The box is then locked in gear, but which gear depends upon how the box was assembled. I am all but sure it will operate for very long periods in either direction, so basically that dog clutch determine which rotation is ahead and which is astern. If it is wrong you go home in moving backwards!

 

They are/were very good and reliable gearboxes, not least because they use engine oil, but if it is a 100 it is at least 49 years old. It may well be a more modern model but it could still be over 30 years old.

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52 minutes ago, Tony Brooks said:

If you look at the first image where the cover has been taken off the box, you will see a fork hanging down from the cover. This locates and secures a sliding dog clutch on the shaft below.  In an emergency you take the cover off, side the dog clutch into the centre of the clutch, and replace the cover. The box is then locked in gear, but which gear depends upon how the box was assembled. I am all but sure it will operate for very long periods in either direction, so basically that dog clutch determine which rotation is ahead and which is astern. If it is wrong you go home in moving backwards!

 

They are/were very good and reliable gearboxes, not least because they use engine oil, but if it is a 100 it is at least 49 years old. It may well be a more modern model but it could still be over 30 years old.

Thanks just found that part about the gear lock in this guide:

100 & 175 & 250 man.pdf (prm-newage.com)

 

Always good news if a box uses engine oil.

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7 hours ago, Alan de Enfield said:

 

Not necessarily you can adjust the trim-tab on the rudder,

Increase the revs slightly on the engine that is on the side that the boat is turning into, or

You can even have contra-rotating props on the same shaft, (which is the normal way of ovecoming prop-walk on a single engine with an outdrive).

 

Counter-rotating propeller sterndrive - Bravo Three® - Mercury

 

 

 

 

 

It's not just boats that have contra-rotating blades:

 

2F2BB456-BFAE-48A0-A68C-8E4AF436F6B8_1_105_c.jpeg.9a47aebd59a383d1042712725265b58c.jpeg

 

2F2BB456-BFAE-48A0-A68C-8E4AF436F6B8_1_105_c.jpeg.9a47aebd59a383d1042712725265b58c.jpeg

 

 

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VW CHROME ROUND PANCAKE AIR FILTER T1 BEETLE T2 TRANSPORTER CAMPER A451 5710412051310 | eBay

 

I know one of the chrome filter units fits a BMC 1500, but as the manual does not list the housing dimensions in intake hole size terms, I've no idea which one. Anyone fitted a reuseable foam and chrome unit ??

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I would be worrying more about getting new rear engine mounts than changing a serviceable air cleaner that, using your words, was fitted by Mr Morris (Except it was not, it was fitted by Newage/Tempest)

 

The video clearly shows the front mounts and they are the standard Newage/Tempest system that employs the standard vehicle  rubber mounts and those rarely fail.

 

The rear mounts are obscured but from the part of the flywheel housing that I can see it looks as if the flywheel housing, of which the engine feet are a part, is also the original Newage/Tempest one. Now the mounts used in these, that look like a tall top hats passing up through a large hole in the foot with the securing screw/bolt down the centre, were made by Metalastic Ltd and I believe they have been unobtainable for a fair number of years.

 

That type of mount are secured into the foot by three small set screws, screwed up from underneath, and when the mount rubber sags they hit the bed and produce vibrations and so on. The screws are not under any significant load, so sometimes it is possible to file the heads of the screws to about half thickness or turn up a thick washer that is the same size as the flange on the bottom of the metal centre to the mount and use that to make up for the sag in the mount, but it is all too easy to mess up the shaft alignment if you make it too thick. Both "solutions" should only be considered as temporary.

Edited by Tony Brooks
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14 minutes ago, Tony Brooks said:

I would be worrying more about getting new rear engine mounts than changing a serviceable air cleaner that, using your words, was fitted by Mr Morris (Except it was not, it was fitted by Newage/Tempest)

 

The video clearly shows the front mounts and they are the standard Newage/Tempest system that employs the standard vehicle  rubber mounts and those rarely fail.

 

The rear mounts are obscured but from the part of the flywheel housing that I can see it looks as if the flywheel housing, of which the engine feet are a part, is also the original Newage/Tempest one. Now the mounts used in these, that look like a tall top hats passing up through a large hole in the foot with the securing screw/bolt down the centre, were made by Metalastic Ltd and I believe they have been unobtainable for a fair number of years.

 

That type of mount are secured into the foot by three small set screws, screwed up from underneath, and when the mount rubber sags they hit the bed and produce vibrations and so on. The screws are not under any significant load, so sometimes it is possible to file the heads of the screws to about half thickness or turn up a thick washer that is the same size as the flange on the bottom of the metal centre to the mount and use that to make up for the sag in the mount, but it is all too easy to mess up the shaft alignment if you make it too thick. Both "solutions" should only be considered as temporary.

Thanks, so what you are saying is that the 4 single bolt mounts should be removed and complete new units fitted, (Wrong angle for the engine beds anyway). I was planning on fitting 2 new dual bolt flexible mounts to the pair of mounting points on the gearbox bell housing that do not have any mounts, (Might not have been in use), fitted at present. So it looks like I might need 6 of these:

Marine Flexible Engine Mount 55KG, 12mm Stud, Volvo Penta, Mercruiser, Beta, | eBay

Just on my Feabay watch list, as there might be better units available. At present it's paint and instrument panel first, and I'm off to look at a good used AZAP (ASAP copy) in the scrap yard this afternoon. If he wants more than 20 quid, (It might be kaput), then I will think about one of these and a second panel for gauges:

Boat, Narrowboat, Fishingboat Instrument panel 12v New any engine.4000 RPM White | eBay

1 minute ago, TNLI said:

Thanks, so what you are saying is that the 4 single bolt mounts should be removed and complete new units fitted, (Wrong angle for the engine beds anyway). I was planning on fitting 2 new dual bolt flexible mounts to the pair of mounting points on the gearbox bell housing that do not have any mounts, (Might not have been in use), fitted at present. So it looks like I might need 6 of these:

Marine Flexible Engine Mount 55KG, 12mm Stud, Volvo Penta, Mercruiser, Beta, | eBay

Just on my Feabay watch list, as there might be better units available. At present it's paint and instrument panel first, and I'm off to look at a good used AZAP (ASAP copy) in the scrap yard this afternoon. If he wants more than 20 quid, (It might be kaput), then I will think about one of these and a second panel for gauges:

Boat, Narrowboat, Fishingboat Instrument panel 12v New any engine.4000 RPM White | eBay

Umm, I think I got rear and fwd mixed up, so the single bolts jobs are good. Nothing is fitted to the gearbox anti torque mounting plate at present. So that will save some dosh, as I only need 2 mounts now!

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14 minutes ago, TNLI said:

Thanks, so what you are saying is that the 4 single bolt mounts should be removed and complete new units fitted, (Wrong angle for the engine beds anyway). I was planning on fitting 2 new dual bolt flexible mounts to the pair of mounting points on the gearbox bell housing that do not have any mounts, (Might not have been in use), fitted at present. So it looks like I might need 6 of these:

Marine Flexible Engine Mount 55KG, 12mm Stud, Volvo Penta, Mercruiser, Beta, | eBay

Just on my Feabay watch list, as there might be better units available. At present it's paint and instrument panel first, and I'm off to look at a good used AZAP (ASAP copy) in the scrap yard this afternoon. If he wants more than 20 quid, (It might be kaput), then I will think about one of these and a second panel for gauges:

Boat, Narrowboat, Fishingboat Instrument panel 12v New any engine.4000 RPM White | eBay

Umm, I think I got rear and fwd mixed up, so the single bolts jobs are good. Nothing is fitted to the gearbox anti torque mounting plate at present. So that will save some dosh, as I only need 2 mounts now!

 

Now you know why the official rear mount (flywheel housing located) are missing and a new set of feet have been fitted to the gearbox. A previous owner found the rear mounts were unobtainable, so bodged at extra set onto the unit, so he still only had four mountings.

 

Unless oil or fuel have been sprayed about in the past, the front rubber mounts, between the engine block brackets and cross member are normally fine but if they have sagged I fully except MG B ones would do the job. The front cross member was bolted directly to the engine bed by Newage/Tempest (Mr Morris) as designed. It was not designed for the  cross member to sit on extra flexible mounts.

 

I think the front mounts that are set at an angle are the main anti-torque members, just as they were in a vehicle. I think the vehicles had just a single rear gearbox mount.

 

It seems that you have managed to buy an engine that has been modified well away from the Newage/Tempest (Mr Morris) design.

 

I am not going to comment on the advisability of using non-standard mount or engine feet in the light of your insistence on the need for "quality" and "reliability" in your earlier posts.

 

We still need images of the rear of the engine, showing the mounts and feet.

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Not sure what TB means by non standard as I can only find Fleabay and ASAP mounts:

Marine Flexible Engine Mountings (asap-supplies.com)

 

These will do for the gearbox pair, as the height does not matter, due to the need to fabricate a new wooden block for each side. The other mounts match up in engine bed terms, but I will take a look at the angles involved. I don't have the tools to fit a heavy diesel, so the actual extra plates, (If required) for the other 4 single bolt and circular damper, (they are available for other BMC diesels, but I could not find them for the 1500), so that game along with shaft alignement and reducing the lenghth of the shaft to allow a flexible coupling will be left to the marine engineer, (If I can find one). no rush as i still need to paint it etc.

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12 minutes ago, TNLI said:

Not sure what TB means by non standard as I can only find Fleabay and ASAP mounts:

Marine Flexible Engine Mountings (asap-supplies.com)

 

These will do for the gearbox pair, as the height does not matter, due to the need to fabricate a new wooden block for each side. The other mounts match up in engine bed terms, but I will take a look at the angles involved. I don't have the tools to fit a heavy diesel, so the actual extra plates, (If required) for the other 4 single bolt and circular damper, (they are available for other BMC diesels, but I could not find them for the 1500), so that game along with shaft alignement and reducing the lenghth of the shaft to allow a flexible coupling will be left to the marine engineer, (If I can find one). no rush as i still need to paint it etc.

 

The way you pick and choose what you feel "Mr Morris" fitted, even though he did not, is important to preserve and what you can alter to suit yourself.   The way you refused to accept that what everybody else calls an engine bed is called a frame, also the way you kept on about high quality, reliability and such like yet managed to buy what may well be a 50 year old engine and gearbox with all the potential wear and machining that implies, that had a different gearbox to that described AND had it's standard rear mounts (that are unobtainable as far as know) missing and with a bodged replacement makes me think that you are a bit of an "old woman" (kindest description) who knows a lot less that you think you do. So on one hand you want reliability and high quality as per the original design and on the other its almost anything will do when it suits you.

 

If my identification of the flywheel housing is correct then the standard engine mounts (the type fitted when the engine was marinised) are missing and more to the point, no longer available. You also seem to want to use non-standard rear engine feet. If you don't understand what I am telling you about what mounts were the standard ones and the ones you propose to use are non-standard for that engine and flywheel housing then I don't know how to make it any clearer.  You are not consistent in defining what you are trying to achieve. Remember that you say that you intend to cross the Atlantic with that engine (plus sails) and it seems the the back of the engine will be supported on non-standard engine feet. Are you sure they will be strong enough when the boat is bucking like a bronco and rolling about for hours on end? I am certainly not going to invite problems for myself if I tell you the mounts you propos to use are OK and the worst happens. THEY ARE NOT THE MOUNTS THAT WERE STANDARD ON THAT ENGINE!

 

If you are going to cut your engine beds about or bolt bits to them then I would be happier if you used the original mount points with a strong, machined stepped washer to fill the holes the original mounts fitted through to use the original rear engine feet. I must also point out that with that gearbox that has, I think, a cast iron case the rear mounts may have to be stronger that the front ones if you intend to use the modern type of mount.

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If you weigh the 4 corners of the complete power unit and consult R&D they will be able to tell you what strength of mount you will need. The rear mounts will have to be sleeved to accept modern mounts, the old pattern are unobtainable.

For a seagoing boat they really need to be strong enough to support the unit in a capsize including any wood bearers or packers you use.

BMC engines with the rear mounts on the bell housing and a cast iron gearbox hanging off the end carry  substantially more weight than the front mounts.  If you get the stiffness wrong you can end up with an engine that wags laterally.  That will quickly damage the coupling and shaft if it is not an Aquadrive or Python.

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4 hours ago, Tracy D'arth said:

If you weigh the 4 corners of the complete power unit and consult R&D they will be able to tell you what strength of mount you will need. The rear mounts will have to be sleeved to accept modern mounts, the old pattern are unobtainable.

For a seagoing boat they really need to be strong enough to support the unit in a capsize including any wood bearers or packers you use.

BMC engines with the rear mounts on the bell housing and a cast iron gearbox hanging off the end carry  substantially more weight than the front mounts.  If you get the stiffness wrong you can end up with an engine that wags laterally.  That will quickly damage the coupling and shaft if it is not an Aquadrive or Python.

Thanks and I kind of think the RNLI engineer who has now agreed to fit my BMC 1500 does know what he is doing, and he will be making support brakets for all 4 mounts, alas he is too busy to do the job until next year, the mounting plates are in a good position, but the angled bolts do need adapter plates that he said do not need welding.

 Oddly enough he is a BMC fan as they used the 1.5 block on the early Thornycroft 37. The new Thornycroft uses a Mitubishi block I think, as does Vetus for their diesels. He did poo poo the idea of using Chinese mounts and cheap flexible couplings in favour of fully certified ones and a Vetus coupling.

 

The reason I like the BMC 1.5 is that a correctly restored one, is far tougher than an equivalent Yanmar or similar. I've had no end of trouble with Yanmars including some serious failures. The only thing modern diesels do that is nice is use a bit less fuel and make less noise. The BMC 1500 also seems to have a cult following that I found odd at first, and about the only negative point about them apart from the need to watch out for fuel contamination in the oil, is that they were marinised by a number of different companies, with a bunch of different options fitted. 

  I took a look at the bell house mounts today and I kind of suspect the canal boat the engine was fitted to did not use them, as the brackets seem too clean where there should be signs of corrosion. 

 

I've decided to treturn to the use of frame rather than beds, as beds is plural and my frame is one unit once it is bolted together. The very forward end of the engine frame does in fact terminate in the captains roll over berth, or bed to landlubbers in Blighty.

Edited by TNLI
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6 minutes ago, TNLI said:

Thanks and I kind of think the RNLI engineer who has now agreed to fit my BMC 1500 does know what he is doing, and he will be making support brakets for all 4 mounts, alas he is too busy to do the job until next year, the mounting plates are in a good position, but the engled bots do need adapter plates that he said do not need welding.

 Oddly enough he is a BMC fan as they used the 1.5 block on the early Thornycroft. The new Thornycroft uses a Mitubishi block I think, as does Vetus for their diesels. He did poo poo the idea of using Chinese mounts in favour of fully certified ones. 

 

The reason I like the BMC 1.5 is that a correctly restored one, is far tougher than an equivalent Yanmar or similar. I've had no end of trouble with Yanmars including some serious failures. The only thing modern diesels do that is nice is use a bit less fuel and make less noise. The BMC 1500 also seems to have a cult following that I found odd at first, and about the only negative point about them apart from the need to watch out for fuel contamination in the oil, is that they were marinised by a number of different companies, with a bunch of different options fitted. 

  I took a look at the bell house mounts today and I kind of suspect the canal boat the engine was fitted to did not use them, as the brackets seem too clean where there should be signs of corrosion. 

 

Our bell housing is alloy - its bolted directly to the Mahogany bearers. Why would you expect to see signs of corrosion?

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2 minutes ago, StephenA said:

 

Our bell housing is alloy - its bolted directly to the Mahogany bearers. Why would you expect to see signs of corrosion?

Thanks, I've not tried removing the black primer or playing with a magnetc to notice it was not steel. It might have sat on Maghogany at the gearbox end, which would explain the lack of marks on the mounting slots.

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10 minutes ago, TNLI said:

Thanks, I've not tried removing the black primer or playing with a magnetc to notice it was not steel. It might have sat on Maghogany at the gearbox end, which would explain the lack of marks on the mounting slots.

 

If it has flexi mounts at one end then it would have them all round - we just went for the very old fashioned solid bearers when we had the boat built.

Edited by StephenA
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2" Car Triple Gauge Kit 3in1 Water Temperature Voltmeter Oil Pressure Gauge BO | eBay

 

Boat, Narrowboat, Fishingboat Instrument panel 12v New any engine.4000 RPM White | eBay

 

Looking at that pair of instrument/switch panel for my missing BMC panel.

 

This is the ASAP single panel equivalent:

 

Deluxe Instrument Panel With Faria Beede Gauges 708065 (asap-supplies.com)

Just a joke, as it's a 24v panel!

Edited by TNLI
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